====================================================== WARNING: possible circular locking dependency detected 4.19.40 #8 Not tainted ------------------------------------------------------ syz-executor.3/13821 is trying to acquire lock: 00000000081ab9c4 (&acct->lock#2){+.+.}, at: acct_pin_kill+0x27/0x100 kernel/acct.c:173 but task is already holding lock: 00000000769bfd4b (sb_writers#4){.+.+}, at: sb_start_write include/linux/fs.h:1575 [inline] 00000000769bfd4b (sb_writers#4){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_writers#4){.+.+}: 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+0x20b/0x360 fs/super.c:1387 sb_start_write include/linux/fs.h:1575 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:360 ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:24 ovl_setattr+0xdd/0x950 fs/overlayfs/inode.c:30 notify_change+0xad9/0xfb0 fs/attr.c:334 do_truncate+0x158/0x220 fs/open.c:63 handle_truncate fs/namei.c:3008 [inline] do_last fs/namei.c:3424 [inline] path_openat+0x2cc6/0x4690 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x550 fs/open.c:1069 __do_sys_openat fs/open.c:1096 [inline] __se_sys_openat fs/open.c:1090 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1090 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&ovl_i_mutex_key[depth]){+.+.}: down_write+0x38/0x90 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:744 [inline] ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:231 call_write_iter include/linux/fs.h:1817 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x58e/0x820 fs/read_write.c:487 __kernel_write+0x110/0x390 fs/read_write.c:506 do_acct_process+0xd37/0x1150 kernel/acct.c:520 acct_pin_kill+0x2f/0x100 kernel/acct.c:174 pin_kill+0x18f/0x860 fs/fs_pin.c:50 acct_on+0x574/0x790 kernel/acct.c:254 __do_sys_acct kernel/acct.c:286 [inline] __se_sys_acct kernel/acct.c:273 [inline] __x64_sys_acct+0xae/0x200 kernel/acct.c:273 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&acct->lock#2){+.+.}: kobject: 'loop4' (000000009dafb0de): kobject_uevent_env lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf7/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 acct_pin_kill+0x27/0x100 kernel/acct.c:173 kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' pin_kill+0x18f/0x860 fs/fs_pin.c:50 acct_on+0x574/0x790 kernel/acct.c:254 __do_sys_acct kernel/acct.c:286 [inline] __se_sys_acct kernel/acct.c:273 [inline] __x64_sys_acct+0xae/0x200 kernel/acct.c:273 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &acct->lock#2 --> &ovl_i_mutex_key[depth] --> sb_writers#4 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#4); lock(&ovl_i_mutex_key[depth]); lock(sb_writers#4); lock(&acct->lock#2); *** DEADLOCK *** 2 locks held by syz-executor.3/13821: #0: 0000000077f47f51 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 0000000077f47f51 (acct_on_mutex){+.+.}, at: __se_sys_acct kernel/acct.c:273 [inline] #0: 0000000077f47f51 (acct_on_mutex){+.+.}, at: __x64_sys_acct+0xa6/0x200 kernel/acct.c:273 #1: 00000000769bfd4b (sb_writers#4){.+.+}, at: sb_start_write include/linux/fs.h:1575 [inline] #1: 00000000769bfd4b (sb_writers#4){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 stack backtrace: CPU: 1 PID: 13821 Comm: syz-executor.3 Not tainted 4.19.40 #8 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+0x172/0x1f0 lib/dump_stack.c:113 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1861 [inline] check_prevs_add kernel/locking/lockdep.c:1974 [inline] validate_chain kernel/locking/lockdep.c:2415 [inline] __lock_acquire+0x2e6d/0x48f0 kernel/locking/lockdep.c:3411 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3900 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf7/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 acct_pin_kill+0x27/0x100 kernel/acct.c:173 pin_kill+0x18f/0x860 fs/fs_pin.c:50 acct_on+0x574/0x790 kernel/acct.c:254 __do_sys_acct kernel/acct.c:286 [inline] __se_sys_acct kernel/acct.c:273 [inline] __x64_sys_acct+0xae/0x200 kernel/acct.c:273 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5ca6a2fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000458da9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000 kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5ca6a306d4 R13: 00000000004becd2 R14: 00000000004cfa50 R15: 00000000ffffffff kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' net_ratelimit: 15 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop0' (000000009c4560e5): kobject_uevent_env protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' Process accounting resumed kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' Process accounting resumed kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' Process accounting resumed kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' Process accounting resumed kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' Process accounting resumed kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' Process accounting resumed kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' Process accounting resumed kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' net_ratelimit: 24 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop4' (000000009dafb0de): kobject_uevent_env kobject: 'loop4' (000000009dafb0de): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (00000000d9c88b1c): kobject_uevent_env kobject: 'loop3' (00000000d9c88b1c): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000004d31ffb): kobject_uevent_env kobject: 'loop5' (0000000004d31ffb): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop2' (0000000027a77dc1): kobject_uevent_env kobject: 'loop2' (0000000027a77dc1): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop1' (00000000c9aa3334): kobject_uevent_env kobject: 'loop1' (00000000c9aa3334): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (000000009c4560e5): kobject_uevent_env kobject: 'loop0' (000000009c4560e5): fill_kobj_path: path = '/devices/virtual/block/loop0'