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| author | Pavel Skripkin <paskripkin@gmail.com> | 2021-06-02 22:26:40 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-06-03 14:13:26 -0700 |
| commit | c47cc304990a2813995b1a92bbc11d0bb9a19ea9 (patch) | |
| tree | 434c67f2c3d561623e2de4ab6fdbc7fdb057bc09 /net/kcm | |
| parent | 261ba78cc364ad595cead555a7d2a61471eac165 (diff) | |
| download | lwn-c47cc304990a2813995b1a92bbc11d0bb9a19ea9.tar.gz lwn-c47cc304990a2813995b1a92bbc11d0bb9a19ea9.zip | |
net: kcm: fix memory leak in kcm_sendmsg
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@syzkaller.appspotmail.com
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/kcm')
| -rw-r--r-- | net/kcm/kcmsock.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index 6201965bd822..1c572c8daced 100644 --- 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); |