Syzkaller expects kernel warnings to panic when the panic_on_warn sysctl is set. More work is needed here to have UBSan reuse the WARN infrastructure, but for now, just check the flag manually. Link: https://lore.kernel.org/lkml/CACT4Y+bsLJ-wFx_TaXqax3JByUOWB3uk787LsyMVcfW6JzzGvg@xxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- lib/ubsan.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/lib/ubsan.c b/lib/ubsan.c index 7b9b58aee72c..429663eef6a7 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -156,6 +156,17 @@ static void ubsan_epilogue(void) "========================================\n"); current->in_ubsan--; + + if (panic_on_warn) { + /* + * This thread may hit another WARN() in the panic path. + * Resetting this prevents additional WARN() from panicking the + * system on this thread. Other threads are blocked by the + * panic_mutex in panic(). + */ + panic_on_warn = 0; + panic("panic_on_warn set ...\n"); + } } static void handle_overflow(struct overflow_data *data, void *lhs, -- 2.20.1
