From: Pavel Skripkin paskripkin@gmail.com
stable inclusion from stable-5.10.58 commit d61dc8c634bb38bac8d68007e6d3cb938a8038f3 bugzilla: 176984 https://gitee.com/openeuler/kernel/issues/I4E2P4
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 7c1a80e80cde008f271bae630d28cf684351e807 ]
Syzbot reported memory leak in xfrm_user_rcv_msg(). The problem was is non-freed skb's frag_list.
In skb_release_all() skb_release_data() will be called only in case of skb->head != NULL, but netlink_skb_destructor() sets head to NULL. So, allocated frag_list skb should be freed manualy, since consume_skb() won't take care of it
Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Reported-and-tested-by: syzbot+fb347cf82c73a90efcca@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin paskripkin@gmail.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- net/xfrm/xfrm_user.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 45f86a97eaf2..6f97665b632e 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2751,6 +2751,16 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
err = link->doit(skb, nlh, attrs);
+ /* We need to free skb allocated in xfrm_alloc_compat() before + * returning from this function, because consume_skb() won't take + * care of frag_list since netlink destructor sets + * sbk->head to NULL. (see netlink_skb_destructor()) + */ + if (skb_has_frag_list(skb)) { + kfree_skb(skb_shinfo(skb)->frag_list); + skb_shinfo(skb)->frag_list = NULL; + } + err: kvfree(nlh64); return err;