From 1b93ae64cabe5e28dd5a1f35f96f938ca4f6ae20 Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@sunset.davemloft.net>
Date: Tue, 27 Dec 2005 13:57:59 -0800
Subject: [PATCH] [NET]: Validate socket filters against BPF_MAXINSNS in one
spot.
Currently the checks are scattered all over and this leads
to inconsistencies and even cases where the check is not made.
Based upon a patch from Kris Katterjohn.
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/ppp_generic.c | 3 ---
net/core/filter.c | 4 ++--
2 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 50430f79f8cf8..1c6d328165bb0 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -524,9 +524,6 @@ static int get_filter(void __user *arg, struct sock_filter **p)
if (copy_from_user(&uprog, arg, sizeof(uprog)))
return -EFAULT;
- if (uprog.len > BPF_MAXINSNS)
- return -EINVAL;
-
if (!uprog.len) {
*p = NULL;
return 0;
diff --git a/net/core/filter.c b/net/core/filter.c
index 2841bfce29d6a..3a10e0bc90e8a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -293,7 +293,7 @@ int sk_chk_filter(struct sock_filter *filter, int flen)
struct sock_filter *ftest;
int pc;
- if (((unsigned int)flen >= (~0U / sizeof(struct sock_filter))) || flen == 0)
+ if (flen == 0 || flen > BPF_MAXINSNS)
return -EINVAL;
/* check the filter code now */
@@ -360,7 +360,7 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
int err;
/* Make sure new filter is there and in the right amounts. */
- if (fprog->filter == NULL || fprog->len > BPF_MAXINSNS)
+ if (fprog->filter == NULL)
return -EINVAL;
fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL);
--
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