linux-stable.git/fs/cifs/dfs_cache.c, branch linux-5.4.y Linux kernel stable tree cifs: Fix potential deadlock when updating vol in cifs_reconnect() 2023-06-28T08:18:37+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2023-06-23T21:34:06+00:00 be178a5eae0f3bc48912d1f2b1fa79be3b335748 commit 06d57378bcc9b2c33640945174842115593795d1 upstream. We can't acquire volume lock while refreshing the DFS cache because cifs_reconnect() may call dfs_cache_update_vol() while we are walking through the volume list. To prevent that, make vol_info refcounted, create a temp list with all volumes eligible for refreshing, and then use it without any locks held. Besides, replace vol_lock with a spinlock and protect cache_ttl from concurrent accesses or changes. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 06d57378bcc9b2c33640945174842115593795d1 upstream.

We can't acquire volume lock while refreshing the DFS cache because
cifs_reconnect() may call dfs_cache_update_vol() while we are walking
through the volume list.

To prevent that, make vol_info refcounted, create a temp list with all
volumes eligible for refreshing, and then use it without any locks
held.

Besides, replace vol_lock with a spinlock and protect cache_ttl from
concurrent accesses or changes.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Merge is_path_valid() into get_normalized_path() 2023-06-28T08:18:37+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2023-06-23T21:34:05+00:00 8a5aaa4562a9ef2ce731e00a658e8bc6489f9aad commit ff2f7fc08268f266372c30a815349749e8499eb5 upstream. Just do the trivial path validation in get_normalized_path(). Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ff2f7fc08268f266372c30a815349749e8499eb5 upstream.

Just do the trivial path validation in get_normalized_path().

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Introduce helpers for finding TCP connection 2023-06-28T08:18:37+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2023-06-23T21:34:04+00:00 339134c15c643eb228766b03faa90d936d72697a commit 345c1a4a9e09dc5842b7bbb6728a77910db69c52 upstream. Add helpers for finding TCP connections that are good candidates for being used by DFS refresh worker. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 345c1a4a9e09dc5842b7bbb6728a77910db69c52 upstream.

Add helpers for finding TCP connections that are good candidates for
being used by DFS refresh worker.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Get rid of kstrdup_const()'d paths 2023-06-28T08:18:37+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2023-06-23T21:34:03+00:00 cf8c7aa90618ac571511235b4d63603fe46eba37 commit 199c6bdfb04b71d88a7765e08285885fbca60df4 upstream. The DFS cache API is mostly used with heap allocated strings. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 199c6bdfb04b71d88a7765e08285885fbca60df4 upstream.

The DFS cache API is mostly used with heap allocated strings.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Clean up DFS referral cache 2023-06-28T08:18:37+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2023-06-23T21:34:02+00:00 3fa4c08104c43c1bd5e43b883b03b27d1ddd4972 commit 185352ae6171c845951e21017b2925a6f2795904 upstream. Do some renaming and code cleanup. No functional changes. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 185352ae6171c845951e21017b2925a6f2795904 upstream.

Do some renaming and code cleanup.

No functional changes.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: fix unitialized variable poential problem with network I/O cache lock patch 2020-02-24T07:36:58+00:00 Steve French stfrench@microsoft.com 2020-01-16T21:58:00+00:00 1d8e40cf86e4f94073e0dcefad0145fc81d3e66a [ Upstream commit 463a7b457c02250a84faa1d23c52da9e3364aed2 ] static analysis with Coverity detected an issue with the following commit: Author: Paulo Alcantara (SUSE) <pc@cjr.nz> Date: Wed Dec 4 17:38:03 2019 -0300 cifs: Avoid doing network I/O while holding cache lock Addresses-Coverity: ("Uninitialized pointer read") Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 463a7b457c02250a84faa1d23c52da9e3364aed2 ]

static analysis with Coverity detected an issue with the following
commit:

 Author: Paulo Alcantara (SUSE) <pc@cjr.nz>
 Date:   Wed Dec 4 17:38:03 2019 -0300

    cifs: Avoid doing network I/O while holding cache lock

Addresses-Coverity: ("Uninitialized pointer read")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cifs: Fix lookup of root ses in DFS referral cache 2020-01-09T09:20:05+00:00 Paulo Alcantara (SUSE) pc@cjr.nz 2019-11-22T15:30:52+00:00 42692a61ab19151159b62887136039840b53f923 commit df3df923b31d298c3d3653a0380202b9f2df9864 upstream. We don't care about module aliasing validation in cifs_compose_mount_options(..., is_smb3) when finding the root SMB session of an DFS namespace in order to refresh DFS referral cache. The following issue has been observed when mounting with '-t smb3' and then specifying 'vers=2.0': ... Nov 08 15:27:08 tw kernel: address conversion returned 0 for FS0.WIN.LOCAL Nov 08 15:27:08 tw kernel: [kworke] ==> dns_query((null),FS0.WIN.LOCAL,13,(null)) Nov 08 15:27:08 tw kernel: [kworke] call request_key(,FS0.WIN.LOCAL,) Nov 08 15:27:08 tw kernel: [kworke] ==> dns_resolver_cmp(FS0.WIN.LOCAL,FS0.WIN.LOCAL) Nov 08 15:27:08 tw kernel: [kworke] <== dns_resolver_cmp() = 1 Nov 08 15:27:08 tw kernel: [kworke] <== dns_query() = 13 Nov 08 15:27:08 tw kernel: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: FS0.WIN.LOCAL to 192.168.30.26 ===> Nov 08 15:27:08 tw kernel: CIFS VFS: vers=2.0 not permitted when mounting with smb3 Nov 08 15:27:08 tw kernel: fs/cifs/dfs_cache.c: CIFS VFS: leaving refresh_tcon (xid = 26) rc = -22 ... Fixes: 5072010ccf05 ("cifs: Fix DFS cache refresher for DFS links") Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit df3df923b31d298c3d3653a0380202b9f2df9864 upstream.

We don't care about module aliasing validation in
cifs_compose_mount_options(..., is_smb3) when finding the root SMB
session of an DFS namespace in order to refresh DFS referral cache.

The following issue has been observed when mounting with '-t smb3' and
then specifying 'vers=2.0':

...
Nov 08 15:27:08 tw kernel: address conversion returned 0 for FS0.WIN.LOCAL
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_query((null),FS0.WIN.LOCAL,13,(null))
Nov 08 15:27:08 tw kernel: [kworke] call request_key(,FS0.WIN.LOCAL,)
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_resolver_cmp(FS0.WIN.LOCAL,FS0.WIN.LOCAL)
Nov 08 15:27:08 tw kernel: [kworke] <== dns_resolver_cmp() = 1
Nov 08 15:27:08 tw kernel: [kworke] <== dns_query() = 13
Nov 08 15:27:08 tw kernel: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: FS0.WIN.LOCAL to 192.168.30.26
===> Nov 08 15:27:08 tw kernel: CIFS VFS: vers=2.0 not permitted when mounting with smb3
Nov 08 15:27:08 tw kernel: fs/cifs/dfs_cache.c: CIFS VFS: leaving refresh_tcon (xid = 26) rc = -22
...

Fixes: 5072010ccf05 ("cifs: Fix DFS cache refresher for DFS links")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs: cifs: Drop unlikely before IS_ERR(_OR_NULL) 2019-07-08T03:37:42+00:00 Kefeng Wang wangkefeng.wang@huawei.com 2019-06-05T14:24:25+00:00 06f2fca7ff51d87c82fc911759373be5e1d0f7b6 IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag, so no need to do that again from its callers. Drop it. Cc: linux-cifs@vger.kernel.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Paulo Alcantara <palcantara@suse.de> 
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag,
so no need to do that again from its callers. Drop it.

Cc: linux-cifs@vger.kernel.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
dfs_cache: fix a wrong use of kfree in flush_cache_ent() 2019-05-29T00:13:58+00:00 Gen Zhang blackgod016574@gmail.com 2019-05-28T01:12:39+00:00 50fbc13dc12666f3604dc2555a47fc8c4e29162b In flush_cache_ent(), 'ce->ce_path' is allocated by kstrdup_const(). It should be freed by kfree_const(), rather than kfree(). Signed-off-by: Gen Zhang <blackgod016574@gmail.com> Reviewed-by: Paulo Alcantara <palcantara@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com> 
In flush_cache_ent(), 'ce->ce_path' is allocated by kstrdup_const().
It should be freed by kfree_const(), rather than kfree().

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: Fix DFS cache refresher for DFS links 2019-05-08T04:24:54+00:00 Paulo Alcantara (SUSE) paulo@paulo.ac 2019-03-19T19:54:29+00:00 5072010ccf0592950f7cfae0eb3c4008e8bf36f7 As per MS-DFSC, when a DFS cache entry is expired and it is a DFS link, then a new DFS referral must be sent to root server in order to refresh the expired entry. This patch ensures that all new DFS referrals for refreshing the cache are sent to DFS root. Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac> Signed-off-by: Steve French <stfrench@microsoft.com> 
As per MS-DFSC, when a DFS cache entry is expired and it is a DFS
link, then a new DFS referral must be sent to root server in order to
refresh the expired entry.

This patch ensures that all new DFS referrals for refreshing the cache
are sent to DFS root.

Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac>
Signed-off-by: Steve French <stfrench@microsoft.com>