[syzbot] [media?] KASAN: slab-use-after-free Read in vb2_core_queue_release (3)

[syzbot] [media?] KASAN: slab-use-after-free Read in vb2_core_queue_release (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    50d05c7c76c9 Merge tag 'landlock-7.3-rc3' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=119dcdf9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5e4e3a0e188a497e
dashboard link: https://syzkaller.appspot.com/bug?extid=eb4706daf505f9c4b547
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/daf497619736/disk-50d05c7c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/748fbd82f647/vmlinux-50d05c7c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e61c59099d07/bzImage-50d05c7c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+eb4706daf505f9c4b547@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in vb2_core_queue_releas
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 ffff888066fa8aa8 by task v4l_id/28733

CPU: 1 UID: 0 PID: 28733 Comm: v4l_id Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0x418/0xa50 fs/file_table.c:512
 fput_close_sync+0x11f/0x240 fs/file_table.c:617
 __do_sys_close fs/open.c:1560 [inline]
 __se_sys_close fs/open.c:1545 [inline]
 __x64_sys_close+0x7e/0x110 fs/open.c:1545
 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: 0033:0x7fd662ca7407
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:00007ffc17b0bb70 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007fd66334d880 RCX: 00007fd662ca7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fd66334d6e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000013
R13: 00007ffc17b0bda0 R14: 00007fd6634b4000 R15: 000055fc994944d8
 </TASK>

Allocated by task 16810:
 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:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
 _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+0x788/0xe50 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_set_configuration+0x1ad8/0x2180 drivers/usb/core/message.c:2268
 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:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2708
 hub_port_connect drivers/usb/core/hub.c:5580 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 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 16811:
 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:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6792
 sur40_disconnect+0xaf/0x140 drivers/input/touchscreen/sur40.c:835
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 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 ffff888066fa8000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2728 bytes inside of
 freed 4096-byte region [ffff888066fa8000, ffff888066fa9000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x66fa8
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 ffff88801b042140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042140 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 100, tgid 100 (kworker/u8:5), ts 122303978933
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_node_track_caller_noprof+0x548/0x720 mm/slub.c:5545
 kmalloc_reserve net/core/skbuff.c:637 [inline]
 __alloc_skb+0x2c1/0x7a0 net/core/skbuff.c:715
 alloc_skb include/linux/skbuff.h:1384 [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/0xb40 drivers/net/netdevsim/dev.c:847
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 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 5633 tgid 5633 ts 122036800450 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 __slab_free+0x274/0x2c0 mm/slub.c:5815
 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:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 kmem_cache_alloc_noprof+0x2b9/0x600 mm/slub.c:5010
 lsm_inode_alloc security/security.c:254 [inline]
 security_inode_alloc+0x39/0x310 security/security.c:1215
 inode_init_always_gfp+0x97e/0xd30 fs/inode.c:298
 inode_init_always include/linux/fs.h:2965 [inline]
 alloc_inode+0x82/0x1b0 fs/inode.c:345
 new_inode_pseudo include/linux/fs.h:3044 [inline]
 sock_alloc net/socket.c:710 [inline]
 __sock_create+0x12d/0x9d0 net/socket.c:1640
 sock_create net/socket.c:1734 [inline]
 __sys_socket_create net/socket.c:1771 [inline]
 __sys_socket+0xd6/0x1b0 net/socket.c:1818
 __do_compat_sys_socketcall net/compat.c:447 [inline]
 __se_compat_sys_socketcall net/compat.c:422 [inline]
 __ia32_compat_sys_socketcall+0x412/0xa50 net/compat.c:422
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x27a/0x6a0 arch/x86/entry/syscall_32.c:291
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:316
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Memory state around the buggy address:
 ffff888066fa8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888066fa8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888066fa8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888066fa8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888066fa8b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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