====================================================== WARNING: possible circular locking dependency detected 4.14.227-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/3723 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: -> #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 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_do_remove+0x67/0xb90 fs/overlayfs/dir.c:759 vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3908 vfs_rmdir fs/namei.c:3893 [inline] do_rmdir+0x334/0x3c0 fs/namei.c:3968 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 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 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.2/3723: #0: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 stack backtrace: CPU: 1 PID: 3723 Comm: syz-executor.2 Not tainted 4.14.227-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 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: 0033:0x466459 RSP: 002b:00007faaa8131188 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 00000000000001f7 RSI: 0000000020000500 RDI: 0000000000000008 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcd718f44f R14: 00007faaa8131300 R15: 0000000000022000 kauditd_printk_skb: 5 callbacks suppressed audit: type=1804 audit(1616913156.650:188): pid=3760 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir028400937/syzkaller.VtPSki/113/file0" dev="sda1" ino=14067 res=1 audit: type=1804 audit(1616913156.700:189): pid=3760 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir028400937/syzkaller.VtPSki/113/file0" dev="sda1" ino=14067 res=1 audit: type=1804 audit(1616913156.790:190): pid=3783 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir028400937/syzkaller.VtPSki/114/bus" dev="sda1" ino=14055 res=1 audit: type=1804 audit(1616913156.960:191): pid=3783 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir028400937/syzkaller.VtPSki/114/bus" dev="sda1" ino=14055 res=1 overlayfs: unrecognized mount option "ìowerdir=./bus" or missing value overlayfs: './bus' not a directory overlayfs: './bus' not a directory REISERFS (device loop3): found reiserfs format "3.5" with non-standard journal REISERFS (device loop3): using ordered data mode reiserfs: using flush barriers audit: type=1804 audit(1616913157.850:192): pid=3924 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir213037684/syzkaller.LUzosb/231/bus" dev="sda1" ino=14113 res=1 REISERFS warning (device loop3): sh-460 journal_init: journal header magic 0 (device loop3) does not match to magic found in super block 384d5673 REISERFS warning (device loop3): sh-2022 reiserfs_fill_super: unable to initialize journal space REISERFS (device loop3): found reiserfs format "3.5" with non-standard journal REISERFS (device loop3): using ordered data mode reiserfs: using flush barriers REISERFS warning (device loop3): sh-460 journal_init: journal header magic 0 (device loop3) does not match to magic found in super block 384d5673 REISERFS warning (device loop3): sh-2022 reiserfs_fill_super: unable to initialize journal space audit: type=1804 audit(1616913158.330:193): pid=3924 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir213037684/syzkaller.LUzosb/231/bus" dev="sda1" ino=14113 res=1 EXT4-fs (loop3): invalid first ino: 2506813677 print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 4 Buffer I/O error on dev loop3, logical block 2, async page read print_req_error: I/O error, dev loop3, sector 6 Buffer I/O error on dev loop3, logical block 3, async page read ubi: mtd0 is already attached to ubi0 ubi0: detaching mtd0 print_req_error: I/O error, dev loop3, sector 0 ubi0: mtd0 is detached ubi0: attaching mtd0 ubi0: scanning is finished *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x00000020000004cb RIP = 0x0000000000000000 RFLAGS=0x00020002 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0xf000, attr=0x0009b, limit=0x0000ffff, base=0x00000000ffff0000 DS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 SS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 ES: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 FS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GDTR: limit=0x0000ffff, base=0x0000000000000000 LDTR: sel=0x0000, attr=0x00082, limit=0x0000ffff, base=0x0000000000000000 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811601fe RSP = 0xffff88809d94f9b8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007fe2ab4e5700 GSBase=ffff8880ba500000 TRBase=fffffe0000034000 GDTBase=fffffe0000032000 IDTBase=fffffe0000000000 CR0=0000000080050033 CR3=00000000422c4000 CR4=00000000001426e0 Sysenter RSP=fffffe0000034000 CS:RIP=0010:ffffffff87401690 EFER = 0x0000000000000d01 PAT = 0x0407050600070106 *** Control State *** PinBased=0000003f CPUBased=b699edfa SecondaryExec=000000e2 EntryControls=0000d1ff ExitControls=002fefff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000003 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xfffffecd0ccf950b EPT pointer = 0x00000000abdfd01e Virtual processor ID = 0x0003 *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 ubi0 error: ubi_attach_mtd_dev: cannot spawn "ubi_bgt0d", error -4 RSP = 0x00000020000004cb RIP = 0x0000000000000000 RFLAGS=0x00020002 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0xf000, attr=0x0009b, limit=0x0000ffff, base=0x00000000ffff0000 DS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 SS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 ES: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 FS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GDTR: limit=0x0000ffff, base=0x0000000000000000 LDTR: sel=0x0000, attr=0x00082, limit=0x0000ffff, base=0x0000000000000000 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811601fe RSP = 0xffff88803fec79b8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007fe2ab4c3700 GSBase=ffff8880ba400000 TRBase=fffffe0000003000 GDTBase=fffffe0000001000 IDTBase=fffffe0000000000 CR0=0000000080050033 CR3=00000000422c4000 CR4=00000000001426f0 Sysenter RSP=fffffe0000003000 CS:RIP=0010:ffffffff87401690 EFER = 0x0000000000000d01 PAT = 0x0407050600070106 *** Control State *** PinBased=0000003f CPUBased=b699edfa SecondaryExec=000000e2 EntryControls=0000d1ff ExitControls=002fefff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000003 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xfffffecd0ccf950b EPT pointer = 0x00000000abdfd01e Virtual processor ID = 0x0003 *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x00000020000004cb RIP = 0x0000000000000000 RFLAGS=0x00020002 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0xf000, attr=0x0009b, limit=0x0000ffff, base=0x00000000ffff0000 DS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 SS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 ES: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 FS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GDTR: limit=0x0000ffff, base=0x0000000000000000 LDTR: sel=0x0000, attr=0x00082, limit=0x0000ffff, base=0x0000000000000000 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811601fe RSP = 0xffff8880b36379b8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007fe2ab4e5700 GSBase=ffff8880ba500000 TRBase=fffffe0000003000 GDTBase=fffffe0000032000 IDTBase=fffffe0000000000 CR0=0000000080050033 CR3=000000009f27e000 CR4=00000000001426e0 Sysenter RSP=fffffe0000034000 CS:RIP=0010:ffffffff87401690 EFER = 0x0000000000000d01 PAT = 0x0407050600070106 *** Control State *** PinBased=0000003f CPUBased=b699edfa SecondaryExec=000000e2 EntryControls=0000d1ff ExitControls=002fefff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000003 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xfffffecbc46ed6fd EPT pointer = 0x000000001471701e Virtual processor ID = 0x0003 *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x00000020000004cb RIP = 0x0000000000000000 RFLAGS=0x00020002 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0xf000, attr=0x0009b, limit=0x0000ffff, base=0x00000000ffff0000 DS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 SS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 ES: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 FS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GDTR: limit=0x0000ffff, base=0x0000000000000000 LDTR: sel=0x0000, attr=0x00082, limit=0x0000ffff, base=0x0000000000000000 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811601fe RSP = 0xffff88803c9179b8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007fe2ab4c3700 GSBase=ffff8880ba400000 TRBase=fffffe0000003000 GDTBase=fffffe0000001000 IDTBase=fffffe0000000000 CR0=0000000080050033 CR3=000000009f27e000 CR4=00000000001426f0 Sysenter RSP=fffffe0000003000 CS:RIP=0010:ffffffff87401690 EFER = 0x0000000000000d01 PAT = 0x0407050600070106 *** Control State *** PinBased=0000003f CPUBased=b699edfa SecondaryExec=000000e2 EntryControls=0000d1ff ExitControls=002fefff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000003 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xfffffecbc46ed6fd EPT pointer = 0x000000001471701e Virtual processor ID = 0x0003 EXT4-fs (loop4): VFS: Can't find ext4 filesystem audit: type=1804 audit(1616913163.380:194): pid=4322 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir892043378/syzkaller.TR6bH2/260/bus" dev="sda1" ino=14094 res=1 audit: type=1800 audit(1616913163.660:195): pid=4369 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="bus" dev="sda1" ino=14673 res=0