This is a note to let you know that I've just added the patch titled
bpf: Fix out-of-bounds write in trie_get_next_key()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-fix-out-of-bounds-write-in-trie_get_next_key.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a6d20a7d82be3a98e8fa4cc3f1f5d36820746abf
Author: Byeonguk Jeong <jungbu2855@xxxxxxxxx>
Date: Sat Oct 26 14:02:43 2024 +0900
bpf: Fix out-of-bounds write in trie_get_next_key()
[ 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 <jungbu2855@xxxxxxxxx>
Reviewed-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Tested-by: Hou Tao <houtao1@xxxxxxxxxx>
Acked-by: Hou Tao <houtao1@xxxxxxxxxx>
Link: https://lore.kernel.org/r/Zxx384ZfdlFYnz6J@localhost.localdomain
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 4ea7fb0ca1ad4..6b2bf71f8de4b 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -644,7 +644,7 @@ 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)
