In the Linux kernel, the following vulnerability has been resolved: bcache: fix NULL pointer in cache_set_flush() 1. LINE#1794 - LINE#1887 is some codes about function of bch_cache_set_alloc(). 2. LINE#2078 - LINE#2142 is some codes about function of register_cache_set(). 3. register_cache_set() will call bch_cache_set_alloc() in LINE#2098. 1794 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) 1795 { ... 1860 if (!(c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL)) || 1861 mempool_init_slab_pool(&c->search, 32, bch_search_cache) || 1862 mempool_init_kmalloc_pool(&c->bio_meta, 2, 1863 sizeof(struct bbio) + sizeof(struct bio_vec) * 1864 bucket_pages(c)) || 1865 mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) || 1866 bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio), 1867 BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER) || 1868 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) || 1869 !(c->moving_gc_wq = alloc_workqueue("bcache_gc", 1870 WQ_MEM_RECLAIM, 0)) || 1871 bch_journal_alloc(c) || 1872 bch_btree_cache_alloc(c) || 1873 bch_open_buckets_alloc(c) || 1874 bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages))) 1875 goto err; ^^^^^^^^ 1876 ... 1883 return c; 1884 err: 1885 bch_cache_set_unregister(c); ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1886 return NULL; 1887 } ... 2078 static const char *register_cache_set(struct cache *ca) 2079 { ... 2098 c = bch_cache_set_alloc(&ca->sb); 2099 if (!c) 2100 return err; ^^^^^^^^^^ ... 2128 ca->set = c; 2129 ca->set->cache[ca->sb.nr_this_dev] = ca; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ... 2138 return NULL; 2139 err: 2140 bch_cache_set_unregister(c); 2141 return err; 2142 } (1) If LINE#1860 - LINE#1874 is true, then do 'goto err'(LINE#1875) and call bch_cache_set_unregister()(LINE#1885). (2) As (1) return NULL(LINE#1886), LINE#2098 - LINE#2100 would return. (3) As (2) has returned, LINE#2128 - LINE#2129 would do *not* give the value to c->cache[], it means that c->cache[] is NULL. LINE#1624 - LINE#1665 is some codes about function of cache_set_flush(). As (1), in LINE#1885 call bch_cache_set_unregister() ---> bch_cache_set_stop() ---> closure_queue() -.-> cache_set_flush() (as below LINE#1624) 1624 static void cache_set_flush(struct closure *cl) 1625 { ... 1654 for_each_cache(ca, c, i) 1655 if (ca->alloc_thread) ^^ 1656 kthread_stop(ca->alloc_thread); ... 1665 } (4) In LINE#1655 ca is NULL(see (3)) in cache_set_flush() then the kernel crash occurred as below: [ 846.712887] bcache: register_cache() error drbd6: cannot allocate memory [ 846.713242] bcache: register_bcache() error : failed to register device [ 846.713336] bcache: cache_set_free() Cache set 2f84bdc1-498a-4f2f-98a7-01946bf54287 unregistered [ 846.713768] BUG: unable to handle kernel NULL pointer dereference at 00000000000009f8 [ 846.714790] PGD 0 P4D 0 [ 846.715129] Oops: 0000 [#1] SMP PTI [ 846.715472] CPU: 19 PID: 5057 Comm: kworker/19:16 Kdump: loaded Tainted: G OE --------- - - 4.18.0-147.5.1.el8_1.5es.3.x86_64 #1 [ 846.716082] Hardware name: ESPAN GI-25212/X11DPL-i, BIOS 2.1 06/15/2018 [ 846.716451] Workqueue: events cache_set_flush [bcache] [ 846.716808] RIP: 0010:cache_set_flush+0xc9/0x1b0 [bcache] [ 846.717155] Code: 00 4c 89 a5 b0 03 00 00 48 8b 85 68 f6 ff ff a8 08 0f 84 88 00 00 00 31 db 66 83 bd 3c f7 ff ff 00 48 8b 85 48 ff ff ff 74 28 <48> 8b b8 f8 09 00 0 ---truncated---
In the Linux kernel, the following vulnerability has been resolved: x86/iopl: Cure TIF_IO_BITMAP inconsistencies io_bitmap_exit() is invoked from exit_thread() when a task exists or when a fork fails. In the latter case the exit_thread() cleans up resources which were allocated during fork(). io_bitmap_exit() invokes task_update_io_bitmap(), which in turn ends up in tss_update_io_bitmap(). tss_update_io_bitmap() operates on the current task. If current has TIF_IO_BITMAP set, but no bitmap installed, tss_update_io_bitmap() crashes with a NULL pointer dereference. There are two issues, which lead to that problem: 1) io_bitmap_exit() should not invoke task_update_io_bitmap() when the task, which is cleaned up, is not the current task. That's a clear indicator for a cleanup after a failed fork(). 2) A task should not have TIF_IO_BITMAP set and neither a bitmap installed nor IOPL emulation level 3 activated. This happens when a kernel thread is created in the context of a user space thread, which has TIF_IO_BITMAP set as the thread flags are copied and the IO bitmap pointer is cleared. Other than in the failed fork() case this has no impact because kernel threads including IO workers never return to user space and therefore never invoke tss_update_io_bitmap(). Cure this by adding the missing cleanups and checks: 1) Prevent io_bitmap_exit() to invoke task_update_io_bitmap() if the to be cleaned up task is not the current task. 2) Clear TIF_IO_BITMAP in copy_thread() unconditionally. For user space forks it is set later, when the IO bitmap is inherited in io_bitmap_share(). For paranoia sake, add a warning into tss_update_io_bitmap() to catch the case, when that code is invoked with inconsistent state.
In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix fb_set_var to prevent null-ptr-deref in fb_videomode_to_var If fb_add_videomode() in fb_set_var() fails to allocate memory for fb_videomode, later it may lead to a null-ptr dereference in fb_videomode_to_var(), as the fb_info is registered while not having the mode in modelist that is expected to be there, i.e. the one that is described in fb_info->var. ================================================================ general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 30371 Comm: syz-executor.1 Not tainted 5.10.226-syzkaller #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:fb_videomode_to_var+0x24/0x610 drivers/video/fbdev/core/modedb.c:901 Call Trace: display_to_var+0x3a/0x7c0 drivers/video/fbdev/core/fbcon.c:929 fbcon_resize+0x3e2/0x8f0 drivers/video/fbdev/core/fbcon.c:2071 resize_screen drivers/tty/vt/vt.c:1176 [inline] vc_do_resize+0x53a/0x1170 drivers/tty/vt/vt.c:1263 fbcon_modechanged+0x3ac/0x6e0 drivers/video/fbdev/core/fbcon.c:2720 fbcon_update_vcs+0x43/0x60 drivers/video/fbdev/core/fbcon.c:2776 do_fb_ioctl+0x6d2/0x740 drivers/video/fbdev/core/fbmem.c:1128 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1203 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 ================================================================ The reason is that fb_info->var is being modified in fb_set_var(), and then fb_videomode_to_var() is called. If it fails to add the mode to fb_info->modelist, fb_set_var() returns error, but does not restore the old value of fb_info->var. Restore fb_info->var on failure the same way it is done earlier in the function. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null pointer check for get_first_active_display() The function mod_hdcp_hdcp1_enable_encryption() calls the function get_first_active_display(), but does not check its return value. The return value is a null pointer if the display list is empty. This will lead to a null pointer dereference in mod_hdcp_hdcp2_enable_encryption(). Add a null pointer check for get_first_active_display() and return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null.
In the Linux kernel, the following vulnerability has been resolved: gve: add missing NULL check for gve_alloc_pending_packet() in TX DQO gve_alloc_pending_packet() can return NULL, but gve_tx_add_skb_dqo() did not check for this case before dereferencing the returned pointer. Add a missing NULL check to prevent a potential NULL pointer dereference when allocation fails. This improves robustness in low-memory scenarios.
In the Linux kernel, the following vulnerability has been resolved: backlight: pm8941: Add NULL check in wled_configure() devm_kasprintf() returns NULL when memory allocation fails. Currently, wled_configure() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved: soc: aspeed: Add NULL check in aspeed_lpc_enable_snoop() devm_kasprintf() returns NULL when memory allocation fails. Currently, aspeed_lpc_enable_snoop() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue. [arj: Fix Fixes: tag to use subject from 3772e5da4454]
In the Linux kernel, the following vulnerability has been resolved: btrfs: avoid NULL pointer dereference if no valid csum tree [BUG] When trying read-only scrub on a btrfs with rescue=idatacsums mount option, it will crash with the following call trace: BUG: kernel NULL pointer dereference, address: 0000000000000208 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page CPU: 1 UID: 0 PID: 835 Comm: btrfs Tainted: G O 6.15.0-rc3-custom+ #236 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:btrfs_lookup_csums_bitmap+0x49/0x480 [btrfs] Call Trace: <TASK> scrub_find_fill_first_stripe+0x35b/0x3d0 [btrfs] scrub_simple_mirror+0x175/0x290 [btrfs] scrub_stripe+0x5f7/0x6f0 [btrfs] scrub_chunk+0x9a/0x150 [btrfs] scrub_enumerate_chunks+0x333/0x660 [btrfs] btrfs_scrub_dev+0x23e/0x600 [btrfs] btrfs_ioctl+0x1dcf/0x2f80 [btrfs] __x64_sys_ioctl+0x97/0xc0 do_syscall_64+0x4f/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e [CAUSE] Mount option "rescue=idatacsums" will completely skip loading the csum tree, so that any data read will not find any data csum thus we will ignore data checksum verification. Normally call sites utilizing csum tree will check the fs state flag NO_DATA_CSUMS bit, but unfortunately scrub does not check that bit at all. This results in scrub to call btrfs_search_slot() on a NULL pointer and triggered above crash. [FIX] Check both extent and csum tree root before doing any tree search.
In the Linux kernel, the following vulnerability has been resolved: phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug The qmp_usb_iomap() helper function currently returns the raw result of devm_ioremap() for non-exclusive mappings. Since devm_ioremap() may return a NULL pointer and the caller only checks error pointers with IS_ERR(), NULL could bypass the check and lead to an invalid dereference. Fix the issue by checking if devm_ioremap() returns NULL. When it does, qmp_usb_iomap() now returns an error pointer via IOMEM_ERR_PTR(-ENOMEM), ensuring safe and consistent error handling.
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw89: pci: configure manual DAC mode via PCI config API only To support 36-bit DMA, configure chip proprietary bit via PCI config API or chip DBI interface. However, the PCI device mmap isn't set yet and the DBI is also inaccessible via mmap, so only if the bit can be accessible via PCI config API, chip can support 36-bit DMA. Otherwise, fallback to 32-bit DMA. With NULL mmap address, kernel throws trace: BUG: unable to handle page fault for address: 0000000000001090 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] PREEMPT SMP PTI CPU: 1 UID: 0 PID: 71 Comm: irq/26-pciehp Tainted: G OE 6.14.2-061402-generic #202504101348 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE RIP: 0010:rtw89_pci_ops_write16+0x12/0x30 [rtw89_pci] RSP: 0018:ffffb0ffc0acf9d8 EFLAGS: 00010206 RAX: ffffffffc158f9c0 RBX: ffff94865e702020 RCX: 0000000000000000 RDX: 0000000000000718 RSI: 0000000000001090 RDI: ffff94865e702020 RBP: ffffb0ffc0acf9d8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000015 R13: 0000000000000719 R14: ffffb0ffc0acfa1f R15: ffffffffc1813060 FS: 0000000000000000(0000) GS:ffff9486f3480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000001090 CR3: 0000000090440001 CR4: 00000000000626f0 Call Trace: <TASK> rtw89_pci_read_config_byte+0x6d/0x120 [rtw89_pci] rtw89_pci_cfg_dac+0x5b/0xb0 [rtw89_pci] rtw89_pci_probe+0xa96/0xbd0 [rtw89_pci] ? __pfx___device_attach_driver+0x10/0x10 ? __pfx___device_attach_driver+0x10/0x10 local_pci_probe+0x47/0xa0 pci_call_probe+0x5d/0x190 pci_device_probe+0xa7/0x160 really_probe+0xf9/0x370 ? pm_runtime_barrier+0x55/0xa0 __driver_probe_device+0x8c/0x140 driver_probe_device+0x24/0xd0 __device_attach_driver+0xcd/0x170 bus_for_each_drv+0x99/0x100 __device_attach+0xb4/0x1d0 device_attach+0x10/0x20 pci_bus_add_device+0x59/0x90 pci_bus_add_devices+0x31/0x80 pciehp_configure_device+0xaa/0x170 pciehp_enable_slot+0xd6/0x240 pciehp_handle_presence_or_link_change+0xf1/0x180 pciehp_ist+0x162/0x1c0 irq_thread_fn+0x24/0x70 irq_thread+0xef/0x1c0 ? __pfx_irq_thread_fn+0x10/0x10 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0xfc/0x230 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x47/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>
In the Linux kernel, the following vulnerability has been resolved: net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered Russell King reports that a system with mv88e6xxx dereferences a NULL pointer when unbinding this driver: https://lore.kernel.org/netdev/Z_lRkMlTJ1KQ0kVX@shell.armlinux.org.uk/ The crash seems to be in devlink_region_destroy(), which is not NULL tolerant but is given a NULL devlink global region pointer. At least on some chips, some devlink regions are conditionally registered since the blamed commit, see mv88e6xxx_setup_devlink_regions_global(): if (cond && !cond(chip)) continue; These are MV88E6XXX_REGION_STU and MV88E6XXX_REGION_PVT. If the chip does not have an STU or PVT, it should crash like this. To fix the issue, avoid unregistering those regions which are NULL, i.e. were skipped at mv88e6xxx_setup_devlink_regions_global() time.
In the Linux kernel, the following vulnerability has been resolved: sunrpc: handle SVC_GARBAGE during svc auth processing as auth error tianshuo han reported a remotely-triggerable crash if the client sends a kernel RPC server a specially crafted packet. If decoding the RPC reply fails in such a way that SVC_GARBAGE is returned without setting the rq_accept_statp pointer, then that pointer can be dereferenced and a value stored there. If it's the first time the thread has processed an RPC, then that pointer will be set to NULL and the kernel will crash. In other cases, it could create a memory scribble. The server sunrpc code treats a SVC_GARBAGE return from svc_authenticate or pg_authenticate as if it should send a GARBAGE_ARGS reply. RFC 5531 says that if authentication fails that the RPC should be rejected instead with a status of AUTH_ERR. Handle a SVC_GARBAGE return as an AUTH_ERROR, with a reason of AUTH_BADCRED instead of returning GARBAGE_ARGS in that case. This sidesteps the whole problem of touching the rpc_accept_statp pointer in this situation and avoids the crash.
In the Linux kernel, the following vulnerability has been resolved: kasan: remove kasan_find_vm_area() to prevent possible deadlock find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); <interrupt occurs> <in softirq> spin_lock(&some_lock); <access invalid address> kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area().
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use list_first_entry_or_null for opinfo_get_list() The list_first_entry() macro never returns NULL. If the list is empty then it returns an invalid pointer. Use list_first_entry_or_null() to check if the list is empty.
In the Linux kernel, the following vulnerability has been resolved: atm: clip: Fix NULL pointer dereference in vcc_sendmsg() atmarpd_dev_ops does not implement the send method, which may cause crash as bellow. BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: Oops: 0010 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffffc9000d3cf778 EFLAGS: 00010246 RAX: 1ffffffff1910dd1 RBX: 00000000000000c0 RCX: dffffc0000000000 RDX: ffffc9000dc82000 RSI: ffff88803e4c4640 RDI: ffff888052cd0000 RBP: ffffc9000d3cf8d0 R08: ffff888052c9143f R09: 1ffff1100a592287 R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff92001a79f00 R13: ffff888052cd0000 R14: ffff88803e4c4640 R15: ffffffff8c886e88 FS: 00007fbc762566c0(0000) GS:ffff88808d6c2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000041f1b000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> vcc_sendmsg+0xa10/0xc50 net/atm/common.c:644 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 ____sys_sendmsg+0x52d/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmmsg+0x227/0x430 net/socket.c:2709 __do_sys_sendmmsg net/socket.c:2736 [inline] __se_sys_sendmmsg net/socket.c:2733 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
In the Linux kernel, the following vulnerability has been resolved: jfs: Fix null-ptr-deref in jfs_ioc_trim [ Syzkaller Report ] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000087: 0000 [#1 KASAN: null-ptr-deref in range [0x0000000000000438-0x000000000000043f] CPU: 2 UID: 0 PID: 10614 Comm: syz-executor.0 Not tainted 6.13.0-rc6-gfbfd64d25c7a-dirty #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Sched_ext: serialise (enabled+all), task: runnable_at=-30ms RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die_body+0x61/0xb0 ? die_addr+0xb1/0xe0 ? exc_general_protection+0x333/0x510 ? asm_exc_general_protection+0x26/0x30 ? jfs_ioc_trim+0x34b/0x8f0 jfs_ioctl+0x3c8/0x4f0 ? __pfx_jfs_ioctl+0x10/0x10 ? __pfx_jfs_ioctl+0x10/0x10 __se_sys_ioctl+0x269/0x350 ? __pfx___se_sys_ioctl+0x10/0x10 ? do_syscall_64+0xfb/0x210 do_syscall_64+0xee/0x210 ? syscall_exit_to_user_mode+0x1e0/0x330 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe51f4903ad Code: c3 e8 a7 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d RSP: 002b:00007fe5202250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe51f5cbf80 RCX: 00007fe51f4903ad RDX: 0000000020000680 RSI: 00000000c0185879 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe520225640 R13: 000000000000000e R14: 00007fe51f44fca0 R15: 00007fe52021d000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Kernel panic - not syncing: Fatal exception [ Analysis ] We believe that we have found a concurrency bug in the `fs/jfs` module that results in a null pointer dereference. There is a closely related issue which has been fixed: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d6c1b3599b2feb5c7291f5ac3a36e5fa7cedb234 ... but, unfortunately, the accepted patch appears to still be susceptible to a null pointer dereference under some interleavings. To trigger the bug, we think that `JFS_SBI(ipbmap->i_sb)->bmap` is set to NULL in `dbFreeBits` and then dereferenced in `jfs_ioc_trim`. This bug manifests quite rarely under normal circumstances, but is triggereable from a syz-program.
In the Linux kernel, the following vulnerability has been resolved: platform/x86: dell_rbu: Fix list usage Pass the correct list head to list_for_each_entry*() when looping through the packet list. Without this patch, reading the packet data via sysfs will show the data incorrectly (because it starts at the wrong packet), and clearing the packet list will result in a NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: Avoid accessing uninitialized arvif->ar during beacon miss During beacon miss handling, ath12k driver iterates over active virtual interfaces (vifs) and attempts to access the radio object (ar) via arvif->deflink->ar. However, after commit aa80f12f3bed ("wifi: ath12k: defer vdev creation for MLO"), arvif is linked to a radio only after vdev creation, typically when a channel is assigned or a scan is requested. For P2P capable devices, a default P2P interface is created by wpa_supplicant along with regular station interfaces, these serve as dummy interfaces for P2P-capable stations, lack an associated netdev and initiate frequent scans to discover neighbor p2p devices. When a scan is initiated on such P2P vifs, driver selects destination radio (ar) based on scan frequency, creates a scan vdev, and attaches arvif to the radio. Once the scan completes or is aborted, the scan vdev is deleted, detaching arvif from the radio and leaving arvif->ar uninitialized. While handling beacon miss for station interfaces, P2P interface is also encountered in the vif iteration and ath12k_mac_handle_beacon_miss_iter() tries to dereference the uninitialized arvif->deflink->ar. Fix this by verifying that vdev is created for the arvif before accessing its ar during beacon miss handling and similar vif iterator callbacks. ========================================================================== wlp6s0: detected beacon loss from AP (missed 7 beacons) - probing KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 5 UID: 0 PID: 0 Comm: swapper/5 Not tainted 6.16.0-rc1-wt-ath+ #2 PREEMPT(full) RIP: 0010:ath12k_mac_handle_beacon_miss_iter+0xb5/0x1a0 [ath12k] Call Trace: __iterate_interfaces+0x11a/0x410 [mac80211] ieee80211_iterate_active_interfaces_atomic+0x61/0x140 [mac80211] ath12k_mac_handle_beacon_miss+0xa1/0xf0 [ath12k] ath12k_roam_event+0x393/0x560 [ath12k] ath12k_wmi_op_rx+0x1486/0x28c0 [ath12k] ath12k_htc_process_trailer.isra.0+0x2fb/0x620 [ath12k] ath12k_htc_rx_completion_handler+0x448/0x830 [ath12k] ath12k_ce_recv_process_cb+0x549/0x9e0 [ath12k] ath12k_ce_per_engine_service+0xbe/0xf0 [ath12k] ath12k_pci_ce_workqueue+0x69/0x120 [ath12k] process_one_work+0xe3a/0x1430 Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1 Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00284.1-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Add NULL check in ufshcd_mcq_compl_pending_transfer() Add a NULL check for the returned hwq pointer by ufshcd_mcq_req_to_hwq(). This is similar to the fix in commit 74736103fb41 ("scsi: ufs: core: Fix ufshcd_abort_one racing issue").
In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: mcq: Add NULL check in ufshcd_mcq_abort() A race can occur between the MCQ completion path and the abort handler: once a request completes, __blk_mq_free_request() sets rq->mq_hctx to NULL, meaning the subsequent ufshcd_mcq_req_to_hwq() call in ufshcd_mcq_abort() can return a NULL pointer. If this NULL pointer is dereferenced, the kernel will crash. Add a NULL check for the returned hwq pointer. If hwq is NULL, log an error and return FAILED, preventing a potential NULL-pointer dereference. As suggested by Bart, the ufshcd_cmd_inflight() check is removed. This is similar to the fix in commit 74736103fb41 ("scsi: ufs: core: Fix ufshcd_abort_one racing issue"). This is found by our static analysis tool KNighter.
In the Linux kernel, the following vulnerability has been resolved: pm: cpupower: bench: Prevent NULL dereference on malloc failure If malloc returns NULL due to low memory, 'config' pointer can be NULL. Add a check to prevent NULL dereference.
In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad7606: check for NULL before calling sw_mode_config() Check that the sw_mode_config function pointer is not NULL before calling it. Not all buses define this callback, which resulted in a NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved: cpufreq: apple-soc: Fix null-ptr-deref in apple_soc_cpufreq_get_rate() cpufreq_cpu_get_raw() can return NULL when the target CPU is not present in the policy->cpus mask. apple_soc_cpufreq_get_rate() does not check for this case, which results in a NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix NULL access in assign channel context handler Currently, when ath12k_mac_assign_vif_to_vdev() fails, the radio handle (ar) gets accessed from the link VIF handle (arvif) for debug logging, This is incorrect. In the fail scenario, radio handle is NULL. Fix the NULL access, avoid radio handle access by moving to the hardware debug logging helper function (ath12k_hw_warn). Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1 Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7925: Fix null-ptr-deref in mt7925_thermal_init() devm_kasprintf() returns NULL on error. Currently, mt7925_thermal_init() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved: ice: add NULL check in eswitch lag check The function ice_lag_is_switchdev_running() is being called from outside of the LAG event handler code. This results in the lag->upper_netdev being NULL sometimes. To avoid a NULL-pointer dereference, there needs to be a check before it is dereferenced.
In the Linux kernel, the following vulnerability has been resolved: ASoC: sma1307: Add NULL check in sma1307_setting_loaded() All varibale allocated by kzalloc and devm_kzalloc could be NULL. Multiple pointer checks and their cleanup are added. This issue is found by our static analysis tool
In the Linux kernel, the following vulnerability has been resolved: HID: pidff: Fix null pointer dereference in pidff_find_fields This function triggered a null pointer dereference if used to search for a report that isn't implemented on the device. This happened both for optional and required reports alike. The same logic was applied to pidff_find_special_field and although pidff_init_fields should return an error earlier if one of the required reports is missing, future modifications could change this logic and resurface this possible null pointer dereference again. LKML bug report: https://lore.kernel.org/all/CAL-gK7f5=R0nrrQdPtaZZr1fd-cdAMbDMuZ_NLA8vM0SX+nGSw@mail.gmail.com
In the Linux kernel, the following vulnerability has been resolved: watchdog: lenovo_se30_wdt: Fix possible devm_ioremap() NULL pointer dereference in lenovo_se30_wdt_probe() devm_ioremap() returns NULL on error. Currently, lenovo_se30_wdt_probe() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_ioremap() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved: ata: pata_pxa: Fix potential NULL pointer dereference in pxa_ata_probe() devm_ioremap() returns NULL on error. Currently, pxa_ata_probe() does not check for this case, which can result in a NULL pointer dereference. Add NULL check after devm_ioremap() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved: ACPI: CPPC: Fix NULL pointer dereference when nosmp is used With nosmp in cmdline, other CPUs are not brought up, leaving their cpc_desc_ptr NULL. CPU0's iteration via for_each_possible_cpu() dereferences these NULL pointers, causing panic. Panic backtrace: [ 0.401123] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8 ... [ 0.403255] [<ffffffff809a5818>] cppc_allow_fast_switch+0x6a/0xd4 ... Kernel panic - not syncing: Attempted to kill init! [ rjw: New subject ]
In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: displayport: Fix NULL pointer access This patch ensures that the UCSI driver waits for all pending tasks in the ucsi_displayport_work workqueue to finish executing before proceeding with the partner removal.
In the Linux kernel, the following vulnerability has been resolved: sched/ext: Prevent update_locked_rq() calls with NULL rq Avoid invoking update_locked_rq() when the runqueue (rq) pointer is NULL in the SCX_CALL_OP and SCX_CALL_OP_RET macros. Previously, calling update_locked_rq(NULL) with preemption enabled could trigger the following warning: BUG: using __this_cpu_write() in preemptible [00000000] This happens because __this_cpu_write() is unsafe to use in preemptible context. rq is NULL when an ops invoked from an unlocked context. In such cases, we don't need to store any rq, since the value should already be NULL (unlocked). Ensure that update_locked_rq() is only called when rq is non-NULL, preventing calling __this_cpu_write() on preemptible context.
In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: Pass ab pointer directly to ath12k_dp_tx_get_encap_type() In ath12k_dp_tx_get_encap_type(), the arvif parameter is only used to retrieve the ab pointer. In vdev delete sequence the arvif->ar could become NULL and that would trigger kernel panic. Since the caller ath12k_dp_tx() already has a valid ab pointer, pass it directly to avoid panic and unnecessary dereferencing. PC points to "ath12k_dp_tx+0x228/0x988 [ath12k]" LR points to "ath12k_dp_tx+0xc8/0x988 [ath12k]". The Backtrace obtained is as follows: ath12k_dp_tx+0x228/0x988 [ath12k] ath12k_mac_tx_check_max_limit+0x608/0x920 [ath12k] ieee80211_process_measurement_req+0x320/0x348 [mac80211] ieee80211_tx_dequeue+0x9ac/0x1518 [mac80211] ieee80211_tx_dequeue+0xb14/0x1518 [mac80211] ieee80211_tx_prepare_skb+0x224/0x254 [mac80211] ieee80211_xmit+0xec/0x100 [mac80211] __ieee80211_subif_start_xmit+0xc50/0xf40 [mac80211] ieee80211_subif_start_xmit+0x2e8/0x308 [mac80211] netdev_start_xmit+0x150/0x18c dev_hard_start_xmit+0x74/0xc0 Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
In the Linux kernel, the following vulnerability has been resolved: usb: acpi: Prevent null pointer dereference in usb_acpi_add_usb4_devlink() As demonstrated by the fix for update_port_device_state, commit 12783c0b9e2c ("usb: core: Prevent null pointer dereference in update_port_device_state"), usb_hub_to_struct_hub() can return NULL in certain scenarios, such as during hub driver unbind or teardown race conditions, even if the underlying usb_device structure exists. Plus, all other places that call usb_hub_to_struct_hub() in the same file do check for NULL return values. If usb_hub_to_struct_hub() returns NULL, the subsequent access to hub->ports[udev->portnum - 1] will cause a null pointer dereference.
In the Linux kernel, the following vulnerability has been resolved: HID: uclogic: Add NULL check in uclogic_input_configured() devm_kasprintf() returns NULL when memory allocation fails. Currently, uclogic_input_configured() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved: pinctrl: mediatek: eint: Fix invalid pointer dereference for v1 platforms Commit 3ef9f710efcb ("pinctrl: mediatek: Add EINT support for multiple addresses") introduced an access to the 'soc' field of struct mtk_pinctrl in mtk_eint_do_init() and for that an include of pinctrl-mtk-common-v2.h. However, pinctrl drivers relying on the v1 common driver include pinctrl-mtk-common.h instead, which provides another definition of struct mtk_pinctrl that does not contain an 'soc' field. Since mtk_eint_do_init() can be called both by v1 and v2 drivers, it will now try to dereference an invalid pointer when called on v1 platforms. This has been observed on Genio 350 EVK (MT8365), which crashes very early in boot (the kernel trace can only be seen with earlycon). In order to fix this, since 'struct mtk_pinctrl' was only needed to get a 'struct mtk_eint_pin', make 'struct mtk_eint_pin' a parameter of mtk_eint_do_init() so that callers need to supply it, removing mtk_eint_do_init()'s dependency on any particular 'struct mtk_pinctrl'.
In the Linux kernel, the following vulnerability has been resolved: serial: jsm: fix NPE during jsm_uart_port_init No device was set which caused serial_base_ctrl_add to crash. BUG: kernel NULL pointer dereference, address: 0000000000000050 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 16 UID: 0 PID: 368 Comm: (udev-worker) Not tainted 6.12.25-amd64 #1 Debian 6.12.25-1 RIP: 0010:serial_base_ctrl_add+0x96/0x120 Call Trace: <TASK> serial_core_register_port+0x1a0/0x580 ? __setup_irq+0x39c/0x660 ? __kmalloc_cache_noprof+0x111/0x310 jsm_uart_port_init+0xe8/0x180 [jsm] jsm_probe_one+0x1f4/0x410 [jsm] local_pci_probe+0x42/0x90 pci_device_probe+0x22f/0x270 really_probe+0xdb/0x340 ? pm_runtime_barrier+0x54/0x90 ? __pfx___driver_attach+0x10/0x10 __driver_probe_device+0x78/0x110 driver_probe_device+0x1f/0xa0 __driver_attach+0xba/0x1c0 bus_for_each_dev+0x8c/0xe0 bus_add_driver+0x112/0x1f0 driver_register+0x72/0xd0 jsm_init_module+0x36/0xff0 [jsm] ? __pfx_jsm_init_module+0x10/0x10 [jsm] do_one_initcall+0x58/0x310 do_init_module+0x60/0x230 Tested with Digi Neo PCIe 8 port card.
In the Linux kernel, the following vulnerability has been resolved: ext4: only dirty folios when data journaling regular files fstest generic/388 occasionally reproduces a crash that looks as follows: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: <TASK> ext4_block_zero_page_range+0x30c/0x380 [ext4] ext4_truncate+0x436/0x440 [ext4] ext4_process_orphan+0x5d/0x110 [ext4] ext4_orphan_cleanup+0x124/0x4f0 [ext4] ext4_fill_super+0x262d/0x3110 [ext4] get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x26/0xd0 vfs_cmd_create+0x59/0xe0 __do_sys_fsconfig+0x4ed/0x6b0 do_syscall_64+0x82/0x170 ... This occurs when processing a symlink inode from the orphan list. The partial block zeroing code in the truncate path calls ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an a_ops vector in ext4, hence the crash. To avoid this problem, update the ext4_dirty_journalled_data() helper to only mark the folio dirty on regular files (for which a_ops is assigned). This also matches the journaling logic in the ext4_symlink() creation path, where ext4_handle_dirty_metadata() is called directly.
In the Linux kernel, the following vulnerability has been resolved: net/tls: fix kernel panic when alloc_page failed We cannot set frag_list to NULL pointer when alloc_page failed. It will be used in tls_strp_check_queue_ok when the next time tls_strp_read_sock is called. This is because we don't reset full_len in tls_strp_flush_anchor_copy() so the recv path will try to continue handling the partial record on the next call but we dettached the rcvq from the frag list. Alternative fix would be to reset full_len. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028 Call trace: tls_strp_check_rcv+0x128/0x27c tls_strp_data_ready+0x34/0x44 tls_data_ready+0x3c/0x1f0 tcp_data_ready+0x9c/0xe4 tcp_data_queue+0xf6c/0x12d0 tcp_rcv_established+0x52c/0x798
In the Linux kernel, the following vulnerability has been resolved: net/sched: Return NULL when htb_lookup_leaf encounters an empty rbtree htb_lookup_leaf has a BUG_ON that can trigger with the following: tc qdisc del dev lo root tc qdisc add dev lo root handle 1: htb default 1 tc class add dev lo parent 1: classid 1:1 htb rate 64bit tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2:1 handle 3: blackhole ping -I lo -c1 -W0.001 127.0.0.1 The root cause is the following: 1. htb_dequeue calls htb_dequeue_tree which calls the dequeue handler on the selected leaf qdisc 2. netem_dequeue calls enqueue on the child qdisc 3. blackhole_enqueue drops the packet and returns a value that is not just NET_XMIT_SUCCESS 4. Because of this, netem_dequeue calls qdisc_tree_reduce_backlog, and since qlen is now 0, it calls htb_qlen_notify -> htb_deactivate -> htb_deactiviate_prios -> htb_remove_class_from_row -> htb_safe_rb_erase 5. As this is the only class in the selected hprio rbtree, __rb_change_child in __rb_erase_augmented sets the rb_root pointer to NULL 6. Because blackhole_dequeue returns NULL, netem_dequeue returns NULL, which causes htb_dequeue_tree to call htb_lookup_leaf with the same hprio rbtree, and fail the BUG_ON The function graph for this scenario is shown here: 0) | htb_enqueue() { 0) + 13.635 us | netem_enqueue(); 0) 4.719 us | htb_activate_prios(); 0) # 2249.199 us | } 0) | htb_dequeue() { 0) 2.355 us | htb_lookup_leaf(); 0) | netem_dequeue() { 0) + 11.061 us | blackhole_enqueue(); 0) | qdisc_tree_reduce_backlog() { 0) | qdisc_lookup_rcu() { 0) 1.873 us | qdisc_match_from_root(); 0) 6.292 us | } 0) 1.894 us | htb_search(); 0) | htb_qlen_notify() { 0) 2.655 us | htb_deactivate_prios(); 0) 6.933 us | } 0) + 25.227 us | } 0) 1.983 us | blackhole_dequeue(); 0) + 86.553 us | } 0) # 2932.761 us | qdisc_warn_nonwc(); 0) | htb_lookup_leaf() { 0) | BUG_ON(); ------------------------------------------ The full original bug report can be seen here [1]. We can fix this just by returning NULL instead of the BUG_ON, as htb_dequeue_tree returns NULL when htb_lookup_leaf returns NULL. [1] https://lore.kernel.org/netdev/pF5XOOIim0IuEfhI-SOxTgRvNoDwuux7UHKnE_Y5-zVd4wmGvNk2ceHjKb8ORnzw0cGwfmVu42g9dL7XyJLf1NEzaztboTWcm0Ogxuojoeo=@willsroot.io/
In the Linux kernel, the following vulnerability has been resolved: x86/resctrl: Fix allocation of cleanest CLOSID on platforms with no monitors Commit 6eac36bb9eb0 ("x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty_rmid") added logic that causes resctrl to search for the CLOSID with the fewest dirty cache lines when creating a new control group, if requested by the arch code. This depends on the values read from the llc_occupancy counters. The logic is applicable to architectures where the CLOSID effectively forms part of the monitoring identifier and so do not allow complete freedom to choose an unused monitoring identifier for a given CLOSID. This support missed that some platforms may not have these counters. This causes a NULL pointer dereference when creating a new control group as the array was not allocated by dom_data_init(). As this feature isn't necessary on platforms that don't have cache occupancy monitors, add this to the check that occurs when a new control group is allocated.
In the Linux kernel, the following vulnerability has been resolved: drm/amd/pp: Fix potential NULL pointer dereference in atomctrl_initialize_mc_reg_table The function atomctrl_initialize_mc_reg_table() and atomctrl_initialize_mc_reg_table_v2_2() does not check the return value of smu_atom_get_data_table(). If smu_atom_get_data_table() fails to retrieve vram_info, it returns NULL which is later dereferenced.
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: Add NULL check in mt7996_thermal_init devm_kasprintf() can return a NULL pointer on failure,but this returned value in mt7996_thermal_init() is not checked. Add NULL check in mt7996_thermal_init(), to handle kernel NULL pointer dereference error.
In the Linux kernel, the following vulnerability has been resolved: fpga: fix potential null pointer deref in fpga_mgr_test_img_load_sgt() fpga_mgr_test_img_load_sgt() allocates memory for sgt using kunit_kzalloc() however it does not check if the allocation failed. It then passes sgt to sg_alloc_table(), which passes it to __sg_alloc_table(). This function calls memset() on sgt in an attempt to zero it out. If the allocation fails then sgt will be NULL and the memset will trigger a NULL pointer dereference. Fix this by checking the allocation with KUNIT_ASSERT_NOT_ERR_OR_NULL().
In the Linux kernel, the following vulnerability has been resolved: power: supply: max77705: Fix workqueue error handling in probe The create_singlethread_workqueue() doesn't return error pointers, it returns NULL. Also cleanup the workqueue on the error paths.
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Guard Possible Null Pointer Dereference [WHY] In some situations, dc->res_pool may be null. [HOW] Check if pointer is null before dereference.
In the Linux kernel, the following vulnerability has been resolved: riscv: fix runtime constant support for nommu kernels the `__runtime_fixup_32` function does not handle the case where `val` is zero correctly (as might occur when patching a nommu kernel and referring to a physical address below the 4GiB boundary whose upper 32 bits are all zero) because nothing in the existing logic prevents the code from taking the `else` branch of both nop-checks and emitting two `nop` instructions. This leaves random garbage in the register that is supposed to receive the upper 32 bits of the pointer instead of zero that when combined with the value for the lower 32 bits yields an invalid pointer and causes a kernel panic when that pointer is eventually accessed. The author clearly considered the fact that if the `lui` is converted into a `nop` that the second instruction needs to be adjusted to become an `li` instead of an `addi`, hence introducing the `addi_insn_mask` variable, but didn't follow that logic through fully to the case where the `else` branch executes. To fix it just adjust the logic to ensure that the second `else` branch is not taken if the first instruction will be patched to a `nop`.
In the Linux kernel, the following vulnerability has been resolved: sch_htb: make htb_deactivate() idempotent Alan reported a NULL pointer dereference in htb_next_rb_node() after we made htb_qlen_notify() idempotent. It turns out in the following case it introduced some regression: htb_dequeue_tree(): |-> fq_codel_dequeue() |-> qdisc_tree_reduce_backlog() |-> htb_qlen_notify() |-> htb_deactivate() |-> htb_next_rb_node() |-> htb_deactivate() For htb_next_rb_node(), after calling the 1st htb_deactivate(), the clprio[prio]->ptr could be already set to NULL, which means htb_next_rb_node() is vulnerable here. For htb_deactivate(), although we checked qlen before calling it, in case of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again which triggers the warning inside. To fix the issues here, we need to: 1) Make htb_deactivate() idempotent, that is, simply return if we already call it before. 2) Make htb_next_rb_node() safe against ptr==NULL. Many thanks to Alan for testing and for the reproducer.
In the Linux kernel, the following vulnerability has been resolved: smb: client: add NULL check in automount_fullpath page is checked for null in __build_path_from_dentry_optional_prefix when tcon->origin_fullpath is not set. However, the check is missing when it is set. Add a check to prevent a potential NULL pointer dereference.