UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

netfilter: nf_tables: reject QUEUE/DROP verdict parameters 

commit f342de4e2f33e0e39165d8639387aa6c19dff660 upstream.

This reverts commit e0abdadcc6.

core.c:nf_hook_slow assumes that the upper 16 bits of NF_DROP
verdicts contain a valid errno, i.e. -EPERM, -EHOSTUNREACH or similar,
or 0.

Due to the reverted commit, its possible to provide a positive
value, e.g. NF_ACCEPT (1), which results in use-after-free.

Its not clear to me why this commit was made.

NF_QUEUE is not used by nftables; "queue" rules in nftables
will result in use of "nft_queue" expression.

If we later need to allow specifiying errno values from userspace
(do not know why), this has to call NF_DROP_GETERR and check that
"err <= 0" holds true.

Fixes: e0abdadcc6 ("netfilter: nf_tables: accept QUEUE/DROP verdict parameters")
Cc: stable@vger.kernel.org
Reported-by: Notselwyn <notselwyn@pwning.tech>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Fuhai Wang <fuhaiwang@tencent.com>
Signed-off-by: caelli <caelli@tencent.com>
This commit is contained in:
Fuhai Wang 2024-04-03 15:33:02 +08:00 committed by Jianping Liu
parent 0baa807ed7
commit 47f0d31be8
1 changed files with 6 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
net/netfilter/nf_tables_api.c
View File

@ -7500,16 +7500,10 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data,
data->verdict.code = ntohl(nla_get_be32(tb[NFTA_VERDICT_CODE])); data->verdict.code = ntohl(nla_get_be32(tb[NFTA_VERDICT_CODE]));
switch (data->verdict.code) { switch (data->verdict.code) {
default: case NF_ACCEPT:
switch (data->verdict.code & NF_VERDICT_MASK) { case NF_DROP:
case NF_ACCEPT: case NF_QUEUE:
case NF_DROP: break;
case NF_QUEUE:
break;
default:
return -EINVAL;
}
/* fall through */
case NFT_CONTINUE: case NFT_CONTINUE:
case NFT_BREAK: case NFT_BREAK:
case NFT_RETURN: case NFT_RETURN:
@ -7528,6 +7522,8 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data,
chain->use++; chain->use++;
data->verdict.chain = chain; data->verdict.chain = chain;
break; break;
default:
return -EINVAL;
} }
desc->len = sizeof(data->verdict); desc->len = sizeof(data->verdict);