====================================================== WARNING: possible circular locking dependency detected 4.14.305-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/13287 is trying to acquire lock: (&ovl_i_mutex_dir_key[depth]){++++}, at: [] iterate_dir+0x387/0x5e0 fs/readdir.c:43 but task is already holding lock: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (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:1551 [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:3571 do_filp_open+0x179/0x3c0 fs/namei.c:3605 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+0x5e/0xd3 -> #0 (&ovl_i_mutex_dir_key[depth]){++++}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 down_write_killable+0x37/0xb0 kernel/locking/rwsem.c:68 iterate_dir+0x387/0x5e0 fs/readdir.c:43 ovl_dir_read fs/overlayfs/readdir.c:306 [inline] ovl_dir_read_merged+0x2c5/0x430 fs/overlayfs/readdir.c:365 ovl_check_empty_dir+0x6e/0x200 fs/overlayfs/readdir.c:870 ovl_check_empty_and_clear+0x72/0xe0 fs/overlayfs/dir.c:306 ovl_rename+0x57d/0xe50 fs/overlayfs/dir.c:959 vfs_rename+0x560/0x1820 fs/namei.c:4498 SYSC_renameat2 fs/namei.c:4646 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4535 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]); lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]); *** DEADLOCK *** 6 locks held by syz-executor.1/13287: #0: (sb_writers#24){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] #0: (sb_writers#24){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 #1: (&type->s_vfs_rename_key#2){+.+.}, at: [] lock_rename+0x54/0x280 fs/namei.c:2889 #2: (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}, at: [] inode_lock_nested include/linux/fs.h:754 [inline] #2: (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}, at: [] lock_rename+0x132/0x280 fs/namei.c:2900 #3: (&ovl_i_mutex_dir_key[depth]#2/2){+.+.}, at: [] inode_lock_nested include/linux/fs.h:754 [inline] #3: (&ovl_i_mutex_dir_key[depth]#2/2){+.+.}, at: [] lock_rename+0x166/0x280 fs/namei.c:2901 #4: (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] #4: (&ovl_i_mutex_dir_key[depth]#2){++++}, at: [] vfs_rename+0xbd8/0x1820 fs/namei.c:4472 #5: (sb_writers#3){.+.+}, at: [] sb_start_write include/linux/fs.h:1551 [inline] #5: (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 stack backtrace: CPU: 1 PID: 13287 Comm: syz-executor.1 Not tainted 4.14.305-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 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 down_write_killable+0x37/0xb0 kernel/locking/rwsem.c:68 iterate_dir+0x387/0x5e0 fs/readdir.c:43 ovl_dir_read fs/overlayfs/readdir.c:306 [inline] ovl_dir_read_merged+0x2c5/0x430 fs/overlayfs/readdir.c:365 ovl_check_empty_dir+0x6e/0x200 fs/overlayfs/readdir.c:870 ovl_check_empty_and_clear+0x72/0xe0 fs/overlayfs/dir.c:306 ovl_rename+0x57d/0xe50 fs/overlayfs/dir.c:959 vfs_rename+0x560/0x1820 fs/namei.c:4498 SYSC_renameat2 fs/namei.c:4646 [inline] SyS_renameat2+0x95b/0xad0 fs/namei.c:4535 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 RIP: 0033:0x7efe0946c0f9 RSP: 002b:00007efe079de168 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007efe0958bf80 RCX: 00007efe0946c0f9 RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000020000100 RBP: 00007efe094c7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe3cf2480f R14: 00007efe079de300 R15: 0000000000022000 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. kauditd_printk_skb: 43 callbacks suppressed audit: type=1800 audit(1676715852.653:123): pid=13390 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.1" name="file1" dev="sda1" ino=13921 res=0 9pnet: Insufficient options for proto=fd veth0_vlan: vlans aren't supported yet for dev_uc|mc_add() IPVS: ftp: loaded support on port[0] = 21 audit: type=1800 audit(1676715856.183:124): pid=13510 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14477 res=0 IPVS: ftp: loaded support on port[0] = 21 audit: type=1800 audit(1676715856.203:125): pid=13510 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14477 res=0 audit: type=1800 audit(1676715856.323:126): pid=13557 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14477 res=0 IPVS: ftp: loaded support on port[0] = 21 audit: type=1800 audit(1676715857.323:127): pid=13574 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14470 res=0 audit: type=1800 audit(1676715857.383:128): pid=13574 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14470 res=0 audit: type=1800 audit(1676715857.513:129): pid=13626 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14470 res=0 audit: type=1800 audit(1676715857.893:130): pid=13590 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=14471 res=0 audit: type=1800 audit(1676715857.923:131): pid=13590 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=14471 res=0 audit: type=1800 audit(1676715857.973:132): pid=13588 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13875 res=0 audit: type=1800 audit(1676715857.983:133): pid=13588 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13875 res=0 audit: type=1800 audit(1676715858.053:134): pid=13641 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=14471 res=0 audit: type=1800 audit(1676715858.213:135): pid=13642 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=13875 res=0 audit: type=1800 audit(1676715858.763:136): pid=13635 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14449 res=0 audit: type=1800 audit(1676715858.793:137): pid=13635 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14449 res=0 audit: type=1800 audit(1676715858.923:138): pid=13666 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=14449 res=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. 9pnet: Could not find request transport: xen Bearer rejected, not supported in standalone mode