diff options
| author | Byeonguk Jeong <[email protected]> | 2024-10-26 14:02:43 +0900 |
|---|---|---|
| committer | Alexei Starovoitov <[email protected]> | 2024-10-29 13:41:40 -0700 |
| commit | 13400ac8fb80c57c2bfb12ebd35ee121ce9b4d21 (patch) | |
| tree | cda75874d697a484f3860d50709212ecb1ace4da | |
| parent | 1fb315892d8395cec2dae04b0cb5558731aefb37 (diff) | |
bpf: Fix out-of-bounds write in trie_get_next_key()
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 <[email protected]>
Reviewed-by: Toke Høiland-Jørgensen <[email protected]>
Tested-by: Hou Tao <[email protected]>
Acked-by: Hou Tao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
| -rw-r--r-- | kernel/bpf/lpm_trie.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 0218a5132ab5..9b60eda0f727 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -655,7 +655,7 @@ 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) |