In the Linux kernel, the following vulnerability has been resolved: erofs: fix pcluster use-after-free on UP platforms During stress testing with CONFIG_SMP disabled, KASAN reports as below: ================================================================== BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30 Read of size 8 at addr ffff8881094223f8 by task stress/7789 CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: <TASK> .. __mutex_lock+0xe5/0xc30 .. z_erofs_do_read_page+0x8ce/0x1560 .. z_erofs_readahead+0x31c/0x580 .. Freed by task 7787 kasan_save_stack+0x1e/0x40 kasan_set_track+0x20/0x30 kasan_set_free_info+0x20/0x40 __kasan_slab_free+0x10c/0x190 kmem_cache_free+0xed/0x380 rcu_core+0x3d5/0xc90 __do_softirq+0x12d/0x389 Last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0x97/0xb0 call_rcu+0x3d/0x3f0 erofs_shrink_workstation+0x11f/0x210 erofs_shrink_scan+0xdc/0x170 shrink_slab.constprop.0+0x296/0x530 drop_slab+0x1c/0x70 drop_caches_sysctl_handler+0x70/0x80 proc_sys_call_handler+0x20a/0x2f0 vfs_write+0x555/0x6c0 ksys_write+0xbe/0x160 do_syscall_64+0x3b/0x90 The root cause is that erofs_workgroup_unfreeze() doesn't reset to orig_val thus it causes a race that the pcluster reuses unexpectedly before freeing. Since UP platforms are quite rare now, such path becomes unnecessary. Let's drop such specific-designed path directly instead.

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix UAF when detecting digest errors We should also bail from the io_work loop when we set rd_enabled to true, so we don't attempt to read data from the socket when the TCP stream is already out-of-sync or corrupted.

In the Linux kernel, the following vulnerability has been resolved: net: ll_temac: Make sure to free skb when it is completely used With the skb pointer piggy-backed on the TX BD, we have a simple and efficient way to free the skb buffer when the frame has been transmitted. But in order to avoid freeing the skb while there are still fragments from the skb in use, we need to piggy-back on the TX BD of the skb, not the first. Without this, we are doing use-after-free on the DMA side, when the first BD of a multi TX BD packet is seen as completed in xmit_done, and the remaining BDs are still being processed.

In the Linux kernel, the following vulnerability has been resolved: drm/msm/a6xx: Allocate enough space for GMU registers In commit 142639a52a01 ("drm/msm/a6xx: fix crashstate capture for A650") we changed a6xx_get_gmu_registers() to read 3 sets of registers. Unfortunately, we didn't change the memory allocation for the array. That leads to a KASAN warning (this was on the chromeos-5.4 kernel, which has the problematic commit backported to it): BUG: KASAN: slab-out-of-bounds in _a6xx_get_gmu_registers+0x144/0x430 Write of size 8 at addr ffffff80c89432b0 by task A618-worker/209 CPU: 5 PID: 209 Comm: A618-worker Tainted: G W 5.4.156-lockdep #22 Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT) Call trace: dump_backtrace+0x0/0x248 show_stack+0x20/0x2c dump_stack+0x128/0x1ec print_address_description+0x88/0x4a0 __kasan_report+0xfc/0x120 kasan_report+0x10/0x18 __asan_report_store8_noabort+0x1c/0x24 _a6xx_get_gmu_registers+0x144/0x430 a6xx_gpu_state_get+0x330/0x25d4 msm_gpu_crashstate_capture+0xa0/0x84c recover_worker+0x328/0x838 kthread_worker_fn+0x32c/0x574 kthread+0x2dc/0x39c ret_from_fork+0x10/0x18 Allocated by task 209: __kasan_kmalloc+0xfc/0x1c4 kasan_kmalloc+0xc/0x14 kmem_cache_alloc_trace+0x1f0/0x2a0 a6xx_gpu_state_get+0x164/0x25d4 msm_gpu_crashstate_capture+0xa0/0x84c recover_worker+0x328/0x838 kthread_worker_fn+0x32c/0x574 kthread+0x2dc/0x39c ret_from_fork+0x10/0x18

In the Linux kernel, the following vulnerability has been resolved: x86/ioremap: Map EFI-reserved memory as encrypted for SEV Some drivers require memory that is marked as EFI boot services data. In order for this memory to not be re-used by the kernel after ExitBootServices(), efi_mem_reserve() is used to preserve it by inserting a new EFI memory descriptor and marking it with the EFI_MEMORY_RUNTIME attribute. Under SEV, memory marked with the EFI_MEMORY_RUNTIME attribute needs to be mapped encrypted by Linux, otherwise the kernel might crash at boot like below: EFI Variables Facility v0.08 2004-May-17 general protection fault, probably for non-canonical address 0x3597688770a868b2: 0000 [#1] SMP NOPTI CPU: 13 PID: 1 Comm: swapper/0 Not tainted 5.12.4-2-default #1 openSUSE Tumbleweed Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:efi_mokvar_entry_next [...] Call Trace: efi_mokvar_sysfs_init ? efi_mokvar_table_init do_one_initcall ? __kmalloc kernel_init_freeable ? rest_init kernel_init ret_from_fork Expand the __ioremap_check_other() function to additionally check for this other type of boot data reserved at runtime and indicate that it should be mapped encrypted for an SEV guest. [ bp: Massage commit message. ]

In the Linux kernel, the following vulnerability has been resolved: mptcp: Fix out of bounds when parsing TCP options The TCP option parser in mptcp (mptcp_get_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options.").

In the Linux kernel, the following vulnerability has been resolved: fsdax: Fix infinite loop in dax_iomap_rw() I got an infinite loop and a WARNING report when executing a tail command in virtiofs. WARNING: CPU: 10 PID: 964 at fs/iomap/iter.c:34 iomap_iter+0x3a2/0x3d0 Modules linked in: CPU: 10 PID: 964 Comm: tail Not tainted 5.19.0-rc7 Call Trace: <TASK> dax_iomap_rw+0xea/0x620 ? __this_cpu_preempt_check+0x13/0x20 fuse_dax_read_iter+0x47/0x80 fuse_file_read_iter+0xae/0xd0 new_sync_read+0xfe/0x180 ? 0xffffffff81000000 vfs_read+0x14d/0x1a0 ksys_read+0x6d/0xf0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The tail command will call read() with a count of 0. In this case, iomap_iter() will report this WARNING, and always return 1 which casuing the infinite loop in dax_iomap_rw(). Fixing by checking count whether is 0 in dax_iomap_rw().

In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries/iommu: LPAR panics during boot up with a frozen PE At the time of LPAR boot up, partition firmware provides Open Firmware property ibm,dma-window for the PE. This property is provided on the PCI bus the PE is attached to. There are execptions where the partition firmware might not provide this property for the PE at the time of LPAR boot up. One of the scenario is where the firmware has frozen the PE due to some error condition. This PE is frozen for 24 hours or unless the whole system is reinitialized. Within this time frame, if the LPAR is booted, the frozen PE will be presented to the LPAR but ibm,dma-window property could be missing. Today, under these circumstances, the LPAR oopses with NULL pointer dereference, when configuring the PCI bus the PE is attached to. BUG: Kernel NULL pointer dereference on read at 0x000000c8 Faulting instruction address: 0xc0000000001024c0 Oops: Kernel access of bad area, sig: 7 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries Modules linked in: Supported: Yes CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-150600.9-default #1 Hardware name: IBM,9043-MRX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_023) hv:phyp pSeries NIP: c0000000001024c0 LR: c0000000001024b0 CTR: c000000000102450 REGS: c0000000037db5c0 TRAP: 0300 Not tainted (6.4.0-150600.9-default) MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 28000822 XER: 00000000 CFAR: c00000000010254c DAR: 00000000000000c8 DSISR: 00080000 IRQMASK: 0 ... NIP [c0000000001024c0] pci_dma_bus_setup_pSeriesLP+0x70/0x2a0 LR [c0000000001024b0] pci_dma_bus_setup_pSeriesLP+0x60/0x2a0 Call Trace: pci_dma_bus_setup_pSeriesLP+0x60/0x2a0 (unreliable) pcibios_setup_bus_self+0x1c0/0x370 __of_scan_bus+0x2f8/0x330 pcibios_scan_phb+0x280/0x3d0 pcibios_init+0x88/0x12c do_one_initcall+0x60/0x320 kernel_init_freeable+0x344/0x3e4 kernel_init+0x34/0x1d0 ret_from_kernel_user_thread+0x14/0x1c

In the Linux kernel, the following vulnerability has been resolved: uio_hv_generic: Don't free decrypted memory In CoCo VMs it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. The VMBus device UIO driver could free decrypted/shared pages if set_memory_decrypted() fails. Check the decrypted field in the gpadl to decide whether to free the memory.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_payload: sanitize offset and length before calling skb_checksum() If access to offset + length is larger than the skbuff length, then skb_checksum() triggers BUG_ON(). skb_checksum() internally subtracts the length parameter while iterating over skbuff, BUG_ON(len) at the end of it checks that the expected length to be included in the checksum calculation is fully consumed.

In the Linux kernel, the following vulnerability has been resolved: sfc/siena: fix null pointer dereference in efx_hard_start_xmit Like in previous patch for sfc, prevent potential (but unlikely) NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: arm64: extable: fix load_unaligned_zeropad() reg indices In ex_handler_load_unaligned_zeropad() we erroneously extract the data and addr register indices from ex->type rather than ex->data. As ex->type will contain EX_TYPE_LOAD_UNALIGNED_ZEROPAD (i.e. 4): * We'll always treat X0 as the address register, since EX_DATA_REG_ADDR is extracted from bits [9:5]. Thus, we may attempt to dereference an arbitrary address as X0 may hold an arbitrary value. * We'll always treat X4 as the data register, since EX_DATA_REG_DATA is extracted from bits [4:0]. Thus we will corrupt X4 and cause arbitrary behaviour within load_unaligned_zeropad() and its caller. Fix this by extracting both values from ex->data as originally intended. On an MTE-enabled QEMU image we are hitting the following crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Call trace: fixup_exception+0xc4/0x108 __do_kernel_fault+0x3c/0x268 do_tag_check_fault+0x3c/0x104 do_mem_abort+0x44/0xf4 el1_abort+0x40/0x64 el1h_64_sync_handler+0x60/0xa0 el1h_64_sync+0x7c/0x80 link_path_walk+0x150/0x344 path_openat+0xa0/0x7dc do_filp_open+0xb8/0x168 do_sys_openat2+0x88/0x17c __arm64_sys_openat+0x74/0xa0 invoke_syscall+0x48/0x148 el0_svc_common+0xb8/0xf8 do_el0_svc+0x28/0x88 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec el0t_64_sync+0x1b4/0x1b8 Code: f8695a69 71007d1f 540000e0 927df12a (f940014a)

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Prevent crash when disable stream [Why] Disabling stream encoder invokes a function that no longer exists. [How] Check if the function declaration is NULL in disable stream encoder.

In the Linux kernel, the following vulnerability has been resolved: net: ks8851: Queue RX packets in IRQ handler instead of disabling BHs Currently the driver uses local_bh_disable()/local_bh_enable() in its IRQ handler to avoid triggering net_rx_action() softirq on exit from netif_rx(). The net_rx_action() could trigger this driver .start_xmit callback, which is protected by the same lock as the IRQ handler, so calling the .start_xmit from netif_rx() from the IRQ handler critical section protected by the lock could lead to an attempt to claim the already claimed lock, and a hang. The local_bh_disable()/local_bh_enable() approach works only in case the IRQ handler is protected by a spinlock, but does not work if the IRQ handler is protected by mutex, i.e. this works for KS8851 with Parallel bus interface, but not for KS8851 with SPI bus interface. Remove the BH manipulation and instead of calling netif_rx() inside the IRQ handler code protected by the lock, queue all the received SKBs in the IRQ handler into a queue first, and once the IRQ handler exits the critical section protected by the lock, dequeue all the queued SKBs and push them all into netif_rx(). At this point, it is safe to trigger the net_rx_action() softirq, since the netif_rx() call is outside of the lock that protects the IRQ handler.

In the Linux kernel, the following vulnerability has been resolved: ASoC: qcom: Fix uninitialized pointer dmactl In the case where __lpass_get_dmactl_handle is called and the driver id dai_id is invalid the pointer dmactl is not being assigned a value, and dmactl contains a garbage value since it has not been initialized and so the null check may not work. Fix this to initialize dmactl to NULL. One could argue that modern compilers will set this to zero, but it is useful to keep this initialized as per the same way in functions __lpass_platform_codec_intf_init and lpass_cdc_dma_daiops_hw_params. Cleans up clang scan build warning: sound/soc/qcom/lpass-cdc-dma.c:275:7: warning: Branch condition evaluates to a garbage value [core.uninitialized.Branch]

Guests can trigger deadlock in Linux netback driver T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The patch for XSA-392 introduced another issue which might result in a deadlock when trying to free the SKB of a packet dropped due to the XSA-392 handling (CVE-2022-42328). Additionally when dropping packages for other reasons the same deadlock could occur in case of netpoll being active for the interface the xen-netback driver is connected to (CVE-2022-42329).

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix possible out-of-bound write in ath12k_wmi_ext_hal_reg_caps() reg_cap.phy_id is extracted from WMI event and could be an unexpected value in case some errors happen. As a result out-of-bound write may occur to soc->hal_reg_cap. Fix it by validating reg_cap.phy_id before using it. This is found during code review. Compile tested only.

In the Linux kernel, the following vulnerability has been resolved: media: vidtv: psi: Add check for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt7629: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: drm: bridge: it66121: Fix invalid connector dereference Fix the NULL pointer dereference when no monitor is connected, and the sound card is opened from userspace. Instead return an empty buffer (of zeroes) as the EDID information to the sound framework if there is no connector attached.

In the Linux kernel, the following vulnerability has been resolved: mfd: qcom-spmi-pmic: Fix revid implementation The Qualcomm SPMI PMIC revid implementation is broken in multiple ways. First, it assumes that just because the sibling base device has been registered that means that it is also bound to a driver, which may not be the case (e.g. due to probe deferral or asynchronous probe). This could trigger a NULL-pointer dereference when attempting to access the driver data of the unbound device. Second, it accesses driver data of a sibling device directly and without any locking, which means that the driver data may be freed while it is being accessed (e.g. on driver unbind). Third, it leaks a struct device reference to the sibling device which is looked up using the spmi_device_from_of() every time a function (child) device is calling the revid function (e.g. on probe). Fix this mess by reimplementing the revid lookup so that it is done only at probe of the PMIC device; the base device fetches the revid info from the hardware, while any secondary SPMI device fetches the information from the base device and caches it so that it can be accessed safely from its children. If the base device has not been probed yet then probe of a secondary device is deferred.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: don't fail inserts if duplicate has expired nftables selftests fail: run-tests.sh testcases/sets/0044interval_overlap_0 Expected: 0-2 . 0-3, got: W: [FAILED] ./testcases/sets/0044interval_overlap_0: got 1 Insertion must ignore duplicate but expired entries. Moreover, there is a strange asymmetry in nft_pipapo_activate: It refetches the current element, whereas the other ->activate callbacks (bitmap, hash, rhash, rbtree) use elem->priv. Same for .remove: other set implementations take elem->priv, nft_pipapo_remove fetches elem->priv, then does a relookup, remove this. I suspect this was the reason for the change that prompted the removal of the expired check in pipapo_get() in the first place, but skipping exired elements there makes no sense to me, this helper is used for normal get requests, insertions (duplicate check) and deactivate callback. In first two cases expired elements must be skipped. For ->deactivate(), this gets called for DELSETELEM, so it seems to me that expired elements should be skipped as well, i.e. delete request should fail with -ENOENT error.

In the Linux kernel, the following vulnerability has been resolved: workqueue: Fix selection of wake_cpu in kick_pool() With cpu_possible_mask=0-63 and cpu_online_mask=0-7 the following kernel oops was observed: smp: Bringing up secondary CPUs ... smp: Brought up 1 node, 8 CPUs Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000000000000 TEID: 0000000000000803 [..] Call Trace: arch_vcpu_is_preempted+0x12/0x80 select_idle_sibling+0x42/0x560 select_task_rq_fair+0x29a/0x3b0 try_to_wake_up+0x38e/0x6e0 kick_pool+0xa4/0x198 __queue_work.part.0+0x2bc/0x3a8 call_timer_fn+0x36/0x160 __run_timers+0x1e2/0x328 __run_timer_base+0x5a/0x88 run_timer_softirq+0x40/0x78 __do_softirq+0x118/0x388 irq_exit_rcu+0xc0/0xd8 do_ext_irq+0xae/0x168 ext_int_handler+0xbe/0xf0 psw_idle_exit+0x0/0xc default_idle_call+0x3c/0x110 do_idle+0xd4/0x158 cpu_startup_entry+0x40/0x48 rest_init+0xc6/0xc8 start_kernel+0x3c4/0x5e0 startup_continue+0x3c/0x50 The crash is caused by calling arch_vcpu_is_preempted() for an offline CPU. To avoid this, select the cpu with cpumask_any_and_distribute() to mask __pod_cpumask with cpu_online_mask. In case no cpu is left in the pool, skip the assignment. tj: This doesn't fully fix the bug as CPUs can still go down between picking the target CPU and the wake call. Fixing that likely requires adding cpu_online() test to either the sched or s390 arch code. However, regardless of how that is fixed, workqueue shouldn't be picking a CPU which isn't online as that would result in unpredictable and worse behavior.

In the Linux kernel, the following vulnerability has been resolved: PCI: Fix active state requirement in PME polling The commit noted in fixes added a bogus requirement that runtime PM managed devices need to be in the RPM_ACTIVE state for PME polling. In fact, only devices in low power states should be polled. However there's still a requirement that the device config space must be accessible, which has implications for both the current state of the polled device and the parent bridge, when present. It's not sufficient to assume the bridge remains in D0 and cases have been observed where the bridge passes the D0 test, but the PM state indicates RPM_SUSPENDING and config space of the polled device becomes inaccessible during pci_pme_wakeup(). Therefore, since the bridge is already effectively required to be in the RPM_ACTIVE state, formalize this in the code and elevate the PM usage count to maintain the state while polling the subordinate device. This resolves a regression reported in the bugzilla below where a Thunderbolt/USB4 hierarchy fails to scan for an attached NVMe endpoint downstream of a bridge in a D3hot power state.

In the Linux kernel, the following vulnerability has been resolved: scsi: megaraid_sas: Fix resource leak in case of probe failure The driver doesn't clean up all the allocated resources properly when scsi_add_host(), megasas_start_aen() function fails during the PCI device probe. Clean up all those resources.

In the Linux kernel, the following vulnerability has been resolved: scsi: pm80xx: Do not call scsi_remove_host() in pm8001_alloc() Calling scsi_remove_host() before scsi_add_host() results in a crash: BUG: kernel NULL pointer dereference, address: 0000000000000108 RIP: 0010:device_del+0x63/0x440 Call Trace: device_unregister+0x17/0x60 scsi_remove_host+0xee/0x2a0 pm8001_pci_probe+0x6ef/0x1b90 [pm80xx] local_pci_probe+0x3f/0x90 We cannot call scsi_remove_host() in pm8001_alloc() because scsi_add_host() has not been called yet at that point in time. Function call tree: pm8001_pci_probe() | `- pm8001_pci_alloc() | | | `- pm8001_alloc() | | | `- scsi_remove_host() | `- scsi_add_host()

In the Linux kernel, the following vulnerability has been resolved: ptp: ocp: Fix a resource leak in an error handling path If an error occurs after a successful 'pci_ioremap_bar()' call, it must be undone by a corresponding 'pci_iounmap()' call, as already done in the remove function.

In the Linux kernel, the following vulnerability has been resolved: RDMA/srp: Do not call scsi_done() from srp_abort() After scmd_eh_abort_handler() has called the SCSI LLD eh_abort_handler callback, it performs one of the following actions: * Call scsi_queue_insert(). * Call scsi_finish_command(). * Call scsi_eh_scmd_add(). Hence, SCSI abort handlers must not call scsi_done(). Otherwise all the above actions would trigger a use-after-free. Hence remove the scsi_done() call from srp_abort(). Keep the srp_free_req() call before returning SUCCESS because we may not see the command again if SUCCESS is returned.

In the Linux kernel, the following vulnerability has been resolved: media: mtk-jpeg: Fix use after free bug due to error path handling in mtk_jpeg_dec_device_run In mtk_jpeg_probe, &jpeg->job_timeout_work is bound with mtk_jpeg_job_timeout_work. In mtk_jpeg_dec_device_run, if error happens in mtk_jpeg_set_dec_dst, it will finally start the worker while mark the job as finished by invoking v4l2_m2m_job_finish. There are two methods to trigger the bug. If we remove the module, it which will call mtk_jpeg_remove to make cleanup. The possible sequence is as follows, which will cause a use-after-free bug. CPU0 CPU1 mtk_jpeg_dec_... | start worker | |mtk_jpeg_job_timeout_work mtk_jpeg_remove | v4l2_m2m_release | kfree(m2m_dev); | | | v4l2_m2m_get_curr_priv | m2m_dev->curr_ctx //use If we close the file descriptor, which will call mtk_jpeg_release, it will have a similar sequence. Fix this bug by starting timeout worker only if started jpegdec worker successfully. Then v4l2_m2m_job_finish will only be called in either mtk_jpeg_job_timeout_work or mtk_jpeg_dec_device_run.

In the Linux kernel, the following vulnerability has been resolved: Input: powermate - fix use-after-free in powermate_config_complete syzbot has found a use-after-free bug [1] in the powermate driver. This happens when the device is disconnected, which leads to a memory free from the powermate_device struct. When an asynchronous control message completes after the kfree and its callback is invoked, the lock does not exist anymore and hence the bug. Use usb_kill_urb() on pm->config to cancel any in-progress requests upon device disconnection. [1] https://syzkaller.appspot.com/bug?extid=0434ac83f907a1dbdd1e

In the Linux kernel, the following vulnerability has been resolved: sh: push-switch: Reorder cleanup operations to avoid use-after-free bug The original code puts flush_work() before timer_shutdown_sync() in switch_drv_remove(). Although we use flush_work() to stop the worker, it could be rescheduled in switch_timer(). As a result, a use-after-free bug can occur. The details are shown below: (cpu 0) | (cpu 1) switch_drv_remove() | flush_work() | ... | switch_timer // timer | schedule_work(&psw->work) timer_shutdown_sync() | ... | switch_work_handler // worker kfree(psw) // free | | psw->state = 0 // use This patch puts timer_shutdown_sync() before flush_work() to mitigate the bugs. As a result, the worker and timer will be stopped safely before the deallocate operations.

In the Linux kernel, the following vulnerability has been resolved: class: fix use-after-free in class_register() The lock_class_key is still registered and can be found in lock_keys_hash hlist after subsys_private is freed in error handler path.A task who iterate over the lock_keys_hash later may cause use-after-free.So fix that up and unregister the lock_class_key before kfree(cp). On our platform, a driver fails to kset_register because of creating duplicate filename '/class/xxx'.With Kasan enabled, it prints a invalid-access bug report. KASAN bug report: BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252 Pointer tag: [15], memory tag: [fe] CPU: 7 PID: 252 Comm: modprobe Tainted: G W 6.6.0-mainline-maybe-dirty #1 Call trace: dump_backtrace+0x1b0/0x1e4 show_stack+0x2c/0x40 dump_stack_lvl+0xac/0xe0 print_report+0x18c/0x4d8 kasan_report+0xe8/0x148 __hwasan_store8_noabort+0x88/0x98 lockdep_register_key+0x19c/0x1bc class_register+0x94/0x1ec init_module+0xbc/0xf48 [rfkill] do_one_initcall+0x17c/0x72c do_init_module+0x19c/0x3f8 ... Memory state around the buggy address: ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe >ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access not use-after-free here.In this case, modprobe is manipulating the corrupted lock_keys_hash hlish where lock_class_key is already freed before. It's worth noting that this only can happen if lockdep is enabled, which is not true for normal system.

In the Linux kernel, the following vulnerability has been resolved: x86/mm, kexec, ima: Use memblock_free_late() from ima_free_kexec_buffer() The code calling ima_free_kexec_buffer() runs long after the memblock allocator has already been torn down, potentially resulting in a use after free in memblock_isolate_range(). With KASAN or KFENCE, this use after free will result in a BUG from the idle task, and a subsequent kernel panic. Switch ima_free_kexec_buffer() over to memblock_free_late() to avoid that bug.

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix potential key use-after-free When ieee80211_key_link() is called by ieee80211_gtk_rekey_add() but returns 0 due to KRACK protection (identical key reinstall), ieee80211_gtk_rekey_add() will still return a pointer into the key, in a potential use-after-free. This normally doesn't happen since it's only called by iwlwifi in case of WoWLAN rekey offload which has its own KRACK protection, but still better to fix, do that by returning an error code and converting that to success on the cfg80211 boundary only, leaving the error for bad callers of ieee80211_gtk_rekey_add().

In the Linux kernel, the following vulnerability has been resolved: binder: fix use-after-free in shinker's callback The mmap read lock is used during the shrinker's callback, which means that using alloc->vma pointer isn't safe as it can race with munmap(). As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") the mmap lock is downgraded after the vma has been isolated. I was able to reproduce this issue by manually adding some delays and triggering page reclaiming through the shrinker's debug sysfs. The following KASAN report confirms the UAF: ================================================================== BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8 Read of size 8 at addr ffff356ed50e50f0 by task bash/478 CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70 Hardware name: linux,dummy-virt (DT) Call trace: zap_page_range_single+0x470/0x4b8 binder_alloc_free_page+0x608/0xadc __list_lru_walk_one+0x130/0x3b0 list_lru_walk_node+0xc4/0x22c binder_shrink_scan+0x108/0x1dc shrinker_debugfs_scan_write+0x2b4/0x500 full_proxy_write+0xd4/0x140 vfs_write+0x1ac/0x758 ksys_write+0xf0/0x1dc __arm64_sys_write+0x6c/0x9c Allocated by task 492: kmem_cache_alloc+0x130/0x368 vm_area_alloc+0x2c/0x190 mmap_region+0x258/0x18bc do_mmap+0x694/0xa60 vm_mmap_pgoff+0x170/0x29c ksys_mmap_pgoff+0x290/0x3a0 __arm64_sys_mmap+0xcc/0x144 Freed by task 491: kmem_cache_free+0x17c/0x3c8 vm_area_free_rcu_cb+0x74/0x98 rcu_core+0xa38/0x26d4 rcu_core_si+0x10/0x1c __do_softirq+0x2fc/0xd24 Last potentially related work creation: __call_rcu_common.constprop.0+0x6c/0xba0 call_rcu+0x10/0x1c vm_area_free+0x18/0x24 remove_vma+0xe4/0x118 do_vmi_align_munmap.isra.0+0x718/0xb5c do_vmi_munmap+0xdc/0x1fc __vm_munmap+0x10c/0x278 __arm64_sys_munmap+0x58/0x7c Fix this issue by performing instead a vma_lookup() which will fail to find the vma that was isolated before the mmap lock downgrade. Note that this option has better performance than upgrading to a mmap write lock which would increase contention. Plus, mmap_write_trylock() has been recently removed anyway.

In the Linux kernel, the following vulnerability has been resolved: net: nfc: fix races in nfc_llcp_sock_get() and nfc_llcp_sock_get_sn() Sili Luo reported a race in nfc_llcp_sock_get(), leading to UAF. Getting a reference on the socket found in a lookup while holding a lock should happen before releasing the lock. nfc_llcp_sock_get_sn() has a similar problem. Finally nfc_llcp_recv_snl() needs to make sure the socket found by nfc_llcp_sock_from_sn() does not disappear.

In the Linux kernel, the following vulnerability has been resolved: jfs: fix uaf in jfs_evict_inode When the execution of diMount(ipimap) fails, the object ipimap that has been released may be accessed in diFreeSpecial(). Asynchronous ipimap release occurs when rcu_core() calls jfs_free_node(). Therefore, when diMount(ipimap) fails, sbi->ipimap should not be initialized as ipimap.

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. Addition and removal of rules from chain bindings within the same transaction causes leads to use-after-free. We recommend upgrading past commit f15f29fd4779be8a418b66e9d52979bb6d6c2325.

In the Linux kernel, the following vulnerability has been resolved: drivers/amd/pm: fix a use-after-free in kv_parse_power_table When ps allocated by kzalloc equals to NULL, kv_parse_power_table frees adev->pm.dpm.ps that allocated before. However, after the control flow goes through the following call chains: kv_parse_power_table |-> kv_dpm_init |-> kv_dpm_sw_init |-> kv_dpm_fini The adev->pm.dpm.ps is used in the for loop of kv_dpm_fini after its first free in kv_parse_power_table and causes a use-after-free bug.

In the Linux kernel, the following vulnerability has been resolved: spmi: mediatek: Fix UAF on device remove The pmif driver data that contains the clocks is allocated along with spmi_controller. On device remove, spmi_controller will be freed first, and then devres , including the clocks, will be cleanup. This leads to UAF because putting the clocks will access the clocks in the pmif driver data, which is already freed along with spmi_controller. This can be reproduced by enabling DEBUG_TEST_DRIVER_REMOVE and building the kernel with KASAN. Fix the UAF issue by using unmanaged clk_bulk_get() and putting the clocks before freeing spmi_controller.

In the Linux kernel, the following vulnerability has been resolved: bpf: Defer the free of inner map when necessary When updating or deleting an inner map in map array or map htab, the map may still be accessed by non-sleepable program or sleepable program. However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map directly through bpf_map_put(), if the ref-counter is the last one (which is true for most cases), the inner map will be freed by ops->map_free() in a kworker. But for now, most .map_free() callbacks don't use synchronize_rcu() or its variants to wait for the elapse of a RCU grace period, so after the invocation of ops->map_free completes, the bpf program which is accessing the inner map may incur use-after-free problem. Fix the free of inner map by invoking bpf_map_free_deferred() after both one RCU grace period and one tasks trace RCU grace period if the inner map has been removed from the outer map before. The deferment is accomplished by using call_rcu() or call_rcu_tasks_trace() when releasing the last ref-counter of bpf map. The newly-added rcu_head field in bpf_map shares the same storage space with work field to reduce the size of bpf_map.

In the Linux kernel, the following vulnerability has been resolved: media: pvrusb2: fix use after free on context disconnection Upon module load, a kthread is created targeting the pvr2_context_thread_func function, which may call pvr2_context_destroy and thus call kfree() on the context object. However, that might happen before the usb hub_event handler is able to notify the driver. This patch adds a sanity check before the invalid read reported by syzbot, within the context disconnection call stack.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix uaf in smb20_oplock_break_ack drop reference after use opinfo.

In the Linux kernel, the following vulnerability has been resolved: tee: amdtee: fix use-after-free vulnerability in amdtee_close_session There is a potential race condition in amdtee_close_session that may cause use-after-free in amdtee_open_session. For instance, if a session has refcount == 1, and one thread tries to free this session via: kref_put(&sess->refcount, destroy_session); the reference count will get decremented, and the next step would be to call destroy_session(). However, if in another thread, amdtee_open_session() is called before destroy_session() has completed execution, alloc_session() may return 'sess' that will be freed up later in destroy_session() leading to use-after-free in amdtee_open_session. To fix this issue, treat decrement of sess->refcount and removal of 'sess' from session list in destroy_session() as a critical section, so that it is executed atomically.

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix UAF in cifs_demultiplex_thread() There is a UAF when xfstests on cifs: BUG: KASAN: use-after-free in smb2_is_network_name_deleted+0x27/0x160 Read of size 4 at addr ffff88810103fc08 by task cifsd/923 CPU: 1 PID: 923 Comm: cifsd Not tainted 6.1.0-rc4+ #45 ... Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 kasan_check_range+0x145/0x1a0 smb2_is_network_name_deleted+0x27/0x160 cifs_demultiplex_thread.cold+0x172/0x5a4 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 </TASK> Allocated by task 923: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_slab_alloc+0x54/0x60 kmem_cache_alloc+0x147/0x320 mempool_alloc+0xe1/0x260 cifs_small_buf_get+0x24/0x60 allocate_buffers+0xa1/0x1c0 cifs_demultiplex_thread+0x199/0x10d0 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 Freed by task 921: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x143/0x1b0 kmem_cache_free+0xe3/0x4d0 cifs_small_buf_release+0x29/0x90 SMB2_negotiate+0x8b7/0x1c60 smb2_negotiate+0x51/0x70 cifs_negotiate_protocol+0xf0/0x160 cifs_get_smb_ses+0x5fa/0x13c0 mount_get_conns+0x7a/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The UAF is because: mount(pid: 921) | cifsd(pid: 923) -------------------------------|------------------------------- | cifs_demultiplex_thread SMB2_negotiate | cifs_send_recv | compound_send_recv | smb_send_rqst | wait_for_response | wait_event_state [1] | | standard_receive3 | cifs_handle_standard | handle_mid | mid->resp_buf = buf; [2] | dequeue_mid [3] KILL the process [4] | resp_iov[i].iov_base = buf | free_rsp_buf [5] | | is_network_name_deleted [6] | callback 1. After send request to server, wait the response until mid->mid_state != SUBMITTED; 2. Receive response from server, and set it to mid; 3. Set the mid state to RECEIVED; 4. Kill the process, the mid state already RECEIVED, get 0; 5. Handle and release the negotiate response; 6. UAF. It can be easily reproduce with add some delay in [3] - [6]. Only sync call has the problem since async call's callback is executed in cifsd process. Add an extra state to mark the mid state to READY before wakeup the waitter, then it can get the resp safely.

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: omap: Don't skip resource freeing if pm_runtime_resume_and_get() failed Returning an error code from .remove() makes the driver core emit the little helpful error message: remove callback returned a non-zero value. This will be ignored. and then remove the device anyhow. So all resources that were not freed are leaked in this case. Skipping serial8250_unregister_port() has the potential to keep enough of the UART around to trigger a use-after-free. So replace the error return (and with it the little helpful error message) by a more useful error message and continue to cleanup.

In the Linux kernel, the following vulnerability has been resolved: mctp: perform route lookups under a RCU read-side lock Our current route lookups (mctp_route_lookup and mctp_route_lookup_null) traverse the net's route list without the RCU read lock held. This means the route lookup is subject to preemption, resulting in an potential grace period expiry, and so an eventual kfree() while we still have the route pointer. Add the proper read-side critical section locks around the route lookups, preventing premption and a possible parallel kfree. The remaining net->mctp.routes accesses are already under a rcu_read_lock, or protected by the RTNL for updates. Based on an analysis from Sili Luo <rootlab@huawei.com>, where introducing a delay in the route lookup could cause a UAF on simultaneous sendmsg() and route deletion.

A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout When the sco connection is established and then, the sco socket is releasing, timeout_work will be scheduled to judge whether the sco disconnection is timeout. The sock will be deallocated later, but it is dereferenced again in sco_sock_timeout. As a result, the use-after-free bugs will happen. The root cause is shown below: Cleanup Thread | Worker Thread sco_sock_release | sco_sock_close | __sco_sock_close | sco_sock_set_timer | schedule_delayed_work | sco_sock_kill | (wait a time) sock_put(sk) //FREE | sco_sock_timeout | sock_hold(sk) //USE The KASAN report triggered by POC is shown below: [ 95.890016] ================================================================== [ 95.890496] BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x5e/0x1c0 [ 95.890755] Write of size 4 at addr ffff88800c388080 by task kworker/0:0/7 ... [ 95.890755] Workqueue: events sco_sock_timeout [ 95.890755] Call Trace: [ 95.890755] <TASK> [ 95.890755] dump_stack_lvl+0x45/0x110 [ 95.890755] print_address_description+0x78/0x390 [ 95.890755] print_report+0x11b/0x250 [ 95.890755] ? __virt_addr_valid+0xbe/0xf0 [ 95.890755] ? sco_sock_timeout+0x5e/0x1c0 [ 95.890755] kasan_report+0x139/0x170 [ 95.890755] ? update_load_avg+0xe5/0x9f0 [ 95.890755] ? sco_sock_timeout+0x5e/0x1c0 [ 95.890755] kasan_check_range+0x2c3/0x2e0 [ 95.890755] sco_sock_timeout+0x5e/0x1c0 [ 95.890755] process_one_work+0x561/0xc50 [ 95.890755] worker_thread+0xab2/0x13c0 [ 95.890755] ? pr_cont_work+0x490/0x490 [ 95.890755] kthread+0x279/0x300 [ 95.890755] ? pr_cont_work+0x490/0x490 [ 95.890755] ? kthread_blkcg+0xa0/0xa0 [ 95.890755] ret_from_fork+0x34/0x60 [ 95.890755] ? kthread_blkcg+0xa0/0xa0 [ 95.890755] ret_from_fork_asm+0x11/0x20 [ 95.890755] </TASK> [ 95.890755] [ 95.890755] Allocated by task 506: [ 95.890755] kasan_save_track+0x3f/0x70 [ 95.890755] __kasan_kmalloc+0x86/0x90 [ 95.890755] __kmalloc+0x17f/0x360 [ 95.890755] sk_prot_alloc+0xe1/0x1a0 [ 95.890755] sk_alloc+0x31/0x4e0 [ 95.890755] bt_sock_alloc+0x2b/0x2a0 [ 95.890755] sco_sock_create+0xad/0x320 [ 95.890755] bt_sock_create+0x145/0x320 [ 95.890755] __sock_create+0x2e1/0x650 [ 95.890755] __sys_socket+0xd0/0x280 [ 95.890755] __x64_sys_socket+0x75/0x80 [ 95.890755] do_syscall_64+0xc4/0x1b0 [ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 95.890755] [ 95.890755] Freed by task 506: [ 95.890755] kasan_save_track+0x3f/0x70 [ 95.890755] kasan_save_free_info+0x40/0x50 [ 95.890755] poison_slab_object+0x118/0x180 [ 95.890755] __kasan_slab_free+0x12/0x30 [ 95.890755] kfree+0xb2/0x240 [ 95.890755] __sk_destruct+0x317/0x410 [ 95.890755] sco_sock_release+0x232/0x280 [ 95.890755] sock_close+0xb2/0x210 [ 95.890755] __fput+0x37f/0x770 [ 95.890755] task_work_run+0x1ae/0x210 [ 95.890755] get_signal+0xe17/0xf70 [ 95.890755] arch_do_signal_or_restart+0x3f/0x520 [ 95.890755] syscall_exit_to_user_mode+0x55/0x120 [ 95.890755] do_syscall_64+0xd1/0x1b0 [ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 95.890755] [ 95.890755] The buggy address belongs to the object at ffff88800c388000 [ 95.890755] which belongs to the cache kmalloc-1k of size 1024 [ 95.890755] The buggy address is located 128 bytes inside of [ 95.890755] freed 1024-byte region [ffff88800c388000, ffff88800c388400) [ 95.890755] [ 95.890755] The buggy address belongs to the physical page: [ 95.890755] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88800c38a800 pfn:0xc388 [ 95.890755] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 [ 95.890755] ano ---truncated---