Commit a50436f2 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller

net: ipmr/ip6mr: fix potential out-of-bounds vif_table access

mfc_parent of cache entries is used to index into the vif_table and is
initialised from mfcctl->mfcc_parent. This can take values of to 2^16-1,
while the vif_table has only MAXVIFS (32) entries. The same problem
affects ip6mr.

Refuse invalid values to fix a potential out-of-bounds access. Unlike
the other validity checks, this is checked in ipmr_mfc_add() instead of
the setsockopt handler since its unused in the delete path and might be
uninitialized.
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ea93fd94
...@@ -802,6 +802,9 @@ static int ipmr_mfc_add(struct net *net, struct mfcctl *mfc, int mrtsock) ...@@ -802,6 +802,9 @@ static int ipmr_mfc_add(struct net *net, struct mfcctl *mfc, int mrtsock)
int line; int line;
struct mfc_cache *uc, *c, **cp; struct mfc_cache *uc, *c, **cp;
if (mfc->mfcc_parent >= MAXVIFS)
return -ENFILE;
line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr); line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
for (cp = &net->ipv4.mfc_cache_array[line]; for (cp = &net->ipv4.mfc_cache_array[line];
......
...@@ -1113,6 +1113,9 @@ static int ip6mr_mfc_add(struct net *net, struct mf6cctl *mfc, int mrtsock) ...@@ -1113,6 +1113,9 @@ static int ip6mr_mfc_add(struct net *net, struct mf6cctl *mfc, int mrtsock)
unsigned char ttls[MAXMIFS]; unsigned char ttls[MAXMIFS];
int i; int i;
if (mfc->mf6cc_parent >= MAXMIFS)
return -ENFILE;
memset(ttls, 255, MAXMIFS); memset(ttls, 255, MAXMIFS);
for (i = 0; i < MAXMIFS; i++) { for (i = 0; i < MAXMIFS; i++) {
if (IF_ISSET(i, &mfc->mf6cc_ifset)) if (IF_ISSET(i, &mfc->mf6cc_ifset))
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment