This patch checks to make sure that the number of instructions doesn't surpass BPF_MAXINSNS in sk_chk_filter().
Signed-off-by: Kris Katterjohn <[EMAIL PROTECTED]> --- This is a diff from 2.6.15-rc5. And I am not subscribed, so please CC me on any replies. The previous check in sk_chk_filter() doesn't seem very logical to me because it should either be limited to BPF_MAXINSNS or only limited by the max value of an `int' (not really limited). sk_attach_filter() and get_filter() in drivers/net/ppp_generic.c limit it to BPF_MAXINSNS, but get_filter() in drivers/isdn/i4l/isdn_ppp.c and anything else that will use it only get this seemingly "random" limit. This way it is checked for in only one place, and has a single constant limit. Thanks! --- x/net/core/filter.c 2005-12-06 04:01:50.000000000 -0600 +++ y/net/core/filter.c 2005-12-06 04:04:23.000000000 -0600 @@ -293,7 +293,8 @@ int sk_chk_filter(struct sock_filter *fi struct sock_filter *ftest; int pc; - if (((unsigned int)flen >= (~0U / sizeof(struct sock_filter))) || flen == 0) + /* check for valid number of instructions -Kris Katterjohn 2005-12-06 */ + if (flen == 0 || flen > BPF_MAXINSNS) return -EINVAL; /* check the filter code now */ @@ -359,9 +360,9 @@ int sk_attach_filter(struct sock_fprog * unsigned int fsize = sizeof(struct sock_filter) * fprog->len; int err; - /* Make sure new filter is there and in the right amounts. */ - if (fprog->filter == NULL || fprog->len > BPF_MAXINSNS) - return -EINVAL; + /* Make sure new filter is there */ + if (fprog->filter == NULL) + return -EINVAL; fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL); if (!fp) - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html