====================================================== WARNING: possible circular locking dependency detected 4.14.228-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/15117 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] lock_trace fs/proc/base.c:407 [inline] (&sig->cred_guard_mutex){+.+.}, at: [] proc_pid_syscall+0xa7/0x2a0 fs/proc/base.c:639 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&p->lock){+.+.}: __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 -> #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+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_xattr_set+0x4d/0x290 fs/overlayfs/inode.c:214 __vfs_setxattr+0xdc/0x130 fs/xattr.c:150 __vfs_setxattr_noperm+0xfd/0x3d0 fs/xattr.c:181 __vfs_setxattr_locked+0x14d/0x250 fs/xattr.c:239 vfs_setxattr+0xcf/0x230 fs/xattr.c:256 setxattr+0x1a9/0x300 fs/xattr.c:523 path_setxattr+0x118/0x130 fs/xattr.c:542 SYSC_setxattr fs/xattr.c:557 [inline] SyS_setxattr+0x36/0x50 fs/xattr.c:553 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] lookup_slow+0x129/0x400 fs/namei.c:1674 lookup_one_len_unlocked+0x3a0/0x410 fs/namei.c:2595 ovl_lookup_single+0x33/0x6d0 fs/overlayfs/namei.c:208 ovl_lookup_layer+0x2ef/0x3d0 fs/overlayfs/namei.c:265 ovl_lookup+0x5d9/0x1120 fs/overlayfs/namei.c:670 lookup_slow+0x20a/0x400 fs/namei.c:1696 walk_component+0x6a1/0xbc0 fs/namei.c:1825 link_path_walk+0x823/0x10a0 fs/namei.c:2154 path_lookupat+0xcb/0x780 fs/namei.c:2342 filename_lookup+0x18a/0x510 fs/namei.c:2377 user_path_at include/linux/namei.h:57 [inline] do_sys_truncate.part.0+0x78/0xf0 fs/open.c:141 do_sys_truncate fs/open.c:137 [inline] SYSC_truncate fs/open.c:155 [inline] SyS_truncate+0x23/0x40 fs/open.c:153 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&ovl_i_mutex_dir_key[depth]#2){++++}: 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:1755 do_execve fs/exec.c:1860 [inline] SYSC_execve fs/exec.c:1941 [inline] SyS_execve+0x3b/0x50 fs/exec.c:1936 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&sig->cred_guard_mutex){+.+.}: 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 lock_trace fs/proc/base.c:407 [inline] proc_pid_syscall+0xa7/0x2a0 fs/proc/base.c:639 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 __vfs_read+0xe4/0x620 fs/read_write.c:411 vfs_read+0x139/0x340 fs/read_write.c:447 SYSC_read fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 fs/read_write.c:567 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: &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.0/15117: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 #1: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 stack backtrace: CPU: 0 PID: 15117 Comm: syz-executor.0 Not tainted 4.14.228-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+0x1b2/0x281 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 __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_syscall+0xa7/0x2a0 fs/proc/base.c:639 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 __vfs_read+0xe4/0x620 fs/read_write.c:411 vfs_read+0x139/0x340 fs/read_write.c:447 SYSC_read fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 fs/read_write.c:567 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f7de7630188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffc6d6e796f R14: 00007f7de7630300 R15: 0000000000022000 f2fs_msg: 6 callbacks suppressed F2FS-fs (loop5): Invalid log sectorsize (3) F2FS-fs (loop5): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop5): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop5): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop5): Invalid log sectorsize (3) F2FS-fs (loop5): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop5): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop5): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop5): Invalid log sectorsize (3) F2FS-fs (loop5): Can't find valid F2FS filesystem in 1th superblock overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: failed to resolve 'file0™9â§+.*ɪƒ£3': -2 IPVS: ftp: loaded support on port[0] = 21 overlayfs: './file0' not a directory EXT4-fs (loop4): Number of reserved GDT blocks insanely large: 39636 EXT4-fs (loop4): Number of reserved GDT blocks insanely large: 39636 bond1: Enslaving bridge2 as a backup interface with an up link EXT4-fs (loop4): Unrecognized mount option "debug_walt_extra_isi=0x000000000000006" or missing value could not allocate digest TFM handle cmac-aes-neon bond2: Enslaving bridge4 as a backup interface with an up link EXT4-fs (loop4): mounted filesystem without journal. Opts: ,errors=continue xt_HL: TTL: invalid or unknown mode 3 xt_HL: TTL: invalid or unknown mode 3 bond3: Enslaving bridge5 as a backup interface with an up link x_tables: ip_tables: rpfilter match: used from hooks INPUT, but only valid from PREROUTING bond4: Enslaving bridge6 as a backup interface with an up link bond5: Enslaving bridge7 as a backup interface with an up link FAT-fs (loop4): bogus number of reserved sectors FAT-fs (loop4): Can't find a valid FAT filesystem kauditd_printk_skb: 20 callbacks suppressed audit: type=1804 audit(1617359914.329:84): pid=15697 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir083141887/syzkaller.ram3Ii/60/bus" dev="sda1" ino=14068 res=1 bond6: Enslaving bridge8 as a backup interface with an up link audit: type=1804 audit(1617359914.669:85): pid=15776 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir192206380/syzkaller.uW8UnU/109/bus" dev="sda1" ino=14417 res=1 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. bond7: Enslaving bridge9 as a backup interface with an up link EXT4-fs error (device sda1): mb_free_blocks:1464: group 10, inode 14425: block 331806:freeing already freed block (bit 4126); block bitmap corrupt. EXT4-fs error (device sda1): ext4_mb_generate_buddy:754: group 10, block bitmap and bg descriptor inconsistent: 28631 vs 28642 free clusters EXT4-fs (sda1): pa ffff88803b53cb78: logic 32768, phys. 331776, len 2048 EXT4-fs error (device sda1): ext4_mb_release_inode_pa:3891: group 10, free 2018, pa_free 2007 FAT-fs (loop4): bogus number of reserved sectors FAT-fs (loop4): Can't find a valid FAT filesystem audit: type=1804 audit(1617359915.189:86): pid=15714 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.4" name="/root/syzkaller-testdir083141887/syzkaller.ram3Ii/60/bus" dev="sda1" ino=14068 res=1 bond8: Enslaving bridge10 as a backup interface with an up link EXT4-fs error (device sda1): mb_free_blocks:1464: group 11, inode 14425: block 364574:freeing already freed block (bit 4126); block bitmap corrupt. EXT4-fs error (device sda1): ext4_mb_generate_buddy:754: group 11, block bitmap and bg descriptor inconsistent: 28631 vs 28642 free clusters EXT4-fs (sda1): pa ffff888049e44e98: logic 32768, phys. 364544, len 2048 EXT4-fs error (device sda1): ext4_mb_release_inode_pa:3891: group 11, free 2018, pa_free 2007 bond9: Enslaving bridge11 as a backup interface with an up link audit: type=1804 audit(1617359915.570:87): pid=15801 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir192206380/syzkaller.uW8UnU/109/bus" dev="sda1" ino=14417 res=1 audit: type=1804 audit(1617359915.580:88): pid=15776 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir192206380/syzkaller.uW8UnU/109/bus" dev="sda1" ino=14417 res=1 bond10: Enslaving bridge12 as a backup interface with an up link bond11: Enslaving bridge13 as a backup interface with an up link bond12: Enslaving bridge14 as a backup interface with an up link bond13: Enslaving bridge15 as a backup interface with an up link bond14: Enslaving bridge16 as a backup interface with an up link bond18: Enslaving bridge20 as a backup interface with an up link bond19: Enslaving bridge21 as a backup interface with an up link bond20: Enslaving bridge22 as a backup interface with an up link ebt_among: dst integrity fail: 102 audit: type=1804 audit(1617359918.100:89): pid=16518 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir192206380/syzkaller.uW8UnU/113/bus" dev="sda1" ino=14437 res=1 audit: type=1804 audit(1617359918.100:90): pid=16518 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir192206380/syzkaller.uW8UnU/113/bus" dev="sda1" ino=14437 res=1 audit: type=1804 audit(1617359918.110:91): pid=16518 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir192206380/syzkaller.uW8UnU/113/bus" dev="sda1" ino=14437 res=1 XFS (loop3): Invalid superblock magic number