KASAN: slab-use-after-free Read in vb2_core_queue_release (3)

Status: upstream: reported on 2026/09/18 00:03
Subsystems: media
Labels: prio:high actionable
[Documentation on labels]
Reported-by: syzbot+eb4706daf505f9c4b547@syzkaller.appspotmail.com
First crash: 50d, last: 3d17h
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision
f419a451 repro-c Reproduced: ✅ ❓ KASAN: slab-use-after-free Read in vb2_core_queue_release (3) 2026/10/31 00:00 2026/10/31 00:00 2026/10/31 02:45 0ec395f8
3ef3176e moderation Actionable: ✅ ❓ KASAN: slab-use-after-free Read in vb2_core_queue_release (3) 2026/09/18 00:00 2026/09/18 00:00 2026/09/18 00:02 8d7d05f1
d81240bf assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: slab-use-after-free Read in vb2_core_queue_release (3) 2026/09/17 00:00 2026/09/17 00:00 2026/09/17 00:45 95928915
42ae5055 assessment-security 💥 KASAN: slab-use-after-free Read in vb2_core_queue_release (3) 2026/09/15 01:18 2026/09/15 01:18 2026/09/15 01:18 81a27d1a
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH v1 2/2] Input: sur40 - keep device state alive until the video node is released 2 (2) 2026/09/30 08:05
[syzbot] [media?] KASAN: slab-use-after-free Read in vb2_core_queue_release (3) 0 (1) 2026/09/18 00:03
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in vb2_core_queue_release media 19 1 436d 432d 0/29 auto-obsoleted due to no activity on 2025/11/21 14:07
upstream KASAN: slab-use-after-free Read in vb2_core_queue_release (2) prio:high media 19 1 213d 209d 0/29 auto-obsoleted due to no activity on 2026/07/03 06:11
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/10/31 10:30 1h55m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 36aad21d50d1af3f6954bb0c988257a908202477 report job log log

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in vb2_core_queue_release+0x12d/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2679
Read of size 4 at addr ffff888035874aa8 by task v4l_id/13928

CPU: 0 UID: 0 PID: 13928 Comm: v4l_id Tainted: G             L       syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS G
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 vb2_core_queue_release+0x12d/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2679
 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:943 [inline]
 _vb2_fop_release drivers/media/common/videobuf2/videobuf2-v4l2.c:1146 [inline]
 vb2_fop_release+0x16e/0x200 drivers/media/common/videobuf2/videobuf2-v4l2.c:1160
 v4l2_release+0x22c/0x350 drivers/media/v4l2-core/v4l2-dev.c:471
 __fput+0x408/0xa40 fs/file_table.c:512
 fput_close_sync+0x11f/0x240 fs/file_table.c:618
 filp_close_sync fs/open.c:1573 [inline]
 __do_sys_close fs/open.c:1596 [inline]
 __se_sys_close+0xa2/0x160 fs/open.c:1583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd31e2a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdd0406800 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007fd31e93f880 RCX: 00007fd31e2a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fd31e93f6e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000013
R13: 00007ffdd0406a30 R14: 00007fd31eaa6000 R15: 00005605d0b6a4d8
 </TASK>

Allocated by task 9112:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 sur40_probe+0x16c/0xfa0 drivers/input/touchscreen/sur40.c:675
 usb_probe_interface+0x751/0xe00 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:707
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:869
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:899
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1027
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:503
 __device_attach+0x2bd/0x430 drivers/base/dd.c:1131
 device_initial_probe+0x9c/0x100 drivers/base/dd.c:1190
 __bus_probe_device+0x126/0x220 drivers/base/bus.c:617
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_set_configuration+0x1bb5/0x2260 drivers/usb/core/message.c:2280
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:707
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:869
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:899
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1027
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:503
 __device_attach+0x2bd/0x430 drivers/base/dd.c:1131
 device_initial_probe+0x9c/0x100 drivers/base/dd.c:1190
 __bus_probe_device+0x126/0x220 drivers/base/bus.c:617
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2713
 hub_port_connect drivers/usb/core/hub.c:5585 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5971
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5704:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6923
 sur40_disconnect+0xaf/0x140 drivers/input/touchscreen/sur40.c:835
 usb_unbind_interface+0x295/0x9c0 drivers/usb/core/driver.c:460
 device_remove drivers/base/dd.c:619 [inline]
 __device_release_driver drivers/base/dd.c:1357 [inline]
 device_release_driver_internal+0x48d/0x7d0 drivers/base/dd.c:1380
 bus_remove_device+0x444/0x560 drivers/base/bus.c:681
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1484
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2355
 hub_port_connect drivers/usb/core/hub.c:5425 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5971
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888035874000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2728 bytes inside of
 freed 4096-byte region [ffff888035874000, ffff888035875000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35870
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813ff23140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff23140 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5935, tgid 5935 (kworker/u8:15), ts 485406248366
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1856
 prep_new_page mm/page_alloc.c:1864 [inline]
 get_page_from_freelist+0x220f/0x2280 mm/page_alloc.c:3935
 __alloc_frozen_pages_noprof+0x1fe/0x410 mm/page_alloc.c:5444
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab+0x7d/0x5e0 mm/slub.c:3499
 new_slab mm/slub.c:3550 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7539
 refill_sheaf mm/slub.c:2917 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811
 alloc_from_pcs mm/slub.c:4887 [inline]
 slab_alloc_node mm/slub.c:5021 [inline]
 __do_kmalloc_node mm/slub.c:5530 [inline]
 __kmalloc_node_track_caller_noprof+0x543/0x720 mm/slub.c:5662
 kmalloc_reserve net/core/skbuff.c:638 [inline]
 __alloc_skb+0x2c1/0x7a0 net/core/skbuff.c:716
 alloc_skb include/linux/skbuff.h:1390 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline]
 nsim_dev_trap_report_work+0x25f/0xb30 drivers/net/netdevsim/dev.c:847
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 5649 tgid 5649 ts 483460194600 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1403 [inline]
 __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2954
 __slab_free+0x269/0x2c0 mm/slub.c:5926
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4720 [inline]
 slab_alloc_node mm/slub.c:5033 [inline]
 kmem_cache_alloc_noprof+0x2b4/0x600 mm/slub.c:5047
 alloc_filename fs/namei.c:147 [inline]
 do_getname+0x2e/0x250 fs/namei.c:187
 getname_flags fs/namei.c:230 [inline]
 class_filename_flags_constructor include/linux/fs.h:2593 [inline]
 user_path_at+0x2a/0x160 fs/namei.c:3640
 ksys_umount fs/namespace.c:2123 [inline]
 __do_sys_umount fs/namespace.c:2131 [inline]
 __se_sys_umount fs/namespace.c:2129 [inline]
 __x64_sys_umount+0xf6/0x170 fs/namespace.c:2129
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888035874980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888035874a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888035874a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888035874b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888035874b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/30 14:14 upstream 4dd16e31135e b498adee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-use-after-free Read in vb2_core_queue_release
2026/10/18 04:31 upstream 58161ead29e5 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root KASAN: slab-use-after-free Read in vb2_core_queue_release
2026/09/13 22:57 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-use-after-free Read in vb2_core_queue_release
* Struck through repros no longer work on HEAD.