Extracting prog: 2m17.729703724s
Minimizing prog: 9m23.058353037s
Simplifying prog options: 0s
Extracting C: 1m14.482402054s
Simplifying C: 9m41.89466381s


extracting reproducer from 24 programs
first checking the prog from the crash report
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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$BTRFS_IOC_SCRUB_CANCEL-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r1=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$BTRFS_IOC_SCRUB_CANCEL(r0, 0x941c, 0x0)
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r1}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
single: successfully extracted reproducer
found reproducer with 4 syscalls
minimizing guilty program
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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$BTRFS_IOC_SCRUB_CANCEL
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {0x0, {'syz', 0x0, '2\x00'}}})
ioctl$BTRFS_IOC_SCRUB_CANCEL(r0, 0x941c, 0x0)

program did not crash
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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r1=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r1}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
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}}): openat$dm_control-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program did not crash
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}}): ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
ioctl$DM_DEV_CREATE(0xffffffffffffffff, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r0=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(0xffffffffffffffff, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r0}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program did not crash
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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, 0x0, 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r1=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r1}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program did not crash
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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, 0x0)
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program did not crash
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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, 0x0)

program did not crash
extracting C reproducer
testing compiled C 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
simplifying C reproducer
testing compiled C program (duration=30s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing compiled C program (duration=30s, {Threaded:false 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:true Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing compiled C program (duration=30s, {Threaded:false Repeat:false 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing compiled C program (duration=30s, {Threaded:false Repeat:false 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
testing program (duration=30s, {Threaded:false Repeat:false 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r1=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r1}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
validation run: crashed=true
testing program (duration=30s, {Threaded:false Repeat:false 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r1=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r1}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
validation run: crashed=true
testing program (duration=30s, {Threaded:false Repeat:false 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}}): openat$dm_control-ioctl$DM_DEV_CREATE-ioctl$DM_TABLE_LOAD
detailed listing:
executing program 0:
r0 = openat$dm_control(0xffffffffffffff9c, &(0x7f0000000240), 0x2, 0x0)
ioctl$DM_DEV_CREATE(r0, 0xc138fd03, &(0x7f00000003c0)={0x4, 0x0, 0x0, 0x138, 0x138, 0x0, 0x0, 0x0, 0x0, 0x0, {<r1=>0x0, {'syz', 0x0, '2\x00'}}})
ioctl$DM_TABLE_LOAD(r0, 0xc138fd09, &(0x7f0000000500)={0x4, 0x0, 0x0, 0x1b8, 0x138, 0x1, 0x0, 0x80000, 0x0, 0x0, @by_dev={r1}, [@snapshot={0x0, 0x440, 0x0, 0x80, 'snapshot\x00', {@ram_num={'1:', 0x0}, 0x20, @ram={'/dev/ram', 0x0}, 0x20, 'N', 0x20, '32', ' 2 discard_zeroes_cow discard_passdown_origin'}}]})

program crashed: KASAN: slab-use-after-free Read in snapshot_ctr
validation run: crashed=true
reproducing took 26m40.245008926s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in snapshot_ctr+0x5cc/0x1340 drivers/md/dm-snap.c:1288
Read of size 8 at addr ffff88802dcf3998 by task syz.0.17/5978

CPU: 1 PID: 5978 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 snapshot_ctr+0x5cc/0x1340 drivers/md/dm-snap.c:1288
 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732
 populate_table drivers/md/dm-ioctl.c:1502 [inline]
 table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544
 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline]
 dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdbad39f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef9781d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdbad625fa0 RCX: 00007fdbad39f559
RDX: 0000200000000500 RSI: 00000000c138fd09 RDI: 0000000000000003
RBP: 00007fdbad436b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdbad625fac R14: 00007fdbad625fa0 R15: 00007fdbad625fa0
 </TASK>

Allocated by task 5978:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kmalloc_node include/linux/slab.h:616 [inline]
 open_table_device drivers/md/dm.c:731 [inline]
 dm_get_table_device+0x248/0x670 drivers/md/dm.c:800
 dm_get_device+0x4b9/0x9e0 drivers/md/dm-table.c:378
 snapshot_ctr+0x2b3/0x1340 drivers/md/dm-snap.c:1273
 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732
 populate_table drivers/md/dm-ioctl.c:1502 [inline]
 table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544
 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline]
 dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 5978:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1833 [inline]
 slab_free_freelist_hook+0x154/0x240 mm/slub.c:1859
 slab_free mm/slub.c:3853 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3866
 close_table_device drivers/md/dm.c:777 [inline]
 dm_put_table_device+0x20e/0x240 drivers/md/dm.c:820
 upgrade_mode drivers/md/dm-table.c:327 [inline]
 dm_get_device+0x7ca/0x9e0 drivers/md/dm-table.c:389
 snapshot_ctr+0x472/0x1340 drivers/md/dm-snap.c:1283
 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732
 populate_table drivers/md/dm-ioctl.c:1502 [inline]
 table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544
 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline]
 dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88802dcf3980
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 24 bytes inside of
 freed 64-byte region [ffff88802dcf3980, ffff88802dcf39c0)

The buggy address belongs to the physical page:
page:ffffea0000b73cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2dcf3
anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888018c41640 ffffea0001ea7f80 dead000000000005
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 21388387852, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
 prep_new_page mm/page_alloc.c:1589 [inline]
 get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2118
 alloc_slab_page+0x5d/0x180 mm/slub.c:1903
 allocate_slab mm/slub.c:2050 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2103
 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3275
 __slab_alloc mm/slub.c:3361 [inline]
 __slab_alloc_node mm/slub.c:3414 [inline]
 slab_alloc_node mm/slub.c:3508 [inline]
 __kmem_cache_alloc_node+0x122/0x260 mm/slub.c:3557
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 rtnl_register_internal+0x229/0x590 net/core/rtnetlink.c:241
 addrconf_init+0x221/0x320 net/ipv6/addrconf.c:7487
 inet6_init+0x3c3/0x6c0 net/ipv6/af_inet6.c:1170
 do_one_initcall+0x242/0x790 init/main.c:1215
 do_initcall_level+0x13d/0x1f0 init/main.c:1277
 do_initcalls+0x69/0xd0 init/main.c:1293
 kernel_init_freeable+0x3d9/0x560 init/main.c:1530
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802dcf3880: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff88802dcf3900: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff88802dcf3980: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                            ^
 ffff88802dcf3a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88802dcf3a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

final repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: slab-use-after-free in snapshot_ctr+0x5cc/0x1340 drivers/md/dm-snap.c:1288
Read of size 8 at addr ffff88802dcf3998 by task syz.0.17/5978

CPU: 1 PID: 5978 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 snapshot_ctr+0x5cc/0x1340 drivers/md/dm-snap.c:1288
 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732
 populate_table drivers/md/dm-ioctl.c:1502 [inline]
 table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544
 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline]
 dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdbad39f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef9781d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdbad625fa0 RCX: 00007fdbad39f559
RDX: 0000200000000500 RSI: 00000000c138fd09 RDI: 0000000000000003
RBP: 00007fdbad436b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdbad625fac R14: 00007fdbad625fa0 R15: 00007fdbad625fa0
 </TASK>

Allocated by task 5978:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kmalloc_node include/linux/slab.h:616 [inline]
 open_table_device drivers/md/dm.c:731 [inline]
 dm_get_table_device+0x248/0x670 drivers/md/dm.c:800
 dm_get_device+0x4b9/0x9e0 drivers/md/dm-table.c:378
 snapshot_ctr+0x2b3/0x1340 drivers/md/dm-snap.c:1273
 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732
 populate_table drivers/md/dm-ioctl.c:1502 [inline]
 table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544
 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline]
 dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 5978:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1833 [inline]
 slab_free_freelist_hook+0x154/0x240 mm/slub.c:1859
 slab_free mm/slub.c:3853 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3866
 close_table_device drivers/md/dm.c:777 [inline]
 dm_put_table_device+0x20e/0x240 drivers/md/dm.c:820
 upgrade_mode drivers/md/dm-table.c:327 [inline]
 dm_get_device+0x7ca/0x9e0 drivers/md/dm-table.c:389
 snapshot_ctr+0x472/0x1340 drivers/md/dm-snap.c:1283
 dm_table_add_target+0x575/0xbc0 drivers/md/dm-table.c:732
 populate_table drivers/md/dm-ioctl.c:1502 [inline]
 table_load+0x2eb/0x7e0 drivers/md/dm-ioctl.c:1544
 ctl_ioctl drivers/md/dm-ioctl.c:2115 [inline]
 dm_ctl_ioctl+0x975/0xd00 drivers/md/dm-ioctl.c:2137
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88802dcf3980
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 24 bytes inside of
 freed 64-byte region [ffff88802dcf3980, ffff88802dcf39c0)

The buggy address belongs to the physical page:
page:ffffea0000b73cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2dcf3
anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888018c41640 ffffea0001ea7f80 dead000000000005
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 21388387852, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
 prep_new_page mm/page_alloc.c:1589 [inline]
 get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2118
 alloc_slab_page+0x5d/0x180 mm/slub.c:1903
 allocate_slab mm/slub.c:2050 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2103
 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3275
 __slab_alloc mm/slub.c:3361 [inline]
 __slab_alloc_node mm/slub.c:3414 [inline]
 slab_alloc_node mm/slub.c:3508 [inline]
 __kmem_cache_alloc_node+0x122/0x260 mm/slub.c:3557
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 rtnl_register_internal+0x229/0x590 net/core/rtnetlink.c:241
 addrconf_init+0x221/0x320 net/ipv6/addrconf.c:7487
 inet6_init+0x3c3/0x6c0 net/ipv6/af_inet6.c:1170
 do_one_initcall+0x242/0x790 init/main.c:1215
 do_initcall_level+0x13d/0x1f0 init/main.c:1277
 do_initcalls+0x69/0xd0 init/main.c:1293
 kernel_init_freeable+0x3d9/0x560 init/main.c:1530
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802dcf3880: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff88802dcf3900: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff88802dcf3980: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                            ^
 ffff88802dcf3a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88802dcf3a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================