linux-kernel - [PATCH 5.10 259/299] smb3: do not attempt multichannel to server which does not support it

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210510102013.507543604@linuxfoundation.org>
Date:   Mon, 10 May 2021 12:20:56 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Shyam Prasad N <sprasad@...rosoft.com>,
        Tom Talpey <tom@...pey.com>,
        Steve French <stfrench@...rosoft.com>
Subject: [PATCH 5.10 259/299] smb3: do not attempt multichannel to server which does not support it

From: Steve French <stfrench@...rosoft.com>

commit 9c2dc11df50d1c8537075ff6b98472198e24438e upstream.

We were ignoring CAP_MULTI_CHANNEL in the server response - if the
server doesn't support multichannel we should not be attempting it.

See MS-SMB2 section 3.2.5.2

Reviewed-by: Shyam Prasad N <sprasad@...rosoft.com>
Reviewed-By: Tom Talpey <tom@...pey.com>
Cc: <stable@...r.kernel.org> # v5.8+
Signed-off-by: Steve French <stfrench@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 fs/cifs/sess.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -92,6 +92,12 @@ int cifs_try_adding_channels(struct cifs
 		return 0;
 	}
 
+	if (!(ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
+		cifs_dbg(VFS, "server %s does not support multichannel\n", ses->server->hostname);
+		ses->chan_max = 1;
+		return 0;
+	}
+
 	/*
 	 * Make a copy of the iface list at the time and use that
 	 * instead so as to not hold the iface spinlock for opening