====================================================== WARNING: possible circular locking dependency detected 4.19.197-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/20748 is trying to acquire lock: 00000000c3668a03 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] 00000000c3668a03 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x63/0x80 fs/pipe.c:70 but task is already holding lock: 000000009fb3edd8 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] 000000009fb3edd8 (sb_writers#3){.+.+}, at: do_splice fs/splice.c:1153 [inline] 000000009fb3edd8 (sb_writers#3){.+.+}, at: __do_sys_splice fs/splice.c:1428 [inline] 000000009fb3edd8 (sb_writers#3){.+.+}, at: __se_sys_splice+0x11de/0x16d0 fs/splice.c:1408 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_writers#3){.+.+}: file_start_write include/linux/fs.h:2779 [inline] ovl_write_iter+0x932/0xb40 fs/overlayfs/file.c:282 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1f0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x389/0x800 fs/splice.c:627 splice_from_pipe fs/splice.c:662 [inline] default_file_splice_write+0xd8/0x180 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice fs/splice.c:1154 [inline] __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice+0xfe7/0x16d0 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&ovl_i_mutex_key[depth]){+.+.}: inode_lock include/linux/fs.h:748 [inline] ovl_write_iter+0x148/0xb40 fs/overlayfs/file.c:270 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1f0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x389/0x800 fs/splice.c:627 splice_from_pipe fs/splice.c:662 [inline] default_file_splice_write+0xd8/0x180 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice fs/splice.c:1154 [inline] __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice+0xfe7/0x16d0 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&pipe->mutex/1){+.+.}: __mutex_lock_common kernel/locking/mutex.c:938 [inline] __mutex_lock+0xd7/0x1200 kernel/locking/mutex.c:1083 pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock+0x63/0x80 fs/pipe.c:70 iter_file_splice_write+0x183/0xbb0 fs/splice.c:700 do_splice_from fs/splice.c:852 [inline] do_splice fs/splice.c:1154 [inline] __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice+0xfe7/0x16d0 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &pipe->mutex/1 --> &ovl_i_mutex_key[depth] --> sb_writers#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_key[depth]); lock(sb_writers#3); lock(&pipe->mutex/1); *** DEADLOCK *** 1 lock held by syz-executor.5/20748: #0: 000000009fb3edd8 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] #0: 000000009fb3edd8 (sb_writers#3){.+.+}, at: do_splice fs/splice.c:1153 [inline] #0: 000000009fb3edd8 (sb_writers#3){.+.+}, at: __do_sys_splice fs/splice.c:1428 [inline] #0: 000000009fb3edd8 (sb_writers#3){.+.+}, at: __se_sys_splice+0x11de/0x16d0 fs/splice.c:1408 stack backtrace: CPU: 0 PID: 20748 Comm: syz-executor.5 Not tainted 4.19.197-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+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __mutex_lock_common kernel/locking/mutex.c:938 [inline] __mutex_lock+0xd7/0x1200 kernel/locking/mutex.c:1083 pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock+0x63/0x80 fs/pipe.c:70 iter_file_splice_write+0x183/0xbb0 fs/splice.c:700 do_splice_from fs/splice.c:852 [inline] do_splice fs/splice.c:1154 [inline] __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice+0xfe7/0x16d0 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb062344188 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004bfcb9 R08: 00000000088000d0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd4797b5ef R14: 00007fb062344300 R15: 0000000000022000 audit: type=1804 audit(1626688870.586:15916): pid=20775 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.2" name="/root/syzkaller-testdir412849690/syzkaller.i670nW/213/file0" dev="sda1" ino=15073 res=1 ptrace attach of "/root/syz-executor.5"[20788] was attempted by "/root/syz-executor.5"[20790] audit: type=1804 audit(1626688870.656:15917): pid=20784 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.2" name="/root/syzkaller-testdir412849690/syzkaller.i670nW/213/file0" dev="sda1" ino=15073 res=1 syz-executor.2 (20805) used greatest stack depth: 22304 bytes left Bluetooth: hci2: command 0x0406 tx timeout ptrace attach of "/root/syz-executor.0"[20867] was attempted by "/root/syz-executor.0"[20869] overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. overlayfs: lowerdir is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection. overlayfs: upperdir is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection. ptrace attach of "/root/syz-executor.5"[20948] was attempted by "/root/syz-executor.5"[20951] ptrace attach of "/root/syz-executor.3"[20954] was attempted by "/root/syz-executor.3"[20956] ptrace attach of "/root/syz-executor.0"[20975] was attempted by "/root/syz-executor.0"[20977] ptrace attach of ""[20976] was attempted by "/root/syz-executor.2"[20982] ptrace attach of "/root/syz-executor.3"[20985] was attempted by "/root/syz-executor.3"[20986] ptrace attach of "/root/syz-executor.0"[20994] was attempted by "/root/syz-executor.0"[20997] overlayfs: unrecognized mount option "workdir\w5T)`)YFnA@T<3ڂ$rcnHwC" -8/" or missing value overlayfs: unrecognized mount option "workdir\w5T)`)YFnA@T<3ڂ$rcnHwC" -8/" or missing value audit: type=1800 audit(1626688873.166:15918): pid=21035 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=14305 res=0 audit: type=1800 audit(1626688873.246:15919): pid=21043 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=14305 res=0 ptrace attach of "/root/syz-executor.3"[21045] was attempted by "/root/syz-executor.3"[21049] EXT4-fs (loop4): bad geometry: block count 64 exceeds size of device (2 blocks) EXT4-fs (loop4): bad geometry: block count 64 exceeds size of device (2 blocks) ptrace attach of "/root/syz-executor.2"[21089] was attempted by "/root/syz-executor.2"[21092] netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'. xt_TCPMSS: path-MTU clamping only supported in FORWARD, OUTPUT and POSTROUTING hooks xt_TCPMSS: path-MTU clamping only supported in FORWARD, OUTPUT and POSTROUTING hooks caif:caif_disconnect_client(): nothing to disconnect ptrace attach of "/root/syz-executor.1"[21168] was attempted by "/root/syz-executor.1"[21171] caif:caif_disconnect_client(): nothing to disconnect 9pnet_virtio: no channels available for device qY3aK ptrace attach of "/root/syz-executor.4"[21206] was attempted by "/root/syz-executor.4"[21209] EXT4-fs (loop3): Unsupported blocksize for fs encryption netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. EXT4-fs (loop3): Unsupported blocksize for fs encryption nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. new mount options do not match the existing superblock, will be ignored new mount options do not match the existing superblock, will be ignored netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. __report_access: 4 callbacks suppressed ptrace attach of "/root/syz-executor.0"[21597] was attempted by "/root/syz-executor.0"[21598] netlink: 'syz-executor.1': attribute type 6 has an invalid length.