==================================================================
BUG: KASAN: slab-use-after-free in v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25
Read of size 8 at addr ffff888051844738 by task v4l_id/9403
CPU: 0 UID: 0 PID: 9403 Comm: v4l_id Not tainted 6.15.0-syzkaller-10820-gcd2e103d57e5 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xcd/0x680 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25
v4l2_fh_open+0x83/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63
em28xx_v4l2_open+0x24e/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2153
v4l2_open+0x225/0x490 drivers/media/v4l2-core/v4l2-dev.c:429
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x744/0x1c10 fs/open.c:964
vfs_open+0x82/0x3f0 fs/open.c:1094
do_open fs/namei.c:3887 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4046
do_filp_open+0x20b/0x470 fs/namei.c:4073
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c182a7407
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:00007ffda4ef1b90 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5c189d7880 RCX: 00007f5c182a7407
RDX: 0000000000000000 RSI: 00007ffda4ef3f1d RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffda4ef1de0 R14: 00007f5c18b3e000 R15: 000055978d2fa4d8
Allocated by task 6041:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
em28xx_v4l2_init+0x114/0x4080 drivers/media/usb/em28xx/em28xx-video.c:2532
em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Freed by task 6041:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kfree+0x2b4/0x4d0 mm/slub.c:4841
em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline]
kref_put include/linux/kref.h:65 [inline]
em28xx_v4l2_init+0x22b5/0x4080 drivers/media/usb/em28xx/em28xx-video.c:2901
em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff888051844000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1848 bytes inside of
freed 8192-byte region [ffff888051844000, ffff888051846000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x51840
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 ffff88801b442280 ffffea0001e54400 0000000000000002
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b442280 ffffea0001e54400 0000000000000002
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001461001 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 9112, tgid 9110 (syz.2.1369), ts 314856651880, free_ts 311900190834
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
prep_new_page mm/page_alloc.c:1712 [inline]
get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
__alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419
alloc_slab_page mm/slub.c:2450 [inline]
allocate_slab mm/slub.c:2618 [inline]
new_slab+0x23b/0x330 mm/slub.c:2672
___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
__slab_alloc_node mm/slub.c:4023 [inline]
slab_alloc_node mm/slub.c:4184 [inline]
__do_kmalloc_node mm/slub.c:4326 [inline]
__kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4346
__do_krealloc mm/slub.c:4904 [inline]
krealloc_noprof+0x156/0x370 mm/slub.c:4957
kvrealloc_noprof+0x31/0xd0 mm/slub.c:5106
push_insn_history+0x35a/0x820 kernel/bpf/verifier.c:3871
do_check kernel/bpf/verifier.c:19482 [inline]
do_check_common+0xbc9/0xc0e0 kernel/bpf/verifier.c:22808
do_check_main kernel/bpf/verifier.c:22899 [inline]
bpf_check+0x7f5e/0xb4f0 kernel/bpf/verifier.c:24065
bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2972
__sys_bpf+0x433c/0x4d80 kernel/bpf/syscall.c:5836
__do_sys_bpf kernel/bpf/syscall.c:5943 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5941 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5941
page last free pid 9 tgid 9 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706
kasan_depopulate_vmalloc_pte+0x5f/0x80 mm/kasan/shadow.c:472
apply_to_pte_range mm/memory.c:3030 [inline]
apply_to_pmd_range mm/memory.c:3074 [inline]
apply_to_pud_range mm/memory.c:3110 [inline]
apply_to_p4d_range mm/memory.c:3146 [inline]
__apply_to_page_range+0xa92/0x1350 mm/memory.c:3182
kasan_release_vmalloc+0xd1/0xe0 mm/kasan/shadow.c:593
kasan_release_vmalloc_node mm/vmalloc.c:2241 [inline]
purge_vmap_node+0x1c4/0xa30 mm/vmalloc.c:2258
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888051844600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888051844680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888051844700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888051844780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888051844800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_write include/linux/instrumented.h:82 [inline]
BUG: KASAN: slab-use-after-free in set_bit include/asm-generic/bitops/instrumented-atomic.h:28 [inline]
BUG: KASAN: slab-use-after-free in v4l2_fh_init+0xd4/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:27
Write of size 8 at addr ffff8880518447a0 by task v4l_id/9403
CPU: 1 UID: 0 PID: 9403 Comm: v4l_id Tainted: G B 6.15.0-syzkaller-10820-gcd2e103d57e5 #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xcd/0x680 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189
instrument_atomic_write include/linux/instrumented.h:82 [inline]
set_bit include/asm-generic/bitops/instrumented-atomic.h:28 [inline]
v4l2_fh_init+0xd4/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:27
v4l2_fh_open+0x83/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63
em28xx_v4l2_open+0x24e/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2153
v4l2_open+0x225/0x490 drivers/media/v4l2-core/v4l2-dev.c:429
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x744/0x1c10 fs/open.c:964
vfs_open+0x82/0x3f0 fs/open.c:1094
do_open fs/namei.c:3887 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4046
do_filp_open+0x20b/0x470 fs/namei.c:4073
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c182a7407
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:00007ffda4ef1b90 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5c189d7880 RCX: 00007f5c182a7407
RDX: 0000000000000000 RSI: 00007ffda4ef3f1d RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffda4ef1de0 R14: 00007f5c18b3e000 R15: 000055978d2fa4d8
Allocated by task 6041:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
em28xx_v4l2_init+0x114/0x4080 drivers/media/usb/em28xx/em28xx-video.c:2532
em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Freed by task 6041:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kfree+0x2b4/0x4d0 mm/slub.c:4841
em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline]
kref_put include/linux/kref.h:65 [inline]
em28xx_v4l2_init+0x22b5/0x4080 drivers/media/usb/em28xx/em28xx-video.c:2901
em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff888051844000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1952 bytes inside of
freed 8192-byte region [ffff888051844000, ffff888051846000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x51840
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 ffff88801b442280 ffffea0001e54400 0000000000000002
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b442280 ffffea0001e54400 0000000000000002
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001461001 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 9112, tgid 9110 (syz.2.1369), ts 314856651880, free_ts 311900190834
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
prep_new_page mm/page_alloc.c:1712 [inline]
get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
__alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419
alloc_slab_page mm/slub.c:2450 [inline]
allocate_slab mm/slub.c:2618 [inline]
new_slab+0x23b/0x330 mm/slub.c:2672
___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
__slab_alloc_node mm/slub.c:4023 [inline]
slab_alloc_node mm/slub.c:4184 [inline]
__do_kmalloc_node mm/slub.c:4326 [inline]
__kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4346
__do_krealloc mm/slub.c:4904 [inline]
krealloc_noprof+0x156/0x370 mm/slub.c:4957
kvrealloc_noprof+0x31/0xd0 mm/slub.c:5106
push_insn_history+0x35a/0x820 kernel/bpf/verifier.c:3871
do_check kernel/bpf/verifier.c:19482 [inline]
do_check_common+0xbc9/0xc0e0 kernel/bpf/verifier.c:22808
do_check_main kernel/bpf/verifier.c:22899 [inline]
bpf_check+0x7f5e/0xb4f0 kernel/bpf/verifier.c:24065
bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2972
__sys_bpf+0x433c/0x4d80 kernel/bpf/syscall.c:5836
__do_sys_bpf kernel/bpf/syscall.c:5943 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5941 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5941
page last free pid 9 tgid 9 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706
kasan_depopulate_vmalloc_pte+0x5f/0x80 mm/kasan/shadow.c:472
apply_to_pte_range mm/memory.c:3030 [inline]
apply_to_pmd_range mm/memory.c:3074 [inline]
apply_to_pud_range mm/memory.c:3110 [inline]
apply_to_p4d_range mm/memory.c:3146 [inline]
__apply_to_page_range+0xa92/0x1350 mm/memory.c:3182
kasan_release_vmalloc+0xd1/0xe0 mm/kasan/shadow.c:593
kasan_release_vmalloc_node mm/vmalloc.c:2241 [inline]
purge_vmap_node+0x1c4/0xa30 mm/vmalloc.c:2258
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888051844680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888051844700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888051844780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888051844800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888051844880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================