[PATCH 5.7 05/15] net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow

From: Greg Kroah-Hartman
Date: Wed Aug 26 2020 - 08:03:45 EST


From: Alaa Hleihel <alaa@xxxxxxxxxxxx>

[ Upstream commit eda814b97dfb8d9f4808eb2f65af9bd3705c4cae ]

tcf_ct_handle_fragments() shouldn't free the skb when ip_defrag() call
fails. Otherwise, we will cause a double-free bug.
In such cases, just return the error to the caller.

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: Alaa Hleihel <alaa@xxxxxxxxxxxx>
Reviewed-by: Roi Dayan <roid@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/act_ct.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -702,7 +702,7 @@ static int tcf_ct_handle_fragments(struc
err = ip_defrag(net, skb, user);
local_bh_enable();
if (err && err != -EINPROGRESS)
- goto out_free;
+ return err;

if (!err) {
*defrag = true;