diff options
| author | Qingfang Deng <dqfext@gmail.com> | 2025-09-03 18:07:26 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-09-04 07:25:48 -0700 |
| commit | 4844123fe0b853a4982c02666cb3fd863d701d50 (patch) | |
| tree | 15b605ed4614c49cded34bf87f568ecb1fb3403e | |
| parent | 8bbceba7dc5090c00105e006ce28d1292cfda8dd (diff) | |
ppp: fix memory leak in pad_compress_skb
If alloc_skb() fails in pad_compress_skb(), it returns NULL without
releasing the old skb. The caller does:
skb = pad_compress_skb(ppp, skb);
if (!skb)
goto drop;
drop:
kfree_skb(skb);
When pad_compress_skb() returns NULL, the reference to the old skb is
lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak.
Align pad_compress_skb() semantics with realloc(): only free the old
skb if allocation and compression succeed. At the call site, use the
new_skb variable so the original skb is not lost when pad_compress_skb()
fails.
Fixes: b3f9b92a6ec1 ("[PPP]: add PPP MPPE encryption module")
Signed-off-by: Qingfang Deng <dqfext@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://patch.msgid.link/20250903100726.269839-1-dqfext@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 824c8dc4120b..702a7f7183ce 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1744,7 +1744,6 @@ pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) */ if (net_ratelimit()) netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); - kfree_skb(skb); consume_skb(new_skb); new_skb = NULL; } @@ -1845,9 +1844,10 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) "down - pkt dropped.\n"); goto drop; } - skb = pad_compress_skb(ppp, skb); - if (!skb) + new_skb = pad_compress_skb(ppp, skb); + if (!new_skb) goto drop; + skb = new_skb; } /* |