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authorKris Katterjohn <kjak@users.sourceforge.net>2005-11-20 13:41:34 -0800
committerDavid S. Miller <davem@davemloft.net>2005-11-20 13:41:34 -0800
commitfb0d366b0803571f06a5b838f02c6706fc287995 (patch)
tree473d0e16f244ef7c7415d865419b7b0187f52a7f
parentaa8751667dcd757dd9a711b51140adf181501c44 (diff)
downloadlinux-fb0d366b0803571f06a5b838f02c6706fc287995.tar.bz2
[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 <kjak@users.sourceforge.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/filter.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index 079c2edff789..2841bfce29d6 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... */