Extracting prog: 1m58.292301596s
Minimizing prog: 9m11.701359289s
Simplifying prog options: 3m49.68520855s
Extracting C: 1m21.134635682s
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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program crashed: possible deadlock in smc_release
single: successfully extracted reproducer
found reproducer with 5 syscalls
minimizing guilty program
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
socket$inet_smc(0x2b, 0x1, 0x0)

program did not crash
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
connect$inet(0xffffffffffffffff, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program did not crash
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program did not crash
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program did not crash
testing program (duration=1m12.886814804s, {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}}): bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
bind$inet(0xffffffffffffffff, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(0xffffffffffffffff, 0x10)
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program did not crash
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, 0x0, 0x0)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program did not crash
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, 0x0, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
program did not crash
simplifying guilty program options
testing program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program crashed: possible deadlock in smc_release
extracting C reproducer
testing compiled C program (duration=1m12.886814804s, {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}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
program did not crash
testing program (duration=1m12.886814804s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program crashed: possible deadlock in smc_release
extracting C reproducer
testing compiled C program (duration=1m12.886814804s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
program did not crash
testing program (duration=1m12.886814804s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program crashed: possible deadlock in smc_release
validation run: crashed=true
testing program (duration=1m12.886814804s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program crashed: possible deadlock in smc_release
validation run: crashed=true
testing program (duration=1m12.886814804s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-listen-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)
listen(r0, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000100)={0x2, 0x4e20, @local}, 0x10)

program crashed: possible deadlock in smc_release
validation run: crashed=true
reproducing took 18m22.087919382s
repro crashed as (corrupted=false):
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.702/6659 is trying to acquire lock:
ffff88803552bc68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:4117 [inline]
ffff88803552bc68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4371 [inline]
ffff88803552bc68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x4ca/0xcb0 kernel/workqueue.c:4403

but task is already holding lock:
ffff88803552cd60 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:353

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5908 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
       lock_sock_nested+0x41/0xf0 net/core/sock.c:3827
       smc_listen_out+0xf2/0x4b0 net/smc/af_smc.c:1934
       smc_listen_out_connected net/smc/af_smc.c:1956 [inline]
       smc_listen_decline net/smc/af_smc.c:1991 [inline]
       smc_listen_work+0x767/0x50e0 net/smc/af_smc.c:2588
       process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
       process_scheduled_works kernel/workqueue.c:3470 [inline]
       worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
       kthread+0x373/0x450 kernel/kthread.c:436
       ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
       check_prevs_add kernel/locking/lockdep.c:3300 [inline]
       validate_chain kernel/locking/lockdep.c:3924 [inline]
       __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254
       lock_acquire kernel/locking/lockdep.c:5908 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
       touch_work_lockdep_map kernel/workqueue.c:4117 [inline]
       start_flush_work kernel/workqueue.c:4371 [inline]
       __flush_work+0x4de/0xcb0 kernel/workqueue.c:4403
       __cancel_work_sync kernel/workqueue.c:4559 [inline]
       cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4596
       smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
       __smc_release+0x5c2/0x880 net/smc/af_smc.c:318
       smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1866
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0x4ff/0x1060 net/smc/smc_close.c:225
       __smc_release+0x634/0x880 net/smc/af_smc.c:294
       smc_release+0x1fc/0x620 net/smc/af_smc.c:361
       __sock_release+0xb3/0x260 net/socket.c:735
       sock_close+0x1c/0x30 net/socket.c:1526
       __fput+0x3ff/0xb50 fs/file_table.c:512
       task_work_run+0x150/0x240 kernel/task_work.c:233
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
       exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
       do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_SMC/1);
                               lock((work_completion)(&new_smc->smc_listen_work));
                               lock(sk_lock-AF_SMC/1);
  lock((work_completion)(&new_smc->smc_listen_work));

 *** DEADLOCK ***

locks held by syz.0.702/6659: 3, last CPU#2:
 #0: ffff888028c31f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888028c31f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:734
 #1: ffff88803552cd60 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:353
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4345 [inline]
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfd/0xcb0 kernel/workqueue.c:4403

stack backtrace:
CPU: 2 UID: 0 PID: 6659 Comm: syz.0.702 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_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2059
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2191
 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
 check_prevs_add kernel/locking/lockdep.c:3300 [inline]
 validate_chain kernel/locking/lockdep.c:3924 [inline]
 __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254
 lock_acquire kernel/locking/lockdep.c:5908 [inline]
 lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
 touch_work_lockdep_map kernel/workqueue.c:4117 [inline]
 start_flush_work kernel/workqueue.c:4371 [inline]
 __flush_work+0x4de/0xcb0 kernel/workqueue.c:4403
 __cancel_work_sync kernel/workqueue.c:4559 [inline]
 cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4596
 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
 __smc_release+0x5c2/0x880 net/smc/af_smc.c:318
 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1866
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0x4ff/0x1060 net/smc/smc_close.c:225
 __smc_release+0x634/0x880 net/smc/af_smc.c:294
 smc_release+0x1fc/0x620 net/smc/af_smc.c:361
 __sock_release+0xb3/0x260 net/socket.c:735
 sock_close+0x1c/0x30 net/socket.c:1526
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f113a79e159
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:00007ffeb3a39c58 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffeb3a39d40 RCX: 00007f113a79e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00000000000134e6 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b33a20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f113aa25fac R14: 00007f113aa25fa8 R15: 00007f113aa25fa0
 </TASK>

final repro crashed as (corrupted=false):
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.702/6659 is trying to acquire lock:
ffff88803552bc68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:4117 [inline]
ffff88803552bc68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4371 [inline]
ffff88803552bc68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x4ca/0xcb0 kernel/workqueue.c:4403

but task is already holding lock:
ffff88803552cd60 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:353

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5908 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
       lock_sock_nested+0x41/0xf0 net/core/sock.c:3827
       smc_listen_out+0xf2/0x4b0 net/smc/af_smc.c:1934
       smc_listen_out_connected net/smc/af_smc.c:1956 [inline]
       smc_listen_decline net/smc/af_smc.c:1991 [inline]
       smc_listen_work+0x767/0x50e0 net/smc/af_smc.c:2588
       process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
       process_scheduled_works kernel/workqueue.c:3470 [inline]
       worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
       kthread+0x373/0x450 kernel/kthread.c:436
       ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
       check_prevs_add kernel/locking/lockdep.c:3300 [inline]
       validate_chain kernel/locking/lockdep.c:3924 [inline]
       __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254
       lock_acquire kernel/locking/lockdep.c:5908 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
       touch_work_lockdep_map kernel/workqueue.c:4117 [inline]
       start_flush_work kernel/workqueue.c:4371 [inline]
       __flush_work+0x4de/0xcb0 kernel/workqueue.c:4403
       __cancel_work_sync kernel/workqueue.c:4559 [inline]
       cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4596
       smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
       __smc_release+0x5c2/0x880 net/smc/af_smc.c:318
       smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1866
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0x4ff/0x1060 net/smc/smc_close.c:225
       __smc_release+0x634/0x880 net/smc/af_smc.c:294
       smc_release+0x1fc/0x620 net/smc/af_smc.c:361
       __sock_release+0xb3/0x260 net/socket.c:735
       sock_close+0x1c/0x30 net/socket.c:1526
       __fput+0x3ff/0xb50 fs/file_table.c:512
       task_work_run+0x150/0x240 kernel/task_work.c:233
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
       exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
       do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_SMC/1);
                               lock((work_completion)(&new_smc->smc_listen_work));
                               lock(sk_lock-AF_SMC/1);
  lock((work_completion)(&new_smc->smc_listen_work));

 *** DEADLOCK ***

locks held by syz.0.702/6659: 3, last CPU#2:
 #0: ffff888028c31f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888028c31f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:734
 #1: ffff88803552cd60 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x3a5/0x620 net/smc/af_smc.c:353
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4345 [inline]
 #2: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfd/0xcb0 kernel/workqueue.c:4403

stack backtrace:
CPU: 2 UID: 0 PID: 6659 Comm: syz.0.702 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_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2059
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2191
 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181
 check_prevs_add kernel/locking/lockdep.c:3300 [inline]
 validate_chain kernel/locking/lockdep.c:3924 [inline]
 __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254
 lock_acquire kernel/locking/lockdep.c:5908 [inline]
 lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
 touch_work_lockdep_map kernel/workqueue.c:4117 [inline]
 start_flush_work kernel/workqueue.c:4371 [inline]
 __flush_work+0x4de/0xcb0 kernel/workqueue.c:4403
 __cancel_work_sync kernel/workqueue.c:4559 [inline]
 cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4596
 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
 __smc_release+0x5c2/0x880 net/smc/af_smc.c:318
 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1866
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0x4ff/0x1060 net/smc/smc_close.c:225
 __smc_release+0x634/0x880 net/smc/af_smc.c:294
 smc_release+0x1fc/0x620 net/smc/af_smc.c:361
 __sock_release+0xb3/0x260 net/socket.c:735
 sock_close+0x1c/0x30 net/socket.c:1526
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f113a79e159
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:00007ffeb3a39c58 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffeb3a39d40 RCX: 00007f113a79e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00000000000134e6 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b33a20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f113aa25fac R14: 00007f113aa25fa8 R15: 00007f113aa25fa0
 </TASK>