panic: kernel diagnostic assertioWn AR"lNwINpcGn:t d e>f= a0u"lt efadil emmd:a p(f)i lse h"a/rsey ztykpalel etor /MmAanP

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: fb02a8ee Simplify userret function signature. From ad@
git tree: netbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=1337fc32e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=824b23e1f4b6c76b
dashboard link: https://syzkaller.appspot.com/bug?extid=df0684886e5b7d787d9e
compiler: g++ (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609

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+df0684...@syzkaller.appspotmail.com

[ 97.6753679] panic: kernel diagnostic assertioWn AR"lNwINpcGn:t d e>f=
a0u"lt efadil emmd:a p(f)i lse h"a/rsey ztykpalel etor
/MmAanP_aPgReIrsVA/TnEet b(psdi-d ku4b4s8 anc/okmmearnndel
s/yszy-se/xkeecrunt/okerr.n3)_
u[
97.6753679] idinfo.c", line 225
[ 97.6753679] cpu0: Begin traceback...
[ 97.6753679] vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
[ 97.6753679] kern_assert() at netbsd:kern_assert+0x63
[ 97.6753679] chglwpcnt() at netbsd:chglwpcnt+0x82
sys/kern/kern_uidinfo.c:225
[ 97.6753679] lwp_free() at netbsd:lwp_free+0x5be sys/kern/kern_lwp.c:1239
[ 97.6753679] lwp_wait() at netbsd:lwp_wait+0x1ad sys/kern/kern_lwp.c:569
[ 97.6753679] exit_lwps() at netbsd:exit_lwps+0x2cb
sys/kern/kern_exit.c:634
[ 97.6753679] exit1() at netbsd:exit1+0x15e ksiginfo_queue_init
sys/sys/signalvar.h:239 [inline]
[ 97.6753679] exit1() at netbsd:exit1+0x15e sys/kern/kern_exit.c:224
[ 97.6753679] sys_exit() at netbsd:sys_exit+0xba sys/kern/kern_exit.c:179
[ 97.6753679] syscall() at netbsd:syscall+0x29a sy_call
sys/sys/syscallvar.h:65 [inline]
[ 97.6753679] syscall() at netbsd:syscall+0x29a sy_invoke
sys/sys/syscallvar.h:94 [inline]
[ 97.6753679] syscall() at netbsd:syscall+0x29a
sys/arch/x86/x86/syscall.c:138
[ 97.6753679] --- syscall (number 1) ---
[ 97.6753679] Skipping crash dump on recursive panic
[ 97.6753679] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:153:24,
member access within misaligned address 0xffffffff for type 'struct
x86_64_frame' which requires 8 byte alignment

[ 97.6753679] Faulted in mid-traceback; aborting...
[ 97.6753679] fatal breakpoint trap in supervisor mode
[ 97.6753679] trap type 1 code 0 rip 0xffffffff8021ddbd cs 0x8 rflags
0x286 cr2 0x9 ilevel 0x8 rsp 0xffffd780b3a69e10
[ 97.6753679] curlwp 0xfffff99b68aef900 pid 965.1 lowest kstack
0xffffd780b3a672c0
Stopped in pid 965.1 (syz-executor.2) at netbsd:breakpoint+0x5:
leave
?
breakpoint() at netbsd:breakpoint+0x5
db_panic() at netbsd:db_panic+0xd1 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+0x8b x86_curcpu
sys/arch/amd64/compile/obj/GENERIC_SYZKALLER/./machine/cpu.h:67 [inline]
db_panic() at netbsd:db_panic+0x8b sys/ddb/db_panic.c:57
vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
kern_assert() at netbsd:kern_assert+0x63
chglwpcnt() at netbsd:chglwpcnt+0x82 sys/kern/kern_uidinfo.c:225
lwp_free() at netbsd:lwp_free+0x5be sys/kern/kern_lwp.c:1239
lwp_wait() at netbsd:lwp_wait+0x1ad sys/kern/kern_lwp.c:569
exit_lwps() at netbsd:exit_lwps+0x2cb sys/kern/kern_exit.c:634
exit1() at netbsd:exit1+0x15e ksiginfo_queue_init sys/sys/signalvar.h:239
[inline]
exit1() at netbsd:exit1+0x15e sys/kern/kern_exit.c:224
sys_exit() at netbsd:sys_exit+0xba sys/kern/kern_exit.c:179
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 1) ---
[ 97.6753679] Skipping crash dump on recursive panic
[ 97.6753679] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:154:14,
member access within misaligned address 0xffffffff for type 'struct
x86_64_frame' which requires 8 byte alignment

[ 97.6753679] Faulted in mid-traceback; aborting...
[ 97.6753679] fatal breakpoint trap in supervisor mode
[ 97.6753679] trap type 1 code 0 rip 0xffffffff8021ddbd cs 0x8 rflags
0x286 cr2 0x9 ilevel 0x8 rsp 0xffffd780b3a68b10
[ 97.6753679] curlwp 0xfffff99b68aef900 pid 965.1 lowest kstack
0xffffd780b3a672c0
Stopped in pid 965.1 (syz-executor.2) at netbsd:breakpoint+0x5:
leave


---
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[Maxime Villard]

malformed duplicate

#syz invalid