Extracting prog: 3m55.126508806s
Minimizing prog: 12m38.702708916s
Simplifying prog options: 0s
Extracting C: 1m27.621585409s
Simplifying C: 11m21.526259816s


1 programs, timeouts [30s 6m0s]
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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x34, &(0x7f0000000000)=ANY=[@ANYBLOB="12010000e0dec14004231a022918010203010902220001000000000904000001e36ec20009050000000000000007058299"], 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x34, &(0x7f0000000000)=ANY=[@ANYBLOB="12010000e0dec14004231a022918010203010902220001000000000904000001e36ec20009050000000000000007058299"], 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x34, 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x34, &(0x7f0000000000)=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 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 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 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 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 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 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
program crashed: KASAN: slab-use-after-free Read in v4l2_fh_init
reproducing took 29m22.977080327s
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 ffff88810d7d8738 by task v4l_id/2836

CPU: 1 UID: 0 PID: 2836 Comm: v4l_id Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25
 v4l2_fh_open+0x89/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63
 em28xx_v4l2_open+0x250/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2155
 v4l2_open+0x228/0x490 drivers/media/v4l2-core/v4l2-dev.c:427
 chrdev_open+0x26d/0x6f0 fs/char_dev.c:414
 do_dentry_open+0x957/0x1490 fs/open.c:959
 vfs_open+0x82/0x3f0 fs/open.c:1089
 do_open fs/namei.c:3727 [inline]
 path_openat+0x2141/0x2d20 fs/namei.c:3886
 do_filp_open+0x1dc/0x430 fs/namei.c:3913
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc5138e69a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffeccea75a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffeccea77b8 RCX: 00007fc5138e69a4
RDX: 0000000000000000 RSI: 00007ffeccea7f27 RDI: 00000000ffffff9c
RBP: 00007ffeccea7f27 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeccea77d0 R14: 0000560f12dc5670 R15: 00007fc513d35a80
 </TASK>

Allocated by task 2678:
 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:370 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2534
 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 2678:
 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:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2256 [inline]
 slab_free mm/slub.c:4477 [inline]
 kfree+0x10b/0x380 mm/slub.c:4598
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x22a4/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2903
 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88810d7d8000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1848 bytes inside of
 freed 8192-byte region [ffff88810d7d8000, ffff88810d7da000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d7d8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: 0xfdffffff(slab)
raw: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000
head: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
head: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000
head: 0200000000000003 ffffea000435f601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
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 2678, tgid 2678 (kworker/1:6), ts 70652345195, free_ts 70586959961
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3446
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4702
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
 allocate_slab mm/slub.c:2488 [inline]
 new_slab+0x84/0x260 mm/slub.c:2541
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
 __slab_alloc_node mm/slub.c:3870 [inline]
 slab_alloc_node mm/slub.c:4029 [inline]
 __kmalloc_cache_noprof+0x27a/0x2c0 mm/slub.c:4188
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2534
 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 2662 tgid 2662 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1101 [inline]
 free_unref_page+0x698/0xce0 mm/page_alloc.c:2619
 __put_partials+0x14c/0x170 mm/slub.c:3055
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3992 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 kmem_cache_alloc_noprof+0x11c/0x2b0 mm/slub.c:4048
 getname_flags.part.0+0x4c/0x550 fs/namei.c:139
 getname_flags+0x93/0xf0 include/linux/audit.h:322
 do_readlinkat+0xb5/0x390 fs/stat.c:536
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x78/0xc0 fs/stat.c:571
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88810d7d8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810d7d8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88810d7d8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88810d7d8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810d7d8800: 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 ffff88810d7d8738 by task v4l_id/2836

CPU: 1 UID: 0 PID: 2836 Comm: v4l_id Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25
 v4l2_fh_open+0x89/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63
 em28xx_v4l2_open+0x250/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2155
 v4l2_open+0x228/0x490 drivers/media/v4l2-core/v4l2-dev.c:427
 chrdev_open+0x26d/0x6f0 fs/char_dev.c:414
 do_dentry_open+0x957/0x1490 fs/open.c:959
 vfs_open+0x82/0x3f0 fs/open.c:1089
 do_open fs/namei.c:3727 [inline]
 path_openat+0x2141/0x2d20 fs/namei.c:3886
 do_filp_open+0x1dc/0x430 fs/namei.c:3913
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc5138e69a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffeccea75a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffeccea77b8 RCX: 00007fc5138e69a4
RDX: 0000000000000000 RSI: 00007ffeccea7f27 RDI: 00000000ffffff9c
RBP: 00007ffeccea7f27 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeccea77d0 R14: 0000560f12dc5670 R15: 00007fc513d35a80
 </TASK>

Allocated by task 2678:
 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:370 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2534
 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 2678:
 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:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2256 [inline]
 slab_free mm/slub.c:4477 [inline]
 kfree+0x10b/0x380 mm/slub.c:4598
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x22a4/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2903
 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88810d7d8000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1848 bytes inside of
 freed 8192-byte region [ffff88810d7d8000, ffff88810d7da000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d7d8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: 0xfdffffff(slab)
raw: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000
head: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
head: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000
head: 0200000000000003 ffffea000435f601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
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 2678, tgid 2678 (kworker/1:6), ts 70652345195, free_ts 70586959961
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3446
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4702
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
 allocate_slab mm/slub.c:2488 [inline]
 new_slab+0x84/0x260 mm/slub.c:2541
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
 __slab_alloc_node mm/slub.c:3870 [inline]
 slab_alloc_node mm/slub.c:4029 [inline]
 __kmalloc_cache_noprof+0x27a/0x2c0 mm/slub.c:4188
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2534
 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117
 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 2662 tgid 2662 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1101 [inline]
 free_unref_page+0x698/0xce0 mm/page_alloc.c:2619
 __put_partials+0x14c/0x170 mm/slub.c:3055
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3992 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 kmem_cache_alloc_noprof+0x11c/0x2b0 mm/slub.c:4048
 getname_flags.part.0+0x4c/0x550 fs/namei.c:139
 getname_flags+0x93/0xf0 include/linux/audit.h:322
 do_readlinkat+0xb5/0x390 fs/stat.c:536
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x78/0xc0 fs/stat.c:571
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88810d7d8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810d7d8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88810d7d8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88810d7d8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88810d7d8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================