1st 0xfffffd807f00d180 vmmaplk (&map->lock) @ /syzkaller/managers/multicore/kernel/sys/uvm/uvm_fault.c:1442 2nd 0xfffffd806a182928 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(ccd146b8d5c77e4a,81,fffffd806a182918,fffffd806a182918,0) at witness_checkorder+0x12f9 witness_debugger sys/kern/subr_witness.c:2543 [inline] witness_checkorder(ccd146b8d5c77e4a,81,fffffd806a182918,fffffd806a182918,0) at witness_checkorder+0x12f9 sys/kern/subr_witness.c:1089 _rw_enter(6cb2c1c51e40a0a1,60b,fffffd806a182918,ffffffff81ed5429) at _rw_enter+0xbf _rrw_enter(b396ed8c21017551,fffffd806a23d1f8,ffffffff819017a0,0) at _rrw_enter+0x5c sys/kern/kern_rwlock.c:410 VOP_LOCK(67ad012ecdee5387,fffffd806a23d1f8) at VOP_LOCK+0x55 sys/kern/vfs_vops.c:598 vn_lock(8a49658cb29774a3,1000) at vn_lock+0x6e sys/kern/vfs_vnops.c:549 uvn_io(f56ba300bcd5294e,0,0,fffffd807aeaa2d8,0) at uvn_io+0x2ca sys/uvm/uvm_vnode.c:1188 uvn_get(81b602e580c5b11b,ffffffff8136c1a0,fffffd807aeaa2d8,fffffd806b5cc980,0,4) at uvn_get+0x206 sys/uvm/uvm_vnode.c:1048 uvm_fault(5fc2f12b0b00921f,20ff9000,0,4) at uvm_fault+0x12c1 sys/uvm/uvm_fault.c:1023 uvm_fault_wire(7b48f9f215348e39,4,20ff9000,fffffd806b5cc980) at uvm_fault_wire+0x70 sys/uvm/uvm_fault.c:1293 uvm_map_pageable_wire(667491abddfa3e56,fffffd806b5cc980,21000000,20a00000,0,4) at uvm_map_pageable_wire+0x2fd sys/uvm/uvm_map.c:2258 uvm_map_protect(ccd146b8d51fedf5,0,ffff800020be5c30,dd740d81608,0) at uvm_map_protect+0x610 sys/uvm/uvm_map.c:3294 syscall(30532860b4a4ca3e) at syscall+0x5a0 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(30532860b4a4ca3e) at syscall+0x5a0 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,ffffffffffffffa4,0,3,dd4f3db7010) at Xsyscall+0x128 end of kernel end trace frame: 0xdd740d81690, count: -14 ddb{1}> show registers rdi 0x3 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c7b040 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800000946000 rax 0xffff80000092e980 r8 0xffffffff81bca74f witness_checkorder+0x12cf r9 0x5 r10 0x1dd9d93f47d2a338 r11 0x24105babf52a4142 r12 0xfffffd80025ccc30 r13 0xffffffff81eba9a8 cmd0646_9_tim_udma+0xd171 r14 0xffffffff822c50b0 w_lodata+0x4fd60 r15 0xffffffff822cb1a0 w_lodata+0x55e50 rip 0xffffffff817711a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c7b030 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=9550 stat=onproc flags process=0 proc=4000000 pri=63, usrpri=63, nice=20 forw=0xffffffffffffffff, list=0xffff800020b752c8,0xffff800020be59e8 process=0xffff800020b95708 user=0xffff800020c76000, vmspace=0xfffffd807f00d168 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 14702 62771 87710 0 2 0 syz-executor0 22917 429934 55273 0 7 0 syz-executor1 *22917 9550 55273 0 7 0x4000000 syz-executor1 55273 132007 86225 0 3 0x82 nanosleep syz-executor1 87710 10549 86225 0 3 0x82 nanosleep syz-executor0 86225 78209 76541 0 3 0x82 thrsleep syz-fuzzer 86225 183000 76541 0 3 0x4000082 nanosleep syz-fuzzer 86225 519250 76541 0 3 0x4000082 thrsleep syz-fuzzer 86225 470435 76541 0 3 0x4000082 thrsleep syz-fuzzer 86225 245938 76541 0 3 0x4000082 thrsleep syz-fuzzer 86225 260967 76541 0 3 0x4000082 thrsleep syz-fuzzer 86225 344441 76541 0 3 0x4000082 thrsleep syz-fuzzer 86225 412561 76541 0 3 0x4000082 nanosleep syz-fuzzer 86225 382378 76541 0 3 0x4000082 kqread syz-fuzzer 86225 482821 76541 0 3 0x4000082 thrsleep syz-fuzzer 76541 341548 51442 0 3 0x10008a pause ksh 51442 523799 14323 0 3 0x92 select sshd 2056 174174 1 0 3 0x100083 ttyin getty 14323 143851 1 0 3 0x80 select sshd 40588 31674 42051 73 2 0x100090 syslogd 42051 340915 1 0 3 0x100082 netio syslogd 25360 413510 1 77 3 0x100090 poll dhclient 28521 110890 1 0 3 0x80 poll dhclient 33789 179971 0 0 2 0x14200 zerothread 78879 89406 0 0 3 0x14200 aiodoned aiodoned 65477 191606 0 0 3 0x14200 syncer update 11173 163631 0 0 3 0x14200 cleaner cleaner 90935 92127 0 0 3 0x14200 reaper reaper 6463 456297 0 0 3 0x14200 pgdaemon pagedaemon 39616 60594 0 0 3 0x14200 bored crynlk 80612 381134 0 0 3 0x14200 bored crypto 19592 216083 0 0 3 0x40014200 acpi0 acpi0 99359 349742 0 0 3 0x40014200 idle1 59848 184670 0 0 3 0x14200 bored softnet 70314 94640 0 0 3 0x14200 bored systqmp 2379 320264 0 0 3 0x14200 bored systq 66418 489883 0 0 3 0x40014200 bored softclock 84449 450128 0 0 3 0x40014200 idle0 1 123089 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper