From 791035c8da5e8a693b3b954db67ff50b4f8695cb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stefan=20E=C3=9Fer?= Date: Sat, 10 Jul 2021 13:00:56 +0200 Subject: [PATCH] libalias: fix divide by zero causing panic The packet_limit can fall to 0, leading to a divide by zero abort in the "packets % packet_limit". An possible solution would be to apply a lower limit of 1 after the calculation of packet_limit, but since any number modulo 1 gives 0, the more efficient solution is to skip the modulo operation for packet_limit <= 1. Reported by: Karl Denninger (cherry picked from commit 58080fbca09fda6d5f011d37059edbca8ceb4c58) --- sys/netinet/libalias/alias_db.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/netinet/libalias/alias_db.c b/sys/netinet/libalias/alias_db.c index 783a8ca3baa..ed222c4133d 100644 --- a/sys/netinet/libalias/alias_db.c +++ b/sys/netinet/libalias/alias_db.c @@ -1769,7 +1769,7 @@ HouseKeeping(struct libalias *la) * Reduce the amount of house keeping work substantially by * sampling over the packets. */ - if (packets % packet_limit == 0) { + if (packet_limit <= 1 || packets % packet_limit == 0) { time_t now; #ifdef _KERNEL