From: Florian Westphal <fw@strlen.de> mainline inclusion from mainline-v6.8-rc2 commit f342de4e2f33e0e39165d8639387aa6c19dff660 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I90B2K CVE: CVE-2024-1086 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- This reverts commit e0abdadcc6e1. 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: e0abdadcc6e1 ("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> Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- net/netfilter/nf_tables_api.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index e07c497e7344..3ee5beb220bd 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7175,16 +7175,10 @@ 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])); switch (data->verdict.code) { - default: - switch (data->verdict.code & NF_VERDICT_MASK) { - case NF_ACCEPT: - case NF_DROP: - case NF_QUEUE: - break; - default: - return -EINVAL; - } - /* fall through */ + case NF_ACCEPT: + case NF_DROP: + case NF_QUEUE: + break; case NFT_CONTINUE: case NFT_BREAK: case NFT_RETURN: @@ -7203,6 +7197,8 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, chain->use++; data->verdict.chain = chain; break; + default: + return -EINVAL; } desc->len = sizeof(data->verdict); -- 2.25.1