From 876c07ee64c6e456f21f0e55e5012c0f06e08420 Mon Sep 17 00:00:00 2001 From: Byeonguk Jeong Date: Thu, 21 Nov 2024 03:14:57 +0000 Subject: [PATCH] bpf: Fix out-of-bounds write in trie_get_next_key() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit stable inclusion from stable-v5.10.229 commit 590976f921723d53ac199c01d5b7b73a94875e68 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IB379Y CVE: CVE-2024-50262 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=590976f92172 -------------------------------- [ Upstream commit 13400ac8fb80c57c2bfb12ebd35ee121ce9b4d21 ] trie_get_next_key() allocates a node stack with size trie->max_prefixlen, while it writes (trie->max_prefixlen + 1) nodes to the stack when it has full paths from the root to leaves. For example, consider a trie with max_prefixlen is 8, and the nodes with key 0x00/0, 0x00/1, 0x00/2, ... 0x00/8 inserted. Subsequent calls to trie_get_next_key with _key with .prefixlen = 8 make 9 nodes be written on the node stack with size 8. Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map") Signed-off-by: Byeonguk Jeong Reviewed-by: Toke Høiland-Jørgensen Tested-by: Hou Tao Acked-by: Hou Tao Link: https://lore.kernel.org/r/Zxx384ZfdlFYnz6J@localhost.localdomain Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin Signed-off-by: Xiaomeng Zhang --- kernel/bpf/lpm_trie.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 00e32f2ec3e6..7bbadd9ac3e9 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -652,7 +652,7 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key) if (!key || key->prefixlen > trie->max_prefixlen) goto find_leftmost; - node_stack = kmalloc_array(trie->max_prefixlen, + node_stack = kmalloc_array(trie->max_prefixlen + 1, sizeof(struct lpm_trie_node *), GFP_ATOMIC | __GFP_NOWARN); if (!node_stack) -- Gitee