syzbot


KASAN: slab-use-after-free Read in vb2_core_queue_release (2)

Status: moderation: reported on 2026/04/08 06:17
Subsystems: media
[Documentation on labels]
Reported-by: syzbot+dea72621ea41b0a18217@syzkaller.appspotmail.com
First crash: 8d08h, last: 8d08h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
14301be9-19b0-43fe-b415-ec07fd06d820 moderation Actionable: ✅  Confident: ✅  KASAN: slab-use-after-free Read in vb2_core_queue_release (2) 2026/04/09 09:48 2026/04/09 09:48 2026/04/09 10:15 38c8e24669882aabb2ec15315fbe22eb28592b44
b3d52a68-815f-475d-9176-937f8dfac47e moderation 💥 KASAN: slab-use-after-free Read in vb2_core_queue_release (2) 2026/04/09 00:02 2026/04/09 00:02 2026/04/09 00:25 d9b7f6215458eb19f62e00ad3a3ab04df934f3f5 Error 400, Message: API key expired. Please renew the API key., Status: INVALID_ARGUMENT, Details: [map[@type:type.googleapis.com/google.rpc.ErrorInfo domain:googleapis.com metadata:map[service:generativelanguage.googleapis.com] reason:API_KEY_INVALID] map[@type:type.googleapis.com/google.rpc.LocalizedMessage locale:en-US message:API key expired. Please renew the API key.]]
Similar bugs (1)
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 232d 228d 0/29 auto-obsoleted due to no activity on 2025/11/21 14:07

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in vb2_core_queue_release+0x150/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2679
Read of size 4 at addr ffff88802d000f48 by task v4l_id/21137

CPU: 0 UID: 0 PID: 21137 Comm: v4l_id Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 vb2_core_queue_release+0x150/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2679
 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:956 [inline]
 _vb2_fop_release+0xe8/0x280 drivers/media/common/videobuf2/videobuf2-v4l2.c:1159
 v4l2_release+0x280/0x390 drivers/media/v4l2-core/v4l2-dev.c:471
 __fput+0x3ff/0xb40 fs/file_table.c:469
 fput_close_sync+0x118/0x250 fs/file_table.c:574
 __do_sys_close fs/open.c:1509 [inline]
 __se_sys_close fs/open.c:1494 [inline]
 __x64_sys_close+0x8b/0x120 fs/open.c:1494
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1adb8a7407
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:00007ffe883bdfc0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f1adbff2880 RCX: 00007f1adb8a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f1adbff26e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffe883be1f0 R14: 00007f1adc159000 R15: 0000562e7d91b4d8
 </TASK>

Allocated by task 29:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 hackrf_probe+0xcf/0x5d0 drivers/media/usb/hackrf/hackrf.c:1351
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2266
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 29:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6483
 hackrf_probe.cold+0x40/0x12f9 drivers/media/usb/hackrf/hackrf.c:1523
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2266
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 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 ffff88802d000000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 3912 bytes inside of
 freed 8192-byte region [ffff88802d000000, ffff88802d002000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2d000
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 ffff88813fe41280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe41280 dead000000000100 dead000000000122
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000b40001 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11594, tgid 11586 (syz.1.1536), ts 456308172457, free_ts 456186809005
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6b0 mm/slub.c:3539
 refill_objects+0x26b/0x400 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_noprof+0x688/0x850 mm/slub.c:5272
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 tomoyo_init_log+0x1224/0x20c0 security/tomoyo/audit.c:275
 tomoyo_supervisor+0x506/0x1340 security/tomoyo/common.c:2232
 tomoyo_audit_path_log security/tomoyo/file.c:169 [inline]
 tomoyo_path_permission security/tomoyo/file.c:592 [inline]
 tomoyo_path_permission+0x270/0x3b0 security/tomoyo/file.c:577
 tomoyo_path_perm+0x3d6/0x460 security/tomoyo/file.c:843
 tomoyo_path_symlink+0x97/0xe0 security/tomoyo/tomoyo.c:212
 security_path_symlink+0x152/0x2d0 security/security.c:1477
 filename_symlinkat+0x122/0x560 fs/namei.c:5644
 __do_sys_symlink fs/namei.c:5673 [inline]
 __se_sys_symlink fs/namei.c:5669 [inline]
 __x64_sys_symlink+0x79/0xb0 fs/namei.c:5669
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
page last free pid 5181 tgid 5181 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kvmalloc_node_noprof+0x316/0xa00 mm/slub.c:6752
 seq_buf_alloc fs/seq_file.c:39 [inline]
 seq_read_iter+0x819/0x1270 fs/seq_file.c:211
 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:297
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x825/0xb30 fs/read_write.c:574
 ksys_read+0x12a/0x250 fs/read_write.c:717
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802d000e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802d000e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802d000f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff88802d000f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802d001000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/04 06:10 upstream 631919fb12fe 4440e7c2 .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
* Struck through repros no longer work on HEAD.