diff options
| author | Taehee Yoo <ap420073@gmail.com> | 2018-04-18 23:35:34 +0900 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-04-19 12:34:13 +0200 |
| commit | d71efb599ad42ef1e564c652d8084252bdc85edf (patch) | |
| tree | 816880956d36c3e9ab53a188eafa5442729ee9bd /net | |
| parent | 39f2ff0816e5421476c2bc538b68b4bb0708a78e (diff) | |
netfilter: nf_tables: fix out-of-bounds in nft_chain_commit_update
When chain name is changed, nft_chain_commit_update is called.
In the nft_chain_commit_update, trans->ctx.chain->name has old chain name
and nft_trans_chain_name(trans) has new chain name.
If new chain name is longer than old chain name, KASAN warns
slab-out-of-bounds.
[ 175.015012] BUG: KASAN: slab-out-of-bounds in strcpy+0x9e/0xb0
[ 175.022735] Write of size 1 at addr ffff880114e022da by task iptables-compat/1458
[ 175.031353] CPU: 0 PID: 1458 Comm: iptables-compat Not tainted 4.16.0-rc7+ #146
[ 175.031353] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 07/08/2015
[ 175.031353] Call Trace:
[ 175.031353] dump_stack+0x68/0xa0
[ 175.031353] print_address_description+0xd0/0x260
[ 175.031353] ? strcpy+0x9e/0xb0
[ 175.031353] kasan_report+0x234/0x350
[ 175.031353] __asan_report_store1_noabort+0x1c/0x20
[ 175.031353] strcpy+0x9e/0xb0
[ 175.031353] nf_tables_commit+0x1ccc/0x2990
[ 175.031353] nfnetlink_rcv+0x141e/0x16c0
[ 175.031353] ? nfnetlink_net_init+0x150/0x150
[ 175.031353] ? lock_acquire+0x370/0x370
[ 175.031353] ? lock_acquire+0x370/0x370
[ 175.031353] netlink_unicast+0x444/0x640
[ 175.031353] ? netlink_attachskb+0x700/0x700
[ 175.031353] ? _copy_from_iter_full+0x180/0x740
[ 175.031353] ? kasan_check_write+0x14/0x20
[ 175.031353] ? _copy_from_user+0x9b/0xd0
[ 175.031353] netlink_sendmsg+0x845/0xc70
[ ... ]
Steps to reproduce:
iptables-compat -N 1
iptables-compat -E 1 aaaaaaaaa
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 102ad873acb4..04d4e3772584 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5745,7 +5745,7 @@ static void nft_chain_commit_update(struct nft_trans *trans) struct nft_base_chain *basechain; if (nft_trans_chain_name(trans)) - strcpy(trans->ctx.chain->name, nft_trans_chain_name(trans)); + swap(trans->ctx.chain->name, nft_trans_chain_name(trans)); if (!nft_is_base_chain(trans->ctx.chain)) return; |