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authorDan Carpenter <dan.carpenter@linaro.org>2023-11-03 09:42:51 +0300
committerPablo Neira Ayuso <pablo@netfilter.org>2023-11-14 16:16:21 +0100
commitc301f0981fdd3fd1ffac6836b423c4d7a8e0eb63 (patch)
tree8affa98af2d39162ba70c261a130b2f8d1a3b7ae /net
parenta44af08e3d4d7566eeea98d7a29fe06e7b9de944 (diff)
netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()
The problem is in nft_byteorder_eval() where we are iterating through a loop and writing to dst[0], dst[1], dst[2] and so on... On each iteration we are writing 8 bytes. But dst[] is an array of u32 so each element only has space for 4 bytes. That means that every iteration overwrites part of the previous element. I spotted this bug while reviewing commit caf3ef7468f7 ("netfilter: nf_tables: prevent OOB access in nft_byteorder_eval") which is a related issue. I think that the reason we have not detected this bug in testing is that most of time we only write one element. Fixes: ce1e7989d989 ("netfilter: nft_byteorder: provide 64bit le/be conversion") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nft_byteorder.c5
-rw-r--r--net/netfilter/nft_meta.c2
2 files changed, 4 insertions, 3 deletions
diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c
index e596d1a842f7..f6e791a68101 100644
--- a/net/netfilter/nft_byteorder.c
+++ b/net/netfilter/nft_byteorder.c
@@ -38,13 +38,14 @@ void nft_byteorder_eval(const struct nft_expr *expr,
switch (priv->size) {
case 8: {
+ u64 *dst64 = (void *)dst;
u64 src64;
switch (priv->op) {
case NFT_BYTEORDER_NTOH:
for (i = 0; i < priv->len / 8; i++) {
src64 = nft_reg_load64(&src[i]);
- nft_reg_store64(&dst[i],
+ nft_reg_store64(&dst64[i],
be64_to_cpu((__force __be64)src64));
}
break;
@@ -52,7 +53,7 @@ void nft_byteorder_eval(const struct nft_expr *expr,
for (i = 0; i < priv->len / 8; i++) {
src64 = (__force __u64)
cpu_to_be64(nft_reg_load64(&src[i]));
- nft_reg_store64(&dst[i], src64);
+ nft_reg_store64(&dst64[i], src64);
}
break;
}
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index f7da7c43333b..ba0d3683a45d 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -63,7 +63,7 @@ nft_meta_get_eval_time(enum nft_meta_keys key,
{
switch (key) {
case NFT_META_TIME_NS:
- nft_reg_store64(dest, ktime_get_real_ns());
+ nft_reg_store64((u64 *)dest, ktime_get_real_ns());
break;
case NFT_META_TIME_DAY:
nft_reg_store8(dest, nft_meta_weekday());