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netfilter: nf_tables: fix audit memory leak in nf_tables_commit

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commit cfbe3650dd3ef2ea9a4420ca89d9a4df98af3fb6 upstream.

In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not
free the adp variable.

Fix this by adding nf_tables_commit_audit_free which frees
the linked list with the head node adl.

backtrace:
  kmalloc include/linux/slab.h:591 [inline]
  kzalloc include/linux/slab.h:721 [inline]
  nf_tables_commit_audit_alloc net/netfilter/nf_tables_api.c:8439 [inline]
  nf_tables_commit+0x16e/0x1760 net/netfilter/nf_tables_api.c:8508
  nfnetlink_rcv_batch+0x512/0xa80 net/netfilter/nfnetlink.c:562
  nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
  nfnetlink_rcv+0x1fa/0x220 net/netfilter/nfnetlink.c:652
  netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
  netlink_unicast+0x2c7/0x3e0 net/netlink/af_netlink.c:1340
  netlink_sendmsg+0x36b/0x6b0 net/netlink/af_netlink.c:1929
  sock_sendmsg_nosec net/socket.c:702 [inline]
  sock_sendmsg+0x56/0x80 net/socket.c:722

Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: c520292f29b8 ("audit: log nftables configuration change events once per table")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dongliang Mu 2021-07-14 11:27:03 +08:00 committed by Greg Kroah-Hartman
parent f3d0db3b43
commit 3debec96ca
1 changed files with 12 additions and 0 deletions

12
net/netfilter/nf_tables_api.c

@ -7819,6 +7819,16 @@ static int nf_tables_commit_audit_alloc(struct list_head *adl,
return 0;
}
static void nf_tables_commit_audit_free(struct list_head *adl)
{
struct nft_audit_data *adp, *adn;
list_for_each_entry_safe(adp, adn, adl, list) {
list_del(&adp->list);
kfree(adp);
}
}
static void nf_tables_commit_audit_collect(struct list_head *adl,
struct nft_table *table, u32 op)
{
@ -7882,6 +7892,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
ret = nf_tables_commit_audit_alloc(&adl, trans->ctx.table);
if (ret) {
nf_tables_commit_chain_prepare_cancel(net);
nf_tables_commit_audit_free(&adl);
return ret;
}
if (trans->msg_type == NFT_MSG_NEWRULE ||
@ -7891,6 +7902,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
ret = nf_tables_commit_chain_prepare(net, chain);
if (ret < 0) {
nf_tables_commit_chain_prepare_cancel(net);
nf_tables_commit_audit_free(&adl);
return ret;
}
}