| Message ID | 20230720165143.30208-4-fw@strlen.de (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 87b5a5c209405cb6b57424cdfa226a6dbd349232 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,1/5] netfilter: nf_tables: fix spurious set element insertion failure | expand |
diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index db526cb7a485..49915a2a58eb 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -1929,7 +1929,11 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set, int i, start, rules_fx; match_start = data; - match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; + + if (nft_set_ext_exists(&e->ext, NFT_SET_EXT_KEY_END)) + match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; + else + match_end = data; start = first_rule; rules_fx = rules_f0;
end key should be equal to start unless NFT_SET_EXT_KEY_END is present. Its possible to add elements that only have a start key ("{ 1.0.0.0 . 2.0.0.0 }") without an internval end. Insertion treats this via: if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) end = (const u8 *)nft_set_ext_key_end(ext)->data; else end = start; but removal side always uses nft_set_ext_key_end(). This is wrong and leads to garbage remaining in the set after removal next lookup/insert attempt will give: BUG: KASAN: slab-use-after-free in pipapo_get+0x8eb/0xb90 Read of size 1 at addr ffff888100d50586 by task nft-pipapo_uaf_/1399 Call Trace: kasan_report+0x105/0x140 pipapo_get+0x8eb/0xb90 nft_pipapo_insert+0x1dc/0x1710 nf_tables_newsetelem+0x31f5/0x4e00 .. Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Reported-by: lonial con <kongln9170@gmail.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> --- net/netfilter/nft_set_pipapo.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)