binder: 32485:32489 ioctl c0506617 0 returned -22
======================================================
WARNING: possible circular locking dependency detected
5.6.0-rc2-next-20200220-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/32489 is trying to acquire lock:
ffff8880a8cb6520 (&p->lock){+.+.}, at: seq_read+0x71/0x1170 fs/seq_file.c:161
but task is already holding lock:
ffff888214e9c418 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline]
ffff888214e9c418 (sb_writers#3){.+.+}, at: do_sendfile+0x9b9/0xd00 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:51 [inline]
__sb_start_write+0x255/0x4a0 fs/super.c:1674
sb_start_write include/linux/fs.h:1649 [inline]
mnt_want_write+0x3f/0xc0 fs/namespace.c:354
ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:21
ovl_create_object+0xb3/0x2c0 fs/overlayfs/dir.c:599
ovl_create+0x28/0x30 fs/overlayfs/dir.c:630
lookup_open+0x12d5/0x1a90 fs/namei.c:3309
do_last fs/namei.c:3401 [inline]
path_openat+0xf2c/0x33f0 fs/namei.c:3607
do_filp_open+0x192/0x260 fs/namei.c:3637
do_sys_openat2+0x5eb/0x7e0 fs/open.c:1149
do_sys_open+0xf2/0x180 fs/open.c:1165
ksys_open include/linux/syscalls.h:1386 [inline]
__do_sys_creat fs/open.c:1233 [inline]
__se_sys_creat fs/open.c:1231 [inline]
__x64_sys_creat+0x61/0x80 fs/open.c:1231
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #2 (&ovl_i_mutex_dir_key[depth]#3){++++}:
down_read+0x95/0x440 kernel/locking/rwsem.c:1492
inode_lock_shared include/linux/fs.h:801 [inline]
do_last fs/namei.c:3400 [inline]
path_openat+0x1c4f/0x33f0 fs/namei.c:3607
do_filp_open+0x192/0x260 fs/namei.c:3637
do_open_execat+0x13b/0x6d0 fs/exec.c:860
__do_execve_file.isra.0+0x16d5/0x2270 fs/exec.c:1791
do_execveat_common fs/exec.c:1897 [inline]
do_execve fs/exec.c:1914 [inline]
__do_sys_execve fs/exec.c:1990 [inline]
__se_sys_execve fs/exec.c:1985 [inline]
__x64_sys_execve+0x8f/0xc0 fs/exec.c:1985
do_syscall_64+0xfa/0x790 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
mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:1133
lock_trace+0x4a/0xe0 fs/proc/base.c:408
proc_pid_stack+0xbf/0x200 fs/proc/base.c:452
proc_single_show+0xfd/0x1c0 fs/proc/base.c:758
seq_read+0x4ca/0x1170 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+0x4a4/0x660 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+0x127/0x180 fs/splice.c:892
splice_direct_to_actor+0x320/0xa30 fs/splice.c:971
do_splice_direct+0x1da/0x2a0 fs/splice.c:1080
do_sendfile+0x597/0xd00 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+0x1dd/0x220 fs/read_write.c:1567
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (&p->lock){+.+.}:
check_prev_add kernel/locking/lockdep.c:2481 [inline]
check_prevs_add kernel/locking/lockdep.c:2586 [inline]
validate_chain kernel/locking/lockdep.c:3203 [inline]
__lock_acquire+0x29cd/0x6320 kernel/locking/lockdep.c:4190
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4720
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
seq_read+0x71/0x1170 fs/seq_file.c:161
full_proxy_read+0x11f/0x190 fs/debugfs/file.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+0x4a4/0x660 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+0x127/0x180 fs/splice.c:892
splice_direct_to_actor+0x320/0xa30 fs/splice.c:971
do_splice_direct+0x1da/0x2a0 fs/splice.c:1080
do_sendfile+0x597/0xd00 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+0x1dd/0x220 fs/read_write.c:1567
do_syscall_64+0xfa/0x790 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_dir_key[depth]#3 --> sb_writers#3
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sb_writers#3);
lock(&ovl_i_mutex_dir_key[depth]#3);
lock(sb_writers#3);
lock(&p->lock);
*** DEADLOCK ***
1 lock held by syz-executor.2/32489:
#0: ffff888214e9c418 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2903 [inline]
#0: ffff888214e9c418 (sb_writers#3){.+.+}, at: do_sendfile+0x9b9/0xd00 fs/read_write.c:1519
stack backtrace:
CPU: 1 PID: 32489 Comm: syz-executor.2 Not tainted 5.6.0-rc2-next-20200220-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+0x197/0x210 lib/dump_stack.c:118
print_circular_bug.isra.0.cold+0x163/0x172 kernel/locking/lockdep.c:1688
check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1812
check_prev_add kernel/locking/lockdep.c:2481 [inline]
check_prevs_add kernel/locking/lockdep.c:2586 [inline]
validate_chain kernel/locking/lockdep.c:3203 [inline]
__lock_acquire+0x29cd/0x6320 kernel/locking/lockdep.c:4190
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4720
__mutex_lock_common kernel/locking/mutex.c:956 [inline]
__mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
seq_read+0x71/0x1170 fs/seq_file.c:161
full_proxy_read+0x11f/0x190 fs/debugfs/file.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+0x4a4/0x660 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+0x127/0x180 fs/splice.c:892
splice_direct_to_actor+0x320/0xa30 fs/splice.c:971
do_splice_direct+0x1da/0x2a0 fs/splice.c:1080
do_sendfile+0x597/0xd00 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+0x1dd/0x220 fs/read_write.c:1567
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
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:00007f6e431dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6e431db6d4 RCX: 000000000045c449
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008d0 R14: 00000000004cb335 R15: 000000000076bf2c