Re: [PATCH] audit: fix memory leak in nf_tables_commit
From: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Date: 2021-07-13 11:47:29
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lkml, netfilter-devel
On Tue, Jul 13, 2021 at 11:42 AM Dongliang Mu [off-list ref] wrote:
In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not free the adp variable. Fix this by freeing the linked list with head 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 <redacted>
As far as I see, the more default way is to reference to syzbot by: Reported-by: syzbot+[[20-letter hex reference]]@syzkaller.appspotmail.com as in for example: Reported-by: syzbot+fee64147a25aecd48055@syzkaller.appspotmail.com A rough count says that format above is used 1300 times, whereas Reported-by: syzbot <redacted> is only used about 330 times. Lukas
quoted hunk ↗ jump to hunk
Fixes: c520292f29b8 ("audit: log nftables configuration change events once per table") Signed-off-by: Dongliang Mu <redacted> --- net/netfilter/nf_tables_api.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)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_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_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_free(adl); return ret; } } --2.25.1 -- You received this message because you are subscribed to the Google Groups "syzkaller" group. To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller/20210713094158.450434-1-mudongliangabcd%40gmail.com.