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 149DB15C83 for ; Mon, 5 Dec 2022 19:26:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E8CEC433D7; Mon, 5 Dec 2022 19:26:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670268404; bh=rFGEtCVS/LQTexZNB+ul0q2QkPV5NYH2AGRZbINoV84=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rpVcIWVmcxFehLEisaohrNepMFiG6pXrmDjEH30+kWtHNbncVt/obQTsMUsSKcHV6 dhtHNgoyTivH84NsyrMytsYtg8oSiMNpSUsNOeLWRYtKdnxfY3iHm0BF63K3AnTygs 5O2/lWLCTtLqAibcVApGP3cRtqjm3W6ywa9WAZas= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shuang Li , Xin Long , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.0 062/124] tipc: re-fetch skb cb after tipc_msg_validate Date: Mon, 5 Dec 2022 20:09:28 +0100 Message-Id: <20221205190810.182667063@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190808.422385173@linuxfoundation.org> References: <20221205190808.422385173@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Xin Long [ Upstream commit 3067bc61fcfe3081bf4807ce65560f499e895e77 ] As the call trace shows, the original skb was freed in tipc_msg_validate(), and dereferencing the old skb cb would cause an use-after-free crash. BUG: KASAN: use-after-free in tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] Call Trace: tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] ... Allocated by task 47078: kmem_cache_alloc_node+0x158/0x4d0 __alloc_skb+0x1c1/0x270 tipc_buf_acquire+0x1e/0xe0 [tipc] tipc_msg_create+0x33/0x1c0 [tipc] tipc_link_build_proto_msg+0x38a/0x2100 [tipc] tipc_link_timeout+0x8b8/0xef0 [tipc] tipc_node_timeout+0x2a1/0x960 [tipc] call_timer_fn+0x2d/0x1c0 ... Freed by task 47078: tipc_msg_validate+0x7b/0x440 [tipc] tipc_crypto_rcv_complete+0x4b5/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] This patch fixes it by re-fetching the skb cb from the new allocated skb after calling tipc_msg_validate(). Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Reported-by: Shuang Li Signed-off-by: Xin Long Link: https://lore.kernel.org/r/1b1cdba762915325bd8ef9a98d0276eb673df2a5.1669398403.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/tipc/crypto.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c index f09316a9035f..d67440de011e 100644 --- a/net/tipc/crypto.c +++ b/net/tipc/crypto.c @@ -1971,6 +1971,9 @@ static void tipc_crypto_rcv_complete(struct net *net, struct tipc_aead *aead, /* Ok, everything's fine, try to synch own keys according to peers' */ tipc_crypto_key_synch(rx, *skb); + /* Re-fetch skb cb as skb might be changed in tipc_msg_validate */ + skb_cb = TIPC_SKB_CB(*skb); + /* Mark skb decrypted */ skb_cb->decrypted = 1; -- 2.35.1