From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Steve French <stfrench@microsoft.com>,
Paulo Alcantara <palcantara@suse.de>,
Pavel Shilovsky <pshilov@microsoft.com>
Subject: [PATCH 4.9 27/30] cifs: Always resolve hostname before reconnecting
Date: Mon, 4 Feb 2019 11:37:05 +0100 [thread overview]
Message-ID: <20190204103610.367598416@linuxfoundation.org> (raw)
In-Reply-To: <20190204103605.271746870@linuxfoundation.org>
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paulo Alcantara <paulo@paulo.ac>
commit 28eb24ff75c5ac130eb326b3b4d0dcecfc0f427d upstream.
In case a hostname resolves to a different IP address (e.g. long
running mounts), make sure to resolve it every time prior to calling
generic_ip_connect() in reconnect.
Suggested-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/cifs/connect.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -48,6 +48,7 @@
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
+#include "dns_resolve.h"
#include "ntlmssp.h"
#include "nterr.h"
#include "rfc1002pdu.h"
@@ -307,6 +308,53 @@ static int cifs_setup_volume_info(struct
const char *devname);
/*
+ * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
+ * get their ip addresses changed at some point.
+ *
+ * This should be called with server->srv_mutex held.
+ */
+#ifdef CONFIG_CIFS_DFS_UPCALL
+static int reconn_set_ipaddr(struct TCP_Server_Info *server)
+{
+ int rc;
+ int len;
+ char *unc, *ipaddr = NULL;
+
+ if (!server->hostname)
+ return -EINVAL;
+
+ len = strlen(server->hostname) + 3;
+
+ unc = kmalloc(len, GFP_KERNEL);
+ if (!unc) {
+ cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
+ return -ENOMEM;
+ }
+ snprintf(unc, len, "\\\\%s", server->hostname);
+
+ rc = dns_resolve_server_name_to_ip(unc, &ipaddr);
+ kfree(unc);
+
+ if (rc < 0) {
+ cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
+ __func__, server->hostname, rc);
+ return rc;
+ }
+
+ rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
+ strlen(ipaddr));
+ kfree(ipaddr);
+
+ return !rc ? -1 : 0;
+}
+#else
+static inline int reconn_set_ipaddr(struct TCP_Server_Info *server)
+{
+ return 0;
+}
+#endif
+
+/*
* cifs tcp session reconnection
*
* mark tcp session as reconnecting so temporarily locked
@@ -403,6 +451,11 @@ cifs_reconnect(struct TCP_Server_Info *s
rc = generic_ip_connect(server);
if (rc) {
cifs_dbg(FYI, "reconnect error %d\n", rc);
+ rc = reconn_set_ipaddr(server);
+ if (rc) {
+ cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
+ __func__, rc);
+ }
mutex_unlock(&server->srv_mutex);
msleep(3000);
} else {
next prev parent reply other threads:[~2019-02-04 10:44 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-04 10:36 [PATCH 4.9 00/30] 4.9.155-stable review Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 01/30] Fix "net: ipv4: do not handle duplicate fragments as overlapping" Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 02/30] fs: add the fsnotify call to vfs_iter_write Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 03/30] ipv6: Consider sk_bound_dev_if when binding a socket to an address Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 04/30] l2tp: copy 4 more bytes to linear part if necessary Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 05/30] net/mlx4_core: Add masking for a few queries on HCA caps Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 06/30] netrom: switch to sock timer API Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 07/30] net/rose: fix NULL ax25_cb kernel panic Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 08/30] ucc_geth: Reset BQL queue when stopping device Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 09/30] net/mlx5e: Allow MAC invalidation while spoofchk is ON Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 10/30] l2tp: remove l2specific_len dependency in l2tp_core Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 11/30] l2tp: fix reading optional fields of L2TPv3 Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 12/30] ipvlan, l3mdev: fix broken l3s mode wrt local routes Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 13/30] CIFS: Do not count -ENODATA as failure for query directory Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 14/30] fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb() Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 15/30] ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 16/30] arm64: kaslr: ensure randomized quantities are clean also when kaslr is off Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 17/30] arm64: hyp-stub: Forbid kprobing of the hyp-stub Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 18/30] arm64: hibernate: Clean the __hyp_text to PoC after resume Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 19/30] gfs2: Revert "Fix loop in gfs2_rbm_find" Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 20/30] platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK Greg Kroah-Hartman
2019-02-04 10:36 ` [PATCH 4.9 21/30] platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 22/30] mmc: sdhci-iproc: handle mmc_of_parse() errors during probe Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 23/30] kernel/exit.c: release ptraced tasks before zap_pid_ns_processes Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 24/30] mm, oom: fix use-after-free in oom_kill_process Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 25/30] mm: hwpoison: use do_send_sig_info() instead of force_sig() Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 26/30] mm: migrate: dont rely on __PageMovable() of newpage after unlocking it Greg Kroah-Hartman
2019-02-04 10:37 ` Greg Kroah-Hartman [this message]
2019-02-04 10:37 ` [PATCH 4.9 28/30] drivers: core: Remove glue dirs from sysfs earlier Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 29/30] fs: dont scan the inode cache before SB_BORN is set Greg Kroah-Hartman
2019-02-04 10:37 ` [PATCH 4.9 30/30] fanotify: fix handling of events on child sub-directory Greg Kroah-Hartman
2019-02-04 10:48 ` Amir Goldstein
2019-02-04 11:03 ` Greg Kroah-Hartman
2019-02-04 21:48 ` [PATCH 4.9 00/30] 4.9.155-stable review Guenter Roeck
2019-02-05 6:39 ` Naresh Kamboju
2019-02-05 11:38 ` Jon Hunter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190204103610.367598416@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=palcantara@suse.de \
--cc=pshilov@microsoft.com \
--cc=stable@vger.kernel.org \
--cc=stfrench@microsoft.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).