From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD43A23EA8A; Tue, 6 Jan 2026 17:16:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767719805; cv=none; b=XxzoemEbZfiUULsgz5ZTX5qbSxoJl58bkMM2u0dy04vRV7jqGwgWod0tNNpXwDEvJQ2kqgAVB7tAdkZizcJD1BMxFEf2C0OacFDY7hUo9AS7nAVX57vGZUpqkKD7gOzglrCSwv2VAnw+dEcg3cZLBGJ6bp0ZQk/CbL0rgTmetl8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767719805; c=relaxed/simple; bh=/aObFD+RR6UvW0Q4/MKunIZlGJ+nRyZAbX7ODXHm3l4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eecWgnWXcbZDKNg/QUo8pb46rACtKXAYgFWmcR1Inn9cLt9d4XLqgZaeBGWXnm/s2mcgC7OfnlUXZThq5nlsb3msPFUEkzIxjh24T1zk/XkNk6xpZcrrXtRHYZh5Q4TCA82glXEXNl+PIW8UmrtrFiJpohqJ0tzE/lRE08AqtXQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oEObd2oP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="oEObd2oP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2FA2C116C6; Tue, 6 Jan 2026 17:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767719805; bh=/aObFD+RR6UvW0Q4/MKunIZlGJ+nRyZAbX7ODXHm3l4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oEObd2oPRt1thryxeeTKMQkiER0WgQ34ikBW93lAKNkH21A3SvSpLCgziJf33S76w TyS+Knq5FHzlBDPzztak1oTesKWENRSBDWIo0FRjs/cO0OELMXwYy6oKJZBDuIXZ3c QVbohS2Zdyam01pJ6k4qiwL3hxZ82gsXbOth4YMA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com, Wang Liang , Paolo Abeni , Sasha Levin Subject: [PATCH 6.12 046/567] netrom: Fix memory leak in nr_sendmsg() Date: Tue, 6 Jan 2026 17:57:08 +0100 Message-ID: <20260106170453.044496000@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260106170451.332875001@linuxfoundation.org> References: <20260106170451.332875001@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wang Liang [ Upstream commit 613d12dd794e078be8ff3cf6b62a6b9acf7f4619 ] syzbot reported a memory leak [1]. When function sock_alloc_send_skb() return NULL in nr_output(), the original skb is not freed, which was allocated in nr_sendmsg(). Fix this by freeing it before return. [1] BUG: memory leak unreferenced object 0xffff888129f35500 (size 240): comm "syz.0.17", pid 6119, jiffies 4294944652 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 10 52 28 81 88 ff ff ..........R(.... backtrace (crc 1456a3e4): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4983 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5340 __alloc_skb+0x203/0x240 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0x69/0x3f0 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x379/0x3e0 net/core/sock.c:2965 sock_alloc_send_skb include/net/sock.h:1859 [inline] nr_sendmsg+0x287/0x450 net/netrom/af_netrom.c:1105 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x293/0x2a0 net/socket.c:1195 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0x143/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-by: syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d7abc36bbbb6d7d40b58 Tested-by: syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Liang Link: https://patch.msgid.link/20251129041315.1550766-1-wangliang74@huawei.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/netrom/nr_out.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netrom/nr_out.c b/net/netrom/nr_out.c index 5e531394a724b..2b3cbceb0b52d 100644 --- a/net/netrom/nr_out.c +++ b/net/netrom/nr_out.c @@ -43,8 +43,10 @@ void nr_output(struct sock *sk, struct sk_buff *skb) frontlen = skb_headroom(skb); while (skb->len > 0) { - if ((skbn = sock_alloc_send_skb(sk, frontlen + NR_MAX_PACKET_SIZE, 0, &err)) == NULL) + if ((skbn = sock_alloc_send_skb(sk, frontlen + NR_MAX_PACKET_SIZE, 0, &err)) == NULL) { + kfree_skb(skb); return; + } skb_reserve(skbn, frontlen); -- 2.51.0