FAT-fs (loop2): error, allocated dir entry found after end-of-directory marker (i_pos 1)
FAT-fs (loop2): Filesystem has been set read-only
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.96/5228 is trying to acquire lock:
ffff0000f7240a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:4126 [inline]
ffff0000f7240a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4380 [inline]
ffff0000f7240a68 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x58c/0xa24 kernel/workqueue.c:4412

but task is already holding lock:
ffff0000f7240ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1d8/0x51c net/smc/af_smc.c:-1

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_sock_nested+0x58/0x110 net/core/sock.c:3837
       smc_listen_out+0xe0/0x3b4 net/smc/af_smc.c:1934
       smc_listen_work+0x410/0xc58 net/smc/af_smc.c:-1
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479
       worker_thread+0x798/0xbd0 kernel/workqueue.c:3560
       kthread+0x304/0x3d4 kernel/kthread.c:436
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x1660/0x2b08 kernel/locking/lockdep.c:5288
       lock_acquire+0x13c/0x320 kernel/locking/lockdep.c:5942
       touch_work_lockdep_map kernel/workqueue.c:4126 [inline]
       start_flush_work kernel/workqueue.c:4380 [inline]
       __flush_work+0x594/0xa24 kernel/workqueue.c:4412
       __cancel_work_sync+0xc8/0x144 kernel/workqueue.c:4568
       cancel_work_sync+0x24/0x38 kernel/workqueue.c:4605
       smc_clcsock_release+0x64/0xe8 net/smc/smc_close.c:29
       __smc_release+0x514/0x698 net/smc/af_smc.c:318
       smc_close_non_accepted+0xd8/0x254 net/smc/af_smc.c:1866
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0x7e4/0x9d0 net/smc/smc_close.c:225
       __smc_release+0x90/0x698 net/smc/af_smc.c:294
       smc_release+0x248/0x51c net/smc/af_smc.c:361
       __sock_release+0xa0/0x1d4 net/socket.c:735
       sock_close+0x24/0x38 net/socket.c:1526
       __fput+0x338/0x74c fs/file_table.c:512
       fput_close_sync+0x10c/0x278 fs/file_table.c:617
       __do_sys_close fs/open.c:1560 [inline]
       __se_sys_close fs/open.c:1545 [inline]
       __arm64_sys_close+0x80/0x110 fs/open.c:1545
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
       do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
       el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796
       el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606

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.2.96/5228: 3, last CPU#0:
 #0: ffff0000f0b6cd00 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff0000f0b6cd00 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x7c/0x1d4 net/socket.c:734
 #1: ffff0000f7240ee0 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x1d8/0x51c net/smc/af_smc.c:-1
 #2: ffff800088c41960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffff800088c41960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffff800088c41960 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4354 [inline]
 #2: ffff800088c41960 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x108/0xa24 kernel/workqueue.c:4412

stack backtrace:
CPU: 0 UID: 0 PID: 5228 Comm: syz.2.96 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2087
 check_noncircular+0x158/0x174 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x1660/0x2b08 kernel/locking/lockdep.c:5288
 lock_acquire+0x13c/0x320 kernel/locking/lockdep.c:5942
 touch_work_lockdep_map kernel/workqueue.c:4126 [inline]
 start_flush_work kernel/workqueue.c:4380 [inline]
 __flush_work+0x594/0xa24 kernel/workqueue.c:4412
 __cancel_work_sync+0xc8/0x144 kernel/workqueue.c:4568
 cancel_work_sync+0x24/0x38 kernel/workqueue.c:4605
 smc_clcsock_release+0x64/0xe8 net/smc/smc_close.c:29
 __smc_release+0x514/0x698 net/smc/af_smc.c:318
 smc_close_non_accepted+0xd8/0x254 net/smc/af_smc.c:1866
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0x7e4/0x9d0 net/smc/smc_close.c:225
 __smc_release+0x90/0x698 net/smc/af_smc.c:294
 smc_release+0x248/0x51c net/smc/af_smc.c:361
 __sock_release+0xa0/0x1d4 net/socket.c:735
 sock_close+0x24/0x38 net/socket.c:1526
 __fput+0x338/0x74c fs/file_table.c:512
 fput_close_sync+0x10c/0x278 fs/file_table.c:617
 __do_sys_close fs/open.c:1560 [inline]
 __se_sys_close fs/open.c:1545 [inline]
 __arm64_sys_close+0x80/0x110 fs/open.c:1545
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606