From: Pablo Neira Ayuso pablo@netfilter.org

mainline inclusion from mainline-v6.9-rc5 commit 29b359cf6d95fd60730533f7f10464e95bd17c73 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9L5O8 CVE: CVE-2024-27017

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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The generation mask can be updated while netlink dump is in progress. The pipapo set backend walk iterator cannot rely on it to infer what view of the datastructure is to be used. Add notation to specify if user wants to read/update the set.

Based on patch from Florian Westphal.

Fixes: 2b84e215f874 ("netfilter: nft_set_pipapo: .walk does not deal with generations") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org

Conflicts: include/net/netfilter/nf_tables.h net/netfilter/nf_tables_api.c net/netfilter/nft_set_pipapo.c [e6ba7cb63b8a ("netfilter: nftables: add helper function to flush set elements") is not applied, so there is no nft_set_flush() function. Adaptation was made in nf_tables_delsetelem(). Other adaptations are context conflicts.] Signed-off-by: Wang Hai wanghai38@huawei.com --- include/net/netfilter/nf_tables.h | 13 +++++++++++++ net/netfilter/nf_tables_api.c | 6 ++++++ net/netfilter/nft_set_pipapo.c | 5 +++-- 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 972832560b9d..5e3529c73e61 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -262,9 +262,22 @@ struct nft_set_elem { void *priv; };

+/** + * enum nft_iter_type - nftables set iterator type + * + * @NFT_ITER_READ: read-only iteration over set elements + * @NFT_ITER_UPDATE: iteration under mutex to update set element state + */ +enum nft_iter_type { + NFT_ITER_UNSPEC, + NFT_ITER_READ, + NFT_ITER_UPDATE, +}; + struct nft_set; struct nft_set_iter { u8 genmask; + enum nft_iter_type type:8; unsigned int count; unsigned int skip; int err; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 68d68f546364..d43006caf3f2 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -593,6 +593,7 @@ static void nft_map_deactivate(const struct nft_ctx *ctx, struct nft_set *set) { struct nft_set_iter iter = { .genmask = nft_genmask_next(ctx->net), + .type = NFT_ITER_UPDATE, .fn = nft_mapelem_deactivate, };

@@ -4727,6 +4728,7 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set, }

iter.genmask = nft_genmask_next(ctx->net); + iter.type = NFT_ITER_UPDATE; iter.skip = 0; iter.count = 0; iter.err = 0; @@ -4780,6 +4782,7 @@ static void nft_map_activate(const struct nft_ctx *ctx, struct nft_set *set) { struct nft_set_iter iter = { .genmask = nft_genmask_next(ctx->net), + .type = NFT_ITER_UPDATE, .fn = nft_mapelem_activate, };

@@ -5093,6 +5096,7 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb) args.cb = cb; args.skb = skb; args.iter.genmask = nft_genmask_cur(net); + args.iter.type = NFT_ITER_READ; args.iter.skip = cb->args[0]; args.iter.count = 0; args.iter.err = 0; @@ -6022,6 +6026,7 @@ static int nf_tables_delsetelem(struct net *net, struct sock *nlsk, if (nla[NFTA_SET_ELEM_LIST_ELEMENTS] == NULL) { struct nft_set_iter iter = { .genmask = genmask, + .type = NFT_ITER_UPDATE, .fn = nft_flush_set, }; set->ops->walk(&ctx, set, &iter); @@ -9131,6 +9136,7 @@ static int nf_tables_check_loops(const struct nft_ctx *ctx, continue;

iter.genmask = nft_genmask_next(ctx->net); + iter.type = NFT_ITER_UPDATE; iter.skip = 0; iter.count = 0; iter.err = 0; diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index b9682e085fce..e083b1a0509a 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -2018,13 +2018,14 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, struct nft_set_iter *iter) { struct nft_pipapo *priv = nft_set_priv(set); - struct net *net = read_pnet(&set->net); struct nft_pipapo_match *m; struct nft_pipapo_field *f; int i, r;

+ WARN_ON_ONCE(iter->type == NFT_ITER_UNSPEC); + rcu_read_lock(); - if (iter->genmask == nft_genmask_cur(net)) + if (iter->type == NFT_ITER_READ) m = rcu_dereference(priv->match); else m = priv->clone;