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 7524839FD0; Fri, 24 Nov 2023 18:20:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Th2se05j" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0935C433C8; Fri, 24 Nov 2023 18:20:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700850048; bh=F3Db+A/s41z/4lZPB3VLkUjThVHd+Uo288WxOIQZAXA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Th2se05jnG7Se1SJRe9vOrC1HfrKB7rRvprNNXPvxNWmEeNhSVl29WkVQGTeS0lhi pdwU77RVnjAh82hrpjzFdgrhufkjY76EcrCKflqYfpmLjV8a0hU+npqhThL/vkyYSS xrIHgGo7Qkg/wv3QXV+Nd7TD05yWRk+ZfySycmy8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eduard Bachmakov , "Paulo Alcantara (SUSE)" , Steve French Subject: [PATCH 6.6 424/530] smb: client: fix mount when dns_resolver key is not available Date: Fri, 24 Nov 2023 17:49:50 +0000 Message-ID: <20231124172040.970792168@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172028.107505484@linuxfoundation.org> References: <20231124172028.107505484@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara commit 5e2fd17f434d2fed78efb123e2fc6711e4f598f1 upstream. There was a wrong assumption that with CONFIG_CIFS_DFS_UPCALL=y there would always be a dns_resolver key set up so we could unconditionally upcall to resolve UNC hostname rather than using the value provided by mount(2). Only require it when performing automount of junctions within a DFS share so users that don't have dns_resolver key still can mount their regular shares with server hostname resolved by mount.cifs(8). Fixes: 348a04a8d113 ("smb: client: get rid of dfs code dep in namespace.c") Cc: stable@vger.kernel.org Tested-by: Eduard Bachmakov Reported-by: Eduard Bachmakov Closes: https://lore.kernel.org/all/CADCRUiNvZuiUZ0VGZZO9HRyPyw6x92kiA7o7Q4tsX5FkZqUkKg@mail.gmail.com/ Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/dfs.c | 18 +++++++++++++----- fs/smb/client/fs_context.h | 1 + fs/smb/client/namespace.c | 17 +++++++++++++++-- 3 files changed, 29 insertions(+), 7 deletions(-) --- a/fs/smb/client/dfs.c +++ b/fs/smb/client/dfs.c @@ -263,15 +263,23 @@ out: return rc; } -/* Resolve UNC hostname in @ctx->source and set ip addr in @ctx->dstaddr */ +/* + * If @ctx->dfs_automount, then update @ctx->dstaddr earlier with the DFS root + * server from where we'll start following any referrals. Otherwise rely on the + * value provided by mount(2) as the user might not have dns_resolver key set up + * and therefore failing to upcall to resolve UNC hostname under @ctx->source. + */ static int update_fs_context_dstaddr(struct smb3_fs_context *ctx) { struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr; - int rc; + int rc = 0; - rc = dns_resolve_server_name_to_ip(ctx->source, addr, NULL); - if (!rc) - cifs_set_port(addr, ctx->port); + if (!ctx->nodfs && ctx->dfs_automount) { + rc = dns_resolve_server_name_to_ip(ctx->source, addr, NULL); + if (!rc) + cifs_set_port(addr, ctx->port); + ctx->dfs_automount = false; + } return rc; } --- a/fs/smb/client/fs_context.h +++ b/fs/smb/client/fs_context.h @@ -268,6 +268,7 @@ struct smb3_fs_context { bool witness:1; /* use witness protocol */ char *leaf_fullpath; struct cifs_ses *dfs_root_ses; + bool dfs_automount:1; /* set for dfs automount only */ }; extern const struct fs_parameter_spec smb3_fs_parameters[]; --- a/fs/smb/client/namespace.c +++ b/fs/smb/client/namespace.c @@ -117,6 +117,18 @@ cifs_build_devname(char *nodename, const return dev; } +static bool is_dfs_mount(struct dentry *dentry) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb); + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); + bool ret; + + spin_lock(&tcon->tc_lock); + ret = !!tcon->origin_fullpath; + spin_unlock(&tcon->tc_lock); + return ret; +} + /* Return full path out of a dentry set for automount */ static char *automount_fullpath(struct dentry *dentry, void *page) { @@ -212,8 +224,9 @@ static struct vfsmount *cifs_do_automoun ctx->source = NULL; goto out; } - cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s\n", - __func__, ctx->source, ctx->UNC, ctx->prepath); + ctx->dfs_automount = is_dfs_mount(mntpt); + cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s dfs_automount=%d\n", + __func__, ctx->source, ctx->UNC, ctx->prepath, ctx->dfs_automount); mnt = fc_mount(fc); out: