1st 0xfffffd807f00d450 vmmaplk (&map->lock) @ /syzkaller/managers/multicore/kernel/sys/uvm/uvm_fault.c:1442 2nd 0xfffffd807ed283d8 inode (&ip->i_lock) @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 lock order "&ip->i_lock"(rrwlock) -> "&map->lock"(rwlock) first seen at: #0 witness_checkorder+0x6d8 #1 _rw_enter+0xbf #2 vm_map_lock_ln+0x14e #3 uvm_map+0x2e2 #4 km_alloc+0x19a #5 pool_multi_alloc_ni+0xe4 #6 pool_p_alloc+0x70 #7 pool_do_get+0x127 #8 pool_get+0x104 #9 ufsdirhash_build+0x40b #10 ufs_lookup+0x2a5 #11 VOP_LOOKUP+0x63 #12 vfs_lookup+0x552 #13 namei+0x4af #14 start_init+0xd6 lock order "&map->lock"(rwlock) -> "&ip->i_lock"(rrwlock) first seen at: #0 witness_checkorder+0x6d8 #1 _rw_enter+0xbf #2 _rrw_enter+0x5c #3 VOP_LOCK+0x55 #4 vn_lock+0x6e #5 uvn_io+0x2ca #6 uvn_get+0x206 #7 uvm_fault+0x12c1 #8 uvm_fault_wire+0x70 #9 uvm_map_pageable_wire+0x2fd #10 uvm_map_protect+0x610 #11 syscall+0x5a0 #12 Xsyscall+0x128 Stopped at db_enter+0x18: addq $0x8,%rsp ddb{1}> ddb{1}> set $lines = 0 ddb{1}> show panic the kernel did not panic ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 witness_checkorder(d0a41d34c39b4ebd,81,fffffd807ed283c8,fffffd807ed283c8,0) at witness_checkorder+0x12f9 witness_debugger sys/kern/subr_witness.c:2543 [inline] witness_checkorder(d0a41d34c39b4ebd,81,fffffd807ed283c8,fffffd807ed283c8,0) at witness_checkorder+0x12f9 sys/kern/subr_witness.c:1089 _rw_enter(92876adbd6d466d5,60b,fffffd807ed283c8,ffffffff81ed5429) at _rw_enter+0xbf _rrw_enter(111c56119511a472,fffffd80791d5828,ffffffff819017a0,0) at _rrw_enter+0x5c sys/kern/kern_rwlock.c:410 VOP_LOCK(8ec456704861dc8,fffffd80791d5828) at VOP_LOCK+0x55 sys/kern/vfs_vops.c:598 vn_lock(266742dc5c86dd5a,1000) at vn_lock+0x6e sys/kern/vfs_vnops.c:549 uvn_io(7a30123f3e91c8a1,0,0,fffffd807ebee560,0) at uvn_io+0x2ca sys/uvm/uvm_vnode.c:1188 uvn_get(7a05660c01c6ee27,ffffffff8136c1a0,fffffd807ebee560,fffffd806bd7dea8,0,2) at uvn_get+0x206 sys/uvm/uvm_vnode.c:1048 uvm_fault(a0cbfdaa658a322d,20ff9000,0,2) at uvm_fault+0x12c1 sys/uvm/uvm_fault.c:1023 uvm_fault_wire(f96a1bf19260209d,2,20ff9000,fffffd806bd7dea8) at uvm_fault_wire+0x70 sys/uvm/uvm_fault.c:1293 uvm_map_pageable_wire(c5b000f6890ee1c9,fffffd806bd7dea8,20fff000,20ff6000,0,4) at uvm_map_pageable_wire+0x2fd sys/uvm/uvm_map.c:2258 uvm_map_protect(d0a41d34c343dd02,0,ffff800020bbb080,ee64759b1f8,0) at uvm_map_protect+0x610 sys/uvm/uvm_map.c:3294 syscall(33877a715dcf77ee) at syscall+0x5a0 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(33877a715dcf77ee) at syscall+0x5a0 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,ffffffffffffffa4,0,3,ee43de0e010) at Xsyscall+0x128 end of kernel end trace frame: 0xee64759b280, count: -14 ddb{1}> show registers rdi 0x3 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c84f50 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800000946000 rax 0xffff800000940d40 r8 0xffffffff81bca74f witness_checkorder+0x12cf r9 0x5 r10 0xbaab8f454c3716ea r11 0x96cfb2dc3ae9ffdd r12 0xfffffd80025ccc30 r13 0xffffffff81eba9a8 cmd0646_9_tim_udma+0xd171 r14 0xffffffff822c2a30 w_lodata+0x4d6e0 r15 0xffffffff822cb040 w_lodata+0x55cf0 rip 0xffffffff817711a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c84f40 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor0) pid=212571 stat=onproc flags process=0 proc=4000000 pri=74, usrpri=74, nice=20 forw=0xffffffffffffffff, list=0xffff800020bba270,0xffff800020bbae38 process=0xffff800020b94d30 user=0xffff800020c80000, vmspace=0xfffffd807f00d438 estcpu=24, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 68304 365216 63296 0 2 0 syz-executor1 68304 341112 63296 0 2 0x4000000 syz-executor1 5422 311868 84763 0 7 0 syz-executor0 * 5422 212571 84763 0 7 0x4000000 syz-executor0 6763 504782 0 0 3 0x14200 bored sosplice 63296 431185 70105 0 3 0x82 nanosleep syz-executor1 84763 355970 70105 0 3 0x82 nanosleep syz-executor0 70105 118436 52019 0 3 0x82 thrsleep syz-fuzzer 70105 435132 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 25637 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 474872 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 386302 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 298081 52019 0 3 0x4000082 kqread syz-fuzzer 70105 280376 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 356996 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 216172 52019 0 3 0x4000082 thrsleep syz-fuzzer 70105 171793 52019 0 3 0x4000082 thrsleep syz-fuzzer 52019 234128 22608 0 3 0x10008a pause ksh 22608 309368 51677 0 3 0x92 select sshd 82903 361613 1 0 3 0x100083 ttyin getty 51677 357277 1 0 3 0x80 select sshd 49660 93509 68177 73 2 0x100090 syslogd 68177 275831 1 0 3 0x100082 netio syslogd 71441 102128 1 77 3 0x100090 poll dhclient 72890 76875 1 0 3 0x80 poll dhclient 75637 277591 0 0 2 0x14200 zerothread 19735 501522 0 0 3 0x14200 aiodoned aiodoned 88292 177388 0 0 3 0x14200 syncer update 22901 210652 0 0 3 0x14200 cleaner cleaner 63492 521380 0 0 3 0x14200 reaper reaper 1501 80723 0 0 3 0x14200 pgdaemon pagedaemon 8458 471824 0 0 3 0x14200 bored crynlk 19508 415511 0 0 3 0x14200 bored crypto 71466 172040 0 0 3 0x40014200 acpi0 acpi0 39777 399879 0 0 3 0x40014200 idle1 65546 187388 0 0 3 0x14200 bored softnet 24695 232081 0 0 3 0x14200 bored systqmp 49110 410685 0 0 3 0x14200 bored systq 59021 268530 0 0 3 0x40014200 bored softclock 78966 4736 0 0 3 0x40014200 idle0 1 164371 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper