====================================================== WARNING: possible circular locking dependency detected 4.14.175-syzkaller #0 Not tainted ------------------------------------------------------ ieee80211 : Selected rate control algorithm 'minstrel_ht' syz-executor.4/24123 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] lock_trace+0x3f/0xc0 fs/proc/base.c:407 but task is already holding lock: ptrace attach of "/root/syz-executor.3"[24135] was attempted by "/root/syz-executor.3"[24136] (&p->lock){+.+.}, at: [] seq_read+0xba/0x1160 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+0xe8/0x1470 kernel/locking/mutex.c:893 seq_read+0xba/0x1160 fs/seq_file.c:165 ieee80211 : hwaddr 02:00:00:00:14:00 registered proc_reg_read+0xf2/0x160 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+0x3e3/0x5a0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x41d/0x870 fs/splice.c:416 do_splice_to+0xfb/0x150 fs/splice.c:880 splice_direct_to_actor+0x20a/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 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+0x42/0xb7 -> #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+0x1a1/0x2e0 fs/super.c:1363 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 binder: BINDER_SET_CONTEXT_MGR already set notify_change+0x8d1/0xd10 fs/attr.c:313 chown_common+0x40b/0x4b0 fs/open.c:631 SYSC_fchownat fs/open.c:661 [inline] SyS_fchownat fs/open.c:641 [inline] SYSC_chown fs/open.c:675 [inline] SyS_chown+0xad/0x130 fs/open.c:673 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 binder: 24142:24144 ioctl 40046207 0 returned -16 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (&ovl_i_mutex_dir_key[depth]#2){++++}: down_read+0x37/0xa0 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] do_last fs/namei.c:3333 [inline] path_openat+0x185a/0x3c50 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_open_execat+0xda/0x430 fs/exec.c:849 do_execveat_common.isra.0+0x694/0x1c70 fs/exec.c:1740 do_execveat fs/exec.c:1858 [inline] SYSC_execveat fs/exec.c:1939 [inline] SyS_execveat+0x49/0x60 fs/exec.c:1931 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 netlink: 20 bytes leftover after parsing attributes in process `syz-executor.0'. -> #0 (&sig->cred_guard_mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 netlink: 20 bytes leftover after parsing attributes in process `syz-executor.0'. lock_trace+0x3f/0xc0 fs/proc/base.c:407 proc_pid_stack+0x10b/0x240 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4d2/0x1160 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+0x3e3/0x5a0 fs/read_write.c:919 binder: BINDER_SET_CONTEXT_MGR already set vfs_readv+0xd3/0x130 fs/read_write.c:981 do_preadv+0x161/0x200 fs/read_write.c:1065 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 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.4/24123: #0: (&p->lock binder: 24142:24144 ioctl 40046207 0 returned -16 ){+.+.}, at: [] seq_read+0xba/0x1160 fs/seq_file.c:165 stack backtrace: CPU: 1 PID: 24123 Comm: syz-executor.4 Not tainted 4.14.175-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+0x13e/0x194 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 lock_trace+0x3f/0xc0 fs/proc/base.c:407 proc_pid_stack+0x10b/0x240 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4d2/0x1160 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+0x3e3/0x5a0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 do_preadv+0x161/0x200 fs/read_write.c:1065 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c889 RSP: 002b:00007f8bcd656c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f8bcd6576d4 RCX: 000000000045c889 RDX: 00000000000003da RSI: 00000000200017c0 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000085a R14: 00000000004cb1ec R15: 000000000076bf0c EXT4-fs (loop2): bad geometry: block count 580964351930795064 exceeds size of device (66048 blocks) CUSE: zero length info key specified netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'. audit: type=1804 audit(1586662673.792:268): pid=24194 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir739549976/syzkaller.IQQnDw/376/file0/file0" dev="loop2" ino=241 res=1 A link change request failed with some changes committed already. Interface ipvlan1 may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. NOHZ: local_softirq_pending 08 IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. A link change request failed with some changes committed already. Interface Y4`Ҙ may have been left with an inconsistent configuration, please check. kvm [24393]: vcpu0, guest rIP: 0x48 Hyper-V uhandled wrmsr: 0x40000004 data 0x45 kvm [24393]: vcpu0, guest rIP: 0x48 Hyper-V uhandled wrmsr: 0x40000004 data 0x44 kvm [24393]: vcpu0, guest rIP: 0x48 Hyper-V uhandled wrmsr: 0x40000004 data 0x46