panic: kernel diagnostic assertion "sb->sb_cc == 0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_socket2.c", line 934 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 510367 47216 0 0 0 1 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821f23e1) at panic+0x15c sys/kern/subr_prf.c:207 __assert(ffffffff8224a072,ffffffff8224e9e7,3a6,ffffffff8223321a) at __assert+0x2b sys/kern/subr_prf.c:154 sbflush(ffff800020aa6d48,ffff800020aa6dd0) at sbflush+0x17d sys/kern/uipc_socket2.c:935 sbrelease(ffff800020aa6d48,ffff800020aa6dd0) at sbrelease+0x2e sys/kern/uipc_socket2.c:525 sorflush(fffffd806f6ea320) at sorflush+0x14b sys/kern/uipc_socket.c:1131 sofree(fffffd806f6ea320,42) at sofree+0x147 sys/kern/uipc_socket.c:257 soclose(fffffd806f6ea320,0) at soclose+0x270 sys/kern/uipc_socket.c:338 soo_close(fffffd806fc8c5f0,ffff800020a6d388) at soo_close+0x40 fdrop(fffffd806fc8c5f0,ffff800020a6d388) at fdrop+0xc2 sys/kern/kern_descrip.c:1276 closef(fffffd806fc8c5f0,ffff800020a6d388) at closef+0x11c sys/kern/kern_descrip.c:1260 fdfree(ffff800020a6d388) at fdfree+0x101 sys/kern/kern_descrip.c:1192 exit1(ffff800020a6d388,1,0,1) at exit1+0x32c sys/kern/kern_exit.c:197 sys_exit(ffff800020a6d388,ffff800020aa71a0,ffff800020aa71f0) at sys_exit+0x16 sys/kern/kern_exit.c:95 end trace frame: 0xffff800020aa7260, count: 0 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic kernel diagnostic assertion "sb->sb_cc == 0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_socket2.c", line 934 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821f23e1) at panic+0x15c sys/kern/subr_prf.c:207 __assert(ffffffff8224a072,ffffffff8224e9e7,3a6,ffffffff8223321a) at __assert+0x2b sys/kern/subr_prf.c:154 sbflush(ffff800020aa6d48,ffff800020aa6dd0) at sbflush+0x17d sys/kern/uipc_socket2.c:935 sbrelease(ffff800020aa6d48,ffff800020aa6dd0) at sbrelease+0x2e sys/kern/uipc_socket2.c:525 sorflush(fffffd806f6ea320) at sorflush+0x14b sys/kern/uipc_socket.c:1131 sofree(fffffd806f6ea320,42) at sofree+0x147 sys/kern/uipc_socket.c:257 soclose(fffffd806f6ea320,0) at soclose+0x270 sys/kern/uipc_socket.c:338 soo_close(fffffd806fc8c5f0,ffff800020a6d388) at soo_close+0x40 fdrop(fffffd806fc8c5f0,ffff800020a6d388) at fdrop+0xc2 sys/kern/kern_descrip.c:1276 closef(fffffd806fc8c5f0,ffff800020a6d388) at closef+0x11c sys/kern/kern_descrip.c:1260 fdfree(ffff800020a6d388) at fdfree+0x101 sys/kern/kern_descrip.c:1192 exit1(ffff800020a6d388,1,0,1) at exit1+0x32c sys/kern/kern_exit.c:197 sys_exit(ffff800020a6d388,ffff800020aa71a0,ffff800020aa71f0) at sys_exit+0x16 sys/kern/kern_exit.c:95 syscall(ffff800020aa7270) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020aa7270) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffce260, count: -16 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020aa6bd0 rbx 0xffff800020aa6c80 rdx 0xffff800020a6d388 rcx 0 rax 0 r8 0xffffffff81ad865f kprintf+0x16f r9 0x1 r10 0x25 r11 0xdfbfbc6396ee21bb r12 0x3000000008 r13 0xffff800020aa6be0 r14 0x100 r15 0x1 rip 0xffffffff81ed6fe8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020aa6bc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (dhclient) pid=226575 stat=onproc flags process=100018 proc=2000 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020a6d118,0xffff800020adfd60 process=0xffff800020a81348 user=0xffff800020aa2000, vmspace=0xfffffd807f0008a0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 47216 510367 78641 0 7 0 syz-executor.1 47216 507628 78641 0 3 0x4000080 fsleep syz-executor.1 67233 198144 40565 0 2 0x480 syz-executor.0 67233 464876 40565 0 3 0x4000080 netcon syz-executor.0 67233 299098 40565 0 3 0x4000080 fsleep syz-executor.0 7221 331239 1 0 3 0x80 nanosleep init 30617 301745 0 0 3 0x14200 bored sosplice 78641 286087 73015 0 2 0x482 syz-executor.1 40565 179400 73015 0 3 0x82 nanosleep syz-executor.0 73015 355216 46677 0 3 0x82 thrsleep syz-fuzzer 73015 41399 46677 0 2 0x4000482 syz-fuzzer 73015 347120 46677 0 3 0x4000082 thrsleep syz-fuzzer 73015 465082 46677 0 3 0x4000082 thrsleep syz-fuzzer 73015 440164 46677 0 3 0x4000082 kqread syz-fuzzer 73015 52660 46677 0 3 0x4000082 thrsleep syz-fuzzer 73015 6927 46677 0 2 0x4000482 syz-fuzzer 73015 42077 46677 0 3 0x4000082 thrsleep syz-fuzzer 73015 247354 46677 0 3 0x4000082 thrsleep syz-fuzzer 73015 421184 46677 0 3 0x4000082 thrsleep syz-fuzzer 46677 185467 86306 0 3 0x10008a pause ksh 86306 41562 43131 0 3 0x92 select sshd 43131 378908 1 0 3 0x80 select sshd 68946 196404 14233 74 2 0x100492 pflogd 14233 487768 1 0 3 0x80 netio pflogd 24340 445350 66329 73 3 0x100090 kqread syslogd 66329 285248 1 0 3 0x100082 netio syslogd 18633 294889 1 0 3 0x80 poll dhclient 37852 212196 0 0 3 0x14200 bored smr 85949 107943 0 0 3 0x14200 pgzero zerothread 76417 298580 0 0 3 0x14200 aiodoned aiodoned 22988 71206 0 0 3 0x14200 syncer update 86810 277003 0 0 3 0x14200 cleaner cleaner 75806 367068 0 0 3 0x14200 reaper reaper 17165 321052 0 0 3 0x14200 pgdaemon pagedaemon 22750 180043 0 0 3 0x14200 bored crynlk 59225 440304 0 0 3 0x14200 bored crypto 32963 512861 0 0 3 0x40014200 acpi0 acpi0 14117 448233 0 0 3 0x40014200 idle1 22141 215600 0 0 3 0x14200 bored softnet 79653 283828 0 0 3 0x14200 bored systqmp 28313 19248 0 0 3 0x14200 bored systq 36522 407536 0 0 2 0x40014200 softclock 99328 457846 0 0 3 0x40014200 idle0 1 298145 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9509 6412K 6806K 78643K 10979 0 pcb 13 8K 8K 78643K 81 0 rtable 88 11K 12K 78643K 312 0 ifaddr 67 13K 15K 78643K 113 0 counters 43 33K 34K 78643K 57 0 ioctlops 0 0K 4K 78643K 1481 0 iov 0 0K 16K 78643K 25 0 mount 1 1K 1K 78643K 1 0 vnodes 1218 77K 77K 78643K 1346 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 6 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 46 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 6 17K 25K 78643K 301 0 sigio 0 0K 0K 78643K 2 0 proc 54 51K 95K 78643K 487 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 61 0 in_multi 52 2K 3K 78643K 104 0 ether_multi 1 0K 0K 78643K 13 0 mrt 0 0K 0K 78643K 8 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 55 254K 254K 78643K 55 0 exec 0 0K 1K 78643K 239 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 107 38K 46K 78643K 1789 0 UVM aobj 18 2K 2K 78643K 18 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 98 0 NDP 11 0K 0K 78643K 24 0 temp 98 3039K 3103K 78643K 3940 0 kqueue 3 4K 16K 78643K 21 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 7 0 3 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 28 0 26 1 0 1 1 0 8 0 rtentry 112 59 0 28 2 0 2 2 0 8 0 unpcb 120 139 0 127 1 0 1 1 0 8 0 syncache 264 6 0 6 2 2 0 1 0 8 0 tcpqe 32 735 0 735 1 1 0 1 0 8 0 tcpcb 544 194 0 186 1 0 1 1 0 8 0 inpcb 280 494 0 484 2 0 2 2 0 8 1 rttmr 72 2 0 2 1 0 1 1 0 8 1 nd6 48 9 0 8 1 0 1 1 0 8 0 pkpcb 40 4 0 4 2 1 1 1 0 8 1 ppxss 1128 2 0 2 1 0 1 1 0 8 1 pffrag 232 2 0 2 1 0 1 1 0 482 1 pffrnode 88 2 0 2 1 0 1 1 0 8 1 pffrent 40 4 0 4 1 0 1 1 0 8 1 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 33 0 3 1 0 1 1 0 8 0 pfstkey 112 33 0 3 1 0 1 1 0 8 0 pfstate 328 33 0 3 3 0 3 3 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 258 0 124 13 0 13 13 0 8 2 art_table 32 260 0 124 2 0 2 2 0 8 0 art_node 16 58 0 29 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 3 1 0 1 1 0 8 0 semapl 112 44 0 34 1 0 1 1 0 8 0 shmpl 112 16 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1812 0 409 46 0 46 46 0 8 0 ffsino 272 1812 0 409 94 0 94 94 0 8 0 nchpl 144 2450 0 833 61 0 61 61 0 8 0 uvmvnodes 72 1938 0 0 36 0 36 36 0 8 0 vnodes 208 1938 0 0 102 0 102 102 0 8 0 namei 1024 6469 0 6469 2 1 1 1 0 8 1 percpumem 16 39 0 7 1 0 1 1 0 8 0 vcpupl 1984 3 0 0 1 0 1 1 0 8 0 vmpool 560 5 0 2 1 0 1 1 0 8 0 scsiplug 64 2 0 2 1 1 0 1 0 8 0 scxspl 192 7157 0 7157 8 7 1 7 0 8 1 plimitpl 152 28 0 21 1 0 1 1 0 8 0 sigapl 424 519 0 486 4 0 4 4 0 8 0 futexpl 56 3825 0 3823 1 0 1 1 0 8 0 knotepl 112 75 0 56 1 0 1 1 0 8 0 kqueuepl 144 42 0 40 1 0 1 1 0 8 0 pipelkpl 48 94 0 84 1 0 1 1 0 8 0 pipepl 120 188 0 169 1 0 1 1 0 8 0 fdescpl 496 503 0 486 3 0 3 3 0 8 0 filepl 152 2736 0 2632 6 1 5 5 0 8 0 lockfpl 104 56 0 55 1 0 1 1 0 8 0 lockfspl 48 19 0 18 1 0 1 1 0 8 0 sessionpl 112 19 0 9 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 206 0 197 1 0 1 1 0 8 0 zombiepl 144 487 0 486 2 1 1 1 0 8 0 processpl 984 519 0 486 6 1 5 5 0 8 0 procpl 624 1010 0 965 4 0 4 4 0 8 0 srpgc 64 1 0 1 1 0 1 1 0 8 1 sosppl 128 3 0 3 1 1 0 1 0 8 0 sockpl 400 665 0 640 6 2 4 4 0 8 1 mcl64k 65536 7 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 217 0 0 27 0 27 27 0 8 0 mtagpl 80 38 0 0 1 0 1 1 0 8 0 mbufpl 256 477 0 0 29 0 29 29 0 8 0 bufpl 280 4517 0 177 310 0 310 310 0 8 0 anonpl 16 66915 0 52212 75 1 74 74 0 124 13 amapchunkpl 152 2648 0 2504 14 3 11 11 0 158 4 amappl16 192 2549 0 1749 55 5 50 51 0 8 8 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 2 0 2 2 2 0 1 0 8 0 amappl13 168 158 0 154 1 0 1 1 0 8 0 amappl12 160 4 0 4 1 1 0 1 0 8 0 amappl11 152 210 0 190 1 0 1 1 0 8 0 amappl10 144 19 0 14 1 0 1 1 0 8 0 amappl9 136 389 0 385 1 0 1 1 0 8 0 amappl8 128 310 0 293 1 0 1 1 0 8 0 amappl7 120 120 0 110 1 0 1 1 0 8 0 amappl6 112 163 0 157 1 0 1 1 0 8 0 amappl5 104 139 0 123 1 0 1 1 0 8 0 amappl4 96 767 0 734 2 1 1 2 0 8 0 amappl3 88 219 0 211 1 0 1 1 0 8 0 amappl2 80 2751 0 2676 3 1 2 3 0 8 0 amappl1 72 20201 0 19779 25 15 10 20 0 8 0 amappl 80 1272 0 1223 2 0 2 2 0 84 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 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 64 17 0 0 1 0 1 1 0 8 0 uaddrrnd 24 508 0 488 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 508 0 488 1 0 1 1 0 8 0 vmmpekpl 168 7042 0 7005 2 0 2 2 0 8 0 vmmpepl 168 66178 0 64176 107 8 99 99 0 357 9 vmsppl 368 507 0 488 2 0 2 2 0 8 0 pdppl 4096 1024 0 979 6 0 6 6 0 8 0 pvpl 32 196433 0 179105 180 3 177 177 0 265 34 pmappl 232 507 0 488 3 1 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 197 0 6 6 0 6 6 0 8 0