| Message ID | 20210714032703.505023-1-mudongliangabcd@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3] audit: fix memory leak in nf_tables_commit | expand |
On Wed, Jul 14, 2021 at 11:27:03AM +0800, Dongliang Mu wrote: > 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 Applied, thanks.
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 390d4466567f..7f45b291be13 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8444,6 +8444,16 @@ 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) { @@ -8508,6 +8518,7 @@ 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 || @@ -8517,6 +8528,7 @@ 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; } }
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> --- v1->v2: fix the compile issue v2->v3: modify the added function to a new name net/netfilter/nf_tables_api.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)