Extracting prog: 3m2.465969662s
Minimizing prog: 12m12.441855757s
Simplifying prog options: 0s
Extracting C: 1m10.260387738s
Simplifying C: 10m17.503204117s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, &(0x7f0000000040)=ANY=[@ANYBLOB="1201000035ffaa20cd0caf104a380102030109021b0001000010000904590201801e2a00090582"], 0x0)

program did not crash
single: failed to extract reproducer
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, &(0x7f0000000040)=ANY=[@ANYBLOB="1201000035ffaa20cd0caf104a380102030109021b0001000010000904590201801e2a00090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
single: successfully extracted reproducer
found reproducer with 1 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, 0x0, 0x0)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, &(0x7f0000000040)=ANY=[@ANYBLOB], 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
simplifying C reproducer
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, &(0x7f0000000040)=ANY=[@ANYBLOB="1201000035ffaa20cd0caf104a380102030109021b0001000010000904590201801e2a00090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, &(0x7f0000000040)=ANY=[@ANYBLOB="1201000035ffaa20cd0caf104a380102030109021b0001000010000904590201801e2a00090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x2d, &(0x7f0000000040)=ANY=[@ANYBLOB="1201000035ffaa20cd0caf104a380102030109021b0001000010000904590201801e2a00090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
validation run: crashed=true
reproducing took 31m29.977423445s
repro crashed as (corrupted=false):
==================================================================
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 ffff888115a9c740 by task v4l_id/5781

CPU: 0 UID: 0 PID: 5781 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) 
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
 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25
 v4l2_fh_open+0x64/0xa0 drivers/media/v4l2-core/v4l2-fh.c:64
 em28xx_v4l2_open+0x11e/0x570 drivers/media/usb/em28xx/em28xx-video.c:2153
 v4l2_open+0x1d2/0x490 drivers/media/v4l2-core/v4l2-dev.c:433
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x68b/0x14b0 fs/open.c:949
 vfs_open+0x82/0x3f0 fs/open.c:1081
 do_open fs/namei.c:4671 [inline]
 path_openat+0x208c/0x31a0 fs/namei.c:4830
 do_file_open+0x20e/0x430 fs/namei.c:4859
 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1383
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa2cd1cb407
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:00007fff10057670 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa2cd0dd880 RCX: 00007fa2cd1cb407
RDX: 0000000000000000 RSI: 00007fff10058f26 RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fff100578c0 R14: 00007fa2cd961000 R15: 000055ecd4d354d8
 </TASK>

Allocated by task 3073:
 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+0x8f/0xa0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 em28xx_v4l2_init.cold+0x94/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2532
 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457
 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+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 3073:
 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+0x43/0x70 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+0x1dc/0x640 mm/slub.c:6483
 kref_put.isra.0+0x56/0x90 include/linux/kref.h:65
 em28xx_v4l2_init.cold+0x280/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2901
 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457
 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+0x6c3/0xcb0 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 ffff888115a9c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1856 bytes inside of
 freed 8192-byte region [ffff888115a9c000, ffff888115a9e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115a98
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 0200000000000003 ffffea000456a601 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3522, tgid 3522 (syz-executor), ts 55390982122, free_ts 54044976044
 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+0xf10/0x39f0 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x273/0x2860 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6c0 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]
 __kmalloc_cache_noprof+0x52c/0x6b0 mm/slub.c:5375
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 mr_table_alloc+0x5f/0x2e0 net/ipv4/ipmr_base.c:41
 ipmr_new_table net/ipv4/ipmr.c:423 [inline]
 ipmr_rules_init net/ipv4/ipmr.c:342 [inline]
 ipmr_net_init net/ipv4/ipmr.c:3234 [inline]
 ipmr_net_init+0x1ef/0x340 net/ipv4/ipmr.c:3226
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
page last free pid 3501 tgid 3501 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7b1/0xfb0 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+0x4e/0x70 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]
 kmem_cache_alloc_noprof+0x2e7/0x6a0 mm/slub.c:4873
 vm_area_dup+0x25/0x6e0 mm/vma_init.c:123
 __split_vma+0x18c/0xd60 mm/vma.c:513
 split_vma mm/vma.c:596 [inline]
 vma_modify+0x10bd/0x21e0 mm/vma.c:1680
 vma_modify_flags+0x1f2/0x350 mm/vma.c:1700
 mprotect_fixup+0x209/0xb70 mm/mprotect.c:756
 do_mprotect_pkey+0x9e1/0xe70 mm/mprotect.c:930
 __do_sys_mprotect mm/mprotect.c:951 [inline]
 __se_sys_mprotect mm/mprotect.c:948 [inline]
 __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:948
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888115a9c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888115a9c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888115a9c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888115a9c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888115a9c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

final repro crashed as (corrupted=false):
==================================================================
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 ffff888115a9c740 by task v4l_id/5781

CPU: 0 UID: 0 PID: 5781 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) 
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
 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25
 v4l2_fh_open+0x64/0xa0 drivers/media/v4l2-core/v4l2-fh.c:64
 em28xx_v4l2_open+0x11e/0x570 drivers/media/usb/em28xx/em28xx-video.c:2153
 v4l2_open+0x1d2/0x490 drivers/media/v4l2-core/v4l2-dev.c:433
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x68b/0x14b0 fs/open.c:949
 vfs_open+0x82/0x3f0 fs/open.c:1081
 do_open fs/namei.c:4671 [inline]
 path_openat+0x208c/0x31a0 fs/namei.c:4830
 do_file_open+0x20e/0x430 fs/namei.c:4859
 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1383
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa2cd1cb407
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:00007fff10057670 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa2cd0dd880 RCX: 00007fa2cd1cb407
RDX: 0000000000000000 RSI: 00007fff10058f26 RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fff100578c0 R14: 00007fa2cd961000 R15: 000055ecd4d354d8
 </TASK>

Allocated by task 3073:
 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+0x8f/0xa0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 em28xx_v4l2_init.cold+0x94/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2532
 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457
 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+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 3073:
 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+0x43/0x70 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+0x1dc/0x640 mm/slub.c:6483
 kref_put.isra.0+0x56/0x90 include/linux/kref.h:65
 em28xx_v4l2_init.cold+0x280/0x3503 drivers/media/usb/em28xx/em28xx-video.c:2901
 em28xx_init_extension+0x13a/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x80 drivers/media/usb/em28xx/em28xx-cards.c:3457
 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+0x6c3/0xcb0 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 ffff888115a9c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1856 bytes inside of
 freed 8192-byte region [ffff888115a9c000, ffff888115a9e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115a98
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 0200000000000003 ffffea000456a601 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3522, tgid 3522 (syz-executor), ts 55390982122, free_ts 54044976044
 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+0xf10/0x39f0 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x273/0x2860 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab mm/slub.c:3481 [inline]
 new_slab+0xa6/0x6c0 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]
 __kmalloc_cache_noprof+0x52c/0x6b0 mm/slub.c:5375
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 mr_table_alloc+0x5f/0x2e0 net/ipv4/ipmr_base.c:41
 ipmr_new_table net/ipv4/ipmr.c:423 [inline]
 ipmr_rules_init net/ipv4/ipmr.c:342 [inline]
 ipmr_net_init net/ipv4/ipmr.c:3234 [inline]
 ipmr_net_init+0x1ef/0x340 net/ipv4/ipmr.c:3226
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x440/0x780 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xc00 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x473/0xad0 kernel/fork.c:3173
 __do_sys_unshare kernel/fork.c:3244 [inline]
 __se_sys_unshare kernel/fork.c:3242 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3242
page last free pid 3501 tgid 3501 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7b1/0xfb0 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+0x4e/0x70 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]
 kmem_cache_alloc_noprof+0x2e7/0x6a0 mm/slub.c:4873
 vm_area_dup+0x25/0x6e0 mm/vma_init.c:123
 __split_vma+0x18c/0xd60 mm/vma.c:513
 split_vma mm/vma.c:596 [inline]
 vma_modify+0x10bd/0x21e0 mm/vma.c:1680
 vma_modify_flags+0x1f2/0x350 mm/vma.c:1700
 mprotect_fixup+0x209/0xb70 mm/mprotect.c:756
 do_mprotect_pkey+0x9e1/0xe70 mm/mprotect.c:930
 __do_sys_mprotect mm/mprotect.c:951 [inline]
 __se_sys_mprotect mm/mprotect.c:948 [inline]
 __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:948
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0x7b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888115a9c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888115a9c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888115a9c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888115a9c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888115a9c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================