print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. ====================================================== WARNING: possible circular locking dependency detected 4.14.189-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/15901 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:2708 [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+0x19a/0x2e0 fs/super.c:1363 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_do_remove+0x65/0xaf0 fs/overlayfs/dir.c:759 vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3908 vfs_rmdir fs/namei.c:3893 [inline] do_rmdir+0x334/0x3c0 fs/namei.c:3968 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:1742 do_execve fs/exec.c:1847 [inline] SYSC_execve fs/exec.c:1928 [inline] SyS_execve+0x3b/0x50 fs/exec.c:1923 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.5/15901: #0: (sb_writers#3){.+.+}, at: [] file_start_write include/linux/fs.h:2708 [inline] #0: (sb_writers#3){.+.+}, at: [] do_sendfile+0x84f/0xb30 fs/read_write.c:1440 stack backtrace: CPU: 0 PID: 15901 Comm: syz-executor.5 Not tainted 4.14.189-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+0x1b2/0x283 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: 0033:0x45c1f9 RSP: 002b:00007f8db1ebbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000026080 RCX: 000000000045c1f9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000010046 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffd64fb63bf R14: 00007f8db1ebc9c0 R15: 000000000078bf0c overlayfs: fs on 'file0' does not support file handles, falling back to index=off. overlayfs: fs on 'file0' does not support file handles, falling back to index=off. overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. overlayfs: fs on 'file0' does not support file handles, falling back to index=off. __ntfs_error: 14 callbacks suppressed ntfs: (device loop3): parse_options(): Unrecognized mount option obj_user. audit: type=1326 audit(1595498551.652:527): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16032 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=228 compat=0 ip=0x45f03a code=0x50000 ntfs: (device loop3): parse_options(): Unrecognized mount option . audit: type=1326 audit(1595498551.652:528): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16032 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498551.652:529): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16032 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. audit: type=1326 audit(1595498551.652:530): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16032 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498551.652:531): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16032 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 ntfs: (device loop3): parse_options(): Unrecognized mount option obj_user. audit: type=1326 audit(1595498551.652:532): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16032 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 ntfs: (device loop3): parse_options(): Unrecognized mount option . overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. kauditd_printk_skb: 24120 callbacks suppressed audit: type=1326 audit(1595498556.632:24635): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24636): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24637): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24638): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24639): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24640): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24641): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24642): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24643): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 audit: type=1326 audit(1595498556.672:24644): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=16122 comm="syz-executor.0" exe="/root/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x45c1f9 code=0x50000 overlayfs: fs on 'file0' does not support file handles, falling back to index=off. print_req_error: I/O error, dev loop3, sector 0 print_req_error: I/O error, dev loop3, sector 0