syzbot
protection_fault: ip6_freemoptions
Status:
upstream: reported on 2026/07/24 23:13
Reported-by: syzbot+c43fcd5f63a17c3b8f2e@syzkaller.appspotmail.com
First crash: 7d22h, last: 7d22h
Sample crash report:
kernel: protection fault trap, code=0
Stopped at ip6_freemoptions+0x65: movq 0x8(%r15),%r13
ddb{1}>
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
the kernel did not panic
ddb{1}> show kasan
No such command
ddb{1}> trace
ip6_freemoptions(ffff800000c438d0) at ip6_freemoptions+0x65 sys/netinet6/ip6_output.c:2147
in_pcbdetach(ffffee806fee2e18) at in_pcbdetach+0x122 sys/netinet/in_pcb.c:608
tcp_close(ffff8000015bb420) at tcp_close+0x194 tcpstat_inc sys/netinet/tcp_var.h:-1 [inline]
tcp_close(ffff8000015bb420) at tcp_close+0x194 sys/netinet/tcp_subr.c:530
tcp_detach(ffff800001635a90) at tcp_detach+0x8f sys/netinet/tcp_usrreq.c:-1
soclose(ffff800001635a90,0) at soclose+0xb0 pru_detach sys/sys/protosw.h:281 [inline]
soclose(ffff800001635a90,0) at soclose+0xb0 sys/kern/uipc_socket.c:403
soo_close(ffffee806d218df0,ffff80003afb8020) at soo_close+0x56 sys/kern/sys_socket.c:-1
fdrop(ffffee806d218df0,ffff80003afb8020) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(ffffee806d218df0,ffff80003afb8020) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff80003afb8020) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff80003afb8020,0,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80003afb8020,ffff80003c3fdf00,ffff80003c3fde50) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c3fdf00) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3fdf00) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x79c7ec74b8d0, count: -13
ddb{1}> show registers
rdi 0xffff800000c438d0
rsi 0x100
rbp 0xffff80003c3fdaf0
rbx 0x8
rdx 0
rcx 0xffff80003afb8020
rax 0xffff80002999dff0
r8 0xffffffffffffffff
r9 0x1
r10 0x4a6e6ae1b51e2f8a
r11 0xc0d4cb843d04ae8a
r12 0
r13 0x100
r14 0xffff800000c438d0
r15 0x96e700004000
rip 0xffffffff82e2a475 ip6_freemoptions+0x65
cs 0x8
rflags 0x10206 __ALIGN_SIZE+0xf206
rsp 0xffff80003c3fdab0
ss 0x10
ip6_freemoptions+0x65: movq 0x8(%r15),%r13
ddb{1}> show proc
PROC (syz-executor) tid=384166 pid=28236 tcnt=0 stat=onproc
flags process=1018<EXITING,SUGID,SINGLEEXIT> proc=2000<WEXIT>
runpri=32, usrpri=55, slppri=32, nice=20
wchan=0x0, wmesg=, ps_single=0xffff80003afb8020 scnt=-1 ecnt=1
forw=0xffffffffffffffff, list=0xffff80003afb9ca8,0xffff80003afb82c8
process=0xffff80003b3d49c0 user=0xffff80003c3f8000, vmspace=0xffffee806d1215e0
estcpu=5, cpticks=7, pctcpu=0.0, user=0, sys=0, intr=0
ddb{1}> ps
PID TID PPID UID S PRLAGS PFLAGS WAIT COMMAND
80774 504332 28829 0 7 0x2 0 syz-executor
37148 112052 11672 32767 3 0x10 0x80 nanoslp syz-executor
37148 284822 11672 32767 3 0x10 0x4000080 kqsel syz-executor
37148 242474 11672 32767 3 0x10 0x4000080 kqsel syz-executor
20559 65185 30388 32767 3 0x10 0x80 piperd syz-executor
37344 143354 37676 32767 3 0x10 0x80 piperd syz-executor
69069 402080 46777 32767 3 0x10 0x80 nanoslp syz-executor
11672 315376 46619 32767 3 0x10 0x80 nanoslp syz-executor
16001 73986 46518 32767 3 0x10 0x80 nanoslp syz-executor
70267 109027 74989 32767 3 0x10 0x80 piperd syz-executor
46777 487584 28829 0 3 0x2 0x80 wait syz-executor
46619 281606 28829 0 3 0x2 0x80 wait syz-executor
30388 101175 28829 0 3 0x2 0x80 wait syz-executor
37676 343210 28829 0 3 0x2 0x80 wait syz-executor
46518 128791 28829 0 3 0x2 0x80 wait syz-executor
74989 176551 28829 0 3 0x2 0x80 wait syz-executor
28829 157175 5929 0 3 0x2 0x80 nanoslp syz-executor
5929 210051 72937 0 3 0x100002 0x88 sigsusp ksh
72937 166805 59849 0 3 0x10 0x88 kqread sshd-session
59849 469529 83985 0 3 0x12 0x80 kqread sshd-session
81161 65388 1 0 3 0x100003 0x80 ttyin getty
83985 395554 1 0 3 0 0x88 kqread sshd
48408 328771 93569 73 3 0x1100010 0x80 kqread syslogd
93569 454655 1 0 3 0x100002 0x80 sbwait syslogd
12668 20189 1 0 3 0x100000 0x80 kqread resolvd
26736 85273 69807 77 3 0x100012 0x80 kqread dhcpleased
23688 288514 69807 77 3 0x100012 0x80 kqread dhcpleased
69807 106420 1 0 3 0 0x80 kqread dhcpleased
59450 301567 0 0 3 0x14000 0x200 bored smr
25893 304158 0 0 2 0x14000 0x200 zerothread
61276 65485 0 0 3 0x14000 0x200 aiodoned aiodoned
80490 1697 0 0 3 0x14000 0x200 syncer update
62794 85946 0 0 3 0x14000 0x200 cleaner cleaner
38241 90016 0 0 3 0x14000 0x200 reaper reaper
91912 469359 0 0 3 0x14000 0x200 pgdaemon pagedaemon
23784 241642 0 0 3 0x14000 0x200 bored viomb
79518 295642 0 0 3 0x14000 0x40000200 acpi0 acpi0
72413 496653 0 0 3 0x14000 0x40000200 idle1
17475 489308 0 0 3 0x14000 0x200 bored softnet1
53489 25259 0 0 3 0x14000 0x200 bored softnet0
1447 298755 0 0 3 0x14000 0x200 bored systqmp
48160 396804 0 0 3 0x14000 0x200 bored systq
71634 79655 0 0 3 0x14000 0x200 tmoslp softclockmp
27357 361204 0 0 3 0x14000 0x40000200 tmoslp softclock
26154 9176 0 0 3 0x14000 0x40000200 idle0
1 416501 0 0 3 0x2 0x80 wait init
0 0 -1 0 3 0x10000 0x200 scheduler swapper
ddb{1}> show all locks
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 11047 12014K 12034K 166960K 12144 0
pcb 17 12K 12K 166960K 17 0
rtable 199 5K 7K 166960K 376 0
pf 27 16K 16K 166960K 31 0
ifaddr 34 6K 7K 166960K 44 0
ifgroup 42 1K 2K 166960K 50 0
sysctl 2 1K 9K 166960K 7 0
counters 66 36K 37K 166960K 70 0
ioctlops 0 0K 2K 166960K 40 0
iov 0 0K 12K 166960K 10 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1287 81K 81K 166960K 1653 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 8 0
VM map 2 1K 1K 166960K 2 0
sem 12 0K 1K 166960K 81 0
dirhash 12 2K 2K 166960K 24 0
ACPI 1734 201K 291K 166960K 11964 0
file desc 18 65K 125K 166960K 477 0
sigio 0 0K 0K 166960K 5 0
proc 58 99K 163K 166960K 529 0
subproc 56 3K 4K 166960K 362 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 1 0K 0K 166960K 59 0
in_multi 77 5K 7K 166960K 106 0
ether_multi 1 0K 0K 166960K 2 0
mrt 0 0K 0K 166960K 15 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 79 360K 360K 166960K 79 0
exec 0 0K 1K 166960K 428 0
fusefs mount 1 32K 32K 166960K 1 0
tdb 3 0K 0K 166960K 3 0
VM swap 8 62K 64K 166960K 10 0
UVM amap 211 159K 187K 166960K 5391 0
UVM aobj 11 2K 2K 166960K 11 0
pinsyscall 39 78K 112K 166960K 1640 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 19 0
NDP 9 0K 2K 166960K 27 0
temp 34 9119K 9182K 166960K 4937 0
kqueue 13 20K 28K 166960K 78 0
SYN cache 2 16K 16K 166960K 2 0
ddb{1}> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache 128 28 0 0 1 0 1 1 0 8 0
rtpcb 120 60 0 57 1 0 1 1 0 8 0
rtentry 176 115 0 24 6 0 6 6 0 8 0
unpcb 144 266 0 251 4 0 4 4 0 8 3
syncache 336 11 0 11 1 0 1 1 0 8 1
tcpqe 32 1 0 1 1 0 1 1 0 8 1
tcpcb 736 102 0 97 2 0 2 2 0 8 1
arp 136 18 0 4 1 0 1 1 0 8 0
ipq 40 1 0 1 1 0 1 1 0 8 1
ipqe 40 2 0 2 1 0 1 1 0 8 1
inpcb 328 287 0 276 2 0 2 2 0 8 0
nd6 152 28 0 7 2 0 2 2 0 8 0
kcovpl 48 40 0 34 1 0 1 1 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 484 0 90 30 0 30 30 0 8 2
art_table 40 485 0 90 5 0 5 5 0 8 0
art_node 32 115 0 32 1 0 1 1 0 8 0
sysvmsgpl 40 8 0 6 1 0 1 1 0 8 0
semapl 72 13 0 3 1 0 1 1 0 8 0
shmpl 112 8 0 0 1 0 1 1 0 8 0
dirhash 1024 25 0 8 3 0 3 3 0 8 0
dino2pl 256 1899 0 401 94 0 94 94 0 8 0
ffsino 296 1899 0 401 116 0 116 116 0 8 0
nchpl 144 2372 0 647 64 0 64 64 0 8 0
vnodes 216 2270 0 0 127 0 127 127 0 8 0
namei 1024 7710 0 7710 1 0 1 1 0 8 1
percpumem 16 51 0 2 1 0 1 1 0 8 0
kstatmem 264 25 0 4 2 0 2 2 0 8 0
scxspl 216 8169 0 8169 3 2 1 2 1 8 1
plimitpl 152 134 0 113 2 0 2 2 0 8 1
sigapl 424 723 0 677 7 0 7 7 0 8 0
knotepl 120 308 0 0 10 0 10 10 0 8 0
kqueuepl 224 86 0 75 1 0 1 1 0 8 0
pipepl 344 297 0 270 4 0 4 4 0 8 0
fdescpl 528 707 0 677 4 0 4 4 0 8 0
filepl 160 3482 0 3292 12 0 12 12 0 8 2
lockfpl 104 42 0 40 1 0 1 1 0 8 0
lockfspl 48 19 0 17 1 0 1 1 0 8 0
sessionpl 144 70 0 56 1 0 1 1 0 8 0
pgrppl 48 111 0 90 1 0 1 1 0 8 0
ucredpl 104 410 0 393 1 0 1 1 0 8 0
zombiepl 144 679 0 677 1 0 1 1 0 8 0
processpl 1232 723 0 677 5 0 5 5 0 8 0
procpl 664 1095 0 1047 7 0 7 7 0 8 1
sosppl 176 7 0 7 1 0 1 1 0 8 1
sockpl 752 615 0 586 10 0 10 10 0 8 6
mcl64k 65536 3 0 0 1 0 1 1 0 8 0
mcl16k 16384 1 0 0 1 0 1 1 0 8 0
mcl12k 12288 1 0 0 1 0 1 1 0 8 0
mcl8k 8192 3 0 0 1 0 1 1 0 8 0
mcl4k 4096 111 0 0 14 0 14 14 0 8 0
mcl2k 2048 24 0 0 3 0 3 3 0 8 0
mextrefs 64 22 0 0 1 0 1 1 0 8 0
mtagpl 96 3 0 0 1 0 1 1 0 8 0
mbufpl 256 193 0 0 13 0 13 13 0 8 0
bufpl 272 2691 0 102 173 0 173 173 0 8 0
anonpl 32 5852 0 0 48 0 48 48 0 247 0
amapchunkpl 152 15774 0 15215 30 0 30 30 0 158 7
amappl16 200 1818 0 1801 6 2 4 5 0 8 2
amappl15 192 3 0 3 1 1 0 1 0 8 0
amappl14 184 414 0 412 1 0 1 1 0 8 0
amappl13 176 131 0 121 1 0 1 1 0 8 0
amappl12 168 954 0 925 2 0 2 2 0 8 0
amappl11 160 4 0 4 1 1 0 1 0 8 0
amappl10 152 87 0 77 1 0 1 1 0 8 0
amappl9 144 268 0 268 1 1 0 1 0 8 0
amappl8 136 95 0 94 1 0 1 1 0 8 0
amappl7 128 150 0 139 1 0 1 1 0 8 0
amappl6 120 151 0 150 1 0 1 1 0 8 0
amappl5 112 114 0 106 1 0 1 1 0 8 0
amappl4 104 294 0 276 1 0 1 1 0 8 0
amappl3 96 2989 0 2887 5 1 4 4 0 8 0
amappl2 88 617 0 562 2 0 2 2 0 8 0
amappl1 80 13878 0 13329 16 0 16 16 0 8 2
amappl 88 4564 0 4416 5 0 5 5 0 92 0
uvmvnodes 80 98 0 0 2 0 2 2 0 8 0
dma4096 4096 1 0 1 1 1 0 1 0 8 0
dma1024 1024 1 0 0 1 0 1 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 72 10 0 0 1 0 1 1 0 8 0
uaddrrnd 24 707 0 677 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 707 0 677 1 0 1 1 0 8 0
vmmpekpl 168 9290 0 9240 3 0 3 3 0 8 0
vmmpepl 168 56978 0 55242 105 0 105 105 0 357 18
vmsppl 488 706 0 677 7 1 6 6 0 8 1
rwobjpl 80 19210 0 18306 24 0 24 24 0 8 1
pdppl 4096 1421 0 1354 121 44 77 97 0 8 10
pvpl 32 12188 0 0 100 1 99 99 0 265 0
pmappl 256 706 0 677 4 1 3 3 0 8 0
extentpl 40 46 0 28 1 0 1 1 0 8 0
phpool 112 466 0 47 12 0 12 12 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
ddb{0}> trace
x86_ipi_db(ffffffff838f3ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__mp_lock(ffffffff83a64880) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff83a64880) at __mp_lock+0x199 sys/kern/kern_lock.c:173
vn_ioctl(ffffee807d8db700,80084b01,ffff80003afc8e50,ffff80003afb82b8) at vn_ioctl+0x4d sys/kern/vfs_vnops.c:520
sys_ioctl(ffff80003afb82b8,ffff80003afc9030,ffff80003afc8f80) at sys_ioctl+0x674 sys/kern/sys_generic.c:-1
syscall(ffff80003afc9030) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003afc9030) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x73234ebe2f20, count: -8
ddb{0}> machine ddbcpu 1
Stopped at ip6_freemoptions+0x65: movq 0x8(%r15),%r13
ddb{1}> trace
ip6_freemoptions(ffff800000c438d0) at ip6_freemoptions+0x65 sys/netinet6/ip6_output.c:2147
in_pcbdetach(ffffee806fee2e18) at in_pcbdetach+0x122 sys/netinet/in_pcb.c:608
tcp_close(ffff8000015bb420) at tcp_close+0x194 tcpstat_inc sys/netinet/tcp_var.h:-1 [inline]
tcp_close(ffff8000015bb420) at tcp_close+0x194 sys/netinet/tcp_subr.c:530
tcp_detach(ffff800001635a90) at tcp_detach+0x8f sys/netinet/tcp_usrreq.c:-1
soclose(ffff800001635a90,0) at soclose+0xb0 pru_detach sys/sys/protosw.h:281 [inline]
soclose(ffff800001635a90,0) at soclose+0xb0 sys/kern/uipc_socket.c:403
soo_close(ffffee806d218df0,ffff80003afb8020) at soo_close+0x56 sys/kern/sys_socket.c:-1
fdrop(ffffee806d218df0,ffff80003afb8020) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(ffffee806d218df0,ffff80003afb8020) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff80003afb8020) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff80003afb8020,0,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80003afb8020,ffff80003c3fdf00,ffff80003c3fde50) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c3fdf00) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3fdf00) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x79c7ec74b8d0, count: -13
Struck through repros no longer work on HEAD.