Extracting prog: 3m52.35814056s
Minimizing prog: 26m45.127417731s
Simplifying prog options: 0s
Extracting C: 1m0.383860381s
Simplifying C: 14m34.420177937s


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:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io-syz_usb_control_io$cdc_ecm-syz_usb_control_io$cdc_ncm-syz_usb_control_io-syz_usb_control_io-syz_usb_control_io$printer
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ecm(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ncm(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$printer(r0, 0x0, 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:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io-syz_usb_control_io$cdc_ecm-syz_usb_control_io$cdc_ncm-syz_usb_control_io-syz_usb_control_io-syz_usb_control_io$printer
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ecm(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ncm(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$printer(r0, 0x0, 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
single: successfully extracted reproducer
found reproducer with 7 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io-syz_usb_control_io$cdc_ecm-syz_usb_control_io$cdc_ncm-syz_usb_control_io-syz_usb_control_io
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ecm(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ncm(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io-syz_usb_control_io$cdc_ecm-syz_usb_control_io$cdc_ncm-syz_usb_control_io
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ecm(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ncm(r0, 0x0, 0x0)
syz_usb_control_io(r0, 0x0, 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io-syz_usb_control_io$cdc_ecm-syz_usb_control_io$cdc_ncm
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ecm(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ncm(r0, 0x0, 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io-syz_usb_control_io$cdc_ecm
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)
syz_usb_control_io$cdc_ecm(r0, 0x0, 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_usb_control_io
detailed listing:
executing program 0:
r0 = syz_usb_connect(0x0, 0x2d, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)
syz_usb_control_io(r0, 0x0, 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true 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, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true 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:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true 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, &(0x7f0000000d00)=ANY=[@ANYBLOB], 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true 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_open
simplifying C reproducer
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true 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_open
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true 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:4 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:true 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_open
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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_open
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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_open
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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_open
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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_open
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000d00)=ANY=[@ANYBLOB="120100021982302013042360e5ec0102030109021b0001000060020904840001ee48b100090582"], 0x0)

program crashed: KASAN: slab-use-after-free Read in v4l2_fh_open
validation run: crashed=true
reproducing took 51m34.653474423s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
BUG: KASAN: slab-use-after-free in v4l2_fh_open+0xac/0x420 drivers/media/v4l2-core/v4l2-fh.c:64
Read of size 8 at addr ffff888065e5c740 by task v4l_id/6120

CPU: 0 UID: 0 PID: 6120 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
 v4l2_fh_open+0xac/0x420 drivers/media/v4l2-core/v4l2-fh.c:64
 em28xx_v4l2_open+0x157/0x9a0 drivers/media/usb/em28xx/em28xx-video.c:2153
 v4l2_open+0x1bf/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:433
 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
 do_dentry_open+0x7e4/0x1430 fs/open.c:962
 vfs_open+0x3b/0x340 fs/open.c:1094
 do_open fs/namei.c:4014 [inline]
 path_openat+0x2efb/0x3860 fs/namei.c:4173
 do_filp_open+0x1fa/0x410 fs/namei.c:4200
 do_sys_openat2+0x121/0x1c0 fs/open.c:1434
 do_sys_open fs/open.c:1449 [inline]
 __do_sys_openat fs/open.c:1465 [inline]
 __se_sys_openat fs/open.c:1460 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1460
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e124a7407
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:00007ffe0f4fc610 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0e12c9e880 RCX: 00007f0e124a7407
RDX: 0000000000000000 RSI: 00007ffe0f4fcf1b RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffe0f4fc860 R14: 00007f0e12e05000 R15: 000055e4a351e4d8
 </TASK>

Allocated by task 5823:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5773
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 em28xx_v4l2_init+0x10b/0x2e70 drivers/media/usb/em28xx/em28xx-video.c:2532
 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5823:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2539 [inline]
 slab_free mm/slub.c:6665 [inline]
 kfree+0x191/0x6e0 mm/slub.c:6873
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x1683/0x2e70 drivers/media/usb/em28xx/em28xx-video.c:2901
 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 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 ffff888065e5c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1856 bytes inside of
 freed 8192-byte region [ffff888065e5c000, ffff888065e5e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x65e58
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813fe27280 ffffea0000cfee00 0000000000000003
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe27280 ffffea0000cfee00 0000000000000003
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001979601 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5907, tgid 5907 (syz-executor), ts 99949150367, free_ts 99477503032
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3920
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3077 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3250
 new_slab mm/slub.c:3304 [inline]
 ___slab_alloc+0xf56/0x1990 mm/slub.c:4653
 __slab_alloc+0x65/0x100 mm/slub.c:4776
 __slab_alloc_node mm/slub.c:4852 [inline]
 slab_alloc_node mm/slub.c:5248 [inline]
 __kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:5768
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 ipv4_sysctl_init_net+0x2af/0x3f0 net/ipv4/sysctl_net_ipv4.c:1670
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x110/0x330 net/core/net_namespace.c:446
 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581
 create_new_namespaces+0x3ab/0x540 kernel/nsproxy.c:121
 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:197
 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3129
 __do_sys_unshare kernel/fork.c:3200 [inline]
 __se_sys_unshare kernel/fork.c:3198 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3198
page last free pid 1164 tgid 1164 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2948
 discard_slab mm/slub.c:3348 [inline]
 __put_partials+0x146/0x170 mm/slub.c:3888
 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3963
 __slab_free+0x288/0x2a0 mm/slub.c:5949
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4950 [inline]
 slab_alloc_node mm/slub.c:5260 [inline]
 __do_kmalloc_node mm/slub.c:5653 [inline]
 __kmalloc_node_track_caller_noprof+0x522/0x810 mm/slub.c:5761
 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:605
 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4407
 unregister_netdevice_many_notify+0x18e6/0x23f0 net/core/dev.c:12395
 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
 ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248
 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425

Memory state around the buggy address:
 ffff888065e5c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888065e5c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888065e5c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888065e5c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888065e5c800: 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 drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
BUG: KASAN: slab-use-after-free in v4l2_fh_open+0xac/0x420 drivers/media/v4l2-core/v4l2-fh.c:64
Read of size 8 at addr ffff888065e5c740 by task v4l_id/6120

CPU: 0 UID: 0 PID: 6120 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
 v4l2_fh_open+0xac/0x420 drivers/media/v4l2-core/v4l2-fh.c:64
 em28xx_v4l2_open+0x157/0x9a0 drivers/media/usb/em28xx/em28xx-video.c:2153
 v4l2_open+0x1bf/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:433
 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
 do_dentry_open+0x7e4/0x1430 fs/open.c:962
 vfs_open+0x3b/0x340 fs/open.c:1094
 do_open fs/namei.c:4014 [inline]
 path_openat+0x2efb/0x3860 fs/namei.c:4173
 do_filp_open+0x1fa/0x410 fs/namei.c:4200
 do_sys_openat2+0x121/0x1c0 fs/open.c:1434
 do_sys_open fs/open.c:1449 [inline]
 __do_sys_openat fs/open.c:1465 [inline]
 __se_sys_openat fs/open.c:1460 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1460
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e124a7407
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:00007ffe0f4fc610 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0e12c9e880 RCX: 00007f0e124a7407
RDX: 0000000000000000 RSI: 00007ffe0f4fcf1b RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffe0f4fc860 R14: 00007f0e12e05000 R15: 000055e4a351e4d8
 </TASK>

Allocated by task 5823:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5773
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 em28xx_v4l2_init+0x10b/0x2e70 drivers/media/usb/em28xx/em28xx-video.c:2532
 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5823:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2539 [inline]
 slab_free mm/slub.c:6665 [inline]
 kfree+0x191/0x6e0 mm/slub.c:6873
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x1683/0x2e70 drivers/media/usb/em28xx/em28xx-video.c:2901
 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 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 ffff888065e5c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1856 bytes inside of
 freed 8192-byte region [ffff888065e5c000, ffff888065e5e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x65e58
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813fe27280 ffffea0000cfee00 0000000000000003
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe27280 ffffea0000cfee00 0000000000000003
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001979601 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5907, tgid 5907 (syz-executor), ts 99949150367, free_ts 99477503032
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3920
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3077 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3250
 new_slab mm/slub.c:3304 [inline]
 ___slab_alloc+0xf56/0x1990 mm/slub.c:4653
 __slab_alloc+0x65/0x100 mm/slub.c:4776
 __slab_alloc_node mm/slub.c:4852 [inline]
 slab_alloc_node mm/slub.c:5248 [inline]
 __kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:5768
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 ipv4_sysctl_init_net+0x2af/0x3f0 net/ipv4/sysctl_net_ipv4.c:1670
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 setup_net+0x110/0x330 net/core/net_namespace.c:446
 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581
 create_new_namespaces+0x3ab/0x540 kernel/nsproxy.c:121
 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:197
 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3129
 __do_sys_unshare kernel/fork.c:3200 [inline]
 __se_sys_unshare kernel/fork.c:3198 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3198
page last free pid 1164 tgid 1164 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2948
 discard_slab mm/slub.c:3348 [inline]
 __put_partials+0x146/0x170 mm/slub.c:3888
 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3963
 __slab_free+0x288/0x2a0 mm/slub.c:5949
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4950 [inline]
 slab_alloc_node mm/slub.c:5260 [inline]
 __do_kmalloc_node mm/slub.c:5653 [inline]
 __kmalloc_node_track_caller_noprof+0x522/0x810 mm/slub.c:5761
 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:605
 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:674
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4407
 unregister_netdevice_many_notify+0x18e6/0x23f0 net/core/dev.c:12395
 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
 ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248
 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
 process_scheduled_works kernel/workqueue.c:3344 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425

Memory state around the buggy address:
 ffff888065e5c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888065e5c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888065e5c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888065e5c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888065e5c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================