Extracting prog: 3m18.030013063s
Minimizing prog: 47m28.816599498s
Simplifying prog options: 0s
Extracting C: 39.783409773s
Simplifying C: 14m26.262277128s


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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
single: successfully extracted reproducer
found reproducer with 3 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}}): timer_create-timer_settime
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 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}}): timer_create-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

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}}): timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, 0x0, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, 0x0)
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, 0x0, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(0x0, 0x0, 0x2)

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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
simplifying C reproducer
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
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:true 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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:true Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
program crashed: KASAN: slab-use-after-free Read in dvb_device_open
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21, 0x2, @thr={0x0, 0x0}}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f0000000500)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
validation run: crashed=true
reproducing took 1h10m22.138234867s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in dvb_device_open+0xc4/0x350 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff88802c878818 by task syz.0.19/5879

CPU: 0 UID: 0 PID: 5879 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 dvb_device_open+0xc4/0x350 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x4dc/0x600 fs/char_dev.c:411
 do_dentry_open+0x849/0x1420 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4694 [inline]
 path_openat+0x2e64/0x3850 fs/namei.c:4857
 do_file_open+0x23e/0x4a0 fs/namei.c:4886
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8cffdde68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f8cff47db28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8cff47e6c0 RCX: 00007f8cffdde68e
RDX: 0000000000000002 RSI: 00007f8cff47dc00 RDI: ffffffffffffff9c
RBP: 00007f8cff47dc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f8d000a6038 R14: 00007f8d000a5fa0 R15: 00007ffc45531d28
 </TASK>

Allocated by task 1:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3cd/0x670 mm/slub.c:5486
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 dvb_register_device+0x309/0x1dd0 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x619/0x900 drivers/media/dvb-core/dvb_frontend.c:3051
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
 vidtv_bridge_probe+0x9d5/0xf60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0xf9/0x190 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x339/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x348/0x670 drivers/base/bus.c:763
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 vidtv_bridge_init+0x3d/0x60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
 do_one_initcall+0x250/0x870 init/main.c:1357
 do_initcall_level+0x10a/0x1a0 init/main.c:1419
 do_initcalls+0x59/0xa0 init/main.c:1435
 kernel_init_freeable+0x29d/0x3e0 init/main.c:1670
 kernel_init+0x22/0x1d0 init/main.c:1560
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5877:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2706 [inline]
 slab_free mm/slub.c:6374 [inline]
 kfree+0x1c5/0x6c0 mm/slub.c:6689
 dvb_free_device drivers/media/dvb-core/dvbdev.c:616 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put drivers/media/dvb-core/dvbdev.c:629 [inline]
 dvb_device_open+0x2c1/0x350 drivers/media/dvb-core/dvbdev.c:113
 chrdev_open+0x4dc/0x600 fs/char_dev.c:411
 do_dentry_open+0x849/0x1420 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4694 [inline]
 path_openat+0x2e64/0x3850 fs/namei.c:4857
 do_file_open+0x23e/0x4a0 fs/namei.c:4886
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802c878800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802c878800, ffff88802c878a00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c878
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813fe39c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813fe39c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 14470810562
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1862
 prep_new_page mm/page_alloc.c:1870 [inline]
 get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x222/0x5b0 mm/page_alloc.c:5385
 alloc_slab_page mm/slub.c:3295 [inline]
 allocate_slab+0x7c/0x5e0 mm/slub.c:3410
 new_slab mm/slub.c:3456 [inline]
 refill_objects+0x2d8/0x350 mm/slub.c:7307
 refill_sheaf mm/slub.c:2833 [inline]
 __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4699
 alloc_from_pcs mm/slub.c:4775 [inline]
 slab_alloc_node mm/slub.c:4909 [inline]
 __kmalloc_cache_noprof+0x467/0x670 mm/slub.c:5482
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 device_private_init drivers/base/core.c:3602 [inline]
 device_add+0xb6/0xb80 drivers/base/core.c:3653
 cdev_device_add+0x1c6/0x380 fs/char_dev.c:553
 i2cdev_attach_adapter+0x2e4/0x500 drivers/i2c/i2c-dev.c:691
 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
 bus_notify+0x146/0x180 drivers/base/bus.c:1086
 device_add+0x53a/0xb80 drivers/base/core.c:3737
 i2c_register_adapter+0xc9f/0x1400 drivers/i2c/i2c-core-base.c:1615
 vidtv_bridge_i2c_register_adap drivers/media/test-drivers/vidtv/vidtv_bridge.c:309 [inline]
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:420 [inline]
 vidtv_bridge_probe+0x29d/0xf60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802c878700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802c878780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802c878800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802c878880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802c878900: 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 dvb_device_open+0xc4/0x350 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff88802c878818 by task syz.0.19/5879

CPU: 0 UID: 0 PID: 5879 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 dvb_device_open+0xc4/0x350 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x4dc/0x600 fs/char_dev.c:411
 do_dentry_open+0x849/0x1420 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4694 [inline]
 path_openat+0x2e64/0x3850 fs/namei.c:4857
 do_file_open+0x23e/0x4a0 fs/namei.c:4886
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8cffdde68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f8cff47db28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8cff47e6c0 RCX: 00007f8cffdde68e
RDX: 0000000000000002 RSI: 00007f8cff47dc00 RDI: ffffffffffffff9c
RBP: 00007f8cff47dc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f8d000a6038 R14: 00007f8d000a5fa0 R15: 00007ffc45531d28
 </TASK>

Allocated by task 1:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3cd/0x670 mm/slub.c:5486
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 dvb_register_device+0x309/0x1dd0 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x619/0x900 drivers/media/dvb-core/dvb_frontend.c:3051
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
 vidtv_bridge_probe+0x9d5/0xf60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0xf9/0x190 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x339/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x348/0x670 drivers/base/bus.c:763
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 vidtv_bridge_init+0x3d/0x60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
 do_one_initcall+0x250/0x870 init/main.c:1357
 do_initcall_level+0x10a/0x1a0 init/main.c:1419
 do_initcalls+0x59/0xa0 init/main.c:1435
 kernel_init_freeable+0x29d/0x3e0 init/main.c:1670
 kernel_init+0x22/0x1d0 init/main.c:1560
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5877:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2706 [inline]
 slab_free mm/slub.c:6374 [inline]
 kfree+0x1c5/0x6c0 mm/slub.c:6689
 dvb_free_device drivers/media/dvb-core/dvbdev.c:616 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put drivers/media/dvb-core/dvbdev.c:629 [inline]
 dvb_device_open+0x2c1/0x350 drivers/media/dvb-core/dvbdev.c:113
 chrdev_open+0x4dc/0x600 fs/char_dev.c:411
 do_dentry_open+0x849/0x1420 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4694 [inline]
 path_openat+0x2e64/0x3850 fs/namei.c:4857
 do_file_open+0x23e/0x4a0 fs/namei.c:4886
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802c878800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802c878800, ffff88802c878a00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c878
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813fe39c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813fe39c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 14470810562
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1862
 prep_new_page mm/page_alloc.c:1870 [inline]
 get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x222/0x5b0 mm/page_alloc.c:5385
 alloc_slab_page mm/slub.c:3295 [inline]
 allocate_slab+0x7c/0x5e0 mm/slub.c:3410
 new_slab mm/slub.c:3456 [inline]
 refill_objects+0x2d8/0x350 mm/slub.c:7307
 refill_sheaf mm/slub.c:2833 [inline]
 __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4699
 alloc_from_pcs mm/slub.c:4775 [inline]
 slab_alloc_node mm/slub.c:4909 [inline]
 __kmalloc_cache_noprof+0x467/0x670 mm/slub.c:5482
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 device_private_init drivers/base/core.c:3602 [inline]
 device_add+0xb6/0xb80 drivers/base/core.c:3653
 cdev_device_add+0x1c6/0x380 fs/char_dev.c:553
 i2cdev_attach_adapter+0x2e4/0x500 drivers/i2c/i2c-dev.c:691
 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
 bus_notify+0x146/0x180 drivers/base/bus.c:1086
 device_add+0x53a/0xb80 drivers/base/core.c:3737
 i2c_register_adapter+0xc9f/0x1400 drivers/i2c/i2c-core-base.c:1615
 vidtv_bridge_i2c_register_adap drivers/media/test-drivers/vidtv/vidtv_bridge.c:309 [inline]
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:420 [inline]
 vidtv_bridge_probe+0x29d/0xf60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802c878700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802c878780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802c878800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802c878880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802c878900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================