======================================================
WARNING: possible circular locking dependency detected
5.6.0-rc7-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/27753 is trying to acquire lock:
ffff8880a7480880 (&p->lock){+.+.}, at: seq_read+0x6b/0x1160 fs/seq_file.c:161
but task is already holding lock:
ffff888099750428 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2904 [inline]
ffff888099750428 (sb_writers#3){.+.+}, at: do_sendfile+0x939/0xc40 fs/read_write.c:1519
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (sb_writers#3){.+.+}:
percpu_down_read include/linux/percpu-rwsem.h:40 [inline]
__sb_start_write+0x21b/0x430 fs/super.c:1674
sb_start_write include/linux/fs.h:1650 [inline]
mnt_want_write+0x3a/0xb0 fs/namespace.c:354
ovl_xattr_set+0x53/0x5b0 fs/overlayfs/inode.c:324
__vfs_setxattr+0x10e/0x170 fs/xattr.c:150
__vfs_setxattr_noperm+0x11a/0x410 fs/xattr.c:181
vfs_setxattr+0xd2/0xf0 fs/xattr.c:224
setxattr+0x23d/0x330 fs/xattr.c:451
path_setxattr+0x170/0x190 fs/xattr.c:470
__do_sys_setxattr fs/xattr.c:485 [inline]
__se_sys_setxattr fs/xattr.c:481 [inline]
__x64_sys_setxattr+0xc0/0x160 fs/xattr.c:481
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #2 (&ovl_i_mutex_key[depth]#2){+.+.}:
down_write+0x8d/0x150 kernel/locking/rwsem.c:1534
inode_lock include/linux/fs.h:792 [inline]
process_measurement+0x68a/0x1740 security/integrity/ima/ima_main.c:230
ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:442
do_last fs/namei.c:3494 [inline]
path_openat+0x127f/0x32b0 fs/namei.c:3607
do_filp_open+0x192/0x260 fs/namei.c:3637
do_open_execat+0x122/0x600 fs/exec.c:860
__do_execve_file.isra.0+0x16d5/0x2270 fs/exec.c:1765
do_execveat_common fs/exec.c:1871 [inline]
do_execve fs/exec.c:1888 [inline]
__do_sys_execve fs/exec.c:1964 [inline]
__se_sys_execve fs/exec.c:1959 [inline]
__x64_sys_execve+0x8a/0xb0 fs/exec.c:1959
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #1 (&sig->cred_guard_mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
lock_trace+0x45/0xe0 fs/proc/base.c:408
proc_pid_stack+0xbd/0x1f0 fs/proc/base.c:452
proc_single_show+0xf7/0x1c0 fs/proc/base.c:758
seq_read+0x4b9/0x1160 fs/seq_file.c:229
do_loop_readv_writev fs/read_write.c:714 [inline]
do_loop_readv_writev fs/read_write.c:701 [inline]
do_iter_read+0x47f/0x650 fs/read_write.c:935
vfs_readv+0xf0/0x160 fs/read_write.c:1053
do_preadv+0x1b6/0x270 fs/read_write.c:1145
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (&p->lock){+.+.}:
check_prev_add kernel/locking/lockdep.c:2475 [inline]
check_prevs_add kernel/locking/lockdep.c:2580 [inline]
validate_chain kernel/locking/lockdep.c:2970 [inline]
__lock_acquire+0x201b/0x3ca0 kernel/locking/lockdep.c:3954
lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4484
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
seq_read+0x6b/0x1160 fs/seq_file.c:161
proc_reg_read+0x1c1/0x280 fs/proc/inode.c:223
do_loop_readv_writev fs/read_write.c:714 [inline]
do_loop_readv_writev fs/read_write.c:701 [inline]
do_iter_read+0x47f/0x650 fs/read_write.c:935
vfs_readv+0xf0/0x160 fs/read_write.c:1053
kernel_readv fs/splice.c:365 [inline]
default_file_splice_read+0x4fb/0xa20 fs/splice.c:422
do_splice_to+0x10e/0x160 fs/splice.c:892
splice_direct_to_actor+0x307/0x980 fs/splice.c:971
do_splice_direct+0x1a8/0x270 fs/splice.c:1080
do_sendfile+0x549/0xc40 fs/read_write.c:1520
__do_sys_sendfile64 fs/read_write.c:1581 [inline]
__se_sys_sendfile64 fs/read_write.c:1567 [inline]
__x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1567
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
other info that might help us debug this:
Chain exists of:
&p->lock --> &ovl_i_mutex_key[depth]#2 --> sb_writers#3
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sb_writers#3);
lock(&ovl_i_mutex_key[depth]#2);
lock(sb_writers#3);
lock(&p->lock);
*** DEADLOCK ***
1 lock held by syz-executor.1/27753:
#0: ffff888099750428 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2904 [inline]
#0: ffff888099750428 (sb_writers#3){.+.+}, at: do_sendfile+0x939/0xc40 fs/read_write.c:1519
stack backtrace:
CPU: 1 PID: 27753 Comm: syz-executor.1 Not tainted 5.6.0-rc7-syzkaller #0
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+0x188/0x20d lib/dump_stack.c:118
check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1808
check_prev_add kernel/locking/lockdep.c:2475 [inline]
check_prevs_add kernel/locking/lockdep.c:2580 [inline]
validate_chain kernel/locking/lockdep.c:2970 [inline]
__lock_acquire+0x201b/0x3ca0 kernel/locking/lockdep.c:3954
lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4484
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
seq_read+0x6b/0x1160 fs/seq_file.c:161
proc_reg_read+0x1c1/0x280 fs/proc/inode.c:223
do_loop_readv_writev fs/read_write.c:714 [inline]
do_loop_readv_writev fs/read_write.c:701 [inline]
do_iter_read+0x47f/0x650 fs/read_write.c:935
vfs_readv+0xf0/0x160 fs/read_write.c:1053
kernel_readv fs/splice.c:365 [inline]
default_file_splice_read+0x4fb/0xa20 fs/splice.c:422
do_splice_to+0x10e/0x160 fs/splice.c:892
splice_direct_to_actor+0x307/0x980 fs/splice.c:971
do_splice_direct+0x1a8/0x270 fs/splice.c:1080
do_sendfile+0x549/0xc40 fs/read_write.c:1520
__do_sys_sendfile64 fs/read_write.c:1581 [inline]
__se_sys_sendfile64 fs/read_write.c:1567 [inline]
__x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1567
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c849
Code: ad b6 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f24fe641c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f24fe6426d4 RCX: 000000000045c849
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000005
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 4000000000010046 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008d4 R14: 00000000004cb786 R15: 000000000076bf0c