Process accounting resumed
======================================================
WARNING: possible circular locking dependency detected
5.1.0-rc6+ #88 Not tainted
------------------------------------------------------
syz-executor.2/4025 is trying to acquire lock:
00000000892c3acb (&ovl_i_mutex_key[depth]){+.+.}, at: inode_lock include/linux/fs.h:772 [inline]
00000000892c3acb (&ovl_i_mutex_key[depth]){+.+.}, at: ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:231
but task is already holding lock:
00000000cd4a402a (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline]
00000000cd4a402a (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline]
00000000cd4a402a (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&acct->lock#2){+.+.}:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211
__mutex_lock_common kernel/locking/mutex.c:925 [inline]
__mutex_lock+0xf7/0x1310 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
acct_pin_kill+0x27/0x100 kernel/acct.c:173
pin_kill+0x18f/0x860 fs/fs_pin.c:50
acct_on+0x574/0x790 kernel/acct.c:254
__do_sys_acct kernel/acct.c:286 [inline]
__se_sys_acct kernel/acct.c:273 [inline]
__x64_sys_acct+0xae/0x200 kernel/acct.c:273
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #1 (sb_writers#3){.+.+}:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211
percpu_down_read include/linux/percpu-rwsem.h:36 [inline]
__sb_start_write+0x20b/0x360 fs/super.c:1613
sb_start_write include/linux/fs.h:1621 [inline]
mnt_want_write+0x3f/0xc0 fs/namespace.c:358
ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:24
ovl_link+0x32/0x24f fs/overlayfs/dir.c:672
vfs_link+0x7a4/0xbc0 fs/namei.c:4239
do_linkat+0x550/0x770 fs/namei.c:4307
__do_sys_link fs/namei.c:4336 [inline]
__se_sys_link fs/namei.c:4334 [inline]
__x64_sys_link+0x61/0x80 fs/namei.c:4334
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (&ovl_i_mutex_key[depth]){+.+.}:
check_prevs_add kernel/locking/lockdep.c:2333 [inline]
validate_chain kernel/locking/lockdep.c:2714 [inline]
__lock_acquire+0x239c/0x3fb0 kernel/locking/lockdep.c:3701
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211
down_write+0x38/0x90 kernel/locking/rwsem.c:70
inode_lock include/linux/fs.h:772 [inline]
ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:231
call_write_iter include/linux/fs.h:1866 [inline]
new_sync_write+0x4c7/0x760 fs/read_write.c:474
__vfs_write+0xe4/0x110 fs/read_write.c:487
__kernel_write+0x110/0x3b0 fs/read_write.c:506
do_acct_process+0xd37/0x1150 kernel/acct.c:520
slow_acct_process kernel/acct.c:579 [inline]
acct_process+0x568/0x61e kernel/acct.c:605
do_exit+0x17bd/0x2fa0 kernel/exit.c:866
do_group_exit+0x135/0x370 kernel/exit.c:980
get_signal+0x399/0x1d50 kernel/signal.c:2577
do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
other info that might help us debug this:
Chain exists of:
&ovl_i_mutex_key[depth] --> sb_writers#3 --> &acct->lock#2
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&acct->lock#2);
lock(sb_writers#3);
lock(&acct->lock#2);
lock(&ovl_i_mutex_key[depth]);
*** DEADLOCK ***
2 locks held by syz-executor.2/4025:
#0: 00000000cd4a402a (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline]
#0: 00000000cd4a402a (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline]
#0: 00000000cd4a402a (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605
#1: 00000000fc4e996d (sb_writers#17){.+.+}, at: file_start_write_trylock include/linux/fs.h:2832 [inline]
#1: 00000000fc4e996d (sb_writers#17){.+.+}, at: do_acct_process+0xf37/0x1150 kernel/acct.c:517
stack backtrace:
CPU: 1 PID: 4025 Comm: syz-executor.2 Not tainted 5.1.0-rc6+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1571
check_prev_add.constprop.0+0xf11/0x23c0 kernel/locking/lockdep.c:2220
check_prevs_add kernel/locking/lockdep.c:2333 [inline]
validate_chain kernel/locking/lockdep.c:2714 [inline]
__lock_acquire+0x239c/0x3fb0 kernel/locking/lockdep.c:3701
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211
down_write+0x38/0x90 kernel/locking/rwsem.c:70
inode_lock include/linux/fs.h:772 [inline]
ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:231
call_write_iter include/linux/fs.h:1866 [inline]
new_sync_write+0x4c7/0x760 fs/read_write.c:474
__vfs_write+0xe4/0x110 fs/read_write.c:487
__kernel_write+0x110/0x3b0 fs/read_write.c:506
do_acct_process+0xd37/0x1150 kernel/acct.c:520
slow_acct_process kernel/acct.c:579 [inline]
acct_process+0x568/0x61e kernel/acct.c:605
do_exit+0x17bd/0x2fa0 kernel/exit.c:866
do_group_exit+0x135/0x370 kernel/exit.c:980
get_signal+0x399/0x1d50 kernel/signal.c:2577
do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458da9
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2798a1bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000128
RAX: 0000000000000001 RBX: 0000000000000004 RCX: 0000000000458da9
RDX: 0000000000000001 RSI: 0000000020001740 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000036 R11: 0000000000000246 R12: 00007f2798a1c6d4
R13: 00000000004c5c06 R14: 00000000004da058 R15: 00000000ffffffff