====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ FAT-fs (loop2): bogus number of reserved sectors syz-executor.3/14384 is trying to acquire lock: 000000000ab4f601 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 000000000ab4f601 (&ovl_i_mutex_dir_key[depth]){++++}, at: lookup_slow fs/namei.c:1688 [inline] 000000000ab4f601 (&ovl_i_mutex_dir_key[depth]){++++}, at: walk_component+0x798/0xda0 fs/namei.c:1811 but task is already holding lock: 0000000005b31ca1 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] 0000000005b31ca1 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: FAT-fs (loop2): Can't find a valid FAT filesystem -> #3 (&sig->cred_guard_mutex){+.+.}: lock_trace fs/proc/base.c:402 [inline] proc_pid_personality+0x4a/0x170 fs/proc/base.c:2938 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 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 (&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 -> #1 (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 -> #0 (&ovl_i_mutex_dir_key[depth]){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] lookup_slow fs/namei.c:1688 [inline] walk_component+0x798/0xda0 fs/namei.c:1811 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_openat+0x1db/0x2df0 fs/namei.c:3536 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 other info that might help us debug this: Chain exists of: &ovl_i_mutex_dir_key[depth] --> &p->lock --> &sig->cred_guard_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sig->cred_guard_mutex); lock(&p->lock); lock(&sig->cred_guard_mutex); lock(&ovl_i_mutex_dir_key[depth]); *** DEADLOCK *** 1 lock held by syz-executor.3/14384: #0: 0000000005b31ca1 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] #0: 0000000005b31ca1 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 stack backtrace: CPU: 0 PID: 14384 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0 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 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 down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] lookup_slow fs/namei.c:1688 [inline] walk_component+0x798/0xda0 fs/namei.c:1811 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_openat+0x1db/0x2df0 fs/namei.c:3536 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 RIP: 0033:0x7fada1264059 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:00007fad9fb76168 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007fada13771d0 RCX: 00007fada1264059 RDX: 0000000020000c40 RSI: 0000000020000600 RDI: 0000000020000180 RBP: 00007fada12be08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd1a1f3e4f R14: 00007fad9fb76300 R15: 0000000000022000 EXT4-fs (loop4): Unrecognized mount option "" or missing value FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. tmpfs: Bad value 'alzy' for mount option 'huge' EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue FAT-fs (loop2): bogus number of reserved sectors EXT4-fs (loop4): Unrecognized mount option "" or missing value FAT-fs (loop2): Can't find a valid FAT filesystem EXT4-fs (loop4): Unrecognized mount option "" or missing value tmpfs: Bad value 'alzy' for mount option 'huge' FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem tmpfs: Bad value 'alzy' for mount option 'huge' EXT4-fs (loop4): Unrecognized mount option "" or missing value FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem EXT4-fs (loop4): Unrecognized mount option "" or missing value TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem IPVS: ftp: loaded support on port[0] = 21 FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem FAT-fs (loop2): bogus number of reserved sectors IPVS: ftp: loaded support on port[0] = 21 FAT-fs (loop2): Can't find a valid FAT filesystem FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem device lo entered promiscuous mode FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem Y4`Ҙ: renamed from lo FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem IPVS: ftp: loaded support on port[0] = 21 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. f2fs_msg: 48 callbacks suppressed F2FS-fs (loop5): Magic Mismatch, valid(0xf2f52010) - read(0x0) EXT4-fs (loop3): mounted filesystem without journal. Opts: noinit_itable,,errors=continue F2FS-fs (loop5): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop5): invalid crc value FAT-fs (loop2): bogus number of reserved sectors F2FS-fs (loop5): SIT is corrupted node# 0 vs 7 F2FS-fs (loop5): Failed to initialize F2FS segment manager FAT-fs (loop2): Can't find a valid FAT filesystem 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 crc value EXT4-fs (loop3): mounted filesystem without journal. Opts: noinit_itable,,errors=continue FAT-fs (loop2): bogus number of reserved sectors F2FS-fs (loop5): SIT is corrupted node# 0 vs 7 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 FAT-fs (loop2): Can't find a valid FAT filesystem F2FS-fs (loop5): Failed to initialize F2FS segment manager CPU: 0 PID: 15006 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 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 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:3088 [inline] prepare_alloc_pages mm/page_alloc.c:4346 [inline] __alloc_pages_nodemask+0x239/0x2890 mm/page_alloc.c:4393 alloc_pages_current+0x193/0x2a0 mm/mempolicy.c:2197 alloc_pages include/linux/gfp.h:532 [inline] skb_page_frag_refill+0x258/0x550 net/core/sock.c:2238 tun_build_skb+0x25e/0x1960 drivers/net/tun.c:1617 tun_get_user+0x83f/0x5100 drivers/net/tun.c:1790 tun_chr_write_iter+0xdb/0x1d0 drivers/net/tun.c:2007 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f16e8fc4b6f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 RSP: 002b:00007f16e7987130 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f16e9124f60 RCX: 00007f16e8fc4b6f RDX: 000000000000003e RSI: 00000000200001c0 RDI: 00000000000000c8 RBP: 00007f16e79871d0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000003e R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe148bc76f R14: 00007f16e7987300 R15: 0000000000022000 EXT4-fs (loop3): mounted filesystem without journal. Opts: noinit_itable,,errors=continue FAT-fs (loop2): bogus number of reserved sectors netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 FAT-fs (loop2): Can't find a valid FAT filesystem CPU: 1 PID: 15042 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 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 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x3f/0x370 mm/slab.c:3557 __build_skb+0x39/0x300 net/core/skbuff.c:281 build_skb+0x1c/0x190 net/core/skbuff.c:312 tun_build_skb+0x51b/0x1960 drivers/net/tun.c:1686 tun_get_user+0x83f/0x5100 drivers/net/tun.c:1790 tun_chr_write_iter+0xdb/0x1d0 drivers/net/tun.c:2007 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f16e8fc4b6f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 RSP: 002b:00007f16e7987130 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f16e9124f60 RCX: 00007f16e8fc4b6f RDX: 000000000000003e RSI: 00000000200001c0 RDI: 00000000000000c8 RBP: 00007f16e79871d0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000003e R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe148bc76f R14: 00007f16e7987300 R15: 0000000000022000 FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem overlayfs: unrecognized mount option "lolerL" or missing value overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. FAT-fs (loop2): bogus number of reserved sectors overlayfs: unrecognized mount option "lolerL" or missing value FAT-fs (loop2): Can't find a valid FAT filesystem overlayfs: './file0' not a directory FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue EXT4-fs error (device loop5): ext4_free_inode:350: comm syz-executor.5: bit already cleared for inode 15 FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue FAT-fs (loop2): bogus number of reserved sectors REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" FAT-fs (loop2): Can't find a valid FAT filesystem REISERFS warning (device loop5): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" netlink: 96 bytes leftover after parsing attributes in process `syz-executor.3'. FAT-fs (loop2): bogus number of reserved sectors netlink: 96 bytes leftover after parsing attributes in process `syz-executor.3'. FAT-fs (loop2): Can't find a valid FAT filesystem REISERFS warning (device loop5): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" REISERFS warning (device loop5): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem REISERFS warning (device loop5): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem netlink: 96 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 96 bytes leftover after parsing attributes in process `syz-executor.3'. REISERFS warning (device loop5): super-6502 reiserfs_getopt: unknown mount option "uid<00000000000000000000" FAT-fs (loop2): bogus number of reserved sectors FAT-fs (loop2): Can't find a valid FAT filesystem netlink: 96 bytes leftover after parsing attributes in process `syz-executor.3'.