panic: UBSan: Undefined [ 154.ADDR] Behavior in /syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/process_ma

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: c8ea5c08 Import bind 9.14.8 (security fix -- limits on con..
git tree: netbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=10180d86e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=824b23e1f4b6c76b
dashboard link: https://syzkaller.appspot.com/bug?extid=2c4441a3ea7f1dd22767

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+2c4441...@syzkaller.appspotmail.com

[ 154.3381882] panic: UBSan: Undefined [ 154.3496704] Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/process_machdep.c:157:2,
member access within misaligned address 0xffffcc00b43ff8c8 for type 'struct
fpreg' which requires 16 byte alignment

[ 154.3496704] cpu0: Begin traceback...
[ 154.3496704] vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
[ 154.3496704] isAlreadyReported() at netbsd:isAlreadyReported
[ 154.3496704] HandleTypeMismatch.part.1() at
netbsd:HandleTypeMismatch.part.1+0xcc
[ 154.3496704] HandleTypeMismatch() at netbsd:HandleTypeMismatch+0x7b
sys/../common/lib/libc/misc/ubsan.c:408
[ 154.3496704] process_read_fpregs() at netbsd:process_read_fpregs+0x3d
sys/arch/amd64/amd64/process_machdep.c:157
[ 154.3496704] proc_regio() at netbsd:proc_regio+0x164
sys/kern/sys_ptrace_common.c:1478
[ 154.3496704] process_dofpregs() at netbsd:process_dofpregs+0xa7
sys/kern/sys_ptrace_common.c:1566
[ 154.3496704] do_ptrace() at netbsd:do_ptrace+0x12d6 ptrace_regs
sys/kern/sys_ptrace_common.c:897 [inline]
[ 154.3496704] do_ptrace() at netbsd:do_ptrace+0x12d6
sys/kern/sys_ptrace_common.c:1429
[ 154.3496704] sys_ptrace() at netbsd:sys_ptrace+0x4f
sys/kern/sys_ptrace.c:218
[ 154.3496704] sys___syscall() at netbsd:sys___syscall+0x1c8 sy_call
sys/sys/syscallvar.h:65 [inline]
[ 154.3496704] sys___syscall() at netbsd:sys___syscall+0x1c8
sys/kern/sys_syscall.c:77
[ 154.3496704] syscall() at netbsd:syscall+0x29a sy_call
sys/sys/syscallvar.h:65 [inline]
[ 154.3496704] syscall() at netbsd:syscall+0x29a sy_invoke
sys/sys/syscallvar.h:94 [inline]
[ 154.3496704] syscall() at netbsd:syscall+0x29a
sys/arch/x86/x86/syscall.c:138
[ 154.3496704] --- syscall (number 198) ---
[ 154.3496704] Skipping crash dump on recursive panic
[ 154.3496704] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:153:24,
member access within misaligned address 0x4 for type 'struct x86_64_frame'
which requires 8 byte alignment

[ 154.3496704] Faulted in mid-traceback; aborting...
[ 154.3496704] fatal breakpoint trap in supervisor mode
[ 154.3496704] trap type 1 code 0 rip 0xffffffff8021ddbd cs 0x8 rflags
0x286 cr2 0x7b28846a3f4c ilevel 0x8 rsp 0xffffcc00b43fe4b0
[ 154.3496704] curlwp 0xffffcae410a7a540 pid 2486.4 lowest kstack
0xffffcc00b43fc2c0
Stopped in pid 2486.4 (syz-executor.5) 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
process_read_fpregs() at netbsd:process_read_fpregs+0x3d
sys/arch/amd64/amd64/process_machdep.c:157
proc_regio() at netbsd:proc_regio+0x164 sys/kern/sys_ptrace_common.c:1478
process_dofpregs() at netbsd:process_dofpregs+0xa7
sys/kern/sys_ptrace_common.c:1566
do_ptrace() at netbsd:do_ptrace+0x12d6 ptrace_regs
sys/kern/sys_ptrace_common.c:897 [inline]
do_ptrace() at netbsd:do_ptrace+0x12d6 sys/kern/sys_ptrace_common.c:1429
sys_ptrace() at netbsd:sys_ptrace+0x4f sys/kern/sys_ptrace.c:218
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) ---
[ 154.3496704] Skipping crash dump on recursive panic
[ 154.3496704] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:154:14,
member access within misaligned address 0x4 for type 'struct x86_64_frame'
which requires 8 byte alignment

[ 154.3496704] Faulted in mid-traceback; aborting...
[ 154.3496704] fatal breakpoint trap in supervisor mode
[ 154.3496704] trap type 1 code 0 rip 0xffffffff8021ddbd cs 0x8 rflags
0x286 cr2 0x7b28846a3f4c ilevel 0x8 rsp 0xffffcc00b43fd1b0
[ 154.3496704] curlwp 0xffffcae410a7a540 pid 2486.4 lowest kstack
0xffffcc00b43fc2c0
Stopped in pid 2486.4 (syz-executor.5) at netbsd:breakpoint+0x5:
leave


---
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[Maxime Villard]

dup but garbage, close

#syz invalid