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| author | Dan Carpenter <dan.carpenter@linaro.org> | 2023-11-03 09:42:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-02-23 08:12:58 +0100 |
| commit | fca41e5b687e029f69e3a35a2fa31e2560e538dc (patch) | |
| tree | 852c17231572a2695ccc4f3ca8eb3bbe567a8846 | |
| parent | f8f51085b4be6132762ce0d8940071ccdcce2504 (diff) | |
| download | linux-stable-fca41e5b687e029f69e3a35a2fa31e2560e538dc.tar.gz linux-stable-fca41e5b687e029f69e3a35a2fa31e2560e538dc.tar.bz2 linux-stable-fca41e5b687e029f69e3a35a2fa31e2560e538dc.zip | |
netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()
commit c301f0981fdd3fd1ffac6836b423c4d7a8e0eb63 upstream.
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>
[Ajay: Modified to apply on v4.19.y]
Signed-off-by: Ajay Kaher <ajay.kaher@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/netfilter/nft_byteorder.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c index dba16126c7ee..8c4ee49a80fb 100644 --- a/net/netfilter/nft_byteorder.c +++ b/net/netfilter/nft_byteorder.c @@ -41,19 +41,20 @@ static 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 = get_unaligned((u64 *)&src[i]); - put_unaligned_be64(src64, &dst[i]); + put_unaligned_be64(src64, &dst64[i]); } break; case NFT_BYTEORDER_HTON: for (i = 0; i < priv->len / 8; i++) { src64 = get_unaligned_be64(&src[i]); - put_unaligned(src64, (u64 *)&dst[i]); + put_unaligned(src64, &dst64[i]); } break; } |