From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793214819; b=UPlXkXJ5xlsxWfD7uRcbnAqOQfsBldVBmPWUIwIGhz271qdvbDEqtANFathqMnpP0XTN 1Am9cz8n38k2LdLte7PXih/CJOHUcgvlilQ1PY7iRAqTM07rPGteNB1YW/vyy+gOWJSiv rWG0TMGkcecGsuEYrfGhbBsFYl/UgxjSPA5tL2LmgXduC50XNurkXJnsDBtu2d5hp1oDW Qyv//hEpJEofQVQahd7Qz1OxpfSwtuDIdht4gj9D0FIs0br8MqJnXkrpfxpqyoT/QalCJ eu4dvTBGPmLzKSHfDnWSAbjM2QtlJgF8BcvX7FGivbhgfnj0rMgDuthIPMuAG0kUUCw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793214819; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=dS4p4GbuweobJUJAdnDLLkkkbyFsKmxXzUWnl7Ljeg4=; b=TYTsf9WIRmkOLtv8Pj3m0YbPDGChH9JEN7J/PNaMKInFjvdivLaaOwUol6uA5I0Utdoh x5WeH/FLoxvkr33Ch3m7+Bf5uL7V0DQcJZwrDgqPfdCnJFCLKXRtRGFSi2NqF3iCQWz0H mIOtJaEefUhu1njm+1Mg0IWT7OqJE7g0BqSOOfhn7n4rEGcQZJOGRbmkHAqwet3PXl+3D Wroot4V+tgCkyNBf594rQY3/8w0fWs4wG0gnz07EmtV2p9H0pG9VRw0xMvx5pOiiNgzK5 5jve+1qxifsi6gxkFwv7tKFF/A9pmKPCkP5YWdUbl2f3HSKq0ZYzRzBe8JVQ1ti+yOQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=RMBhKa3M; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 08800606AB09; Wed, 28 Oct 2026 19:13:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=RMBhKa3M Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AA081F01825; Wed, 28 Oct 2026 19:13:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793214818; bh=dS4p4GbuweobJUJAdnDLLkkkbyFsKmxXzUWnl7Ljeg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RMBhKa3MjysYRF+hAO5TCgPkisgsh22NF036lgAX75BVoSds+p/84HbFjv3OyX/GF tfu+iJL/0NCXsOBlmdnM2Gsag5Xmrzyxqm+4cQLATx4pOv8gQ817hj8rZnqlBrABhw UWETiLBNjDa/wUyrrnN3ie56OIQQkwrU8W7iomUA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nicholas Carlini , Stefan Metzmacher , Namjae Jeon , Steve French , Sasha Levin Subject: [PATCH 6.1 0991/1887] ksmbd: fix signededness bug in smb_direct_prepare_negotiation() Date: Wed, 28 Oct 2026 17:51:27 +0100 Message-ID: <20261028170521.963936003@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Carlini [ Upstream commit 6b4f875aac344cdd52a1f34cc70ed2f874a65757 ] smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message. By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow. This fix replaces min_t(int, ...) with min_t(u32) Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Signed-off-by: Nicholas Carlini Reviewed-by: Stefan Metzmacher Acked-by: Stefan Metzmacher Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/smb/server/transport_rdma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c index 1290c0fa7dd18..bcf0631ce10a6 100644 --- a/fs/smb/server/transport_rdma.c +++ b/fs/smb/server/transport_rdma.c @@ -1967,9 +1967,9 @@ static int smb_direct_prepare(struct ksmbd_transport *t) goto out; req = (struct smb_direct_negotiate_req *)recvmsg->packet; - st->max_recv_size = min_t(int, st->max_recv_size, + st->max_recv_size = min_t(u32, st->max_recv_size, le32_to_cpu(req->preferred_send_size)); - st->max_send_size = min_t(int, st->max_send_size, + st->max_send_size = min_t(u32, st->max_send_size, le32_to_cpu(req->max_receive_size)); st->max_fragmented_send_size = le32_to_cpu(req->max_fragmented_size); -- 2.53.0