F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock ====================================================== WARNING: possible circular locking dependency detected 4.14.106+ #30 Not tainted ------------------------------------------------------ syz-executor.4/4913 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] lock_trace+0x3f/0xc0 fs/proc/base.c:408 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xcd/0x1180 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&p->lock){+.+.}: -> #1 (&pipe->mutex/1){+.+.}: -> #0 (&sig->cred_guard_mutex){+.+.}: other info that might help us debug this: Chain exists of: &sig->cred_guard_mutex --> &pipe->mutex/1 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(&pipe->mutex/1); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 1 lock held by syz-executor.4/4913: #0: (&p->lock){+.+.}, at: [] seq_read+0xcd/0x1180 fs/seq_file.c:165 stack backtrace: CPU: 0 PID: 4913 Comm: syz-executor.4 Not tainted 4.14.106+ #30 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 print_circular_bug.isra.0.cold+0x2dc/0x425 kernel/locking/lockdep.c:1258 F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Failed to get valid F2FS checkpoint audit: type=1326 audit(1552837355.654:150): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=5193 comm="syz-executor.3" exe="/root/syz-executor.3" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45aeda code=0x0 audit: type=1326 audit(1552837357.064:151): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=5253 comm="syz-executor.3" exe="/root/syz-executor.3" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45aeda code=0x0 audit: type=1326 audit(1552837358.304:152): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=5306 comm="syz-executor.3" exe="/root/syz-executor.3" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45aeda code=0x0 audit: type=1326 audit(1552837359.454:153): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=5359 comm="syz-executor.3" exe="/root/syz-executor.3" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45aeda code=0x0 audit: type=1326 audit(1552837360.284:154): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=5408 comm="syz-executor.3" exe="/root/syz-executor.3" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45aeda code=0x0