From: Takeshi Misawa <jeliantsurux@gmail.com>
To: linux-ppp@vger.kernel.org
Subject: [PATCH] ppp: Fix memory leak in ppp_write
Date: Sat, 14 Sep 2019 04:09:58 +0000 [thread overview]
Message-ID: <20190914040958.GA2363@DESKTOP> (raw)
When ppp is closing, __ppp_xmit_process() failed to enqueue skb
and skb allocated in ppp_write() is leaked.
syzbot reported :
BUG: memory leak
unreferenced object 0xffff88812a17bc00 (size 224):
comm "syz-executor673", pid 6952, jiffies 4294942888 (age 13.040s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d110fff9>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
[<00000000d110fff9>] slab_post_alloc_hook mm/slab.h:522 [inline]
[<00000000d110fff9>] slab_alloc_node mm/slab.c:3262 [inline]
[<00000000d110fff9>] kmem_cache_alloc_node+0x163/0x2f0 mm/slab.c:3574
[<000000002d616113>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:197
[<000000000167fc45>] alloc_skb include/linux/skbuff.h:1055 [inline]
[<000000000167fc45>] ppp_write+0x48/0x120 drivers/net/ppp/ppp_generic.c:502
[<000000009ab42c0b>] __vfs_write+0x43/0xa0 fs/read_write.c:494
[<00000000086b2e22>] vfs_write fs/read_write.c:558 [inline]
[<00000000086b2e22>] vfs_write+0xee/0x210 fs/read_write.c:542
[<00000000a2b70ef9>] ksys_write+0x7c/0x130 fs/read_write.c:611
[<00000000ce5e0fdd>] __do_sys_write fs/read_write.c:623 [inline]
[<00000000ce5e0fdd>] __se_sys_write fs/read_write.c:620 [inline]
[<00000000ce5e0fdd>] __x64_sys_write+0x1e/0x30 fs/read_write.c:620
[<00000000d9d7b370>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296
[<0000000006e6d506>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by freeing skb, if ppp is closing.
Reported-and-tested-by: syzbot+d9c8bf24e56416d7ce2c@syzkaller.appspotmail.com
Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
---
Dear Paul Mackerras
syzbot reported memory leak in net/ppp.
[TITLE] memory leak in ppp_write
I send a patch that passed syzbot reproducer test.
Please consider this memory leak and patch.
Regards.
---
drivers/net/ppp/ppp_generic.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index a30e41a56085..9a1b006904a7 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1415,6 +1415,8 @@ static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
netif_wake_queue(ppp->dev);
else
netif_stop_queue(ppp->dev);
+ } else {
+ kfree_skb(skb);
}
ppp_xmit_unlock(ppp);
}
--
2.17.1
next reply other threads:[~2019-09-14 4:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-14 4:09 Takeshi Misawa [this message]
2019-09-14 10:36 ` [PATCH] ppp: Fix memory leak in ppp_write walter harms
2019-09-17 22:40 ` Guillaume Nault
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190914040958.GA2363@DESKTOP \
--to=jeliantsurux@gmail.com \
--cc=linux-ppp@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.