====================================================== WARNING: possible circular locking dependency detected 4.14.222-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/14147 is trying to acquire lock: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 but task is already holding lock: (sb_writers#3){.+.+}, at: [] file_start_write include/linux/fs.h:2712 [inline] (sb_writers#3){.+.+}, at: [] do_sendfile+0x84f/0xb30 fs/read_write.c:1440 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sb_writers#3){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_create_object+0x75/0x1d0 fs/overlayfs/dir.c:538 lookup_open+0x77a/0x1750 fs/namei.c:3241 do_last fs/namei.c:3334 [inline] path_openat+0xe08/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (&ovl_i_mutex_dir_key[depth]){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] do_last fs/namei.c:3333 [inline] path_openat+0x149b/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_open_execat+0xd3/0x450 fs/exec.c:849 do_execveat_common+0x711/0x1f30 fs/exec.c:1755 do_execve fs/exec.c:1860 [inline] SYSC_execve fs/exec.c:1941 [inline] SyS_execve+0x3b/0x50 fs/exec.c:1936 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&sig->cred_guard_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 lock_trace fs/proc/base.c:407 [inline] proc_pid_stack+0x13f/0x2f0 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&p->lock){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 seq_read+0xba/0x1120 fs/seq_file.c:165 proc_reg_read+0xee/0x1a0 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x418/0x910 fs/splice.c:416 do_splice_to+0xfb/0x140 fs/splice.c:880 splice_direct_to_actor+0x207/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x47f/0xb30 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: &p->lock --> &ovl_i_mutex_dir_key[depth] --> sb_writers#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]); lock(sb_writers#3); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz-executor.0/14147: #0: (sb_writers#3){.+.+}, at: [] file_start_write include/linux/fs.h:2712 [inline] #0: (sb_writers#3){.+.+}, at: [] do_sendfile+0x84f/0xb30 fs/read_write.c:1440 stack backtrace: CPU: 1 PID: 14147 Comm: syz-executor.0 Not tainted 4.14.222-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 seq_read+0xba/0x1120 fs/seq_file.c:165 proc_reg_read+0xee/0x1a0 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x418/0x910 fs/splice.c:416 do_splice_to+0xfb/0x140 fs/splice.c:880 splice_direct_to_actor+0x207/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x47f/0xb30 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x465ef9 RSP: 002b:00007fac6a84c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465ef9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 00000000004bcd1c R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000010046 R11: 0000000000000246 R12: 000000000056c0b0 R13: 00007fff288f183f R14: 00007fac6a84c300 R15: 0000000000022000 audit: type=1804 audit(1614249695.484:87): pid=14154 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir162179216/syzkaller.557Zz0/76/bus" dev="sda1" ino=16042 res=1 FAT-fs (loop1): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop1): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) f2fs_msg: 4 callbacks suppressed F2FS-fs (loop2): Invalid segment count (0) F2FS-fs (loop2): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop2): invalid crc value UDF-fs: bad mount option "mask=jMAEC" or missing value kvm [14184]: vcpu0, guest rIP: 0x135 Hyper-V unhandled rdmsr: 0x40000024 kvm [14184]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x40000068 kvm [14184]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x4000008b kauditd_printk_skb: 4 callbacks suppressed audit: type=1800 audit(1614249697.174:92): pid=14237 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16037 res=0 kvm [14184]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x40000008 UDF-fs: bad mount option "mask=jMAEC" or missing value audit: type=1804 audit(1614249697.204:93): pid=14237 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/36/file0" dev="sda1" ino=16037 res=1 kvm [14184]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x4000002b F2FS-fs (loop2): Try to recover 2th superblock, ret: 0 F2FS-fs (loop2): Mounted with checkpoint version = 753bd00b F2FS-fs (loop2): Invalid segment count (0) F2FS-fs (loop2): Can't find valid F2FS filesystem in 2th superblock audit: type=1800 audit(1614249697.794:94): pid=14302 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16084 res=0 F2FS-fs (loop2): invalid crc value kvm [14281]: vcpu0, guest rIP: 0x135 Hyper-V unhandled rdmsr: 0x40000024 UDF-fs: bad mount option "mask=jMAEC" or missing value kvm [14281]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x40000068 audit: type=1804 audit(1614249697.814:95): pid=14302 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/37/file0" dev="sda1" ino=16084 res=1 kvm [14281]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x4000008b kvm [14281]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x40000008 kvm [14281]: vcpu0, guest rIP: 0x145 Hyper-V unhandled rdmsr: 0x4000002b UDF-fs: bad mount option "mask=jMAEC" or missing value audit: type=1800 audit(1614249698.094:96): pid=14325 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16092 res=0 UDF-fs: bad mount option "mask=jMAEC" or missing value audit: type=1800 audit(1614249698.334:97): pid=14352 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16003 res=0 F2FS-fs (loop2): Try to recover 2th superblock, ret: 0 F2FS-fs (loop2): Mounted with checkpoint version = 753bd00b audit: type=1804 audit(1614249698.334:98): pid=14352 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/39/file0" dev="sda1" ino=16003 res=1 audit: type=1800 audit(1614249698.654:99): pid=14384 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=15798 res=0 UDF-fs: bad mount option "mask=jMAEC" or missing value audit: type=1804 audit(1614249698.664:100): pid=14373 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/40/file0" dev="sda1" ino=15798 res=1 print_req_error: I/O error, dev loop0, sector 0 audit: type=1800 audit(1614249698.924:101): pid=14401 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16092 res=0 UDF-fs: bad mount option "mask=jMAEC" or missing value UDF-fs: bad mount option "mask=jMAEC" or missing value UDF-fs: bad mount option "mask=jMAEC" or missing value UDF-fs: bad mount option "mask=jMAEC" or missing value IPVS: sync thread started: state = MASTER, mcast_ifn = veth1, syncid = 0, id = 0 hub 9-0:1.0: USB hub found hub 9-0:1.0: 8 ports detected UDF-fs: bad mount option "mask=jMAEC" or missing value hub 9-0:1.0: USB hub found hub 9-0:1.0: 8 ports detected hub 9-0:1.0: USB hub found hub 9-0:1.0: 8 ports detected f2fs_msg: 20 callbacks suppressed F2FS-fs (loop0): Invalid segment count (0) F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock UDF-fs: bad mount option "mask=jMAEC" or missing value F2FS-fs (loop0): invalid crc value kauditd_printk_skb: 18 callbacks suppressed audit: type=1800 audit(1614249702.324:120): pid=14721 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16104 res=0 UDF-fs: bad mount option "mask=jMAEC" or missing value audit: type=1804 audit(1614249702.324:121): pid=14721 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/51/file0" dev="sda1" ino=16104 res=1 F2FS-fs (loop0): Try to recover 2th superblock, ret: 0 F2FS-fs (loop0): Mounted with checkpoint version = 753bd00b UDF-fs: bad mount option "mask=jMAEC" or missing value audit: type=1800 audit(1614249702.954:122): pid=14770 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16114 res=0 audit: type=1804 audit(1614249702.954:123): pid=14770 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/52/file0" dev="sda1" ino=16114 res=1 F2FS-fs (loop0): Invalid segment count (0) audit: type=1800 audit(1614249703.354:124): pid=14806 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16121 res=0 F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop0): invalid crc value F2FS-fs (loop0): Try to recover 2th superblock, ret: 0 F2FS-fs (loop0): Mounted with checkpoint version = 753bd00b UDF-fs: warning (device loop3): udf_load_vrs: No VRS found audit: type=1800 audit(1614249703.904:125): pid=14840 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16126 res=0 UDF-fs: Scanning with blocksize 512 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found audit: type=1800 audit(1614249704.114:126): pid=14856 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16130 res=0 UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found audit: type=1804 audit(1614249704.134:127): pid=14856 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/55/file0" dev="sda1" ino=16130 res=1 UDF-fs: Scanning with blocksize 4096 failed audit: type=1800 audit(1614249704.455:128): pid=14873 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16132 res=0 UDF-fs: warning (device loop3): udf_load_vrs: No VRS found audit: type=1804 audit(1614249704.455:129): pid=14873 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir707171667/syzkaller.QmnTGN/56/file0" dev="sda1" ino=16132 res=1 UDF-fs: Scanning with blocksize 512 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 4096 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 512 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop3): udf_load_vrs: No VRS found