syzbot
netbsd boot error: panic: UBSan: Undefined Behavior in /syzkaller/managers/netbsd-kubsan/kernel/sys/kern/vfs_subr.c:LINE, member access wit
Status:
fixed on 2019/11/17 08:54
Reported-by: syzbot+d27bc1be926b3641c0ad@syzkaller.appspotmail.com
Fix commit:
473e202ba108
NULL-check the structure pointer, not the address of its first field. This is clearer and also appeases syzbot.
First crash: 2452d, last: 2442d
Sample crash report:
[ 1.5901550] panic: UBSan: Undefined Behavior in /syzkaller/managers/netbsd-kubsan/kernel/sys/kern/vfs_subr.c:793:14, member access within null pointer of type 'struct vnode_impl'
[ 1.6025195] cpu0: Begin traceback...
[ 1.6066290] vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
[ 1.6266633] isAlreadyReported() at netbsd:isAlreadyReported
[ 1.6366788] HandleTypeMismatch.part.1() at netbsd:HandleTypeMismatch.part.1+0x15b
[ 1.6567132] HandleTypeMismatch() at netbsd:HandleTypeMismatch+0x7b sys/../common/lib/libc/misc/ubsan.c:408
[ 1.6767468] sched_sync() at netbsd:sched_sync+0x50a sys/kern/vfs_subr.c:793
[ 1.6767468] cpu0: End traceback...
[ 1.6767468] fatal breakpoint trap in supervisor mode
[ 1.6876654] trap type 1 code 0 rip 0xffffffff8021dddd cs 0x8 rflags 0x286 cr2 0 ilevel 0 rsp 0xffffb180a691a9e0
[ 1.6876654] curlwp 0xfffff6a8b821f660 pid 0.55 lowest kstack 0xffffb180a69172c0
Stopped in pid 0.55 (system) at netbsd:breakpoint+0x5: leave
db{0}>
* Struck through repros no longer work on HEAD.