1st 0xfffffd807f00dcc0 vmmaplk (&map->lock) @ /syzkaller/managers/multicore/kernel/sys/uvm/uvm_fault.c:1442 2nd 0xfffffd806e7acb38 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(b1168495607f70ca,81,fffffd806e7acb28,fffffd806e7acb28,0) at witness_checkorder+0x12f9 witness_debugger sys/kern/subr_witness.c:2543 [inline] witness_checkorder(b1168495607f70ca,81,fffffd806e7acb28,fffffd806e7acb28,0) at witness_checkorder+0x12f9 sys/kern/subr_witness.c:1089 _rw_enter(8698711129028347,60b,fffffd806e7acb28,ffffffff81ed5429) at _rw_enter+0xbf _rrw_enter(8863ee58f1f81d9b,fffffd807da0e300,ffffffff819017a0,0) at _rrw_enter+0x5c sys/kern/kern_rwlock.c:410 VOP_LOCK(f9ae9f3c7bd2d2c9,fffffd807da0e300) at VOP_LOCK+0x55 sys/kern/vfs_vops.c:598 vn_lock(4dc053466f7720f4,1000) at vn_lock+0x6e sys/kern/vfs_vnops.c:549 uvn_io(c6d58d533e5269ed,0,0,fffffd8065d517a0,0) at uvn_io+0x2ca sys/uvm/uvm_vnode.c:1188 uvn_get(c69bab04f9278493,ffffffff8136c1a0,fffffd8065d517a0,fffffd806aeb6cb8,0,4) at uvn_get+0x206 sys/uvm/uvm_vnode.c:1048 uvm_fault(3a9e548588046105,20ffe000,0,4) at uvm_fault+0x12c1 sys/uvm/uvm_fault.c:1023 uvm_fault_wire(826bf5bd2912c47c,4,20ffe000,fffffd806aeb6cb8) at uvm_fault_wire+0x70 sys/uvm/uvm_fault.c:1293 uvm_map_pageable_wire(7cd1e1896d2193b9,fffffd806aeb6cb8,21000000,20a00000,0,4) at uvm_map_pageable_wire+0x2fd sys/uvm/uvm_map.c:2258 uvm_map_protect(b116849560a7e375,0,ffff800020b93c38,bcd1e3d74f8,0) at uvm_map_protect+0x610 sys/uvm/uvm_map.c:3294 syscall(92ca2efd5d726235) at syscall+0x5a0 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(92ca2efd5d726235) at syscall+0x5a0 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,ffffffffffffffa4,0,3,bca9ac26010) at Xsyscall+0x128 end of kernel end trace frame: 0xbcd1e3d7580, count: -14 ddb{1}> show registers rdi 0x3 rsi 0x3ffff acpi_pdirpa+0x2be67 rbp 0xffff800020c75460 rbx 0x3 rdx 0x40000 acpi_pdirpa+0x2be68 rcx 0xffff800002b48000 rax 0xffff800001946940 r8 0xffffffff81bca74f witness_checkorder+0x12cf r9 0x5 r10 0xd23344aa6bc2ebb3 r11 0x508c990edaaebadf r12 0xfffffd80025ccc30 r13 0xffffffff81eba9a8 cmd0646_9_tim_udma+0xd171 r14 0xffffffff822c1010 w_lodata+0x4bcc0 r15 0xffffffff822cb040 w_lodata+0x55cf0 rip 0xffffffff817711a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c75450 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=473711 stat=onproc flags process=0 proc=4000000 pri=80, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffff800020b92270,0xffff800020b924d8 process=0xffff800020b949e8 user=0xffff800020c70000, vmspace=0xfffffd807f00dca8 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 40196 243329 55910 0 2 0 syz-executor0 40196 516262 55910 0 2 0x4000000 syz-executor0 98882 302583 72370 0 7 0 syz-executor1 *98882 473711 72370 0 7 0x4000000 syz-executor1 63721 431606 0 0 3 0x14200 bored sosplice 72370 297700 20249 0 3 0x82 nanosleep syz-executor1 55910 1960 20249 0 3 0x82 nanosleep syz-executor0 20249 509631 23995 0 3 0x82 thrsleep syz-fuzzer 20249 84907 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 125874 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 331687 23995 0 3 0x4000082 kqread syz-fuzzer 20249 138611 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 480498 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 175278 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 520598 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 379983 23995 0 3 0x4000082 thrsleep syz-fuzzer 20249 63694 23995 0 3 0x4000082 thrsleep syz-fuzzer 23995 360991 99901 0 3 0x10008a pause ksh 99901 440677 34512 0 3 0x92 select sshd 74333 341262 1 0 3 0x100083 ttyin getty 34512 74063 1 0 3 0x80 select sshd 90670 399019 80019 73 2 0x100090 syslogd 80019 148218 1 0 3 0x100082 netio syslogd 11983 204761 1 77 3 0x100090 poll dhclient 41335 404182 1 0 3 0x80 poll dhclient 88160 115270 0 0 2 0x14200 zerothread 57551 331871 0 0 3 0x14200 aiodoned aiodoned 62282 176789 0 0 3 0x14200 syncer update 66333 501995 0 0 3 0x14200 cleaner cleaner 83929 505769 0 0 3 0x14200 reaper reaper 33819 373811 0 0 3 0x14200 pgdaemon pagedaemon 71205 313952 0 0 3 0x14200 bored crynlk 67675 80743 0 0 3 0x14200 bored crypto 5459 312387 0 0 3 0x40014200 acpi0 acpi0 63368 40495 0 0 3 0x40014200 idle1 26228 332681 0 0 3 0x14200 bored softnet 90399 178546 0 0 3 0x14200 bored systqmp 67960 243008 0 0 3 0x14200 bored systq 46637 68886 0 0 3 0x40014200 bored softclock 11757 170996 0 0 3 0x40014200 idle0 1 162393 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper