====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/14115 is trying to acquire lock: 000000001368c123 (&sig->cred_guard_mutex){+.+.}, at: do_io_accounting fs/proc/base.c:2750 [inline] 000000001368c123 (&sig->cred_guard_mutex){+.+.}, at: proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799 but task is already holding lock: 00000000828a06b3 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->lock){+.+.}: seq_read+0x6b/0x11c0 fs/seq_file.c:164 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_create_object+0x96/0x290 fs/overlayfs/dir.c:602 lookup_open+0x893/0x1a20 fs/namei.c:3235 do_last fs/namei.c:3327 [inline] path_openat+0x1094/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&ovl_i_mutex_dir_key[depth]){++++}: inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&sig->cred_guard_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 do_io_accounting fs/proc/base.c:2750 [inline] proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 __vfs_read+0xf7/0x750 fs/read_write.c:416 vfs_read+0x194/0x3c0 fs/read_write.c:452 ksys_read+0x12b/0x2a0 fs/read_write.c:579 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: &sig->cred_guard_mutex --> sb_writers#3 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(sb_writers#3); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 2 locks held by syz-executor.4/14115: #0: 0000000039ef24c7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 #1: 00000000828a06b3 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164 stack backtrace: CPU: 0 PID: 14115 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 mkiss: ax0: crc mode is auto. 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 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. 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 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. do_io_accounting fs/proc/base.c:2750 [inline] proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 __vfs_read+0xf7/0x750 fs/read_write.c:416 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. audit: type=1804 audit(1654962474.872:742): pid=14120 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/200/bus" dev="sda1" ino=14690 res=1 vfs_read+0x194/0x3c0 fs/read_write.c:452 ksys_read+0x12b/0x2a0 fs/read_write.c:579 audit: type=1804 audit(1654962474.872:743): pid=14120 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/200/bus" dev="sda1" ino=14690 res=1 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f921d1a6109 audit: type=1804 audit(1654962474.872:744): pid=14144 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/201/bus" dev="sda1" ino=14487 res=1 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f921bb1b168 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f921d2b8f60 RCX: 00007f921d1a6109 RDX: 0000000000002020 RSI: 0000000020000000 RDI: 0000000000000003 audit: type=1804 audit(1654962474.872:745): pid=14143 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/201/bus" dev="sda1" ino=14487 res=1 RBP: 00007f921d2000ad R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd9383a81f R14: 00007f921bb1b300 R15: 0000000000022000 audit: type=1804 audit(1654962475.752:746): pid=14181 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/202/bus" dev="sda1" ino=14540 res=1 xt_NFQUEUE: number of queues (978) out of range (got 66004) mkiss: ax0: crc mode is auto. audit: type=1804 audit(1654962475.782:747): pid=14181 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/202/bus" dev="sda1" ino=14540 res=1 xt_NFQUEUE: number of queues (978) out of range (got 66004) audit: type=1804 audit(1654962475.802:748): pid=14181 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/202/bus" dev="sda1" ino=14540 res=1 mkiss: ax0: crc mode is auto. xt_NFQUEUE: number of queues (978) out of range (got 66004) audit: type=1804 audit(1654962475.802:749): pid=14181 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/202/bus" dev="sda1" ino=14540 res=1 syz-executor.2 uses old SIOCAX25GETINFO xt_NFQUEUE: number of queues (978) out of range (got 66004) overlayfs: unrecognized mount option "l^werdł‹%e:file0" or missing value xt_NFQUEUE: number of queues (978) out of range (got 66004) audit: type=1804 audit(1654962475.802:750): pid=14181 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/202/bus" dev="sda1" ino=14540 res=1 overlayfs: failed to resolve 'H/Pile1': -2 XFS (loop4): Invalid superblock magic number audit: type=1804 audit(1654962475.812:751): pid=14182 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir255396470/syzkaller.IkRDDV/537/bus" dev="sda1" ino=14133 res=1 VFS: unable to find oldfs superblock on device loop5 overlayfs: unrecognized mount option "l^werdł‹%e:file0" or missing value XFS (loop4): Invalid superblock magic number VFS: unable to find oldfs superblock on device loop5 VFS: unable to find oldfs superblock on device loop5 overlayfs: unrecognized mount option "l^werdł‹%e:file0" or missing value overlayfs: failed to resolve 'H/Pile1': -2 overlayfs: unrecognized mount option "l^werdł‹%e:file0" or missing value overlayfs: failed to resolve 'H/Pile1': -2 bridge0: port 4(erspan0) entered blocking state bridge0: port 4(erspan0) entered disabled state device erspan0 entered promiscuous mode bridge0: port 4(erspan0) entered blocking state bridge0: port 4(erspan0) entered forwarding state bridge0: port 3(erspan0) entered blocking state bridge0: port 3(erspan0) entered disabled state device erspan0 entered promiscuous mode bridge0: port 3(erspan0) entered blocking state bridge0: port 3(erspan0) entered forwarding state kauditd_printk_skb: 12 callbacks suppressed audit: type=1804 audit(1654962480.343:764): pid=14927 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/213/bus" dev="sda1" ino=14542 res=1 audit: type=1804 audit(1654962480.543:765): pid=14955 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/213/bus" dev="sda1" ino=14542 res=1 audit: type=1804 audit(1654962481.773:766): pid=15032 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/214/bus" dev="sda1" ino=14572 res=1 audit: type=1804 audit(1654962481.903:767): pid=15033 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/214/bus" dev="sda1" ino=14572 res=1 audit: type=1804 audit(1654962482.113:768): pid=15043 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/215/bus" dev="sda1" ino=15479 res=1 audit: type=1804 audit(1654962482.203:769): pid=15052 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/215/bus" dev="sda1" ino=15479 res=1 audit: type=1804 audit(1654962483.243:770): pid=15123 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/216/bus" dev="sda1" ino=14551 res=1 audit: type=1804 audit(1654962483.353:771): pid=15124 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/216/bus" dev="sda1" ino=14551 res=1 audit: type=1804 audit(1654962484.213:772): pid=15166 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/217/bus" dev="sda1" ino=15489 res=1 audit: type=1804 audit(1654962484.303:773): pid=15170 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.0" name="/root/syzkaller-testdir1056068991/syzkaller.NERiVZ/217/bus" dev="sda1" ino=15489 res=1 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall * 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 b8 ff ff ff mov $0xffffffffffffffb8,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W