exclusive rrwlock inode r = 0 (0xfffffd806e5e8d68) locked @ /syzkallepanic:r/managers/multi thcore/kernel/sys/read 0xffff800020b74018 cannot exit while holding sleeplocks Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 196897 13911 0 0x2 0x480 0 syz-executor.0 *407016 50334 0 0x14000 0x200 1 reaper db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x174 sys/kern/subr_prf.c:208 witness_thread_exit(ffff800020b74018) at witness_thread_exit+0x283 sys/kern/subr_witness.c:1422 reaper(ffff800020ac1c20) at reaper+0x14f sys/kern/kern_exit.c:412 end trace frame: 0x0, count: 11 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic thread 0xffff800020b74018 cannot exit while holding sleeplocks ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x174 sys/kern/subr_prf.c:208 witness_thread_exit(ffff800020b74018) at witness_thread_exit+0x283 sys/kern/subr_witness.c:1422 reaper(ffff800020ac1c20) at reaper+0x14f sys/kern/kern_exit.c:412 end trace frame: 0x0, count: -4 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b0d1f0 rbx 0xffff800020b0d2a0 rdx 0xffffffff81f834ca apollo_pio_rec+0x8fc0 rcx 0 rax 0 r8 0xffffffff81161783 kprintf+0x183 r9 0x1 r10 0x25 r11 0x1b9429cadf688d6b r12 0x3000000008 r13 0xffff800020b0d200 r14 0x100 r15 0x1 rip 0xffffffff81e12a38 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b0d1e0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (reaper) pid=407016 stat=onproc flags process=14000 proc=200 pri=4, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac19c8,0xffff800020b15c38 process=0xffff800020afa698 user=0xffff800020b08000, vmspace=0xffffffff82383300 estcpu=1, cpticks=3, pctcpu=0.41 user=0, sys=3, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 13911 196897 25303 0 7 0x482 syz-executor.0 66882 189608 1 0 3 0x100083 ttyin getty 81408 371789 0 0 3 0x14200 bored sosplice 79251 254107 25303 0 3 0x82 piperd syz-executor.1 25303 291166 61418 0 3 0x82 thrsleep syz-fuzzer 25303 258046 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 71029 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 275890 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 9223 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 413792 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 422221 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 385081 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 253183 61418 0 3 0x4000082 thrsleep syz-fuzzer 25303 358552 61418 0 3 0x4000082 kqread syz-fuzzer 61418 49808 6188 0 3 0x10008a pause ksh 6188 339819 1076 0 3 0x92 select sshd 1076 462508 1 0 3 0x80 select sshd 40351 281377 19398 73 3 0x100010 ffs_fsync syslogd 19398 332960 1 0 3 0x100082 netio syslogd 37457 59322 1 77 3 0x100090 poll dhclient 52249 330113 1 0 3 0x80 poll dhclient 68570 445818 0 0 3 0x14200 pgzero zerothread 32919 221633 0 0 3 0x14200 aiodoned aiodoned 25899 482225 0 0 3 0x14200 syncer update 85789 373511 0 0 3 0x14200 cleaner cleaner *50334 407016 0 0 7 0x14200 reaper 96923 423632 0 0 3 0x14200 pgdaemon pagedaemon 78315 471160 0 0 3 0x14200 bored crynlk 9217 291790 0 0 3 0x14200 bored crypto 34990 266619 0 0 3 0x40014200 acpi0 acpi0 78589 468593 0 0 3 0x40014200 idle1 19580 267175 0 0 3 0x14200 bored softnet 91749 279594 0 0 3 0x14200 bored systqmp 66948 406542 0 0 3 0x14200 bored systq 64651 60406 0 0 3 0x40014200 bored softclock 3139 235776 0 0 3 0x40014200 idle0 63413 288094 0 0 3 0x14200 bored smr 1 341385 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 40351 (syslogd) thread 0xffff800020b77078 (281377) exclusive rrwlock inode r = 0 (0xfffffd806eba93c8) locked @ /syzkaller/managers/multicore/kernel/sys/ufs/ufs/ufs_vnops.c:1547 #0 witness_lock+0x594 sys/kern/subr_witness.c:1205 #1 _rw_enter+0x45d sys/kern/kern_rwlock.c:280 #2 _rrw_enter+0x60 sys/kern/kern_rwlock.c:410 #3 VOP_LOCK+0x57 sys/kern/vfs_vops.c:602 #4 vn_lock+0x6e sys/kern/vfs_vnops.c:549 #5 sys_fsync+0x114 sys/kern/vfs_syscalls.c:2704 #6 syscall+0x5b8 mi_syscall sys/sys/syscall_mi.h:99 [inline] #6 syscall+0x5b8 sys/arch/amd64/amd64/trap.c:574 #7 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9517 6383K 6390K 78643K 10989 0 0 pcb 23 9K 11K 78643K 630 0 0 rtable 100 3K 4K 78643K 407 0 0 ifaddr 54 13K 13K 78643K 184 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 31 0 0 iov 0 0K 20K 78643K 141 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1208 76K 76K 78643K 1877 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 20 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 1K 78643K 125 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 4 9K 25K 78643K 1048 0 0 sigio 0 0K 0K 78643K 10 0 0 proc 42 38K 70K 78643K 399 0 0 subproc 64 65538K 67586K 78643K 116 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 135 0 0 in_multi 33 2K 2K 78643K 95 0 0 ether_multi 1 0K 0K 78643K 11 0 0 mrt 0 0K 0K 78643K 18 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 251 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 90 21K 25K 78643K 4184 0 0 UVM aobj 42 2K 2K 78643K 50 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 43 0 0 NDP 11 0K 0K 78643K 51 0 0 temp 163 2379K 3019K 78643K 5745 0 0 kqueue 0 0K 0K 78643K 6 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 5 0 1 1 0 1 1 0 8 0 inpcbpl 280 574 0 567 1 0 1 1 0 8 0 plimitpl 152 27 0 20 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 56 0 16 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 764 0 764 1 1 0 1 0 8 0 tcpcb 544 189 0 185 1 0 1 1 0 8 0 rttmr 72 7 0 7 3 2 1 1 0 8 1 nd6 48 6 0 2 1 0 1 1 0 8 0 ppxss 1128 24 0 24 4 3 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 230 0 41 12 0 12 12 0 8 0 art_table 32 231 0 41 2 0 2 2 0 8 0 art_node 16 55 0 21 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 5 1 0 1 1 0 8 0 semapl 112 123 0 113 1 0 1 1 0 8 0 shmpl 112 48 0 8 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3443 0 2031 46 0 46 46 0 8 0 ffsino 272 3443 0 2031 95 0 95 95 0 8 0 nchpl 144 5170 0 3563 61 0 61 61 0 8 0 uvmvnodes 72 3635 0 0 67 0 67 67 0 8 0 vnodes 200 3635 0 0 192 0 192 192 0 8 0 namei 1024 14768 0 14768 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 3 0 3 2 2 0 1 0 8 0 scxspl 192 15528 0 15527 13 12 1 6 0 8 0 sigapl 432 1214 0 1202 2 0 2 2 0 8 0 futexpl 56 12266 0 12266 1 0 1 1 0 8 1 knotepl 112 299 0 272 3 2 1 2 0 8 0 kqueuepl 104 283 0 281 1 0 1 1 0 8 0 pipepl 112 674 0 655 2 1 1 1 0 8 0 fdescpl 488 1215 0 1202 3 1 2 3 0 8 0 filepl 152 7377 0 7283 6 1 5 5 0 8 1 lockfpl 104 376 0 376 2 1 1 1 0 8 1 lockfspl 32 389 0 389 2 1 1 1 0 8 1 sessionpl 112 19 0 9 1 0 1 1 0 8 0 pgrppl 48 32 0 22 1 0 1 1 0 8 0 ucredpl 96 1842 0 1835 1 0 1 1 0 8 0 zombiepl 144 1202 0 1201 3 2 1 1 0 8 0 processpl 840 1231 0 1201 4 0 4 4 0 8 0 procpl 600 3532 0 3491 4 0 4 4 0 8 0 srpgc 64 11 0 11 3 2 1 1 0 8 1 sosppl 128 27 0 27 4 3 1 1 0 8 1 sockpl 384 1112 0 1095 4 1 3 4 0 8 1 mcl64k 65536 264 0 0 33 1 32 33 0 8 1 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 11 0 0 2 0 2 2 0 8 0 mcl9k 9216 5 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 129 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 421 0 0 20 0 20 20 0 8 0 bufpl 256 7983 0 1031 435 0 435 435 0 8 0 anonpl 16 123583 0 115325 83 44 39 51 0 125 4 amapchunkpl 152 6855 0 6751 13 8 5 9 0 158 0 amappl16 192 5747 0 5309 63 39 24 34 0 8 1 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 446 0 441 1 0 1 1 0 8 0 amappl13 168 193 0 186 1 0 1 1 0 8 0 amappl12 160 427 0 425 2 1 1 1 0 8 0 amappl11 152 707 0 697 1 0 1 1 0 8 0 amappl10 144 60 0 58 2 1 1 1 0 8 0 amappl9 136 870 0 865 1 0 1 1 0 8 0 amappl8 128 134 0 115 1 0 1 1 0 8 0 amappl7 120 111 0 105 1 0 1 1 0 8 0 amappl6 112 475 0 466 1 0 1 1 0 8 0 amappl5 104 143 0 132 1 0 1 1 0 8 0 amappl4 96 279 0 256 2 1 1 2 0 8 0 amappl3 88 212 0 207 1 0 1 1 0 8 0 amappl2 80 10437 0 10384 3 1 2 2 0 8 0 amappl1 72 34908 0 34482 23 13 10 19 0 8 0 amappl 72 3762 0 3723 1 0 1 1 0 75 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 49 0 8 1 0 1 1 0 8 0 uaddrrnd 24 1215 0 1201 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1215 0 1201 1 0 1 1 0 8 0 vmmpekpl 168 13748 0 13726 3 1 2 2 0 8 0 vmmpepl 168 134568 0 133170 137 67 70 76 0 357 5 vmsppl 360 1214 0 1201 2 0 2 2 0 8 0 pdppl 4096 2438 0 2402 6 1 5 6 0 8 0 pvpl 32 374960 0 363624 203 87 116 133 0 265 21 pmappl 224 1214 0 1201 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 628 0 6 18 0 18 18 0 8 0