From fb0d366b0803571f06a5b838f02c6706fc287995 Mon Sep 17 00:00:00 2001 From: Kris Katterjohn Date: Sun, 20 Nov 2005 13:41:34 -0800 Subject: [PATCH] [NET]: Reject socket filter if division by constant zero is attempted. This way we don't have to check it in sk_run_filter(). Signed-off-by: Kris Katterjohn Signed-off-by: David S. Miller --- net/core/filter.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 079c2edff78..2841bfce29d 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -116,8 +116,6 @@ int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen) A /= X; continue; case BPF_ALU|BPF_DIV|BPF_K: - if (fentry->k == 0) - return 0; A /= fentry->k; continue; case BPF_ALU|BPF_AND|BPF_X: @@ -320,6 +318,10 @@ int sk_chk_filter(struct sock_filter *filter, int flen) } } + /* check for division by zero -Kris Katterjohn 2005-10-30 */ + if (ftest->code == (BPF_ALU|BPF_DIV|BPF_K) && ftest->k == 0) + return -EINVAL; + /* check that memory operations use valid addresses. */ if (ftest->k >= BPF_MEMWORDS) { /* but it might not be a memory operation... */ -- 2.39.3