From eb7bf413e59945df03d4567b73ce464eebe2f4ea Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 17 Apr 2026 16:22:42 +0800 Subject: [PATCH] nf_tables: nft_dynset: fix possible stateful expression memleak in error path MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 0548a13b5a145b16e4da0628b5936baf35f51b43 ] If cloning the second stateful expression in the element via GFP_ATOMIC fails, then the first stateful expression remains in place without being released.   unreferenced object (percpu) 0x607b97e9cab8 (size 16):     comm "softirq", pid 0, jiffies 4294931867     hex dump (first 16 bytes on cpu 3):       00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00     backtrace (crc 0):       pcpu_alloc_noprof+0x453/0xd80       nft_counter_clone+0x9c/0x190 [nf_tables]       nft_expr_clone+0x8f/0x1b0 [nf_tables]       nft_dynset_new+0x2cb/0x5f0 [nf_tables]       nft_rhash_update+0x236/0x11c0 [nf_tables]       nft_dynset_eval+0x11f/0x670 [nf_tables]       nft_do_chain+0x253/0x1700 [nf_tables]       nft_do_chain_ipv4+0x18d/0x270 [nf_tables]       nf_hook_slow+0xaa/0x1e0       ip_local_deliver+0x209/0x330 Fixes: 563125a73ac3 ("netfilter: nftables: generalize set extension to support for several expressions") Reported-by: Gurpreet Shergill Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal [ Minor conflict resolved. ] Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Sasha Levin --- include/net/netfilter/nf_tables.h | 2 ++ net/netfilter/nf_tables_api.c | 4 ++-- net/netfilter/nft_dynset.c | 10 +++++++++- 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 9f68155e054c..2b977d5d6f30 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -821,6 +821,8 @@ void *nft_set_elem_init(const struct nft_set *set, u64 timeout, u64 expiration, gfp_t gfp); int nft_set_elem_expr_clone(const struct nft_ctx *ctx, struct nft_set *set, struct nft_expr *expr_array[]); +void nft_set_elem_expr_destroy(const struct nft_ctx *ctx, + struct nft_set_elem_expr *elem_expr); void nft_set_elem_destroy(const struct nft_set *set, void *elem, bool destroy_expr); void nf_tables_set_elem_destroy(const struct nft_ctx *ctx, diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 53d7dd39a95b..623b776bf792 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5919,8 +5919,8 @@ static void __nft_set_elem_expr_destroy(const struct nft_ctx *ctx, } } -static void nft_set_elem_expr_destroy(const struct nft_ctx *ctx, - struct nft_set_elem_expr *elem_expr) +void nft_set_elem_expr_destroy(const struct nft_ctx *ctx, + struct nft_set_elem_expr *elem_expr) { struct nft_expr *expr; u32 size; diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c index ecdd4a60db9c..673c5e6a3e8d 100644 --- a/net/netfilter/nft_dynset.c +++ b/net/netfilter/nft_dynset.c @@ -30,18 +30,26 @@ static int nft_dynset_expr_setup(const struct nft_dynset *priv, const struct nft_set_ext *ext) { struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext); + struct nft_ctx ctx = { + .net = read_pnet(&priv->set->net), + .family = priv->set->table->family, + }; struct nft_expr *expr; int i; for (i = 0; i < priv->num_exprs; i++) { expr = nft_setelem_expr_at(elem_expr, elem_expr->size); if (nft_expr_clone(expr, priv->expr_array[i], GFP_ATOMIC) < 0) - return -1; + goto err_out; elem_expr->size += priv->expr_array[i]->ops->size; } return 0; +err_out: + nft_set_elem_expr_destroy(&ctx, elem_expr); + + return -1; } static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,