audit: type=1804 audit(1668499236.244:15987): pid=16214 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2015/cgroup.controllers" dev="sda1" ino=14162 res=1 ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/16225 is trying to acquire lock: 00000000420ef6fb (&sig->cred_guard_mutex){+.+.}, at: lock_trace fs/proc/base.c:402 [inline] 00000000420ef6fb (&sig->cred_guard_mutex){+.+.}, at: proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635 but task is already holding lock: 000000009f6c9747 (&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 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 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]#2){++++}: 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 lock_trace fs/proc/base.c:402 [inline] proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635 proc_single_show+0xeb/0x170 fs/proc/base.c:755 traverse.part.0+0xcf/0x5f0 fs/seq_file.c:116 traverse fs/seq_file.c:106 [inline] seq_read+0x99d/0x11c0 fs/seq_file.c:191 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:1502 [inline] __se_sys_sendfile64+0xc4/0x160 fs/read_write.c:1494 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.4/16225: #0: 00000000f1726253 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] #0: 00000000f1726253 (sb_writers#4){.+.+}, at: do_sendfile+0x97d/0xc30 fs/read_write.c:1446 #1: 000000009f6c9747 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164 stack backtrace: CPU: 0 PID: 16225 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 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:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 lock_trace fs/proc/base.c:402 [inline] proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635 proc_single_show+0xeb/0x170 fs/proc/base.c:755 traverse.part.0+0xcf/0x5f0 fs/seq_file.c:116 traverse fs/seq_file.c:106 [inline] seq_read+0x99d/0x11c0 fs/seq_file.c:191 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:1502 [inline] __se_sys_sendfile64+0xc4/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f1571e9a639 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:00007f157040d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f1571fbaf80 RCX: 00007f1571e9a639 RDX: 0000000020000040 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 00007f1571ef5ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa375da1f R14: 00007f157040d300 R15: 0000000000022000 audit: type=1804 audit(1668499236.474:15988): pid=16224 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.0" name="/root/syzkaller-testdir521846441/syzkaller.DCk5QX/15082/bus" dev="sda1" ino=15314 res=1 EXT4-fs (loop1): invalid inodes per group: 203296 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 EXT4-fs (loop1): invalid inodes per group: 204832 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499237.624:15989): pid=16272 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2016/cgroup.controllers" dev="sda1" ino=14817 res=1 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 208928 erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 215072 EXT4-fs (loop1): invalid inodes per group: 222240 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 227360 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 229408 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ audit: type=1804 audit(1668499238.864:15990): pid=16460 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2020/cgroup.controllers" dev="sda1" ino=15218 res=1 erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 236576 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 236832 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499239.394:15991): pid=16514 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2021/cgroup.controllers" dev="sda1" ino=13864 res=1 EXT4-fs (loop1): invalid inodes per group: 239136 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 EXT4-fs (loop1): invalid inodes per group: 327712 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499239.884:15992): pid=16567 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2022/cgroup.controllers" dev="sda1" ino=15339 res=1 EXT4-fs (loop1): invalid inodes per group: 393248 erofs: read_super, device -> /dev/loop5 EXT4-fs (loop1): invalid inodes per group: 458784 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499240.294:15993): pid=16624 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2023/cgroup.controllers" dev="sda1" ino=13889 res=1 EXT4-fs (loop1): invalid inodes per group: 589856 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 786464 erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499240.764:15994): pid=16685 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2024/cgroup.controllers" dev="sda1" ino=15275 res=1 EXT4-fs (loop1): invalid inodes per group: 917536 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 1704736 erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499241.174:15995): pid=16740 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2025/cgroup.controllers" dev="sda1" ino=15076 res=1 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 2097184 erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 2097952 audit: type=1804 audit(1668499241.674:15996): pid=16792 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2026/cgroup.controllers" dev="sda1" ino=15366 res=1 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 2293792 EXT4-fs (loop1): invalid inodes per group: 2490400 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499242.114:15997): pid=16854 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2027/cgroup.controllers" dev="sda1" ino=15275 res=1 EXT4-fs (loop1): invalid inodes per group: 2621984 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 2949152 audit: type=1804 audit(1668499242.514:15998): pid=16898 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2028/cgroup.controllers" dev="sda1" ino=15357 res=1 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 EXT4-fs (loop1): invalid inodes per group: 3014688 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499242.924:15999): pid=16936 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2029/cgroup.controllers" dev="sda1" ino=15373 res=1 EXT4-fs (loop1): invalid inodes per group: 3015200 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 3146528 erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 EXT4-fs (loop1): invalid inodes per group: 3277088 erofs: options -> u\kľ erofs: cannot find valid erofs superblock erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 3670048 erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 4128800 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 4194336 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock kauditd_printk_skb: 2 callbacks suppressed audit: type=1804 audit(1668499244.284:16002): pid=17083 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2032/cgroup.controllers" dev="sda1" ino=15402 res=1 EXT4-fs (loop1): invalid inodes per group: 4719392 erofs: read_super, device -> /dev/loop5 audit: type=1804 audit(1668499244.474:16003): pid=17104 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2033/cgroup.controllers" dev="sda1" ino=15389 res=1 EXT4-fs (loop1): invalid inodes per group: 4981280 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499244.724:16004): pid=17128 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2034/cgroup.controllers" dev="sda1" ino=15373 res=1 EXT4-fs (loop1): invalid inodes per group: 5636128 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ audit: type=1804 audit(1668499244.924:16005): pid=17169 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2035/cgroup.controllers" dev="sda1" ino=15351 res=1 erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 5964064 erofs: read_super, device -> /dev/loop5 audit: type=1804 audit(1668499245.194:16006): pid=17197 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2036/cgroup.controllers" dev="sda1" ino=14918 res=1 erofs: options -> u\kľ EXT4-fs (loop1): invalid inodes per group: 6291488 erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499245.454:16007): pid=17209 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2037/cgroup.controllers" dev="sda1" ino=15404 res=1 Y4`Ҙ: renamed from lo erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499245.964:16008): pid=17229 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2038/cgroup.controllers" dev="sda1" ino=15405 res=1 EXT4-fs (loop1): invalid inodes per group: 6554400 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock EXT4-fs (loop1): invalid inodes per group: 6946848 erofs: read_super, device -> /dev/loop5 erofs: options -> u\kľ erofs: cannot find valid erofs superblock audit: type=1804 audit(1668499246.264:16009): pid=17290 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir983436647/syzkaller.MscIiY/2039/cgroup.controllers" dev="sda1" ino=15251 res=1