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path: root/fs/cifs/connect.c
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2020-12-01cifs: fix potential use-after-free in cifs_echo_request()Paulo Alcantara1-0/+2
This patch fixes a potential use-after-free bug in cifs_echo_request(). For instance, thread 1 -------- cifs_demultiplex_thread() clean_demultiplex_info() kfree(server) thread 2 (workqueue) -------- apic_timer_interrupt() smp_apic_timer_interrupt() irq_exit() __do_softirq() run_timer_softirq() call_timer_fn() cifs_echo_request() <- use-after-free in server ptr Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> CC: Stable <stable@vger.kernel.org> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-22cifs: move smb version mount options into fs_context.cRonnie Sahlberg1-85/+0
This and related patches which move mount related code to fs_context.c has the advantage of shriking the code in fs/cifs/connect.c (which had the second most lines of code of any of the files in cifs.ko and was getting harder to read due to its size) and will also make it easier to switch over to the new mount API in the future. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-22cifs: move cache mount options to fs_context.chRonnie Sahlberg1-62/+0
Helps to shrink connect.c and make it more readable by moving mount related code to fs_context.c and fs_context.h Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-10-22cifs: move security mount options into fs_context.chRonnie Sahlberg1-84/+1
This patch moves the parsing of security mount options into fs_context.ch. There are no changes to any logic. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-10-22smb3: do not try to cache root directory if dir leases not supportedSteve French1-1/+4
To servers which do not support directory leases (e.g. Samba) it is wasteful to try to open_shroot (ie attempt to cache the root directory handle). Skip attempt to open_shroot when server does not indicate support for directory leases. Cuts the number of requests on mount from 17 to 15, and cuts the number of requests on stat of the root directory from 4 to 3. Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> # v5.1+
2020-10-22cifs: Print the address and port we are connecting to in generic_ip_connect()Samuel Cabrero1-2/+10
Can be helpful in debugging mount and reconnect issues Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-16Handle STATUS_IO_TIMEOUT gracefullyRohith Surabattula1-1/+14
Currently STATUS_IO_TIMEOUT is not treated as retriable error. It is currently mapped to ETIMEDOUT and returned to userspace for most system calls. STATUS_IO_TIMEOUT is returned by server in case of unavailability or throttling errors. This patch will map the STATUS_IO_TIMEOUT to EAGAIN, so that it can be retried. Also, added a check to drop the connection to not overload the server in case of ongoing unavailability. Signed-off-by: Rohith Surabattula <rohiths@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-30Merge tag '5.9-rc2-smb-fix' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds1-1/+1
Pull cfis fix from Steve French: "DFS fix for referral problem when using SMB1" * tag '5.9-rc2-smb-fix' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix check of tcon dfs in smb1
2020-08-28cifs: fix check of tcon dfs in smb1Paulo Alcantara1-1/+1
For SMB1, the DFS flag should be checked against tcon->Flags rather than tcon->share_flags. While at it, add an is_tcon_dfs() helper to check for DFS capability in a more generic way. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-5/+5
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-15Merge tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds1-0/+1
Pull cifs fixes from Steve French: "Three small cifs/smb3 fixes, one for stable fixing mkdir path with the 'idsfromsid' mount option" * tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: SMB3: Fix mkdir when idsfromsid configured on mount cifs: Convert to use the fallthrough macro cifs: Fix an error pointer dereference in cifs_mount()
2020-08-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-5/+5
Merge misc updates from Andrew Morton: - a few MM hotfixes - kthread, tools, scripts, ntfs and ocfs2 - some of MM Subsystems affected by this patch series: kthread, tools, scripts, ntfs, ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore, sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits) mm: vmscan: consistent update to pgrefill mm/vmscan.c: fix typo khugepaged: khugepaged_test_exit() check mmget_still_valid() khugepaged: retract_page_tables() remember to test exit khugepaged: collapse_pte_mapped_thp() protect the pmd lock khugepaged: collapse_pte_mapped_thp() flush the right range mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible mm: thp: replace HTTP links with HTTPS ones mm/page_alloc: fix memalloc_nocma_{save/restore} APIs mm/page_alloc.c: skip setting nodemask when we are in interrupt mm/page_alloc: fallbacks at most has 3 elements mm/page_alloc: silence a KASAN false positive mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask() mm/page_alloc.c: simplify pageblock bitmap access mm/page_alloc.c: extract the common part in pfn_to_bitidx() mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits mm/shuffle: remove dynamic reconfiguration mm/memory_hotplug: document why shuffle_zone() is relevant mm/page_alloc: remove nr_free_pagecache_pages() mm: remove vm_total_pages ...
2020-08-07mm, treewide: rename kzfree() to kfree_sensitive()Waiman Long1-5/+5
As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07cifs: Fix an error pointer dereference in cifs_mount()Dan Carpenter1-0/+1
The error handling calls kfree(full_path) so we can't let it be a NULL pointer. There used to be a NULL assignment here but we accidentally deleted it. Add it back. Fixes: 7efd08158261 ("cifs: document and cleanup dfs mount") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-08-03cifs: document and cleanup dfs mountPaulo Alcantara1-188/+182
cifs_mount() for DFS mounts is for a long time way too complex to follow, mostly because it lacks some documentation, does a lot of operations like resolving DFS roots and links, checking for path components, perform failover, crap code, etc. Besides adding some documentation to it, do some cleanup and ensure that the following is implemented and supported: * non-DFS mounts * DFS failover * DFS root mounts - tcon and cifs_sb must contain DFS path (NOT including prefix) - if prefix path, then save it in cifs_sb and it must not be changed * DFS link mounts - tcon and cifs_sb must contain DFS path (including prefix) - if prefix path, then save it in cifs_sb and it may be changed * prevent recursion on broken link referrals (MAX_NESTED_LINKS) * check every path component of the currently resolved target (including prefix), and chase them accordingly * make sure that DFS referrals go through newly resolved root servers Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-03cifs: only update prefix path of DFS links in cifs_tree_connect()Paulo Alcantara1-2/+7
For DFS root mounts that contain a prefix path, do not change them after failover. E.g., if the user mounts //srvA/root/dir1 and then lost connection to srvA, it will reconnect to //srvB/root/dir1 In case of DFS links, which may resolve to different prefix paths depending on their list of targets, the following must be supported: - mount //srvA/root/link/bar - connect to //srvA/share - set prefix path to "bar" - lost connection to srvA - reconnect to next target: //srvB/share/foo - set new prefix path to "foo/bar" In cifs_tree_connect(), check the server_type field of the cached DFS referral to determine whether or not prefix path should be updated. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-03cifs: fix double free error on share and prefixColin Ian King1-0/+2
Currently if the call dfs_cache_get_tgt_share fails we cannot fully guarantee that share and prefix are set to NULL and the next iteration of the loop can end up potentially double freeing these pointers. Since the semantics of dfs_cache_get_tgt_share are ambiguous for failure cases with the setting of share and prefix (currently now and the possibly the future), it seems prudent to set the pointers to NULL when the objects are free'd to avoid any double frees. Addresses-Coverity: ("Double free") Fixes: 96296c946a2a ("cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnect") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-08-03cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnectPaulo Alcantara1-6/+11
Use PathConsumed field when parsing prefixes of referral paths that either match a cache entry or are a complete prefix path of an existing entry. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-03cifs: handle empty list of targets in cifs_reconnect()Paulo Alcantara1-4/+6
In case there were no cached DFS referrals in reconn_setup_dfs_targets(), set cifs_sb to NULL prior to calling reconn_set_next_dfs_target() so it would not try to access an empty tgt_list. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-03cifs: rename reconn_inval_dfs_target()Paulo Alcantara1-7/+6
This function has nothing to do with *invalidation* but setting up the next target server from a cached referral. Rename it to reconn_set_next_dfs_target(). While at it, get rid of some meaningless checks. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-03cifs: merge __{cifs,smb2}_reconnect[_tcon]() into cifs_tree_connect()Stefan Metzmacher1-0/+100
They were identical execpt to CIFSTCon() vs. SMB2_tcon(). These are also available via ops->tree_connect(). Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-03cifs: convert to use be32_add_cpu()Qinglang Miao1-2/+1
Convert cpu_to_be32(be32_to_cpu(E1) + E2) to use be32_add_cpu(). Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-07-02SMB3: Honor 'posix' flag for multiuser mountsPaul Aurich1-4/+1
The flag from the primary tcon needs to be copied into the volume info so that cifs_get_tcon will try to enable extensions on the per-user tcon. At that point, since posix extensions must have already been enabled on the superblock, don't try to needlessly adjust the mount flags. Fixes: ce558b0e17f8 ("smb3: Add posix create context for smb3.11 posix mounts") Fixes: b326614ea215 ("smb3: allow "posix" mount option to enable new SMB311 protocol extensions") Signed-off-by: Paul Aurich <paul@darkrain42.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-07-02SMB3: Honor 'handletimeout' flag for multiuser mountsPaul Aurich1-0/+1
Fixes: ca567eb2b3f0 ("SMB3: Allow persistent handle timeout to be configurable on mount") Signed-off-by: Paul Aurich <paul@darkrain42.org> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-07-02SMB3: Honor lease disabling for multiuser mountsPaul Aurich1-0/+1
Fixes: 3e7a02d47872 ("smb3: allow disabling requesting leases") Signed-off-by: Paul Aurich <paul@darkrain42.org> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-07-02SMB3: Honor persistent/resilient handle flags for multiuser mountsPaul Aurich1-0/+2
Without this: - persistent handles will only be enabled for per-user tcons if the server advertises the 'Continuous Availabity' capability - resilient handles would never be enabled for per-user tcons Signed-off-by: Paul Aurich <paul@darkrain42.org> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-07-02SMB3: Honor 'seal' flag for multiuser mountsPaul Aurich1-0/+1
Ensure multiuser SMB3 mounts use encryption for all users' tcons if the mount options are configured to require encryption. Without this, only the primary tcon and IPC tcons are guaranteed to be encrypted. Per-user tcons would only be encrypted if the server was configured to require encryption. Signed-off-by: Paul Aurich <paul@darkrain42.org> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-06-06Merge tag '5.8-rc-smb3-fixes-part-1' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds1-62/+68
Pull cifs updates from Steve French: "22 changesets, 2 for stable. Includes big performance improvement for large i/o when using multichannel, also includes DFS fixes" * tag '5.8-rc-smb3-fixes-part-1' of git://git.samba.org/sfrench/cifs-2.6: (22 commits) cifs: update internal module version number cifs: multichannel: try to rebind when reconnecting a channel cifs: multichannel: use pointer for binding channel smb3: remove static checker warning cifs: multichannel: move channel selection above transport layer cifs: multichannel: always zero struct cifs_io_parms cifs: dump Security Type info in DebugData smb3: fix incorrect number of credits when ioctl MaxOutputResponse > 64K smb3: default to minimum of two channels when multichannel specified cifs: multichannel: move channel selection in function cifs: fix minor typos in comments and log messages smb3: minor update to compression header definitions cifs: minor fix to two debug messages cifs: Standardize logging output smb3: Add new parm "nodelete" cifs: move some variables off the stack in smb2_ioctl_query_info cifs: reduce stack use in smb2_compound_op cifs: get rid of unused parameter in reconn_setup_dfs_targets() cifs: handle hostnames that resolve to same ip in failover cifs: set up next DFS target before generic_ip_connect() ...
2020-06-04smb3: default to minimum of two channels when multichannel specifiedSteve French1-0/+4
When "multichannel" is specified on mount, make sure to default to at least two channels. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-06-01cifs: Standardize logging outputJoe Perches1-45/+32
Use pr_fmt to standardize all logging for fs/cifs. Some logging output had no CIFS: specific prefix. Now all output has one of three prefixes: o CIFS: o CIFS: VFS: o Root-CIFS: Miscellanea: o Convert printks to pr_<level> o Neaten macro definitions o Remove embedded CIFS: prefixes from formats o Convert "illegal" to "invalid" o Coalesce formats o Add missing '\n' format terminations o Consolidate multiple cifs_dbg continuations into single calls o More consistent use of upper case first word output logging o Multiline statement argument alignment and wrapping Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01smb3: Add new parm "nodelete"Steve French1-1/+8
In order to handle workloads where it is important to make sure that a buggy app did not delete content on the drive, the new mount option "nodelete" allows standard permission checks on the server to work, but prevents on the client any attempts to unlink a file or delete a directory on that mount point. This can be helpful when running a little understood app on a network mount that contains important content that should not be deleted. Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-06-01cifs: get rid of unused parameter in reconn_setup_dfs_targets()Paulo Alcantara1-3/+2
The target iterator parameter "it" is not used in reconn_setup_dfs_targets(), so just remove it. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01cifs: handle hostnames that resolve to same ip in failoverPaulo Alcantara1-3/+3
In order to support reconnect to hostnames that resolve to same ip address, besides relying on the currently set hostname to match DFS targets, attempt to resolve the targets and then match their addresses with the reconnected server ip address. For instance, if we have two hostnames "FOO" and "BAR", and both resolve to the same ip address, we would be able to handle failover in DFS paths like \\FOO\dfs\link1 -> [ \BAZ\share2 (*), \BAR\share1 ] \\FOO\dfs\link2 -> [ \BAZ\share2 (*), \FOO\share1 ] so when "BAZ" is no longer accessible, link1 and link2 would get reconnected despite having different target hostnames. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01cifs: set up next DFS target before generic_ip_connect()Paulo Alcantara1-9/+9
If we mount a very specific DFS link \\FS0.FOO.COM\dfs\link -> \FS0\share1, \FS1\share2 where its target list contains NB names ("FS0" & "FS1") rather than FQDN ones ("FS0.FOO.COM" & "FS1.FOO.COM"), we end up connecting to \FOO\share1 but server->hostname will have "FOO.COM". The reason is because both "FS0" and "FS0.FOO.COM" resolve to same IP address and they share same TCP server connection, but "FS0.FOO.COM" was the first hostname set -- which is OK. However, if the echo thread timeouts and we still have a good connection to "FS0", in cifs_reconnect() rc = generic_ip_connect(server) -> success if (rc) { ... reconn_inval_dfs_target(server, cifs_sb, &tgt_list, &tgt_it); ... } ... it successfully reconnects to "FS0" server but does not set up next DFS target - which should be the same target server "\FS0\share1" - and server->hostname remains set to "FS0.FOO.COM" rather than "FS0", as reconn_inval_dfs_target() would have it set to "FS0" if called earlier. Finally, in __smb2_reconnect(), the reconnect of tcons would fail because tcon->ses->server->hostname (FS0.FOO.COM) does not match DFS target's hostname (FS0). Fix that by calling reconn_inval_dfs_target() before generic_ip_connect() so server->hostname will get updated correctly prior to reconnecting its tcons in __smb2_reconnect(). With "cifs: handle hostnames that resolve to same ip in failover" patch - The above problem would not occur. - We could save an DNS query to find out that they both resolve to the same ip address. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01cifs: handle "nolease" option for vers=1.0Kenneth D'souza1-1/+10
The "nolease" mount option is only supported for SMB2+ mounts. Fail with appropriate error message if vers=1.0 option is passed. Signed-off-by: Kenneth D'souza <kdsouza@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-05-28tcp: add tcp_sock_set_nodelayChristoph Hellwig1-8/+2
Add a helper to directly set the TCP_NODELAY sockopt from kernel space without going through a fake uaccess. Cleanup the callers to avoid pointless wrappers now that this is a simple function call. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Sagi Grimberg <sagi@grimberg.me> Acked-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-23cifs: do not share tcons with DFSPaulo Alcantara1-0/+4
This disables tcon re-use for DFS shares. tcon->dfs_path stores the path that the tcon should connect to when doing failing over. If that tcon is used multiple times e.g. 2 mounts using it with different prefixpath, each will need a different dfs_path but there is only one tcon. The other solution would be to split the tcon in 2 tcons during failover but that is much harder. tcons could not be shared with DFS in cifs.ko because in a DFS namespace like: //domain/dfsroot -> /serverA/dfsroot, /serverB/dfsroot //serverA/dfsroot/link -> /serverA/target1/aa/bb //serverA/dfsroot/link2 -> /serverA/target1/cc/dd you can see that link and link2 are two DFS links that both resolve to the same target share (/serverA/target1), so cifs.ko will only contain a single tcon for both link and link2. The problem with that is, if we (auto)mount "link" and "link2", cifs.ko will only contain a single tcon for both DFS links so we couldn't perform failover or refresh the DFS cache for both links because tcon->dfs_path was set to either "link" or "link2", but not both -- which is wrong. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-04-21cifs: protect updating server->dstaddr with a spinlockRonnie Sahlberg1-0/+2
We use a spinlock while we are reading and accessing the destination address for a server. We need to also use this spinlock to protect when we are modifying this address from reconn_set_ipaddr(). Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-23cifs: clear PF_MEMALLOC before exiting demultiplex threadEric Biggers1-1/+4
Leaving PF_MEMALLOC set when exiting a kthread causes it to remain set during do_exit(). That can confuse things. For example, if BSD process accounting is enabled and the accounting file has FS_SYNC_FL set and is located on an ext4 filesystem without a journal, then do_exit() can end up calling ext4_write_inode(). That triggers the WARN_ON_ONCE(current->flags & PF_MEMALLOC) there, as it assumes (appropriately) that inodes aren't written when allocating memory. This was originally reported for another kernel thread, xfsaild() [1]. cifs_demultiplex_thread() also exits with PF_MEMALLOC set, so it's potentially subject to this same class of issue -- though I haven't been able to reproduce the WARN_ON_ONCE() via CIFS, since unlike xfsaild(), cifs_demultiplex_thread() is sent SIGKILL before exiting, and that interrupts the write to the BSD process accounting file. Either way, leaving PF_MEMALLOC set is potentially problematic. Let's clean this up by properly saving and restoring PF_MEMALLOC. [1] https://lore.kernel.org/r/0000000000000e7156059f751d7b@google.com Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-23CIFS: Warn less noisily on default mountSteve French1-5/+6
The warning we print on mount about how to use less secure dialects (when the user does not specify a version on mount) is useful but is noisy to print on every default mount, and can be changed to a warn_once. Slightly updated the warning text as well to note SMB3.1.1 which has been the default which is typically negotiated (for a few years now) by most servers. "No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3.1.1), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3.1.1 (or even SMB3 or SMB2.1) specify vers=1.0 on mount." Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-03-23cifs: print warning mounting with vers=1.0Steve French1-0/+3
We really, really don't want people using insecure dialects unless they realize what they are doing ... Add mount warning if mounting with vers=1.0 (older SMB1/CIFS dialect) instead of the default (SMB2.1 or later, typically SMB3.1.1). Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com> Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-03-23cifs: call wake_up(&server->response_q) inside of cifs_reconnect()Stefan Metzmacher1-5/+2
This means it's consistently called and the callers don't need to care about it. Signed-off-by: Stefan Metzmacher <metze@samba.org> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-23cifs: handle prefix paths in reconnectPaulo Alcantara (SUSE)1-51/+12
For the case where we have a DFS path like below and we're currently connected to targetA: //dfsroot/link -> //targetA/share/foo, //targetB/share/bar after failover, we should make sure to update cifs_sb->prepath so the next operations will use the new prefix path "/bar". Besides, in order to simplify the use of different prefix paths, enforce CIFS_MOUNT_USE_PREFIX_PATH for DFS mounts so we don't have to revalidate the root dentry every time we set a new prefix path. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-13cifs: Fix mode output in debugging statementsFrank Sorenson1-1/+1
A number of the debug statements output file or directory mode in hex. Change these to print using octal. Signed-off-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-04SMB3: Backup intent flag missing from some more opsAmir Goldstein1-1/+1
When "backup intent" is requested on the mount (e.g. backupuid or backupgid mount options), the corresponding flag was missing from some of the operations. Change all operations to use the macro cifs_create_options() to set the backup intent flag if needed. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-27cifs: fix NULL dereference in match_prepathRonnie Sahlberg1-2/+4
RHBZ: 1760879 Fix an oops in match_prepath() by making sure that the prepath string is not NULL before we pass it into strcmp(). This is similar to other checks we make for example in cifs_root_iget() Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-04cifs: Fix lookup of SMB connections on multichannelPaulo Alcantara (SUSE)1-1/+5
With the addition of SMB session channels, we introduced new TCP server pointers that have no sessions or tcons associated with them. In this case, when we started looking for TCP connections, we might end up picking session channel rather than the master connection, hence failing to get either a session or a tcon. In order to fix that, this patch introduces a new "is_channel" field to TCP_Server_Info structure so we can skip session channels during lookup of connections. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Fix retrieval of DFS referrals in cifs_mount()Paulo Alcantara (SUSE)1-10/+22
Make sure that DFS referrals are sent to newly resolved root targets as in a multi tier DFS setup. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Link: https://lkml.kernel.org/r/05aa2995-e85e-0ff4-d003-5bb08bd17a22@canonical.com Cc: stable@vger.kernel.org Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Fix use-after-free bug in cifs_reconnect()Paulo Alcantara (SUSE)1-11/+35
Ensure we grab an active reference in cifs superblock while doing failover to prevent automounts (DFS links) of expiring and then destroying the superblock pointer. This patch fixes the following KASAN report: [ 464.301462] BUG: KASAN: use-after-free in cifs_reconnect+0x6ab/0x1350 [ 464.303052] Read of size 8 at addr ffff888155e580d0 by task cifsd/1107 [ 464.304682] CPU: 3 PID: 1107 Comm: cifsd Not tainted 5.4.0-rc4+ #13 [ 464.305552] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58-rebuilt.opensuse.org 04/01/2014 [ 464.307146] Call Trace: [ 464.307875] dump_stack+0x5b/0x90 [ 464.308631] print_address_description.constprop.0+0x16/0x200 [ 464.309478] ? cifs_reconnect+0x6ab/0x1350 [ 464.310253] ? cifs_reconnect+0x6ab/0x1350 [ 464.311040] __kasan_report.cold+0x1a/0x41 [ 464.311811] ? cifs_reconnect+0x6ab/0x1350 [ 464.312563] kasan_report+0xe/0x20 [ 464.313300] cifs_reconnect+0x6ab/0x1350 [ 464.314062] ? extract_hostname.part.0+0x90/0x90 [ 464.314829] ? printk+0xad/0xde [ 464.315525] ? _raw_spin_lock+0x7c/0xd0 [ 464.316252] ? _raw_read_lock_irq+0x40/0x40 [ 464.316961] ? ___ratelimit+0xed/0x182 [ 464.317655] cifs_readv_from_socket+0x289/0x3b0 [ 464.318386] cifs_read_from_socket+0x98/0xd0 [ 464.319078] ? cifs_readv_from_socket+0x3b0/0x3b0 [ 464.319782] ? try_to_wake_up+0x43c/0xa90 [ 464.320463] ? cifs_small_buf_get+0x4b/0x60 [ 464.321173] ? allocate_buffers+0x98/0x1a0 [ 464.321856] cifs_demultiplex_thread+0x218/0x14a0 [ 464.322558] ? cifs_handle_standard+0x270/0x270 [ 464.323237] ? __switch_to_asm+0x40/0x70 [ 464.323893] ? __switch_to_asm+0x34/0x70 [ 464.324554] ? __switch_to_asm+0x40/0x70 [ 464.325226] ? __switch_to_asm+0x40/0x70 [ 464.325863] ? __switch_to_asm+0x34/0x70 [ 464.326505] ? __switch_to_asm+0x40/0x70 [ 464.327161] ? __switch_to_asm+0x34/0x70 [ 464.327784] ? finish_task_switch+0xa1/0x330 [ 464.328414] ? __switch_to+0x363/0x640 [ 464.329044] ? __schedule+0x575/0xaf0 [ 464.329655] ? _raw_spin_lock_irqsave+0x82/0xe0 [ 464.330301] kthread+0x1a3/0x1f0 [ 464.330884] ? cifs_handle_standard+0x270/0x270 [ 464.331624] ? kthread_create_on_node+0xd0/0xd0 [ 464.332347] ret_from_fork+0x35/0x40 [ 464.333577] Allocated by task 1110: [ 464.334381] save_stack+0x1b/0x80 [ 464.335123] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 464.335848] cifs_smb3_do_mount+0xd4/0xb00 [ 464.336619] legacy_get_tree+0x6b/0xa0 [ 464.337235] vfs_get_tree+0x41/0x110 [ 464.337975] fc_mount+0xa/0x40 [ 464.338557] vfs_kern_mount.part.0+0x6c/0x80 [ 464.339227] cifs_dfs_d_automount+0x336/0xd29 [ 464.339846] follow_managed+0x1b1/0x450 [ 464.340449] lookup_fast+0x231/0x4a0 [ 464.341039] path_openat+0x240/0x1fd0 [ 464.341634] do_filp_open+0x126/0x1c0 [ 464.342277] do_sys_open+0x1eb/0x2c0 [ 464.342957] do_syscall_64+0x5e/0x190 [ 464.343555] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 464.344772] Freed by task 0: [ 464.345347] save_stack+0x1b/0x80 [ 464.345966] __kasan_slab_free+0x12c/0x170 [ 464.346576] kfree+0xa6/0x270 [ 464.347211] rcu_core+0x39c/0xc80 [ 464.347800] __do_softirq+0x10d/0x3da [ 464.348919] The buggy address belongs to the object at ffff888155e58000 which belongs to the cache kmalloc-256 of size 256 [ 464.350222] The buggy address is located 208 bytes inside of 256-byte region [ffff888155e58000, ffff888155e58100) [ 464.351575] The buggy address belongs to the page: [ 464.352333] page:ffffea0005579600 refcount:1 mapcount:0 mapping:ffff88815a803400 index:0x0 compound_mapcount: 0 [ 464.353583] flags: 0x200000000010200(slab|head) [ 464.354209] raw: 0200000000010200 ffffea0005576200 0000000400000004 ffff88815a803400 [ 464.355353] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 464.356458] page dumped because: kasan: bad access detected [ 464.367005] Memory state around the buggy address: [ 464.367787] ffff888155e57f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 464.368877] ffff888155e58000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.369967] >ffff888155e58080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.371111] ^ [ 464.371775] ffff888155e58100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 464.372893] ffff888155e58180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 464.373983] ================================================================== Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: try opening channels after mountingAurelien Aptel1-13/+35
After doing mount() successfully we call cifs_try_adding_channels() which will open as many channels as it can. Channels are closed when the master session is closed. The master connection becomes the first channel. ,-------------> global cifs_tcp_ses_list <-------------------------. | | '- TCP_Server_Info <--> TCP_Server_Info <--> TCP_Server_Info <-' (master con) (chan#1 con) (chan#2 con) | ^ ^ ^ v '--------------------|--------------------' cifs_ses | - chan_count = 3 | - chans[] ---------------------' - smb3signingkey[] (master signing key) Note how channel connections don't have sessions. That's because cifs_ses can only be part of one linked list (list_head are internal to the elements). For signing keys, each channel has its own signing key which must be used only after the channel has been bound. While it's binding it must use the master session signing key. For encryption keys, since channel connections do not have sessions attached we must now find matching session by looping over all sessions in smb2_get_enc_key(). Each channel is opened like a regular server connection but at the session setup request step it must set the SMB2_SESSION_REQ_FLAG_BINDING flag and use the session id to bind to. Finally, while sending in compound_send_recv() for requests that aren't negprot, ses-setup or binding related, use a channel by cycling through the available ones (round-robin). Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>