This is a note to let you know that I've just added the patch titled
net: kcm: fix memory leak in kcm_sendmsg
to the 5.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-kcm-fix-memory-leak-in-kcm_sendmsg.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c47cc304990a2813995b1a92bbc11d0bb9a19ea9 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@xxxxxxxxx>
Date: Wed, 2 Jun 2021 22:26:40 +0300
Subject: net: kcm: fix memory leak in kcm_sendmsg
From: Pavel Skripkin <paskripkin@xxxxxxxxx>
commit c47cc304990a2813995b1a92bbc11d0bb9a19ea9 upstream.
Syzbot reported memory leak in kcm_sendmsg()[1].
The problem was in non-freed frag_list in case of error.
In the while loop:
if (head == skb)
skb_shinfo(head)->frag_list = tskb;
else
skb->next = tskb;
frag_list filled with skbs, but nothing was freeing them.
backtrace:
[<0000000094c02615>] __alloc_skb+0x5e/0x250 net/core/skbuff.c:198
[<00000000e5386cbd>] alloc_skb include/linux/skbuff.h:1083 [inline]
[<00000000e5386cbd>] kcm_sendmsg+0x3b6/0xa50 net/kcm/kcmsock.c:967 [1]
[<00000000f1613a8a>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000f1613a8a>] sock_sendmsg+0x4c/0x60 net/socket.c:672
Reported-and-tested-by: syzbot+b039f5699bd82e1fb011@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/kcm/kcmsock.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1066,6 +1066,11 @@ out_error:
goto partial_message;
}
+ if (skb_has_frag_list(head)) {
+ kfree_skb_list(skb_shinfo(head)->frag_list);
+ skb_shinfo(head)->frag_list = NULL;
+ }
+
if (head != kcm->seq_skb)
kfree_skb(head);
Patches currently in stable-queue which might be from paskripkin@xxxxxxxxx are
queue-5.12/net-kcm-fix-memory-leak-in-kcm_sendmsg.patch
queue-5.12/net-caif-fix-memory-leak-in-cfusbl_device_notify.patch
queue-5.12/net-caif-added-cfserl_release-function.patch
queue-5.12/net-caif-add-proper-error-handling.patch
queue-5.12/net-caif-fix-memory-leak-in-caif_device_notify.patch
