In the Linux kernel, the following vulnerability has been resolved: secretmem: disable memfd_secret() if arch cannot set direct map Return -ENOSYS from memfd_secret() syscall if !can_set_direct_map(). This is the case for example on some arm64 configurations, where marking 4k PTEs in the direct map not present can only be done if the direct map is set up at 4k granularity in the first place (as ARM's break-before-make semantics do not easily allow breaking apart large/gigantic pages). More precisely, on arm64 systems with !can_set_direct_map(), set_direct_map_invalid_noflush() is a no-op, however it returns success (0) instead of an error. This means that memfd_secret will seemingly "work" (e.g. syscall succeeds, you can mmap the fd and fault in pages), but it does not actually achieve its goal of removing its memory from the direct map. Note that with this patch, memfd_secret() will start erroring on systems where can_set_direct_map() returns false (arm64 with CONFIG_RODATA_FULL_DEFAULT_ENABLED=n, CONFIG_DEBUG_PAGEALLOC=n and CONFIG_KFENCE=n), but that still seems better than the current silent failure. Since CONFIG_RODATA_FULL_DEFAULT_ENABLED defaults to 'y', most arm64 systems actually have a working memfd_secret() and aren't be affected. From going through the iterations of the original memfd_secret patch series, it seems that disabling the syscall in these scenarios was the intended behavior [1] (preferred over having set_direct_map_invalid_noflush return an error as that would result in SIGBUSes at page-fault time), however the check for it got dropped between v16 [2] and v17 [3], when secretmem moved away from CMA allocations. [1]: https://lore.kernel.org/lkml/20201124164930.GK8537@kernel.org/ [2]: https://lore.kernel.org/lkml/20210121122723.3446-11-rppt@kernel.org/#t [3]: https://lore.kernel.org/lkml/20201125092208.12544-10-rppt@kernel.org/

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled When only PHY1 is used (for example on Odroid-HC4), the regmap init code uses the usb2 ports when doesn't initialize the PHY1 regmap entry. This fixes: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ... pc : regmap_update_bits_base+0x40/0xa0 lr : dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8 ... Call trace: regmap_update_bits_base+0x40/0xa0 dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8 dwc3_meson_g12a_usb2_init+0x7c/0xc8 dwc3_meson_g12a_usb_init+0x28/0x48 dwc3_meson_g12a_probe+0x298/0x540 platform_probe+0x70/0xe0 really_probe+0xf0/0x4d8 driver_probe_device+0xfc/0x168 ...

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs Use the kvm_for_each_vcpu() helper to iterate over vCPUs when encrypting VMSAs for SEV, which effectively switches to use online_vcpus instead of created_vcpus. This fixes a possible null-pointer dereference as created_vcpus does not guarantee a vCPU exists, since it is updated at the very beginning of KVM_CREATE_VCPU. created_vcpus exists to allow the bulk of vCPU creation to run in parallel, while still correctly restricting the max number of max vCPUs.

In the Linux kernel, the following vulnerability has been resolved: HID: amd_sfh: Fix potential NULL pointer dereference devm_add_action_or_reset() can suddenly invoke amd_mp2_pci_remove() at registration that will cause NULL pointer dereference since corresponding data is not initialized yet. The patch moves initialization of data before devm_add_action_or_reset(). Found by Linux Driver Verification project (linuxtesting.org). [jkosina@suse.cz: rebase]

In the Linux kernel, the following vulnerability has been resolved: net: tun: Fix memory leaks of napi_get_frags kmemleak reports after running test_progs: unreferenced object 0xffff8881b1672dc0 (size 232): comm "test_progs", pid 394388, jiffies 4354712116 (age 841.975s) hex dump (first 32 bytes): e0 84 d7 a8 81 88 ff ff 80 2c 67 b1 81 88 ff ff .........,g..... 00 40 c5 9b 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. backtrace: [<00000000c8f01748>] napi_skb_cache_get+0xd4/0x150 [<0000000041c7fc09>] __napi_build_skb+0x15/0x50 [<00000000431c7079>] __napi_alloc_skb+0x26e/0x540 [<000000003ecfa30e>] napi_get_frags+0x59/0x140 [<0000000099b2199e>] tun_get_user+0x183d/0x3bb0 [tun] [<000000008a5adef0>] tun_chr_write_iter+0xc0/0x1b1 [tun] [<0000000049993ff4>] do_iter_readv_writev+0x19f/0x320 [<000000008f338ea2>] do_iter_write+0x135/0x630 [<000000008a3377a4>] vfs_writev+0x12e/0x440 [<00000000a6b5639a>] do_writev+0x104/0x280 [<00000000ccf065d8>] do_syscall_64+0x3b/0x90 [<00000000d776e329>] entry_SYSCALL_64_after_hwframe+0x63/0xcd The issue occurs in the following scenarios: tun_get_user() napi_gro_frags() napi_frags_finish() case GRO_NORMAL: gro_normal_one() list_add_tail(&skb->list, &napi->rx_list); <-- While napi->rx_count < READ_ONCE(gro_normal_batch), <-- gro_normal_list() is not called, napi->rx_list is not empty <-- not ask to complete the gro work, will cause memory leaks in <-- following tun_napi_del() ... tun_napi_del() netif_napi_del() __netif_napi_del() <-- &napi->rx_list is not empty, which caused memory leaks To fix, add napi_complete() after napi_gro_frags().

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix leaks in probe These two error paths should clean up before returning.

In the Linux kernel, the following vulnerability has been resolved: dm btree remove: assign new_root only when removal succeeds remove_raw() in dm_btree_remove() may fail due to IO read error (e.g. read the content of origin block fails during shadowing), and the value of shadow_spine::root is uninitialized, but the uninitialized value is still assign to new_root in the end of dm_btree_remove(). For dm-thin, the value of pmd->details_root or pmd->root will become an uninitialized value, so if trying to read details_info tree again out-of-bound memory may occur as showed below: general protection fault, probably for non-canonical address 0x3fdcb14c8d7520 CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6 Hardware name: QEMU Standard PC RIP: 0010:metadata_ll_load_ie+0x14/0x30 Call Trace: sm_metadata_count_is_more_than_one+0xb9/0xe0 dm_tm_shadow_block+0x52/0x1c0 shadow_step+0x59/0xf0 remove_raw+0xb2/0x170 dm_btree_remove+0xf4/0x1c0 dm_pool_delete_thin_device+0xc3/0x140 pool_message+0x218/0x2b0 target_message+0x251/0x290 ctl_ioctl+0x1c4/0x4d0 dm_ctl_ioctl+0xe/0x20 __x64_sys_ioctl+0x7b/0xb0 do_syscall_64+0x40/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixing it by only assign new_root when removal succeeds

In the Linux kernel, the following vulnerability has been resolved: Input: gpio-keys - cancel delayed work only in case of GPIO gpio_keys module can either accept gpios or interrupts. The module initializes delayed work in case of gpios only and is only used if debounce timer is not used, so make sure cancel_delayed_work_sync() is called only when its gpio-backed and debounce_use_hrtimer is false. This fixes the issue seen below when the gpio_keys module is unloaded and an interrupt pin is used instead of GPIO: [ 360.297569] ------------[ cut here ]------------ [ 360.302303] WARNING: CPU: 0 PID: 237 at kernel/workqueue.c:3066 __flush_work+0x414/0x470 [ 360.310531] Modules linked in: gpio_keys(-) [ 360.314797] CPU: 0 PID: 237 Comm: rmmod Not tainted 5.18.0-rc5-arm64-renesas-00116-g73636105874d-dirty #166 [ 360.324662] Hardware name: Renesas SMARC EVK based on r9a07g054l2 (DT) [ 360.331270] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 360.338318] pc : __flush_work+0x414/0x470 [ 360.342385] lr : __cancel_work_timer+0x140/0x1b0 [ 360.347065] sp : ffff80000a7fba00 [ 360.350423] x29: ffff80000a7fba00 x28: ffff000012b9c5c0 x27: 0000000000000000 [ 360.357664] x26: ffff80000a7fbb80 x25: ffff80000954d0a8 x24: 0000000000000001 [ 360.364904] x23: ffff800009757000 x22: 0000000000000000 x21: ffff80000919b000 [ 360.372143] x20: ffff00000f5974e0 x19: ffff00000f5974e0 x18: ffff8000097fcf48 [ 360.379382] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000053f40 [ 360.386622] x14: ffff800009850e88 x13: 0000000000000002 x12: 000000000000a60c [ 360.393861] x11: 000000000000a610 x10: 0000000000000000 x9 : 0000000000000008 [ 360.401100] x8 : 0101010101010101 x7 : 00000000a473c394 x6 : 0080808080808080 [ 360.408339] x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffff80000919b458 [ 360.415578] x2 : ffff8000097577f0 x1 : 0000000000000001 x0 : 0000000000000000 [ 360.422818] Call trace: [ 360.425299] __flush_work+0x414/0x470 [ 360.429012] __cancel_work_timer+0x140/0x1b0 [ 360.433340] cancel_delayed_work_sync+0x10/0x18 [ 360.437931] gpio_keys_quiesce_key+0x28/0x58 [gpio_keys] [ 360.443327] devm_action_release+0x10/0x18 [ 360.447481] release_nodes+0x8c/0x1a0 [ 360.451194] devres_release_all+0x90/0x100 [ 360.455346] device_unbind_cleanup+0x14/0x60 [ 360.459677] device_release_driver_internal+0xe8/0x168 [ 360.464883] driver_detach+0x4c/0x90 [ 360.468509] bus_remove_driver+0x54/0xb0 [ 360.472485] driver_unregister+0x2c/0x58 [ 360.476462] platform_driver_unregister+0x10/0x18 [ 360.481230] gpio_keys_exit+0x14/0x828 [gpio_keys] [ 360.486088] __arm64_sys_delete_module+0x1e0/0x270 [ 360.490945] invoke_syscall+0x40/0xf8 [ 360.494661] el0_svc_common.constprop.3+0xf0/0x110 [ 360.499515] do_el0_svc+0x20/0x78 [ 360.502877] el0_svc+0x48/0xf8 [ 360.505977] el0t_64_sync_handler+0x88/0xb0 [ 360.510216] el0t_64_sync+0x148/0x14c [ 360.513930] irq event stamp: 4306 [ 360.517288] hardirqs last enabled at (4305): [<ffff8000080b0300>] __cancel_work_timer+0x130/0x1b0 [ 360.526359] hardirqs last disabled at (4306): [<ffff800008d194fc>] el1_dbg+0x24/0x88 [ 360.534204] softirqs last enabled at (4278): [<ffff8000080104a0>] _stext+0x4a0/0x5e0 [ 360.542133] softirqs last disabled at (4267): [<ffff8000080932ac>] irq_exit_rcu+0x18c/0x1b0 [ 360.550591] ---[ end trace 0000000000000000 ]---

In the Linux kernel, the following vulnerability has been resolved: drm/msm/mdp5: Return error code in mdp5_mixer_release when deadlock is detected There is a possibility for mdp5_get_global_state to return -EDEADLK when acquiring the modeset lock, but currently global_state in mdp5_mixer_release doesn't check for if an error is returned. To avoid a NULL dereference error, let's have mdp5_mixer_release check if an error is returned and propagate that error. Patchwork: https://patchwork.freedesktop.org/patch/485181/

In the Linux kernel, the following vulnerability has been resolved: powerpc/64: Init jump labels before parse_early_param() On 64-bit, calling jump_label_init() in setup_feature_keys() is too late because static keys may be used in subroutines of parse_early_param() which is again subroutine of early_init_devtree(). For example booting with "threadirqs": static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init() WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120 ... NIP static_key_enable_cpuslocked+0xfc/0x120 LR static_key_enable_cpuslocked+0xf8/0x120 Call Trace: static_key_enable_cpuslocked+0xf8/0x120 (unreliable) static_key_enable+0x30/0x50 setup_forced_irqthreads+0x28/0x40 do_early_param+0xa0/0x108 parse_args+0x290/0x4e0 parse_early_options+0x48/0x5c parse_early_param+0x58/0x84 early_init_devtree+0xd4/0x518 early_setup+0xb4/0x214 So call jump_label_init() just before parse_early_param() in early_init_devtree(). [mpe: Add call trace to change log and minor wording edits.]

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Prevent RSB underflow before vmenter On VMX, there are some balanced returns between the time the guest's SPEC_CTRL value is written, and the vmenter. Balanced returns (matched by a preceding call) are usually ok, but it's at least theoretically possible an NMI with a deep call stack could empty the RSB before one of the returns. For maximum paranoia, don't allow *any* returns (balanced or otherwise) between the SPEC_CTRL write and the vmenter. [ bp: Fix 32-bit build. ]

In the Linux kernel, the following vulnerability has been resolved: dm mirror log: round up region bitmap size to BITS_PER_LONG The code in dm-log rounds up bitset_size to 32 bits. It then uses find_next_zero_bit_le on the allocated region. find_next_zero_bit_le accesses the bitmap using unsigned long pointers. So, on 64-bit architectures, it may access 4 bytes beyond the allocated size. Fix this bug by rounding up bitset_size to BITS_PER_LONG. This bug was found by running the lvm2 testsuite with kasan.

In the Linux kernel, the following vulnerability has been resolved: mmc: jz4740: Apply DMA engine limits to maximum segment size Do what is done in other DMA-enabled MMC host drivers (cf. host/mmci.c) and limit the maximum segment size based on the DMA engine's capabilities. This is needed to avoid warnings like the following with CONFIG_DMA_API_DEBUG=y. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 21 at kernel/dma/debug.c:1162 debug_dma_map_sg+0x2f4/0x39c DMA-API: jz4780-dma 13420000.dma-controller: mapping sg segment longer than device claims to support [len=98304] [max=65536] CPU: 0 PID: 21 Comm: kworker/0:1H Not tainted 5.18.0-rc1 #19 Workqueue: kblockd blk_mq_run_work_fn Stack : 81575aec 00000004 80620000 80620000 80620000 805e7358 00000009 801537ac 814c832c 806276e3 806e34b4 80620000 81575aec 00000001 81575ab8 09291444 00000000 00000000 805e7358 81575958 ffffffea 8157596c 00000000 636f6c62 6220646b 80387a70 0000000f 6d5f6b6c 80620000 00000000 81575ba4 00000009 805e170c 80896640 00000001 00010000 00000000 00000000 00006098 806e0000 ... Call Trace: [<80107670>] show_stack+0x84/0x120 [<80528cd8>] __warn+0xb8/0xec [<80528d78>] warn_slowpath_fmt+0x6c/0xb8 [<8016f1d4>] debug_dma_map_sg+0x2f4/0x39c [<80169d4c>] __dma_map_sg_attrs+0xf0/0x118 [<8016a27c>] dma_map_sg_attrs+0x14/0x28 [<804f66b4>] jz4740_mmc_prepare_dma_data+0x74/0xa4 [<804f6714>] jz4740_mmc_pre_request+0x30/0x54 [<804f4ff4>] mmc_blk_mq_issue_rq+0x6e0/0x7bc [<804f5590>] mmc_mq_queue_rq+0x220/0x2d4 [<8038b2c0>] blk_mq_dispatch_rq_list+0x480/0x664 [<80391040>] blk_mq_do_dispatch_sched+0x2dc/0x370 [<80391468>] __blk_mq_sched_dispatch_requests+0xec/0x164 [<80391540>] blk_mq_sched_dispatch_requests+0x44/0x94 [<80387900>] __blk_mq_run_hw_queue+0xb0/0xcc [<80134c14>] process_one_work+0x1b8/0x264 [<80134ff8>] worker_thread+0x2ec/0x3b8 [<8013b13c>] kthread+0x104/0x10c [<80101dcc>] ret_from_kernel_thread+0x14/0x1c ---[ end trace 0000000000000000 ]---

In the Linux kernel, the following vulnerability has been resolved: ACPI: PAD: fix crash in exit_round_robin() The kernel occasionally crashes in cpumask_clear_cpu(), which is called within exit_round_robin(), because when executing clear_bit(nr, addr) with nr set to 0xffffffff, the address calculation may cause misalignment within the memory, leading to access to an invalid memory address. ---------- BUG: unable to handle kernel paging request at ffffffffe0740618 ... CPU: 3 PID: 2919323 Comm: acpi_pad/14 Kdump: loaded Tainted: G OE X --------- - - 4.18.0-425.19.2.el8_7.x86_64 #1 ... RIP: 0010:power_saving_thread+0x313/0x411 [acpi_pad] Code: 89 cd 48 89 d3 eb d1 48 c7 c7 55 70 72 c0 e8 64 86 b0 e4 c6 05 0d a1 02 00 01 e9 bc fd ff ff 45 89 e4 42 8b 04 a5 20 82 72 c0 <f0> 48 0f b3 05 f4 9c 01 00 42 c7 04 a5 20 82 72 c0 ff ff ff ff 31 RSP: 0018:ff72a5d51fa77ec8 EFLAGS: 00010202 RAX: 00000000ffffffff RBX: ff462981e5d8cb80 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 RBP: ff46297556959d80 R08: 0000000000000382 R09: ff46297c8d0f38d8 R10: 0000000000000000 R11: 0000000000000001 R12: 000000000000000e R13: 0000000000000000 R14: ffffffffffffffff R15: 000000000000000e FS: 0000000000000000(0000) GS:ff46297a800c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffe0740618 CR3: 0000007e20410004 CR4: 0000000000771ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? acpi_pad_add+0x120/0x120 [acpi_pad] kthread+0x10b/0x130 ? set_kthread_struct+0x50/0x50 ret_from_fork+0x1f/0x40 ... CR2: ffffffffe0740618 crash> dis -lr ffffffffc0726923 ... /usr/src/debug/kernel-4.18.0-425.19.2.el8_7/linux-4.18.0-425.19.2.el8_7.x86_64/./include/linux/cpumask.h: 114 0xffffffffc0726918 <power_saving_thread+776>: mov %r12d,%r12d /usr/src/debug/kernel-4.18.0-425.19.2.el8_7/linux-4.18.0-425.19.2.el8_7.x86_64/./include/linux/cpumask.h: 325 0xffffffffc072691b <power_saving_thread+779>: mov -0x3f8d7de0(,%r12,4),%eax /usr/src/debug/kernel-4.18.0-425.19.2.el8_7/linux-4.18.0-425.19.2.el8_7.x86_64/./arch/x86/include/asm/bitops.h: 80 0xffffffffc0726923 <power_saving_thread+787>: lock btr %rax,0x19cf4(%rip) # 0xffffffffc0740620 <pad_busy_cpus_bits> crash> px tsk_in_cpu[14] $66 = 0xffffffff crash> px 0xffffffffc072692c+0x19cf4 $99 = 0xffffffffc0740620 crash> sym 0xffffffffc0740620 ffffffffc0740620 (b) pad_busy_cpus_bits [acpi_pad] crash> px pad_busy_cpus_bits[0] $42 = 0xfffc0 ---------- To fix this, ensure that tsk_in_cpu[tsk_index] != -1 before calling cpumask_clear_cpu() in exit_round_robin(), just as it is done in round_robin_cpu(). [ rjw: Subject edit, avoid updates to the same value ]

In the Linux kernel, the following vulnerability has been resolved: cxl/pmem: Fix cxl_pmem_region and cxl_memdev leak When a cxl_nvdimm object goes through a ->remove() event (device physically removed, nvdimm-bridge disabled, or nvdimm device disabled), then any associated regions must also be disabled. As highlighted by the cxl-create-region.sh test [1], a single device may host multiple regions, but the driver was only tracking one region at a time. This leads to a situation where only the last enabled region per nvdimm device is cleaned up properly. Other regions are leaked, and this also causes cxl_memdev reference leaks. Fix the tracking by allowing cxl_nvdimm objects to track multiple region associations.

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: fix memory leak in query_regdb_file() In the function query_regdb_file() the alpha2 parameter is duplicated using kmemdup() and subsequently freed in regdb_fw_cb(). However, request_firmware_nowait() can fail without calling regdb_fw_cb() and thus leak memory.

In the Linux kernel, the following vulnerability has been resolved: ptp: unregister virtual clocks when unregistering physical clock. When unregistering a physical clock which has some virtual clocks, unregister the virtual clocks with it. This fixes the following oops, which can be triggered by unloading a driver providing a PTP clock when it has enabled virtual clocks: BUG: unable to handle page fault for address: ffffffffc04fc4d8 Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:ptp_vclock_read+0x31/0xb0 Call Trace: timecounter_read+0xf/0x50 ptp_vclock_refresh+0x2c/0x50 ? ptp_clock_release+0x40/0x40 ptp_aux_kworker+0x17/0x30 kthread_worker_fn+0x9b/0x240 ? kthread_should_park+0x30/0x30 kthread+0xe2/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30

In the Linux kernel, the following vulnerability has been resolved: drm/drv: Fix potential memory leak in drm_dev_init() drm_dev_init() will add drm_dev_init_release() as a callback. When drmm_add_action() failed, the release function won't be added. As the result, the ref cnt added by device_get() in drm_dev_init() won't be put by drm_dev_init_release(), which leads to the memleak. Use drmm_add_action_or_reset() instead of drmm_add_action() to prevent memleak. unreferenced object 0xffff88810bc0c800 (size 2048): comm "modprobe", pid 8322, jiffies 4305809845 (age 15.292s) hex dump (first 32 bytes): e8 cc c0 0b 81 88 ff ff ff ff ff ff 00 00 00 00 ................ 20 24 3c 0c 81 88 ff ff 18 c8 c0 0b 81 88 ff ff $<............. backtrace: [<000000007251f72d>] __kmalloc+0x4b/0x1c0 [<0000000045f21f26>] platform_device_alloc+0x2d/0xe0 [<000000004452a479>] platform_device_register_full+0x24/0x1c0 [<0000000089f4ea61>] 0xffffffffa0736051 [<00000000235b2441>] do_one_initcall+0x7a/0x380 [<0000000001a4a177>] do_init_module+0x5c/0x230 [<000000002bf8a8e2>] load_module+0x227d/0x2420 [<00000000637d6d0a>] __do_sys_finit_module+0xd5/0x140 [<00000000c99fc324>] do_syscall_64+0x3f/0x90 [<000000004d85aa77>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Fix null pointer dereference of pointer perfmon In the unlikely event that pointer perfmon is null the WARN_ON return path occurs after the pointer has already been deferenced. Fix this by only dereferencing perfmon after it has been null checked.

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits Use the recently introduced __try_cmpxchg_user() to update guest PTE A/D bits instead of mapping the PTE into kernel address space. The VM_PFNMAP path is broken as it assumes that vm_pgoff is the base pfn of the mapped VMA range, which is conceptually wrong as vm_pgoff is the offset relative to the file and has nothing to do with the pfn. The horrific hack worked for the original use case (backing guest memory with /dev/mem), but leads to accessing "random" pfns for pretty much any other VM_PFNMAP case.

In the Linux kernel, the following vulnerability has been resolved: net: xfrm: unexport __init-annotated xfrm4_protocol_init() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it has been broken for a decade. Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds. There are two ways to fix it: - Remove __init - Remove EXPORT_SYMBOL I chose the latter for this case because the only in-tree call-site, net/ipv4/xfrm4_policy.c is never compiled as modular. (CONFIG_XFRM is boolean)

In the Linux kernel, the following vulnerability has been resolved: md/bitmap: don't set sb values if can't pass sanity check If bitmap area contains invalid data, kernel will crash then mdadm triggers "Segmentation fault". This is cluster-md speical bug. In non-clustered env, mdadm will handle broken metadata case. In clustered array, only kernel space handles bitmap slot info. But even this bug only happened in clustered env, current sanity check is wrong, the code should be changed. How to trigger: (faulty injection) dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sda dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdb mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb mdadm -Ss echo aaa > magic.txt == below modifying slot 2 bitmap data == dd if=magic.txt of=/dev/sda seek=16384 bs=1 count=3 <== destroy magic dd if=/dev/zero of=/dev/sda seek=16436 bs=1 count=4 <== ZERO chunksize mdadm -A /dev/md0 /dev/sda /dev/sdb == kernel crashes. mdadm outputs "Segmentation fault" == Reason of kernel crash: In md_bitmap_read_sb (called by md_bitmap_create), bad bitmap magic didn't block chunksize assignment, and zero value made DIV_ROUND_UP_SECTOR_T() trigger "divide error". Crash log: kernel: md: md0 stopped. kernel: md/raid1:md0: not clean -- starting background reconstruction kernel: md/raid1:md0: active with 2 out of 2 mirrors kernel: dlm: ... ... kernel: md-cluster: Joined cluster 44810aba-38bb-e6b8-daca-bc97a0b254aa slot 1 kernel: md0: invalid bitmap file superblock: bad magic kernel: md_bitmap_copy_from_slot can't get bitmap from slot 2 kernel: md-cluster: Could not gather bitmaps from slot 2 kernel: divide error: 0000 [#1] SMP NOPTI kernel: CPU: 0 PID: 1603 Comm: mdadm Not tainted 5.14.6-1-default kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod] kernel: RSP: 0018:ffffc22ac0843ba0 EFLAGS: 00010246 kernel: ... ... kernel: Call Trace: kernel: ? dlm_lock_sync+0xd0/0xd0 [md_cluster 77fe..7a0] kernel: md_bitmap_copy_from_slot+0x2c/0x290 [md_mod 24ea..d3a] kernel: load_bitmaps+0xec/0x210 [md_cluster 77fe..7a0] kernel: md_bitmap_load+0x81/0x1e0 [md_mod 24ea..d3a] kernel: do_md_run+0x30/0x100 [md_mod 24ea..d3a] kernel: md_ioctl+0x1290/0x15a0 [md_mod 24ea....d3a] kernel: ? mddev_unlock+0xaa/0x130 [md_mod 24ea..d3a] kernel: ? blkdev_ioctl+0xb1/0x2b0 kernel: block_ioctl+0x3b/0x40 kernel: __x64_sys_ioctl+0x7f/0xb0 kernel: do_syscall_64+0x59/0x80 kernel: ? exit_to_user_mode_prepare+0x1ab/0x230 kernel: ? syscall_exit_to_user_mode+0x18/0x40 kernel: ? do_syscall_64+0x69/0x80 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae kernel: RIP: 0033:0x7f4a15fa722b kernel: ... ... kernel: ---[ end trace 8afa7612f559c868 ]--- kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod]

In the Linux kernel, the following vulnerability has been resolved: media: stk1160: If start stream fails, return buffers with VB2_BUF_STATE_QUEUED If the callback 'start_streaming' fails, then all queued buffers in the driver should be returned with state 'VB2_BUF_STATE_QUEUED'. Currently, they are returned with 'VB2_BUF_STATE_ERROR' which is wrong. Fix this. This also fixes the warning: [ 65.583633] WARNING: CPU: 5 PID: 593 at drivers/media/common/videobuf2/videobuf2-core.c:1612 vb2_start_streaming+0xd4/0x160 [videobuf2_common] [ 65.585027] Modules linked in: snd_usb_audio snd_hwdep snd_usbmidi_lib snd_rawmidi snd_soc_hdmi_codec dw_hdmi_i2s_audio saa7115 stk1160 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc crct10dif_ce panfrost snd_soc_simple_card snd_soc_audio_graph_card snd_soc_spdif_tx snd_soc_simple_card_utils gpu_sched phy_rockchip_pcie snd_soc_rockchip_i2s rockchipdrm analogix_dp dw_mipi_dsi dw_hdmi cec drm_kms_helper drm rtc_rk808 rockchip_saradc industrialio_triggered_buffer kfifo_buf rockchip_thermal pcie_rockchip_host ip_tables x_tables ipv6 [ 65.589383] CPU: 5 PID: 593 Comm: v4l2src0:src Tainted: G W 5.16.0-rc4-62408-g32447129cb30-dirty #14 [ 65.590293] Hardware name: Radxa ROCK Pi 4B (DT) [ 65.590696] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 65.591304] pc : vb2_start_streaming+0xd4/0x160 [videobuf2_common] [ 65.591850] lr : vb2_start_streaming+0x6c/0x160 [videobuf2_common] [ 65.592395] sp : ffff800012bc3ad0 [ 65.592685] x29: ffff800012bc3ad0 x28: 0000000000000000 x27: ffff800012bc3cd8 [ 65.593312] x26: 0000000000000000 x25: ffff00000d8a7800 x24: 0000000040045612 [ 65.593938] x23: ffff800011323000 x22: ffff800012bc3cd8 x21: ffff00000908a8b0 [ 65.594562] x20: ffff00000908a8c8 x19: 00000000fffffff4 x18: ffffffffffffffff [ 65.595188] x17: 000000040044ffff x16: 00400034b5503510 x15: ffff800011323f78 [ 65.595813] x14: ffff000013163886 x13: ffff000013163885 x12: 00000000000002ce [ 65.596439] x11: 0000000000000028 x10: 0000000000000001 x9 : 0000000000000228 [ 65.597064] x8 : 0101010101010101 x7 : 7f7f7f7f7f7f7f7f x6 : fefefeff726c5e78 [ 65.597690] x5 : ffff800012bc3990 x4 : 0000000000000000 x3 : ffff000009a34880 [ 65.598315] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000007cd99f0 [ 65.598940] Call trace: [ 65.599155] vb2_start_streaming+0xd4/0x160 [videobuf2_common] [ 65.599672] vb2_core_streamon+0x17c/0x1a8 [videobuf2_common] [ 65.600179] vb2_streamon+0x54/0x88 [videobuf2_v4l2] [ 65.600619] vb2_ioctl_streamon+0x54/0x60 [videobuf2_v4l2] [ 65.601103] v4l_streamon+0x3c/0x50 [videodev] [ 65.601521] __video_do_ioctl+0x1a4/0x428 [videodev] [ 65.601977] video_usercopy+0x320/0x828 [videodev] [ 65.602419] video_ioctl2+0x3c/0x58 [videodev] [ 65.602830] v4l2_ioctl+0x60/0x90 [videodev] [ 65.603227] __arm64_sys_ioctl+0xa8/0xe0 [ 65.603576] invoke_syscall+0x54/0x118 [ 65.603911] el0_svc_common.constprop.3+0x84/0x100 [ 65.604332] do_el0_svc+0x34/0xa0 [ 65.604625] el0_svc+0x1c/0x50 [ 65.604897] el0t_64_sync_handler+0x88/0xb0 [ 65.605264] el0t_64_sync+0x16c/0x170 [ 65.605587] ---[ end trace 578e0ba07742170d ]---

In the Linux kernel, the following vulnerability has been resolved: tcp: fix tcp_mtup_probe_success vs wrong snd_cwnd syzbot got a new report [1] finally pointing to a very old bug, added in initial support for MTU probing. tcp_mtu_probe() has checks about starting an MTU probe if tcp_snd_cwnd(tp) >= 11. But nothing prevents tcp_snd_cwnd(tp) to be reduced later and before the MTU probe succeeds. This bug would lead to potential zero-divides. Debugging added in commit 40570375356c ("tcp: add accessors to read/set tp->snd_cwnd") has paid off :) While we are at it, address potential overflows in this code. [1] WARNING: CPU: 1 PID: 14132 at include/net/tcp.h:1219 tcp_mtup_probe_success+0x366/0x570 net/ipv4/tcp_input.c:2712 Modules linked in: CPU: 1 PID: 14132 Comm: syz-executor.2 Not tainted 5.18.0-syzkaller-07857-gbabf0bb978e3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tcp_snd_cwnd_set include/net/tcp.h:1219 [inline] RIP: 0010:tcp_mtup_probe_success+0x366/0x570 net/ipv4/tcp_input.c:2712 Code: 74 08 48 89 ef e8 da 80 17 f9 48 8b 45 00 65 48 ff 80 80 03 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 aa b0 c5 f8 <0f> 0b e9 16 fe ff ff 48 8b 4c 24 08 80 e1 07 38 c1 0f 8c c7 fc ff RSP: 0018:ffffc900079e70f8 EFLAGS: 00010287 RAX: ffffffff88c0f7f6 RBX: ffff8880756e7a80 RCX: 0000000000040000 RDX: ffffc9000c6c4000 RSI: 0000000000031f9e RDI: 0000000000031f9f RBP: 0000000000000000 R08: ffffffff88c0f606 R09: ffffc900079e7520 R10: ffffed101011226d R11: 1ffff1101011226c R12: 1ffff1100eadcf50 R13: ffff8880756e72c0 R14: 1ffff1100eadcf89 R15: dffffc0000000000 FS: 00007f643236e700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1ab3f1e2a0 CR3: 0000000064fe7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_clean_rtx_queue+0x223a/0x2da0 net/ipv4/tcp_input.c:3356 tcp_ack+0x1962/0x3c90 net/ipv4/tcp_input.c:3861 tcp_rcv_established+0x7c8/0x1ac0 net/ipv4/tcp_input.c:5973 tcp_v6_do_rcv+0x57b/0x1210 net/ipv6/tcp_ipv6.c:1476 sk_backlog_rcv include/net/sock.h:1061 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2849 release_sock+0x5d/0x1c0 net/core/sock.c:3404 sk_stream_wait_memory+0x700/0xdc0 net/core/stream.c:145 tcp_sendmsg_locked+0x111d/0x3fc0 net/ipv4/tcp.c:1410 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1448 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] __sys_sendto+0x439/0x5c0 net/socket.c:2119 __do_sys_sendto net/socket.c:2131 [inline] __se_sys_sendto net/socket.c:2127 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2127 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f6431289109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f643236e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f643139c100 RCX: 00007f6431289109 RDX: 00000000d0d0c2ac RSI: 0000000020000080 RDI: 000000000000000a RBP: 00007f64312e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff372533af R14: 00007f643236e300 R15: 0000000000022000

In the Linux kernel, the following vulnerability has been resolved: ath10k: Fix error handling in ath10k_setup_msa_resources The device_node pointer is returned by of_parse_phandle() with refcount incremented. We should use of_node_put() on it when done. This function only calls of_node_put() in the regular path. And it will cause refcount leak in error path.

In the Linux kernel, the following vulnerability has been resolved: drm/msm/disp/dpu1: avoid clearing hw interrupts if hw_intr is null during drm uninit If edp modeset init is failed due to panel being not ready and probe defers during drm bind, avoid clearing irqs and dereference hw_intr when hw_intr is null. BUG: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Call trace: dpu_core_irq_uninstall+0x50/0xb0 dpu_irq_uninstall+0x18/0x24 msm_drm_uninit+0xd8/0x16c msm_drm_bind+0x580/0x5fc try_to_bring_up_master+0x168/0x1c0 __component_add+0xb4/0x178 component_add+0x1c/0x28 dp_display_probe+0x38c/0x400 platform_probe+0xb0/0xd0 really_probe+0xcc/0x2c8 __driver_probe_device+0xbc/0xe8 driver_probe_device+0x48/0xf0 __device_attach_driver+0xa0/0xc8 bus_for_each_drv+0x8c/0xd8 __device_attach+0xc4/0x150 device_initial_probe+0x1c/0x28 Changes in V2: - Update commit message and coreect fixes tag. Patchwork: https://patchwork.freedesktop.org/patch/484430/

In the Linux kernel, the following vulnerability has been resolved: powerpc/rtas: Keep MSR[RI] set when calling RTAS RTAS runs in real mode (MSR[DR] and MSR[IR] unset) and in 32-bit big endian mode (MSR[SF,LE] unset). The change in MSR is done in enter_rtas() in a relatively complex way, since the MSR value could be hardcoded. Furthermore, a panic has been reported when hitting the watchdog interrupt while running in RTAS, this leads to the following stack trace: watchdog: CPU 24 Hard LOCKUP watchdog: CPU 24 TB:997512652051031, last heartbeat TB:997504470175378 (15980ms ago) ... Supported: No, Unreleased kernel CPU: 24 PID: 87504 Comm: drmgr Kdump: loaded Tainted: G E X 5.14.21-150400.71.1.bz196362_2-default #1 SLE15-SP4 (unreleased) 0d821077ef4faa8dfaf370efb5fdca1fa35f4e2c NIP: 000000001fb41050 LR: 000000001fb4104c CTR: 0000000000000000 REGS: c00000000fc33d60 TRAP: 0100 Tainted: G E X (5.14.21-150400.71.1.bz196362_2-default) MSR: 8000000002981000 <SF,VEC,VSX,ME> CR: 48800002 XER: 20040020 CFAR: 000000000000011c IRQMASK: 1 GPR00: 0000000000000003 ffffffffffffffff 0000000000000001 00000000000050dc GPR04: 000000001ffb6100 0000000000000020 0000000000000001 000000001fb09010 GPR08: 0000000020000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 80040000072a40a8 c00000000ff8b680 0000000000000007 0000000000000034 GPR16: 000000001fbf6e94 000000001fbf6d84 000000001fbd1db0 000000001fb3f008 GPR20: 000000001fb41018 ffffffffffffffff 000000000000017f fffffffffffff68f GPR24: 000000001fb18fe8 000000001fb3e000 000000001fb1adc0 000000001fb1cf40 GPR28: 000000001fb26000 000000001fb460f0 000000001fb17f18 000000001fb17000 NIP [000000001fb41050] 0x1fb41050 LR [000000001fb4104c] 0x1fb4104c Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX Oops: Unrecoverable System Reset, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries ... Supported: No, Unreleased kernel CPU: 24 PID: 87504 Comm: drmgr Kdump: loaded Tainted: G E X 5.14.21-150400.71.1.bz196362_2-default #1 SLE15-SP4 (unreleased) 0d821077ef4faa8dfaf370efb5fdca1fa35f4e2c NIP: 000000001fb41050 LR: 000000001fb4104c CTR: 0000000000000000 REGS: c00000000fc33d60 TRAP: 0100 Tainted: G E X (5.14.21-150400.71.1.bz196362_2-default) MSR: 8000000002981000 <SF,VEC,VSX,ME> CR: 48800002 XER: 20040020 CFAR: 000000000000011c IRQMASK: 1 GPR00: 0000000000000003 ffffffffffffffff 0000000000000001 00000000000050dc GPR04: 000000001ffb6100 0000000000000020 0000000000000001 000000001fb09010 GPR08: 0000000020000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 80040000072a40a8 c00000000ff8b680 0000000000000007 0000000000000034 GPR16: 000000001fbf6e94 000000001fbf6d84 000000001fbd1db0 000000001fb3f008 GPR20: 000000001fb41018 ffffffffffffffff 000000000000017f fffffffffffff68f GPR24: 000000001fb18fe8 000000001fb3e000 000000001fb1adc0 000000001fb1cf40 GPR28: 000000001fb26000 000000001fb460f0 000000001fb17f18 000000001fb17000 NIP [000000001fb41050] 0x1fb41050 LR [000000001fb4104c] 0x1fb4104c Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX ---[ end trace 3ddec07f638c34a2 ]--- This happens because MSR[RI] is unset when entering RTAS but there is no valid reason to not set it here. RTAS is expected to be called with MSR[RI] as specified in PAPR+ section "7.2.1 Machine State": R1–7.2.1–9. If called with MSR[RI] equal to 1, then RTAS must protect its own critical regions from recursion by setting the MSR[RI] bit to 0 when in the critical regions. Fixing this by reviewing the way MSR is compute before calling RTAS. Now a hardcoded value meaning real ---truncated---

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3: Fix error handling in gic_populate_ppi_partitions of_get_child_by_name() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. When kcalloc fails, it missing of_node_put() and results in refcount leak. Fix this by goto out_put_node label.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix deadlock in nilfs_count_free_blocks() A semaphore deadlock can occur if nilfs_get_block() detects metadata corruption while locating data blocks and a superblock writeback occurs at the same time: task 1 task 2 ------ ------ * A file operation * nilfs_truncate() nilfs_get_block() down_read(rwsem A) <-- nilfs_bmap_lookup_contig() ... generic_shutdown_super() nilfs_put_super() * Prepare to write superblock * down_write(rwsem B) <-- nilfs_cleanup_super() * Detect b-tree corruption * nilfs_set_log_cursor() nilfs_bmap_convert_error() nilfs_count_free_blocks() __nilfs_error() down_read(rwsem A) <-- nilfs_set_error() down_write(rwsem B) <-- *** DEADLOCK *** Here, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem) and then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata corruption, __nilfs_error() is called from nilfs_bmap_convert_error() inside the lock section. Since __nilfs_error() calls nilfs_set_error() unless the filesystem is read-only and nilfs_set_error() attempts to writelock rwsem B (= nilfs->ns_sem) to write back superblock exclusively, hierarchical lock acquisition occurs in the order rwsem A -> rwsem B. Now, if another task starts updating the superblock, it may writelock rwsem B during the lock sequence above, and can deadlock trying to readlock rwsem A in nilfs_count_free_blocks(). However, there is actually no need to take rwsem A in nilfs_count_free_blocks() because it, within the lock section, only reads a single integer data on a shared struct with nilfs_sufile_get_ncleansegs(). This has been the case after commit aa474a220180 ("nilfs2: add local variable to cache the number of clean segments"), that is, even before this bug was introduced. So, this resolves the deadlock problem by just not taking the semaphore in nilfs_count_free_blocks().

In the Linux kernel, the following vulnerability has been resolved: block: Fix potential deadlock in blk_ia_range_sysfs_show() When being read, a sysfs attribute is already protected against removal with the kobject node active reference counter. As a result, in blk_ia_range_sysfs_show(), there is no need to take the queue sysfs lock when reading the value of a range attribute. Using the queue sysfs lock in this function creates a potential deadlock situation with the disk removal, something that a lockdep signals with a splat when the device is removed: [ 760.703551] Possible unsafe locking scenario: [ 760.703551] [ 760.703554] CPU0 CPU1 [ 760.703556] ---- ---- [ 760.703558] lock(&q->sysfs_lock); [ 760.703565] lock(kn->active#385); [ 760.703573] lock(&q->sysfs_lock); [ 760.703579] lock(kn->active#385); [ 760.703587] [ 760.703587] *** DEADLOCK *** Solve this by removing the mutex_lock()/mutex_unlock() calls from blk_ia_range_sysfs_show().

In the Linux kernel, the following vulnerability has been resolved: watch_queue: Fix NULL dereference in error cleanup In watch_queue_set_size(), the error cleanup code doesn't take account of the fact that __free_page() can't handle a NULL pointer when trying to free up buffer pages that did get allocated. Fix this by only calling __free_page() on the pages actually allocated. Without the fix, this can lead to something like the following: BUG: KASAN: null-ptr-deref in __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473 Read of size 4 at addr 0000000000000034 by task syz-executor168/3599 ... Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:446 [inline] kasan_report.cold+0x66/0xdf mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] page_ref_count include/linux/page_ref.h:67 [inline] put_page_testzero include/linux/mm.h:717 [inline] __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473 watch_queue_set_size+0x499/0x630 kernel/watch_queue.c:275 pipe_ioctl+0xac/0x2b0 fs/pipe.c:632 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: media: i2c: dw9714: Disable the regulator when the driver fails to probe When the driver fails to probe, we will get the following splat: [ 59.305988] ------------[ cut here ]------------ [ 59.306417] WARNING: CPU: 2 PID: 395 at drivers/regulator/core.c:2257 _regulator_put+0x3ec/0x4e0 [ 59.310345] RIP: 0010:_regulator_put+0x3ec/0x4e0 [ 59.318362] Call Trace: [ 59.318582] <TASK> [ 59.318765] regulator_put+0x1f/0x30 [ 59.319058] devres_release_group+0x319/0x3d0 [ 59.319420] i2c_device_probe+0x766/0x940 Fix this by disabling the regulator in error handling.

In the Linux kernel, the following vulnerability has been resolved: net: bgmac: Fix a BUG triggered by wrong bytes_compl On one of our machines we got: kernel BUG at lib/dynamic_queue_limits.c:27! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM CPU: 0 PID: 1166 Comm: irq/41-bgmac Tainted: G W O 4.14.275-rt132 #1 Hardware name: BRCM XGS iProc task: ee3415c0 task.stack: ee32a000 PC is at dql_completed+0x168/0x178 LR is at bgmac_poll+0x18c/0x6d8 pc : [<c03b9430>] lr : [<c04b5a18>] psr: 800a0313 sp : ee32be14 ip : 000005ea fp : 00000bd4 r10: ee558500 r9 : c0116298 r8 : 00000002 r7 : 00000000 r6 : ef128810 r5 : 01993267 r4 : 01993851 r3 : ee558000 r2 : 000070e1 r1 : 00000bd4 r0 : ee52c180 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 12c5387d Table: 8e88c04a DAC: 00000051 Process irq/41-bgmac (pid: 1166, stack limit = 0xee32a210) Stack: (0xee32be14 to 0xee32c000) be00: ee558520 ee52c100 ef128810 be20: 00000000 00000002 c0116298 c04b5a18 00000000 c0a0c8c4 c0951780 00000040 be40: c0701780 ee558500 ee55d520 ef05b340 ef6f9780 ee558520 00000001 00000040 be60: ffffe000 c0a56878 ef6fa040 c0952040 0000012c c0528744 ef6f97b0 fffcfb6a be80: c0a04104 2eda8000 c0a0c4ec c0a0d368 ee32bf44 c0153534 ee32be98 ee32be98 bea0: ee32bea0 ee32bea0 ee32bea8 ee32bea8 00000000 c01462e4 ffffe000 ef6f22a8 bec0: ffffe000 00000008 ee32bee4 c0147430 ffffe000 c094a2a8 00000003 ffffe000 bee0: c0a54528 00208040 0000000c c0a0c8c4 c0a65980 c0124d3c 00000008 ee558520 bf00: c094a23c c0a02080 00000000 c07a9910 ef136970 ef136970 ee30a440 ef136900 bf20: ee30a440 00000001 ef136900 ee30a440 c016d990 00000000 c0108db0 c012500c bf40: ef136900 c016da14 ee30a464 ffffe000 00000001 c016dd14 00000000 c016db28 bf60: ffffe000 ee21a080 ee30a400 00000000 ee32a000 ee30a440 c016dbfc ee25fd70 bf80: ee21a09c c013edcc ee32a000 ee30a400 c013ec7c 00000000 00000000 00000000 bfa0: 00000000 00000000 00000000 c0108470 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [<c03b9430>] (dql_completed) from [<c04b5a18>] (bgmac_poll+0x18c/0x6d8) [<c04b5a18>] (bgmac_poll) from [<c0528744>] (net_rx_action+0x1c4/0x494) [<c0528744>] (net_rx_action) from [<c0124d3c>] (do_current_softirqs+0x1ec/0x43c) [<c0124d3c>] (do_current_softirqs) from [<c012500c>] (__local_bh_enable+0x80/0x98) [<c012500c>] (__local_bh_enable) from [<c016da14>] (irq_forced_thread_fn+0x84/0x98) [<c016da14>] (irq_forced_thread_fn) from [<c016dd14>] (irq_thread+0x118/0x1c0) [<c016dd14>] (irq_thread) from [<c013edcc>] (kthread+0x150/0x158) [<c013edcc>] (kthread) from [<c0108470>] (ret_from_fork+0x14/0x24) Code: a83f15e0 0200001a 0630a0e1 c3ffffea (f201f0e7) The issue seems similar to commit 90b3b339364c ("net: hisilicon: Fix a BUG trigered by wrong bytes_compl") and potentially introduced by commit b38c83dd0866 ("bgmac: simplify tx ring index handling"). If there is an RX interrupt between setting ring->end and netdev_sent_queue() we can hit the BUG_ON as bgmac_dma_tx_free() can miscalculate the queue size while called from bgmac_poll(). The machine which triggered the BUG runs a v4.14 RT kernel - but the issue seems present in mainline too.

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix lockdep splat in in6_dump_addrs() As reported by syzbot, we should not use rcu_dereference() when rcu_read_lock() is not held. WARNING: suspicious RCU usage 5.19.0-rc2-syzkaller #0 Not tainted net/ipv6/addrconf.c:5175 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor326/3617: #0: ffffffff8d5848e8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xae/0xc20 net/netlink/af_netlink.c:2223 stack backtrace: CPU: 0 PID: 3617 Comm: syz-executor326 Not tainted 5.19.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 in6_dump_addrs+0x12d1/0x1790 net/ipv6/addrconf.c:5175 inet6_dump_addr+0x9c1/0xb50 net/ipv6/addrconf.c:5300 netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380 netlink_dump_start include/linux/netlink.h:245 [inline] rtnetlink_rcv_msg+0x73e/0xc90 net/core/rtnetlink.c:6046 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2492 ___sys_sendmsg+0xf3/0x170 net/socket.c:2546 __sys_sendmsg net/socket.c:2575 [inline] __do_sys_sendmsg net/socket.c:2584 [inline] __se_sys_sendmsg net/socket.c:2582 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2582 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0

In the Linux kernel, the following vulnerability has been resolved: MIPS: pgalloc: fix memory leak caused by pgd_free() pgd page is freed by generic implementation pgd_free() since commit f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()"), however, there are scenarios that the system uses more than one page as the pgd table, in such cases the generic implementation pgd_free() won't be applicable anymore. For example, when PAGE_SIZE_4KB is enabled and MIPS_VA_BITS_48 is not enabled in a 64bit system, the macro "PGD_ORDER" will be set as "1", which will cause allocating two pages as the pgd table. Well, at the same time, the generic implementation pgd_free() just free one pgd page, which will result in the memory leak. The memory leak can be easily detected by executing shell command: "while true; do ls > /dev/null; grep MemFree /proc/meminfo; done"

In the Linux kernel, the following vulnerability has been resolved: 9p/trans_fd: always use O_NONBLOCK read/write syzbot is reporting hung task at p9_fd_close() [1], for p9_mux_poll_stop() from p9_conn_destroy() from p9_fd_close() is failing to interrupt already started kernel_read() from p9_fd_read() from p9_read_work() and/or kernel_write() from p9_fd_write() from p9_write_work() requests. Since p9_socket_open() sets O_NONBLOCK flag, p9_mux_poll_stop() does not need to interrupt kernel_read()/kernel_write(). However, since p9_fd_open() does not set O_NONBLOCK flag, but pipe blocks unless signal is pending, p9_mux_poll_stop() needs to interrupt kernel_read()/kernel_write() when the file descriptor refers to a pipe. In other words, pipe file descriptor needs to be handled as if socket file descriptor. We somehow need to interrupt kernel_read()/kernel_write() on pipes. A minimal change, which this patch is doing, is to set O_NONBLOCK flag from p9_fd_open(), for O_NONBLOCK flag does not affect reading/writing of regular files. But this approach changes O_NONBLOCK flag on userspace- supplied file descriptors (which might break userspace programs), and O_NONBLOCK flag could be changed by userspace. It would be possible to set O_NONBLOCK flag every time p9_fd_read()/p9_fd_write() is invoked, but still remains small race window for clearing O_NONBLOCK flag. If we don't want to manipulate O_NONBLOCK flag, we might be able to surround kernel_read()/kernel_write() with set_thread_flag(TIF_SIGPENDING) and recalc_sigpending(). Since p9_read_work()/p9_write_work() works are processed by kernel threads which process global system_wq workqueue, signals could not be delivered from remote threads when p9_mux_poll_stop() from p9_conn_destroy() from p9_fd_close() is called. Therefore, calling set_thread_flag(TIF_SIGPENDING)/recalc_sigpending() every time would be needed if we count on signals for making kernel_read()/kernel_write() non-blocking. [Dominique: add comment at Christian's suggestion]

In the Linux kernel, the following vulnerability has been resolved: tls: stop recv() if initial process_rx_list gave us non-DATA If we have a non-DATA record on the rx_list and another record of the same type still on the queue, we will end up merging them: - process_rx_list copies the non-DATA record - we start the loop and process the first available record since it's of the same type - we break out of the loop since the record was not DATA Just check the record type and jump to the end in case process_rx_list did some work.

In the Linux kernel, the following vulnerability has been resolved: tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd() test_gen_kprobe_cmd() only free buf in fail path, hence buf will leak when there is no failure. Move kfree(buf) from fail path to common path to prevent the memleak. The same reason and solution in test_gen_kretprobe_cmd(). unreferenced object 0xffff888143b14000 (size 2048): comm "insmod", pid 52490, jiffies 4301890980 (age 40.553s) hex dump (first 32 bytes): 70 3a 6b 70 72 6f 62 65 73 2f 67 65 6e 5f 6b 70 p:kprobes/gen_kp 72 6f 62 65 5f 74 65 73 74 20 64 6f 5f 73 79 73 robe_test do_sys backtrace: [<000000006d7b836b>] kmalloc_trace+0x27/0xa0 [<0000000009528b5b>] 0xffffffffa059006f [<000000008408b580>] do_one_initcall+0x87/0x2a0 [<00000000c4980a7e>] do_init_module+0xdf/0x320 [<00000000d775aad0>] load_module+0x3006/0x3390 [<00000000e9a74b80>] __do_sys_finit_module+0x113/0x1b0 [<000000003726480d>] do_syscall_64+0x35/0x80 [<000000003441e93b>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix dentry leak in cachefiles_open_file() A dentry leak may be caused when a lookup cookie and a cull are concurrent: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // get dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Returns an error but doesn't put dentry After that the following WARNING will be triggered when the backend folder is umounted: ================================================================== BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda] WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Call Trace: <TASK> d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ================================================================== Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released. Therefore release that reference count in cachefiles_look_up_object() to fix the above issue and simplify the code.

In the Linux kernel, the following vulnerability has been resolved: clk: mmp: pxa1908-apbcp: Fix a NULL vs IS_ERR() check The devm_kzalloc() function doesn't return error pointers, it returns NULL on error. Update the check to match.

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: prohibit deactivating all links In the internal API this calls this is a WARN_ON, but that should remain since internally we want to know about bugs that may cause this. Prevent deactivating all links in the debugfs write directly.

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix PM usage_count for console handover When console is enabled, univ8250_console_setup() calls serial8250_console_setup() before .dev is set to uart_port. Therefore, it will not call pm_runtime_get_sync(). Later, when the actual driver is going to take over univ8250_console_exit() is called. As .dev is already set, serial8250_console_exit() makes pm_runtime_put_sync() call with usage count being zero triggering PM usage count warning (extra debug for univ8250_console_setup(), univ8250_console_exit(), and serial8250_register_ports()): [ 0.068987] univ8250_console_setup ttyS0 nodev [ 0.499670] printk: console [ttyS0] enabled [ 0.717955] printk: console [ttyS0] printing thread started [ 1.960163] serial8250_register_ports assigned dev for ttyS0 [ 1.976830] printk: console [ttyS0] disabled [ 1.976888] printk: console [ttyS0] printing thread stopped [ 1.977073] univ8250_console_exit ttyS0 usage:0 [ 1.977075] serial8250 serial8250: Runtime PM usage count underflow! [ 1.977429] dw-apb-uart.6: ttyS0 at MMIO 0x4010006000 (irq = 33, base_baud = 115200) is a 16550A [ 1.977812] univ8250_console_setup ttyS0 usage:2 [ 1.978167] printk: console [ttyS0] printing thread started [ 1.978203] printk: console [ttyS0] enabled To fix the issue, call pm_runtime_get_sync() in serial8250_register_ports() as soon as .dev is set for an uart_port if it has console enabled. This problem became apparent only recently because 82586a721595 ("PM: runtime: Avoid device usage count underflows") added the warning printout. I confirmed this problem also occurs with v5.18 (w/o the warning printout, obviously).

In the Linux kernel, the following vulnerability has been resolved: ata: pata_octeon_cf: Fix refcount leak in octeon_cf_probe of_find_device_by_node() takes reference, we should use put_device() to release it when not need anymore. Add missing put_device() to avoid refcount leak.

In the Linux kernel, the following vulnerability has been resolved: ionic: Fix netdev notifier unregister on failure If register_netdev() fails, then the driver leaks the netdev notifier. Fix this by calling ionic_lif_unregister() on register_netdev() failure. This will also call ionic_lif_unregister_phc() if it has already been registered.

In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: Intel: hda-dai: Ensure DAI widget is valid during params Each cpu DAI should associate with a widget. However, the topology might not create the right number of DAI widgets for aggregated amps. And it will cause NULL pointer deference. Check that the DAI widget associated with the CPU DAI is valid to prevent NULL pointer deference due to missing DAI widgets in topologies with aggregated amps.

In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reproduce this issue, create a file which has at least 10 extents, and then perform shrinking truncate into middle of the last extent record, so that the number of remaining extents is not under or divisible by 8. This causes the last extent record (8 extents) to be removed totally instead of truncating into middle of it. Thus this causes corruption, and lost data. Fix for this is simply checking if the new truncated end is below the start of this extent record, making it safe to remove the full extent record. However call to hfs_brec_remove() can't be moved to it's previous place since we're dropping ->tree_lock and it can cause a race condition and the cached info being invalidated possibly corrupting the node data. Another issue is related to this one. When entering into the block (blk_cnt > start) we are not holding the ->tree_lock. We break out from the loop not holding the lock, but hfs_find_exit() does unlock it. Not sure if it's possible for someone else to take the lock under our feet, but it can cause hard to debug errors and premature unlocking. Even if there's no real risk of it, the locking should still always be kept in balance. Thus taking the lock now just before the check.

In the Linux kernel, the following vulnerability has been resolved: ALSA: memalloc: prefer dma_mapping_error() over explicit address checking With CONFIG_DMA_API_DEBUG enabled, the following warning is observed: DMA-API: snd_hda_intel 0000:03:00.1: device driver failed to check map error[device address=0x00000000ffff0000] [size=20480 bytes] [mapped as single] WARNING: CPU: 28 PID: 2255 at kernel/dma/debug.c:1036 check_unmap+0x1408/0x2430 CPU: 28 UID: 42 PID: 2255 Comm: wireplumber Tainted: G W L 6.12.0-10-133577cad6bf48e5a7848c4338124081393bfe8a+ #759 debug_dma_unmap_page+0xe9/0xf0 snd_dma_wc_free+0x85/0x130 [snd_pcm] snd_pcm_lib_free_pages+0x1e3/0x440 [snd_pcm] snd_pcm_common_ioctl+0x1c9a/0x2960 [snd_pcm] snd_pcm_ioctl+0x6a/0xc0 [snd_pcm] ... Check for returned DMA addresses using specialized dma_mapping_error() helper which is generally recommended for this purpose by Documentation/core-api/dma-api.rst.

In the Linux kernel, the following vulnerability has been resolved: ALSA: us122l: Use snd_card_free_when_closed() at disconnection The USB disconnect callback is supposed to be short and not too-long waiting. OTOH, the current code uses snd_card_free() at disconnection, but this waits for the close of all used fds, hence it can take long. It eventually blocks the upper layer USB ioctls, which may trigger a soft lockup. An easy workaround is to replace snd_card_free() with snd_card_free_when_closed(). This variant returns immediately while the release of resources is done asynchronously by the card device release at the last close. The loop of us122l->mmap_count check is dropped as well. The check is useless for the asynchronous operation with *_when_closed().

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: fix divide error in DM plane scale calcs dm_get_plane_scale doesn't take into account plane scaled size equal to zero, leading to a kernel oops due to division by zero. Fix by setting out-scale size as zero when the dst size is zero, similar to what is done by drm_calc_scale(). This issue started with the introduction of cursor ovelay mode that uses this function to assess cursor mode changes via dm_crtc_get_cursor_mode() before checking plane state. [Dec17 17:14] Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI [ +0.000018] CPU: 5 PID: 1660 Comm: surface-DP-1 Not tainted 6.10.0+ #231 [ +0.000007] Hardware name: Valve Jupiter/Jupiter, BIOS F7A0131 01/30/2024 [ +0.000004] RIP: 0010:dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000553] Code: 44 0f b7 41 3a 44 0f b7 49 3e 83 e0 0f 48 0f a3 c2 73 21 69 41 28 e8 03 00 00 31 d2 41 f7 f1 31 d2 89 06 69 41 2c e8 03 00 00 <41> f7 f0 89 07 e9 d7 d8 7e e9 44 89 c8 45 89 c1 41 89 c0 eb d4 66 [ +0.000005] RSP: 0018:ffffa8df0de6b8a0 EFLAGS: 00010246 [ +0.000006] RAX: 00000000000003e8 RBX: ffff9ac65c1f6e00 RCX: ffff9ac65d055500 [ +0.000003] RDX: 0000000000000000 RSI: ffffa8df0de6b8b0 RDI: ffffa8df0de6b8b4 [ +0.000004] RBP: ffff9ac64e7a5800 R08: 0000000000000000 R09: 0000000000000a00 [ +0.000003] R10: 00000000000000ff R11: 0000000000000054 R12: ffff9ac6d0700010 [ +0.000003] R13: ffff9ac65d054f00 R14: ffff9ac65d055500 R15: ffff9ac64e7a60a0 [ +0.000004] FS: 00007f869ea00640(0000) GS:ffff9ac970080000(0000) knlGS:0000000000000000 [ +0.000004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000003] CR2: 000055ca701becd0 CR3: 000000010e7f2000 CR4: 0000000000350ef0 [ +0.000004] Call Trace: [ +0.000007] <TASK> [ +0.000006] ? __die_body.cold+0x19/0x27 [ +0.000009] ? die+0x2e/0x50 [ +0.000007] ? do_trap+0xca/0x110 [ +0.000007] ? do_error_trap+0x6a/0x90 [ +0.000006] ? dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000504] ? exc_divide_error+0x38/0x50 [ +0.000005] ? dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000488] ? asm_exc_divide_error+0x1a/0x20 [ +0.000011] ? dm_get_plane_scale+0x3f/0x60 [amdgpu] [ +0.000593] dm_crtc_get_cursor_mode+0x33f/0x430 [amdgpu] [ +0.000562] amdgpu_dm_atomic_check+0x2ef/0x1770 [amdgpu] [ +0.000501] drm_atomic_check_only+0x5e1/0xa30 [drm] [ +0.000047] drm_mode_atomic_ioctl+0x832/0xcb0 [drm] [ +0.000050] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10 [drm] [ +0.000047] drm_ioctl_kernel+0xb3/0x100 [drm] [ +0.000062] drm_ioctl+0x27a/0x4f0 [drm] [ +0.000049] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10 [drm] [ +0.000055] amdgpu_drm_ioctl+0x4e/0x90 [amdgpu] [ +0.000360] __x64_sys_ioctl+0x97/0xd0 [ +0.000010] do_syscall_64+0x82/0x190 [ +0.000008] ? __pfx_drm_mode_createblob_ioctl+0x10/0x10 [drm] [ +0.000044] ? srso_return_thunk+0x5/0x5f [ +0.000006] ? drm_ioctl_kernel+0xb3/0x100 [drm] [ +0.000040] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? __check_object_size+0x50/0x220 [ +0.000007] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? drm_ioctl+0x2a4/0x4f0 [drm] [ +0.000039] ? __pfx_drm_mode_createblob_ioctl+0x10/0x10 [drm] [ +0.000043] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? __pm_runtime_suspend+0x69/0xc0 [ +0.000006] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? amdgpu_drm_ioctl+0x71/0x90 [amdgpu] [ +0.000366] ? srso_return_thunk+0x5/0x5f [ +0.000006] ? syscall_exit_to_user_mode+0x77/0x210 [ +0.000007] ? srso_return_thunk+0x5/0x5f [ +0.000005] ? do_syscall_64+0x8e/0x190 [ +0.000006] ? srso_return_thunk+0x5/0x5f [ +0.000006] ? do_syscall_64+0x8e/0x190 [ +0.000006] ? srso_return_thunk+0x5/0x5f [ +0.000007] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ +0.000008] RIP: 0033:0x55bb7cd962bc [ +0.000007] Code: 4c 89 6c 24 18 4c 89 64 24 20 4c 89 74 24 28 0f 57 c0 0f 11 44 24 30 89 c7 48 8d 54 24 08 b8 10 00 00 00 be bc 64 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: idpf: convert workqueues to unbound When a workqueue is created with `WQ_UNBOUND`, its work items are served by special worker-pools, whose host workers are not bound to any specific CPU. In the default configuration (i.e. when `queue_delayed_work` and friends do not specify which CPU to run the work item on), `WQ_UNBOUND` allows the work item to be executed on any CPU in the same node of the CPU it was enqueued on. While this solution potentially sacrifices locality, it avoids contention with other processes that might dominate the CPU time of the processor the work item was scheduled on. This is not just a theoretical problem: in a particular scenario misconfigured process was hogging most of the time from CPU0, leaving less than 0.5% of its CPU time to the kworker. The IDPF workqueues that were using the kworker on CPU0 suffered large completion delays as a result, causing performance degradation, timeouts and eventual system crash. * I have also run a manual test to gauge the performance improvement. The test consists of an antagonist process (`./stress --cpu 2`) consuming as much of CPU 0 as possible. This process is run under `taskset 01` to bind it to CPU0, and its priority is changed with `chrt -pQ 9900 10000 ${pid}` and `renice -n -20 ${pid}` after start. Then, the IDPF driver is forced to prefer CPU0 by editing all calls to `queue_delayed_work`, `mod_delayed_work`, etc... to use CPU 0. Finally, `ktraces` for the workqueue events are collected. Without the current patch, the antagonist process can force arbitrary delays between `workqueue_queue_work` and `workqueue_execute_start`, that in my tests were as high as `30ms`. With the current patch applied, the workqueue can be migrated to another unloaded CPU in the same node, and, keeping everything else equal, the maximum delay I could see was `6us`.