Extracting prog: 2m25.135961533s
Minimizing prog: 16m47.672797268s
Simplifying prog options: 0s
Extracting C: 1m9.602903303s
Simplifying C: 10m49.689280406s


extracting reproducer from 22 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL-madvise
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 0x0})
madvise(&(0x7f0000000000/0x600000)=nil, 0x600000, 0x15)

program crashed: possible deadlock in blkdev_buffered_write
single: successfully extracted reproducer
found reproducer with 7 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 0x0})

program crashed: possible deadlock in blkdev_buffered_write
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$nullb-dup-mmap-madvise-write$binfmt_aout
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)

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$nullb-dup-mmap-madvise-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 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$nullb-dup-mmap-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 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$nullb-dup-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 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$nullb-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, 0xffffffffffffffff, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(0xffffffffffffffff, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 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}}): dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = dup(0xffffffffffffffff)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r0, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r0, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, 0x0, 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
simplifying C reproducer
testing compiled C program (duration=30s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program did not crash
testing compiled C program (duration=30s, {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}}): openat$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
testing compiled C program (duration=30s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:true Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
testing compiled C program (duration=30s, {Threaded:true 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
testing compiled C program (duration=30s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
testing compiled C program (duration=30s, {Threaded:true 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
testing compiled C program (duration=30s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
program crashed: possible deadlock in blkdev_buffered_write
testing program (duration=30s, {Threaded:true 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 0x0})

program crashed: possible deadlock in blkdev_buffered_write
validation run: crashed=true
testing program (duration=30s, {Threaded:true 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 0x0})

program crashed: possible deadlock in blkdev_buffered_write
validation run: crashed=true
testing program (duration=30s, {Threaded:true 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$nullb-dup-mmap-madvise-write$binfmt_aout-ioctl$sock_SIOCETHTOOL
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x4000000004002, 0x0)
r1 = dup(r0)
mmap(&(0x7f0000000000/0xb36000)=nil, 0xb36000, 0xa, 0x13, r1, 0x5000)
madvise(&(0x7f0000000000/0xc00000)=nil, 0xc00000, 0x17)
write$binfmt_aout(r1, 0x0, 0xffffffdb)
ioctl$sock_SIOCETHTOOL(0xffffffffffffffff, 0x89b0, &(0x7f0000000240)={'macvtap0\x00', 0x0})

program crashed: possible deadlock in blkdev_buffered_write
validation run: crashed=true
reproducing took 35m17.595955848s
repro crashed as (corrupted=false):
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.17/5896 is trying to acquire lock:
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_buffered_write+0xd7/0x160 block/fops.c:738

but task is already holding lock:
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_write_iter+0x6c5/0x810 block/fops.c:815

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&sb->s_type->i_mutex_key#10);
  lock(&sb->s_type->i_mutex_key#10);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

locks held by syz.0.17/5896: 1, last CPU#0:
 #0: ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_write_iter+0x6c5/0x810 block/fops.c:815

stack backtrace:
CPU: 0 UID: 0 PID: 5896 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3085
 check_deadlock kernel/locking/lockdep.c:3137 [inline]
 validate_chain kernel/locking/lockdep.c:3939 [inline]
 __lock_acquire+0x25db/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 down_read+0x45/0x320 kernel/locking/rwsem.c:1574
 inode_lock_shared include/linux/fs.h:1039 [inline]
 blkdev_buffered_write+0xd7/0x160 block/fops.c:738
 blkdev_write_iter+0x6d5/0x810 block/fops.c:816
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:1036
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f877c39e559
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:00007f877b9fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f877c626090 RCX: 00007f877c39e559
RDX: 00000000ffffffdb RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f877c4358b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f877c626128 R14: 00007f877c626090 R15: 00007fff936825f8
 </TASK>

final repro crashed as (corrupted=false):
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.17/5896 is trying to acquire lock:
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_buffered_write+0xd7/0x160 block/fops.c:738

but task is already holding lock:
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_write_iter+0x6c5/0x810 block/fops.c:815

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&sb->s_type->i_mutex_key#10);
  lock(&sb->s_type->i_mutex_key#10);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

locks held by syz.0.17/5896: 1, last CPU#0:
 #0: ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff8880289f4168 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_write_iter+0x6c5/0x810 block/fops.c:815

stack backtrace:
CPU: 0 UID: 0 PID: 5896 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3085
 check_deadlock kernel/locking/lockdep.c:3137 [inline]
 validate_chain kernel/locking/lockdep.c:3939 [inline]
 __lock_acquire+0x25db/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 down_read+0x45/0x320 kernel/locking/rwsem.c:1574
 inode_lock_shared include/linux/fs.h:1039 [inline]
 blkdev_buffered_write+0xd7/0x160 block/fops.c:738
 blkdev_write_iter+0x6d5/0x810 block/fops.c:816
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:1036
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f877c39e559
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:00007f877b9fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f877c626090 RCX: 00007f877c39e559
RDX: 00000000ffffffdb RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f877c4358b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f877c626128 R14: 00007f877c626090 R15: 00007fff936825f8
 </TASK>