Extracting prog: 1m7.840735215s
Minimizing prog: 4m35.751693255s
Simplifying prog options: 2m23.130487171s
Extracting C: 28.831264657s
Simplifying C: 0s


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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$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=33.077681158s, {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, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, 0x0, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, 0x0)
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, 0x0, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(0x0, 0x0, 0x2)

program did not crash
extracting C reproducer
testing compiled C program (duration=33.077681158s, {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$dvb_frontend
program did not crash
simplifying guilty program options
testing program (duration=33.077681158s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false 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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program did not crash
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
extracting C reproducer
testing compiled C program (duration=33.077681158s, {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$dvb_frontend
program did not crash
testing program (duration=33.077681158s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): timer_create-timer_settime-syz_open_dev$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{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=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
validation run: crashed=true
testing program (duration=33.077681158s, {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$dvb_frontend
detailed listing:
executing program 0:
timer_create(0x0, &(0x7f0000000200)={0x0, 0x21, 0x2, @tid=0xffffffffffffffff}, &(0x7f0000000300))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_open_dev$dvb_frontend(&(0x7f0000000080), 0x0, 0x2)

program crashed: KASAN: slab-use-after-free Read in dvb_device_open
validation run: crashed=true
reproducing took 10m33.516707808s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff888000bd5618 by task syz.0.19/5922

CPU: 1 UID: 0 PID: 5922 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x14b/0x720 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71b74eb
Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 f7 a1 ff ff 66 90 66 90 66 90 90 53
RSP: 002b:00000000f687503c EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f6875100
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 1:
 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+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5489
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 dvb_register_device+0x1d6/0x1e20 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x552/0x820 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+0x44b/0xa30 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 vidtv_bridge_init+0x52/0x80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
 do_one_initcall+0x11d/0x700 init/main.c:1353
 do_initcall_level init/main.c:1415 [inline]
 do_initcalls init/main.c:1431 [inline]
 do_basic_setup init/main.c:1451 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1666
 kernel_init+0x21/0x1e0 init/main.c:1556
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5920:
 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+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2677 [inline]
 slab_free mm/slub.c:6377 [inline]
 kfree+0x22b/0x6c0 mm/slub.c:6692
 dvb_free_device drivers/media/dvb-core/dvbdev.c:616 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put.part.0+0x57/0x90 drivers/media/dvb-core/dvbdev.c:629
 dvb_device_put drivers/media/dvb-core/dvbdev.c:628 [inline]
 dvb_device_open+0x2ba/0x3b0 drivers/media/dvb-core/dvbdev.c:113
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x14b/0x720 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598

The buggy address belongs to the object at ffff888000bd5600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 24 bytes inside of
 freed 256-byte region [ffff888000bd5600, ffff888000bd5700)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbd4
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x7ff00000000040(head|node=0|zone=0|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 007ff00000000040 ffff88801bc42b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 007ff00000000040 ffff88801bc42b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 007ff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 13040529166, free_ts 12993023717
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab mm/slub.c:3380 [inline]
 new_slab+0xa2/0x640 mm/slub.c:3426
 refill_objects+0xe3/0x410 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __kmalloc_cache_noprof+0x479/0x6c0 mm/slub.c:5485
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 bus_add_driver+0x92/0x5b0 drivers/base/bus.c:747
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 i2c_register_driver+0xd9/0x1f0 drivers/i2c/i2c-core-base.c:2045
 do_one_initcall+0x11d/0x700 init/main.c:1353
 do_initcall_level init/main.c:1415 [inline]
 do_initcalls init/main.c:1431 [inline]
 do_basic_setup init/main.c:1451 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1666
 kernel_init+0x21/0x1e0 init/main.c:1556
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 24 tgid 24 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
 __free_contig_range mm/page_alloc.c:6942 [inline]
 free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3461
 vfree mm/vmalloc.c:3510 [inline]
 vfree+0x107/0x750 mm/vmalloc.c:3484
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3414
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888000bd5500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888000bd5580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888000bd5600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888000bd5680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888000bd5700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	57                   	push   %rdi
   1:	56                   	push   %rsi
   2:	53                   	push   %rbx
   3:	8b 44 24 14          	mov    0x14(%rsp),%eax
   7:	f6 00 08             	testb  $0x8,(%rax)
   a:	75 23                	jne    0x2f
   c:	8b 44 24 18          	mov    0x18(%rsp),%eax
  10:	8b 5c 24 1c          	mov    0x1c(%rsp),%ebx
  14:	8b 4c 24 20          	mov    0x20(%rsp),%ecx
  18:	8b 54 24 24          	mov    0x24(%rsp),%edx
  1c:	8b 74 24 28          	mov    0x28(%rsp),%esi
  20:	8b 7c 24 2c          	mov    0x2c(%rsp),%edi
  24:	8b 6c 24 30          	mov    0x30(%rsp),%ebp
  28:	cd 80                	int    $0x80
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	5e                   	pop    %rsi
  2c:	5f                   	pop    %rdi
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	5b                   	pop    %rbx
  30:	5e                   	pop    %rsi
  31:	5f                   	pop    %rdi
  32:	5d                   	pop    %rbp
  33:	e9 f7 a1 ff ff       	jmp    0xffffa22f
  38:	66 90                	xchg   %ax,%ax
  3a:	66 90                	xchg   %ax,%ax
  3c:	66 90                	xchg   %ax,%ax
  3e:	90                   	nop
  3f:	53                   	push   %rbx

final repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff888000bd5618 by task syz.0.19/5922

CPU: 1 UID: 0 PID: 5922 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x14b/0x720 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71b74eb
Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 f7 a1 ff ff 66 90 66 90 66 90 90 53
RSP: 002b:00000000f687503c EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f6875100
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 1:
 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+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5489
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 dvb_register_device+0x1d6/0x1e20 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x552/0x820 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+0x44b/0xa30 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 vidtv_bridge_init+0x52/0x80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
 do_one_initcall+0x11d/0x700 init/main.c:1353
 do_initcall_level init/main.c:1415 [inline]
 do_initcalls init/main.c:1431 [inline]
 do_basic_setup init/main.c:1451 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1666
 kernel_init+0x21/0x1e0 init/main.c:1556
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5920:
 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+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2677 [inline]
 slab_free mm/slub.c:6377 [inline]
 kfree+0x22b/0x6c0 mm/slub.c:6692
 dvb_free_device drivers/media/dvb-core/dvbdev.c:616 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put.part.0+0x57/0x90 drivers/media/dvb-core/dvbdev.c:629
 dvb_device_put drivers/media/dvb-core/dvbdev.c:628 [inline]
 dvb_device_open+0x2ba/0x3b0 drivers/media/dvb-core/dvbdev.c:113
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x14b/0x720 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598

The buggy address belongs to the object at ffff888000bd5600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 24 bytes inside of
 freed 256-byte region [ffff888000bd5600, ffff888000bd5700)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbd4
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x7ff00000000040(head|node=0|zone=0|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 007ff00000000040 ffff88801bc42b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 007ff00000000040 ffff88801bc42b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 007ff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 13040529166, free_ts 12993023717
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab mm/slub.c:3380 [inline]
 new_slab+0xa2/0x640 mm/slub.c:3426
 refill_objects+0xe3/0x410 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __kmalloc_cache_noprof+0x479/0x6c0 mm/slub.c:5485
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 bus_add_driver+0x92/0x5b0 drivers/base/bus.c:747
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 i2c_register_driver+0xd9/0x1f0 drivers/i2c/i2c-core-base.c:2045
 do_one_initcall+0x11d/0x700 init/main.c:1353
 do_initcall_level init/main.c:1415 [inline]
 do_initcalls init/main.c:1431 [inline]
 do_basic_setup init/main.c:1451 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1666
 kernel_init+0x21/0x1e0 init/main.c:1556
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 24 tgid 24 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
 __free_contig_range mm/page_alloc.c:6942 [inline]
 free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3461
 vfree mm/vmalloc.c:3510 [inline]
 vfree+0x107/0x750 mm/vmalloc.c:3484
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3414
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888000bd5500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888000bd5580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888000bd5600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888000bd5680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888000bd5700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	57                   	push   %rdi
   1:	56                   	push   %rsi
   2:	53                   	push   %rbx
   3:	8b 44 24 14          	mov    0x14(%rsp),%eax
   7:	f6 00 08             	testb  $0x8,(%rax)
   a:	75 23                	jne    0x2f
   c:	8b 44 24 18          	mov    0x18(%rsp),%eax
  10:	8b 5c 24 1c          	mov    0x1c(%rsp),%ebx
  14:	8b 4c 24 20          	mov    0x20(%rsp),%ecx
  18:	8b 54 24 24          	mov    0x24(%rsp),%edx
  1c:	8b 74 24 28          	mov    0x28(%rsp),%esi
  20:	8b 7c 24 2c          	mov    0x2c(%rsp),%edi
  24:	8b 6c 24 30          	mov    0x30(%rsp),%ebp
  28:	cd 80                	int    $0x80
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	5e                   	pop    %rsi
  2c:	5f                   	pop    %rdi
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	5b                   	pop    %rbx
  30:	5e                   	pop    %rsi
  31:	5f                   	pop    %rdi
  32:	5d                   	pop    %rbp
  33:	e9 f7 a1 ff ff       	jmp    0xffffa22f
  38:	66 90                	xchg   %ax,%ax
  3a:	66 90                	xchg   %ax,%ax
  3c:	66 90                	xchg   %ax,%ax
  3e:	90                   	nop
  3f:	53                   	push   %rbx