panic: UBSan: Undefined Behavior in /syzkaller/managers/netbsd-kubsan/kernel/sys/net/rtsock_shared.c:LINE, member acc

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 1abe2958 - Simplify sc->mii_anegticks setting. Same as Fre..
git tree: netbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=1414d0eae00000
kernel config: https://syzkaller.appspot.com/x/.config?x=824b23e1f4b6c76b
dashboard link: https://syzkaller.appspot.com/bug?extid=d82ebab1313fe21d5baa

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d82eba...@syzkaller.appspotmail.com

�
�
[
93.4889630]
panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/net/rtsock_shared.c:631:41,
member access within misaligned address 0xffffb673a753e74c for type 'struct
rt_msghdr' which requires 8 byte alignment

[ 93.5115624] cpu0: Begin traceback...
[
93.5390017] vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
[ 93.5993244] isAlreadyReported() at netbsd:isAlreadyReported
[ 93.6495874] HandleTypeMismatch.part.1() at
netbsd:HandleTypeMismatch.part.1+0xcc
[ 93.6998537] HandleTypeMismatch() at netbsd:HandleTypeMismatch+0x7b
sys/../common/lib/libc/misc/ubsan.c:408
[ 93.7601725] route_output() at netbsd:route_output+0x17d4
sys/net/rtsock_shared.c:631
[ 93.8204901] raw_send() at netbsd:raw_send+0x20b sys/net/raw_usrreq.c:182
[ 93.8808103] route_send_wrapper() at netbsd:route_send_wrapper+0x9f
route_send sys/net/rtsock_shared.c:464 [inline]
[ 93.8808103] route_send_wrapper() at netbsd:route_send_wrapper+0x9f
sys/net/rtsock_shared.c:1661
[ 93.9310778] sosend() at netbsd:sosend+0x15ac sys/kern/uipc_socket.c:1059
[ 93.9813419] soo_write() at netbsd:soo_write+0x88
sys/kern/sys_socket.c:122
[ 94.0316076] do_filewritev.part.1() at netbsd:do_filewritev.part.1+0x415
[ 94.0919277] sys_writev() at netbsd:sys_writev+0x54 do_filewritev
sys/kern/sys_generic.c:381 [inline]
[ 94.0919277] sys_writev() at netbsd:sys_writev+0x54
sys/kern/sys_generic.c:381
[ 94.1321397] sys___syscall() at netbsd:sys___syscall+0x1c8 sy_call
sys/sys/syscallvar.h:65 [inline]
[ 94.1321397] sys___syscall() at netbsd:sys___syscall+0x1c8
sys/kern/sys_syscall.c:77
[ 94.1924604] syscall() at netbsd:syscall+0x29a sy_call
sys/sys/syscallvar.h:65 [inline]
[ 94.1924604] syscall() at netbsd:syscall+0x29a sy_invoke
sys/sys/syscallvar.h:94 [inline]
[ 94.1924604] syscall() at netbsd:syscall+0x29a
sys/arch/x86/x86/syscall.c:138
[ 94.2126744] --- syscall (number 198) ---
[ 94.2126744] Skipping crash dump on recursive panic
[ 94.2126744] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:153:24,
member access within misaligned address 0x3 for type 'struct x86_64_frame'
which requires 8 byte alignment

[ 94.2432247] Faulted in mid-traceback; aborting...
[ 94.2432247] fatal breakpoint trap in supervisor mode
[ 94.2530768] trap type 1 code 0 rip 0xffffffff8021ddbd cs 0x8 rflags
0x286 cr2 0x70d846025000 ilevel 0x4 rsp 0xffffd680b3b146a0
[ 94.2644588] curlwp 0xffffb673bc076920 pid 1174.3 lowest kstack
0xffffd680b3b122c0
Stopped in pid 1174.3 (syz-executor.4) at netbsd:breakpoint+0x5:
leave
?
breakpoint() at netbsd:breakpoint+0x5
db_panic() at netbsd:db_panic+0x109 sys/ddb/db_panic.c:67
vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
isAlreadyReported() at netbsd:isAlreadyReported
HandleTypeMismatch.part.1() at netbsd:HandleTypeMismatch.part.1+0xcc
HandleTypeMismatch() at netbsd:HandleTypeMismatch+0x7b
sys/../common/lib/libc/misc/ubsan.c:408
db_nextframe() at netbsd:db_nextframe+0x6f6
sys/arch/amd64/amd64/db_machdep.c:153
db_stack_trace_print() at netbsd:db_stack_trace_print+0x2c4
sys/arch/x86/x86/db_trace.c:277
db_panic() at netbsd:db_panic+0xa3 x86_curcpu
sys/arch/amd64/compile/obj/GENERIC_SYZKALLER/./machine/cpu.h:67 [inline]
db_panic() at netbsd:db_panic+0xa3 sys/ddb/db_panic.c:57
vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
isAlreadyReported() at netbsd:isAlreadyReported
HandleTypeMismatch.part.1() at netbsd:HandleTypeMismatch.part.1+0xcc
HandleTypeMismatch() at netbsd:HandleTypeMismatch+0x7b
sys/../common/lib/libc/misc/ubsan.c:408
route_output() at netbsd:route_output+0x17d4 sys/net/rtsock_shared.c:631
raw_send() at netbsd:raw_send+0x20b sys/net/raw_usrreq.c:182
route_send_wrapper() at netbsd:route_send_wrapper+0x9f route_send
sys/net/rtsock_shared.c:464 [inline]
route_send_wrapper() at netbsd:route_send_wrapper+0x9f
sys/net/rtsock_shared.c:1661
sosend() at netbsd:sosend+0x15ac sys/kern/uipc_socket.c:1059
soo_write() at netbsd:soo_write+0x88 sys/kern/sys_socket.c:122
do_filewritev.part.1() at netbsd:do_filewritev.part.1+0x415
sys_writev() at netbsd:sys_writev+0x54 do_filewritev
sys/kern/sys_generic.c:381 [inline]
sys_writev() at netbsd:sys_writev+0x54 sys/kern/sys_generic.c:381
sys___syscall() at netbsd:sys___syscall+0x1c8 sy_call
sys/sys/syscallvar.h:65 [inline]
sys___syscall() at netbsd:sys___syscall+0x1c8 sys/kern/sys_syscall.c:77
syscall() at netbsd:syscall+0x29a sy_call sys/sys/syscallvar.h:65 [inline]
syscall() at netbsd:syscall+0x29a sy_invoke sys/sys/syscallvar.h:94 [inline]
syscall() at netbsd:syscall+0x29a sys/arch/x86/x86/syscall.c:138
--- syscall (number 198) ---
[ 94.2644588] Skipping crash dump on recursive panic
[ 94.2644588] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:154:14,
member access within misaligned address 0x3 for type 'struct x86_64_frame'
which requires 8 byte alignment

[ 94.2644588] Faulted in mid-traceback; aborting...
[ 94.2644588] fatal breakpoint trap in supervisor mode
[ 94.2644588] trap type 1 code 0 rip 0xffffffff8021ddbd cs 0x8 rflags
0x286 cr2 0x70d846025000 ilevel 0x8 rsp 0xffffd680b3b133a0
[ 94.2644588] curlwp 0xffffb673bc076920 pid 1174.3 lowest kstack
0xffffd680b3b122c0
Stopped in pid 1174.3 (syz-executor.4) at netbsd:breakpoint+0x5:
leave


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[Maxime Villard]

dup but garbage, close

#syz invalid