====================================================== WARNING: possible circular locking dependency detected 4.14.210-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/23070 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_personality+0x48/0x160 fs/proc/base.c:2913 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: -> #3 (&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 -> #2 (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_setattr+0x52/0x500 fs/overlayfs/inode.c:38 notify_change+0x56b/0xd10 fs/attr.c:313 chown_common+0x40b/0x4b0 fs/open.c:631 SYSC_fchownat fs/open.c:661 [inline] SyS_fchownat+0xf6/0x190 fs/open.c:641 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_personality+0x48/0x160 fs/proc/base.c:2913 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 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 overlayfs: missing 'lowerdir' vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb overlayfs: unrecognized mount option "­" or missing value 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 *** 1 lock held by syz-executor.2/23070: #0: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 stack backtrace: CPU: 1 PID: 23070 Comm: syz-executor.2 Not tainted 4.14.210-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+0x1b2/0x283 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_personality+0x48/0x160 fs/proc/base.c:2913 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 fs/seq_file.c:237 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 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e0f9 RSP: 002b:00007f2fffacdc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e0f9 RDX: 00000000000003ca RSI: 00000000200017c0 RDI: 0000000000000005 RBP: 000000000119bfd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffcd351db2f R14: 00007f2ffface9c0 R15: 000000000119bf8c overlayfs: unrecognized mount option "­" or missing value overlayfs: missing 'lowerdir' netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. EXT4-fs (loop5): Unrecognized mount option "" or missing value device bond1 entered promiscuous mode EXT4-fs (loop5): Unrecognized mount option "" or missing value netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. bond1: The slave device specified does not support setting the MAC address bond1: Setting fail_over_mac to active for active-backup mode bond1: making interface gtp1 the new active one device gtp1 entered promiscuous mode bond1: Enslaving gtp1 as an active interface with an up link bond2 (uninitialized): Released all slaves netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. bridge0: port 2(bridge_slave_1) entered disabled state bridge0: port 1(bridge_slave_0) entered disabled state device bond2 entered promiscuous mode netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. bond2: The slave device specified does not support setting the MAC address bond2: Setting fail_over_mac to active for active-backup mode bond2: making interface gtp4 the new active one device gtp4 entered promiscuous mode bond2: Enslaving gtp4 as an active interface with an up link device bond1 entered promiscuous mode netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. bond1: The slave device specified does not support setting the MAC address bond1: Setting fail_over_mac to active for active-backup mode bond1: making interface gtp1 the new active one device gtp1 entered promiscuous mode bond1: Enslaving gtp1 as an active interface with an up link device bond3 entered promiscuous mode bond3: The slave device specified does not support setting the MAC address bond3: Setting fail_over_mac to active for active-backup mode bond3: making interface gtp6 the new active one device gtp6 entered promiscuous mode bond3: Enslaving gtp6 as an active interface with an up link device bond4 entered promiscuous mode nla_parse: 2 callbacks suppressed netlink: 8 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. bond4: The slave device specified does not support setting the MAC address bond4: Setting fail_over_mac to active for active-backup mode bond4: making interface gtp8 the new active one device gtp8 entered promiscuous mode bond4: Enslaving gtp8 as an active interface with an up link device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves rxrpc: AF_RXRPC: Leaked local ffff8880a179e940 {1} ------------[ cut here ]------------ kernel BUG at net/rxrpc/local_object.c:408! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 15734 Comm: kworker/u4:7 Not tainted 4.14.210-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net task: ffff88809b996480 task.stack: ffff88805a238000 RIP: 0010:rxrpc_destroy_all_locals+0xe6/0xf2 net/rxrpc/local_object.c:408 RSP: 0018:ffff88805a23fc28 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: ffff8880592f0980 RCX: fffffbfff17d69a8 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000286 RBP: ffff8880592f09a0 R08: ffff88809b996480 R09: dffffc0000000000 R10: 0000000000000000 R11: ffff88809b996480 R12: ffff8880592f09a0 R13: ffff8880592f09b0 R14: dffffc0000000000 R15: fffffbfff13c2733 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f183a8b7000 CR3: 000000009d240000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rxrpc_exit_net+0x158/0x260 net/rxrpc/net_ns.c:78 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:142 cleanup_net+0x3b3/0x840 net/core/net_namespace.c:484 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 00 00 00 00 fc ff df 48 83 eb 20 e8 b4 cc bc fa 4c 8d 63 20 4c 39 e5 0f 85 52 00 00 00 e8 a2 cc bc fa 4c 89 ef e8 aa 51 85 00 <0f> 0b 48 89 ef e8 f0 9c e6 fa eb c0 e8 89 cc bc fa 48 c7 c7 e0 RIP: rxrpc_destroy_all_locals+0xe6/0xf2 net/rxrpc/local_object.c:408 RSP: ffff88805a23fc28 ---[ end trace 371c78ef4f4e2796 ]---