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2025-03-17smb: client: don't retry IO on failed negprotos with soft mountsPaulo Alcantara
If @server->tcpStatus is set to CifsNeedReconnect after acquiring @ses->session_mutex in smb2_reconnect() or cifs_reconnect_tcon(), it means that a concurrent thread failed to negotiate, in which case the server is no longer responding to any SMB requests, so there is no point making the caller retry the IO by returning -EAGAIN. Fix this by returning -EHOSTDOWN to the callers on soft mounts. Cc: David Howells <dhowells@redhat.com> Reported-by: Jay Shin <jaeshin@redhat.com> Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13smb: client: Fix match_session bug preventing session reuseHenrique Carvalho
Fix a bug in match_session() that can causes the session to not be reused in some cases. Reproduction steps: mount.cifs //server/share /mnt/a -o credentials=creds mount.cifs //server/share /mnt/b -o credentials=creds,sec=ntlmssp cat /proc/fs/cifs/DebugData | grep SessionId | wc -l mount.cifs //server/share /mnt/b -o credentials=creds,sec=ntlmssp mount.cifs //server/share /mnt/a -o credentials=creds cat /proc/fs/cifs/DebugData | grep SessionId | wc -l Cc: stable@vger.kernel.org Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13cifs: Fix integer overflow while processing closetimeo mount optionMurad Masimov
User-provided mount parameter closetimeo of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 5efdd9122eff ("smb3: allow deferred close timeout to be configurable") Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13cifs: Fix integer overflow while processing actimeo mount optionMurad Masimov
User-provided mount parameter actimeo of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 6d20e8406f09 ("cifs: add attribute cache timeout (actimeo) tunable") Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13cifs: Fix integer overflow while processing acdirmax mount optionMurad Masimov
User-provided mount parameter acdirmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 4c9f948142a5 ("cifs: Add new mount parameter "acdirmax" to allow caching directory metadata") Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13cifs: Fix integer overflow while processing acregmax mount optionMurad Masimov
User-provided mount parameter acregmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 5780464614f6 ("cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout") Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-13smb: client: fix regression with guest optionPaulo Alcantara
When mounting a CIFS share with 'guest' mount option, mount.cifs(8) will set empty password= and password2= options. Currently we only handle empty strings from user= and password= options, so the mount will fail with cifs: Bad value for 'password2' Fix this by handling empty string from password2= option as well. Link: https://bbs.archlinux.org/viewtopic.php?id=303927 Reported-by: Adam Williamson <awilliam@redhat.com> Closes: https://lore.kernel.org/r/83c00b5fea81c07f6897a5dd3ef50fd3b290f56c.camel@redhat.com Fixes: 35f834265e0d ("smb3: fix broken reconnect when password changing on the server by allowing password rotation") Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-02cifs: fix incorrect validation for num_aces field of smb_aclNamjae Jeon
parse_dcal() validate num_aces to allocate ace array. f (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) It is an incorrect validation that we can create an array of size ULONG_MAX. smb_acl has ->size field to calculate actual number of aces in response buffer size. Use this to check invalid num_aces. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-03-02smb: common: change the data type of num_aces to le16Namjae Jeon
2.4.5 in [MS-DTYP].pdf describe the data type of num_aces as le16. AceCount (2 bytes): An unsigned 16-bit integer that specifies the count of the number of ACE records in the ACL. Change it to le16 and add reserved field to smb_acl struct. Reported-by: Igor Leite Ladessa <igor-ladessa@hotmail.com> Tested-by: Igor Leite Ladessa <igor-ladessa@hotmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-25cifs: Fix the smb1 readv callback to correctly call netfsDavid Howells
Fix cifs_readv_callback() to call netfs_read_subreq_terminated() rather than queuing the subrequest work item (which is unset). Also call the I/O progress tracepoint. cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reported-by: Jean-Christophe Guillain <jean-christophe@guillain.net> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219793 Tested-by: Jean-Christophe Guillain <jean-christophe@guillain.net> Tested-by: Pali Rohár <pali@kernel.org> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-20smb: client: Add check for next_buffer in receive_encrypted_standard()Haoxiang Li
Add check for the return value of cifs_buf_get() and cifs_small_buf_get() in receive_encrypted_standard() to prevent null pointer dereference. Fixes: eec04ea11969 ("smb: client: fix OOB in receive_encrypted_standard()") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-19cifs: Treat unhandled directory name surrogate reparse points as mount ↵Pali Rohár
directory nodes If the reparse point was not handled (indicated by the -EOPNOTSUPP from ops->parse_reparse_point() call) but reparse tag is of type name surrogate directory type, then treat is as a new mount point. Name surrogate reparse point represents another named entity in the system. From SMB client point of view, this another entity is resolved on the SMB server, and server serves its content automatically. Therefore from Linux client point of view, this name surrogate reparse point of directory type crosses mount point. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-19cifs: Throw -EOPNOTSUPP error on unsupported reparse point type from ↵Pali Rohár
parse_reparse_point() This would help to track and detect by caller if the reparse point type was processed or not. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-19smb311: failure to open files of length 1040 when mounting with SMB3.1.1 ↵Steve French
POSIX extensions If a file size has bits 0x410 = ATTR_DIRECTORY | ATTR_REPARSE set then during queryinfo (stat) the file is regarded as a directory and subsequent opens can fail. A simple test example is trying to open any file 1040 bytes long when mounting with "posix" (SMB3.1.1 POSIX/Linux Extensions). The cause of this bug is that Attributes field in smb2_file_all_info struct occupies the same place that EndOfFile field in smb311_posix_qinfo, and sometimes the latter struct is incorrectly processed as if it was the first one. Reported-by: Oleh Nykyforchyn <oleh.nyk@gmail.com> Tested-by: Oleh Nykyforchyn <oleh.nyk@gmail.com> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-19smb: client, common: Avoid multiple -Wflex-array-member-not-at-end warningsGustavo A. R. Silva
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. So, in order to avoid ending up with flexible-array members in the middle of other structs, we use the `__struct_group()` helper to separate the flexible arrays from the rest of the members in the flexible structures. We then use the newly created tagged `struct smb2_file_link_info_hdr` and `struct smb2_file_rename_info_hdr` to replace the type of the objects causing trouble: `rename_info` and `link_info` in `struct smb2_compound_vars`. We also want to ensure that when new members need to be added to the flexible structures, they are always included within the newly created tagged structs. For this, we use `static_assert()`. This ensures that the memory layout for both the flexible structure and the new tagged struct is the same after any changes. So, with these changes, fix 86 of the following warnings: fs/smb/client/cifsglob.h:2335:36: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] fs/smb/client/cifsglob.h:2334:38: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-16smb: client: fix chmod(2) regression with ATTR_READONLYPaulo Alcantara
When the user sets a file or directory as read-only (e.g. ~S_IWUGO), the client will set the ATTR_READONLY attribute by sending an SMB2_SET_INFO request to the server in cifs_setattr_{,nounix}(), but cifsInodeInfo::cifsAttrs will be left unchanged as the client will only update the new file attributes in the next call to {smb311_posix,cifs}_get_inode_info() with the new metadata filled in @data parameter. Commit a18280e7fdea ("smb: cilent: set reparse mount points as automounts") mistakenly removed the @data NULL check when calling is_inode_cache_good(), which broke the above case as the new ATTR_READONLY attribute would end up not being updated on files with a read lease. Fix this by updating the inode whenever we have cached metadata in @data parameter. Reported-by: Horst Reiterer <horst.reiterer@fabasoft.com> Closes: https://lore.kernel.org/r/85a16504e09147a195ac0aac1c801280@fabasoft.com Fixes: a18280e7fdea ("smb: cilent: set reparse mount points as automounts") Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-11cifs: pick channels for individual subrequestsShyam Prasad N
The netfs library could break down a read request into multiple subrequests. When multichannel is used, there is potential to improve performance when each of these subrequests pick a different channel. Today we call cifs_pick_channel when the main read request is initialized in cifs_init_request. This change moves this to cifs_prepare_read, which is the right place to pick channel since it gets called for each subrequest. Interestingly cifs_prepare_write already does channel selection for individual subreq, but looks like it was missed for read. This is especially important when multichannel is used with increased rasize. In my test setup, with rasize set to 8MB, a sequential read of large file was taking 11.5s without this change. With the change, it completed in 9s. The difference is even more signigicant with bigger rasize. Cc: <stable@vger.kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-06smb: client: change lease epoch type from unsigned int to __u16Meetakshi Setiya
MS-SMB2 section 2.2.13.2.10 specifies that 'epoch' should be a 16-bit unsigned integer used to track lease state changes. Change the data type of all instances of 'epoch' from unsigned int to __u16. This simplifies the epoch change comparisons and makes the code more compliant with the protocol spec. Cc: stable@vger.kernel.org Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-05smb: client: get rid of kstrdup() in get_ses_refpath()Paulo Alcantara
After commit 36008fe6e3dc ("smb: client: don't try following DFS links in cifs_tree_connect()"), TCP_Server_Info::leaf_fullpath will no longer be changed, so there is no need to kstrdup() it. Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-05smb: client: fix noisy when tree connecting to DFS interlink targetsPaulo Alcantara
When the client attempts to tree connect to a domain-based DFS namespace from a DFS interlink target, the server will return STATUS_BAD_NETWORK_NAME and the following will appear on dmesg: CIFS: VFS: BAD_NETWORK_NAME: \\dom\dfs Since a DFS share might contain several DFS interlinks and they expire after 10 minutes, the above message might end up being flooded on dmesg when mounting or accessing them. Print this only once per share. Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-05smb: client: don't trust DFSREF_STORAGE_SERVER bitPaulo Alcantara
Some servers don't respect the DFSREF_STORAGE_SERVER bit, so unconditionally tree connect to DFS link target and then decide whether or not continue chasing DFS referrals for DFS interlinks. Otherwise the client would fail to mount such shares. Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-02-01Merge tag 'v6.14-rc-smb3-client-fixes-part2' of ↵Linus Torvalds
git://git.samba.org/sfrench/cifs-2.6 Pull more smb client updates from Steve French: - various updates for special file handling: symlink handling, support for creating sockets, cleanups, new mount options (e.g. to allow disabling using reparse points for them, and to allow overriding the way symlinks are saved), and fixes to error paths - fix for kerberos mounts (allow IAKerb) - SMB1 fix for stat and for setting SACL (auditing) - fix an incorrect error code mapping - cleanups" * tag 'v6.14-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: (21 commits) cifs: Fix parsing native symlinks directory/file type cifs: update internal version number cifs: Add support for creating WSL-style symlinks smb3: add support for IAKerb cifs: Fix struct FILE_ALL_INFO cifs: Add support for creating NFS-style symlinks cifs: Add support for creating native Windows sockets cifs: Add mount option -o reparse=none cifs: Add mount option -o symlink= for choosing symlink create type cifs: Fix creating and resolving absolute NT-style symlinks cifs: Simplify reparse point check in cifs_query_path_info() function cifs: Remove symlink member from cifs_open_info_data union cifs: Update description about ACL permissions cifs: Rename struct reparse_posix_data to reparse_nfs_data_buffer and move to common/smb2pdu.h cifs: Remove struct reparse_posix_data from struct cifs_open_info_data cifs: Remove unicode parameter from parse_reparse_point() function cifs: Fix getting and setting SACLs over SMB1 cifs: Remove intermediate object of failed create SFU call cifs: Validate EAs for WSL reparse points cifs: Change translation of STATUS_PRIVILEGE_NOT_HELD to -EPERM ...
2025-01-31cifs: Fix parsing native symlinks directory/file typePali Rohár
As SMB protocol distinguish between symlink to directory and symlink to file, add some mechanism to disallow resolving incompatible types. When SMB symlink is of the directory type, ensure that its target path ends with slash. This forces Linux to not allow resolving such symlink to file. And when SMB symlink is of the file type and its target path ends with slash then returns an error as such symlink is unresolvable. Such symlink always points to invalid location as file cannot end with slash. As POSIX server does not distinguish between symlinks to file and symlink directory, do not apply this change for symlinks from POSIX SMB server. For POSIX SMB servers, this change does nothing. This mimics Windows behavior of native SMB symlinks. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31cifs: update internal version numberSteve French
To 2.53 Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31cifs: Add support for creating WSL-style symlinksPali Rohár
This change implements support for creating new symlink in WSL-style by Linux cifs client when -o reparse=wsl mount option is specified. WSL-style symlink uses reparse point with tag IO_REPARSE_TAG_LX_SYMLINK and symlink target location is stored in reparse buffer in UTF-8 encoding prefixed by 32-bit flags. Flags bits are unknown, but it was observed that WSL always sets flags to value 0x02000000. Do same in Linux cifs client. New symlinks would be created in WSL-style only in case the mount option -o reparse=wsl is specified, which is not by default. So default CIFS mounts are not affected by this change. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31smb3: add support for IAKerbSteve French
There are now more servers which advertise support for IAKerb (passthrough Kerberos authentication via proxy). IAKerb is a public extension industry standard Kerberos protocol that allows a client without line-of-sight to a Domain Controller to authenticate. There can be cases where we would fail to mount if the server only advertises the OID for IAKerb in SPNEGO/GSSAPI. Add code to allow us to still upcall to userspace in these cases to obtain the Kerberos ticket. Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31cifs: Fix struct FILE_ALL_INFOPali Rohár
struct FILE_ALL_INFO for level 263 (0x107) used by QPathInfo does not have any IndexNumber, AccessFlags, IndexNumber1, CurrentByteOffset, Mode or AlignmentRequirement members. So remove all of them. Also adjust code in move_cifs_info_to_smb2() function which converts struct FILE_ALL_INFO to struct smb2_file_all_info. Fixed content of struct FILE_ALL_INFO was verified that is correct against: * [MS-CIFS] section 2.2.8.3.10 SMB_QUERY_FILE_ALL_INFO * Samba server implementation of trans2 query file/path for level 263 * Packet structure tests against Windows SMB servers This change fixes CIFSSMBQFileInfo() and CIFSSMBQPathInfo() functions which directly copy received FILE_ALL_INFO network buffers into kernel structures of FILE_ALL_INFO type. struct FILE_ALL_INFO is the response structure returned by the SMB server. So the incorrect definition of this structure can lead to returning bogus information in stat() call. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31cifs: Add support for creating NFS-style symlinksPali Rohár
CIFS client is currently able to parse NFS-style symlinks, but is not able to create them. This functionality is useful when the mounted SMB share is used also by Windows NFS server (on Windows Server 2012 or new). It allows interop of symlinks between SMB share mounted by Linux CIFS client and same export from Windows NFS server mounted by some NFS client. New symlinks would be created in NFS-style only in case the mount option -o reparse=nfs is specified, which is not by default. So default CIFS mounts are not affected by this change. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-31cifs: Add support for creating native Windows socketsPali Rohár
Native Windows sockets created by WinSock on Windows 10 April 2018 Update (version 1803) or Windows Server 2019 (version 1809) or later versions is reparse point with IO_REPARSE_TAG_AF_UNIX tag, with empty reparse point data buffer and without any EAs. Create AF_UNIX sockets in this native format if -o nonativesocket was not specified. This change makes AF_UNIX sockets created by Linux CIFS client compatible with AF_UNIX sockets created by Windows applications on NTFS volumes. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-30Merge tag 'pull-revalidate' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs d_revalidate updates from Al Viro: "Provide stable parent and name to ->d_revalidate() instances Most of the filesystem methods where we care about dentry name and parent have their stability guaranteed by the callers; ->d_revalidate() is the major exception. It's easy enough for callers to supply stable values for expected name and expected parent of the dentry being validated. That kills quite a bit of boilerplate in ->d_revalidate() instances, along with a bunch of races where they used to access ->d_name without sufficient precautions" * tag 'pull-revalidate' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: 9p: fix ->rename_sem exclusion orangefs_d_revalidate(): use stable parent inode and name passed by caller ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller nfs: fix ->d_revalidate() UAF on ->d_name accesses nfs{,4}_lookup_validate(): use stable parent inode passed by caller gfs2_drevalidate(): use stable parent inode and name passed by caller fuse_dentry_revalidate(): use stable parent inode and name passed by caller vfat_revalidate{,_ci}(): use stable parent inode passed by caller exfat_d_revalidate(): use stable parent inode passed by caller fscrypt_d_revalidate(): use stable parent inode passed by caller ceph_d_revalidate(): propagate stable name down into request encoding ceph_d_revalidate(): use stable parent inode passed by caller afs_d_revalidate(): use stable name and parent inode passed by caller Pass parent directory inode and expected name to ->d_revalidate() generic_ci_d_compare(): use shortname_storage ext4 fast_commit: make use of name_snapshot primitives dissolve external_name.u into separate members make take_dentry_name_snapshot() lockless dcache: back inline names with a struct-wrapped array of unsigned long make sure that DNAME_INLINE_LEN is a multiple of word size
2025-01-29cifs: Add mount option -o reparse=nonePali Rohár
This new mount option allows to completely disable creating new reparse points. When -o sfu or -o mfsymlinks or -o symlink= is not specified then creating any special file (fifo, socket, symlink, block and char) will fail with -EOPNOTSUPP error. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Add mount option -o symlink= for choosing symlink create typePali Rohár
Currently Linux CIFS client creates a new symlink of the first flavor which is allowed by mount options, parsed in this order: -o (no)mfsymlinks, -o (no)sfu, -o (no)unix (+ its aliases) and -o reparse=[type]. Introduce a new mount option -o symlink= for explicitly choosing a symlink flavor. Possible options are: -o symlink=default - The default behavior, like before this change. -o symlink=none - Disallow creating a new symlinks -o symlink=native - Create as native SMB symlink reparse point -o symlink=unix - Create via SMB1 unix extension command -o symlink=mfsymlinks - Create as regular file of mfsymlinks format -o symlink=sfu - Create as regular system file of SFU format -o symlink=nfs - Create as NFS reparse point -o symlink=wsl - Create as WSL reparse point So for example specifying -o sfu,mfsymlinks,symlink=native will allow to parse symlinks also of SFU and mfsymlinks types (which are disabled by default unless mount option is explicitly specified), but new symlinks will be created under native SMB type (which parsing is always enabled). Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Fix creating and resolving absolute NT-style symlinksPali Rohár
If the SMB symlink is stored on NT server in absolute form then it points to the NT object hierarchy, which is different from POSIX one and needs some conversion / mapping. To make interoperability with Windows SMB server and WSL subsystem, reuse its logic of mapping between NT paths and POSIX paths into Linux SMB client. WSL subsystem on Windows uses for -t drvfs mount option -o symlinkroot= which specifies the POSIX path where are expected to be mounted lowercase Windows drive letters (without colon). Do same for Linux SMB client and add a new mount option -o symlinkroot= which mimics the drvfs mount option of the same name. It specifies where in the Linux VFS hierarchy is the root of the DOS / Windows drive letters, and translates between absolute NT-style symlinks and absolute Linux VFS symlinks. Default value of symlinkroot is "/mnt", same what is using WSL. Note that DOS / Windows drive letter symlinks are just subset of all possible NT-style symlinks. Drive letters live in NT subtree \??\ and important details about NT paths and object hierarchy are in the comments in this change. When symlink target location from non-POSIX SMB server is in absolute form (indicated by absence of SYMLINK_FLAG_RELATIVE) then it is converted to Linux absolute symlink according to symlinkroot configuration. And when creating a new symlink on non-POSIX SMB server in absolute form then Linux absolute target is converted to NT-style according to symlinkroot configuration. When SMB server is POSIX, then this change does not affect neither reading target location of symlink, nor creating a new symlink. It is expected that POSIX SMB server works with POSIX paths where the absolute root is /. This change improves interoperability of absolute SMB symlinks with Windows SMB servers. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Simplify reparse point check in cifs_query_path_info() functionPali Rohár
For checking if path is reparse point and setting data->reparse_point member, it is enough to check if ATTR_REPARSE is present. It is not required to call CIFS_open() without OPEN_REPARSE_POINT and checking for -EOPNOTSUPP error code. Signed-off-by: Pali Rohár <pali@kernel.org> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Remove symlink member from cifs_open_info_data unionPali Rohár
Member 'symlink' is part of the union in struct cifs_open_info_data. Its value is assigned on few places, but is always read through another union member 'reparse_point'. So to make code more readable, always use only 'reparse_point' member and drop whole union structure. No function change. Signed-off-by: Pali Rohár <pali@kernel.org> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Update description about ACL permissionsPali Rohár
There are some incorrect information about individual SMB permission constants like WRITE_DAC can change ownership, or incomplete information to distinguish between ACL types (discretionary vs system) and there is completely missing information how permissions apply for directory objects and what is meaning of GENERIC_* bits. Also there is missing constant for MAXIMUM_ALLOWED permission. Fix and extend description of all SMB permission constants to match the reality, how the reference Windows SMB / NTFS implementation handles them. Links to official Microsoft documentation related to permissions: https://learn.microsoft.com/en-us/windows/win32/fileio/file-access-rights-constants https://learn.microsoft.com/en-us/windows/win32/secauthz/access-mask https://learn.microsoft.com/en-us/windows/win32/secauthz/standard-access-rights https://learn.microsoft.com/en-us/windows/win32/secauthz/generic-access-rights https://learn.microsoft.com/en-us/windows/win32/api/winternl/nf-winternl-ntcreatefile https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/nf-ntifs-ntcreatefile Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Rename struct reparse_posix_data to reparse_nfs_data_buffer and move ↵Pali Rohár
to common/smb2pdu.h Function parse_reparse_posix() parses NFS-style reparse points, which are used only by Windows NFS server since Windows Server 2012 version. This style is not understood by Microsoft POSIX/Interix/SFU/SUA subsystems. So make it clear that parse_reparse_posix() function and reparse_posix_data structure are not POSIX general, but rather NFS specific. All reparse buffer structures are defined in common/smb2pdu.h and have _buffer suffix. So move struct reparse_posix_data from client/cifspdu.h to common/smb2pdu.h and rename it to reparse_nfs_data_buffer for consistency. Note that also SMB specification in [MS-FSCC] document, section 2.1.2.6 defines it under name "Network File System (NFS) Reparse Data Buffer". So use this name for consistency. Having this structure in common/smb2pdu.h can be useful for ksmbd server code as NFS-style reparse points is the preferred way for implementing support for special files. Signed-off-by: Pali Rohár <pali@kernel.org> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Remove struct reparse_posix_data from struct cifs_open_info_dataPali Rohár
Linux SMB client already supports more reparse point types but only the reparse_posix_data is defined in union of struct cifs_open_info_data. This union is currently used as implicit casting between point types. With this code style, it hides information that union is used for pointer casting, and just in mknod_nfs() and posix_reparse_to_fattr() functions. Other reparse point buffers do not use this kind of casting. So remove reparse_posix_data from reparse part of struct cifs_open_info_data and for all cases of reparse buffer use just struct reparse_data_buffer *buf. Signed-off-by: Pali Rohár <pali@kernel.org> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Remove unicode parameter from parse_reparse_point() functionPali Rohár
This parameter is always true, so remove it and also remove dead code which is never called (for all false code paths). Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Fix getting and setting SACLs over SMB1Pali Rohár
SMB1 callback get_cifs_acl_by_fid() currently ignores its last argument and therefore ignores request for SACL_SECINFO. Fix this issue by correctly propagating info argument from get_cifs_acl() and get_cifs_acl_by_fid() to CIFSSMBGetCIFSACL() function and pass SACL_SECINFO when requested. For accessing SACLs it is needed to open object with SYSTEM_SECURITY access. Pass this flag when trying to get or set SACLs. Same logic is in the SMB2+ code path. This change fixes getting and setting of "system.cifs_ntsd_full" and "system.smb3_ntsd_full" xattrs over SMB1 as currently it silentely ignored SACL part of passed xattr buffer. Fixes: 3970acf7ddb9 ("SMB3: Add support for getting and setting SACLs") Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Remove intermediate object of failed create SFU callPali Rohár
Check if the server honored ATTR_SYSTEM flag by CREATE_OPTION_SPECIAL option. If not then server does not support ATTR_SYSTEM and newly created file is not SFU compatible, which means that the call failed. If CREATE was successful but either setting ATTR_SYSTEM failed or writing type/data information failed then remove the intermediate object created by CREATE. Otherwise intermediate empty object stay on the server. This ensures that if the creating of SFU files with system attribute is unsupported by the server then no empty file stay on the server as a result of unsupported operation. This is for example case with Samba server and Linux tmpfs storage without enabled xattr support (where Samba stores ATTR_SYSTEM bit). Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Validate EAs for WSL reparse pointsPali Rohár
Major and minor numbers for char and block devices are mandatory for stat. So check that the WSL EA $LXDEV is present for WSL CHR and BLK reparse points. WSL reparse point tag determinate type of the file. But file type is present also in the WSL EA $LXMOD. So check that both file types are same. Fixes: 78e26bec4d6d ("smb: client: parse uid, gid, mode and dev from WSL reparse points") Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-29cifs: Change translation of STATUS_PRIVILEGE_NOT_HELD to -EPERMPali Rohár
STATUS_PRIVILEGE_NOT_HELD indicates that user does not have privilege to issue some operation, for example to create symlink. Currently STATUS_PRIVILEGE_NOT_HELD is translated to -EIO. Change it to -EPERM which better describe this error code. Note that there is no ERR* code usable in ntstatus_to_dos_map[] table which can be used to -EPERM translation, so do explicit translation in map_smb_to_linux_error() function. Signed-off-by: Pali Rohár <pali@kernel.org> Acked-by: Tom Talpey <tom@talpey.com> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-27Pass parent directory inode and expected name to ->d_revalidate()Al Viro
->d_revalidate() often needs to access dentry parent and name; that has to be done carefully, since the locking environment varies from caller to caller. We are not guaranteed that dentry in question will not be moved right under us - not unless the filesystem is such that nothing on it ever gets renamed. It can be dealt with, but that results in boilerplate code that isn't even needed - the callers normally have just found the dentry via dcache lookup and want to verify that it's in the right place; they already have the values of ->d_parent and ->d_name stable. There is a couple of exceptions (overlayfs and, to less extent, ecryptfs), but for the majority of calls that song and dance is not needed at all. It's easier to make ecryptfs and overlayfs find and pass those values if there's a ->d_revalidate() instance to be called, rather than doing that in the instances. This commit only changes the calling conventions; making use of supplied values is left to followups. NOTE: some instances need more than just the parent - things like CIFS may need to build an entire path from filesystem root, so they need more precautions than the usual boilerplate. This series doesn't do anything to that need - these filesystems have to keep their locking mechanisms (rename_lock loops, use of dentry_path_raw(), private rwsem a-la v9fs). One thing to keep in mind when using name is that name->name will normally point into the pathname being resolved; the filename in question occupies name->len bytes starting at name->name, and there is NUL somewhere after it, but it the next byte might very well be '/' rather than '\0'. Do not ignore name->len. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-01-26cifs: Change translation of STATUS_NOT_A_REPARSE_POINT to -ENODATAPali Rohár
STATUS_NOT_A_REPARSE_POINT indicates that object does not have reparse point buffer attached, for example returned by FSCTL_GET_REPARSE_POINT. Currently STATUS_NOT_A_REPARSE_POINT is translated to -EIO. Change it to -ENODATA which better describe the situation when no reparse point is set. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-23Merge tag 'v6.14-rc-smb3-client-fixes-part' of ↵Linus Torvalds
git://git.samba.org/sfrench/cifs-2.6 Pull smb client updates from Steve French: - Fix oops in DebugData when link speed 0 - Two reparse point fixes - Ten DFS (global namespace) fixes - Symlink error handling fix - Two SMB1 fixes - Four cleanup fixes - Improved debugging of status codes - Fix incorrect output of tracepoints for compounding, and add missing compounding tracepoint * tag 'v6.14-rc-smb3-client-fixes-part' of git://git.samba.org/sfrench/cifs-2.6: (23 commits) smb: client: handle lack of EA support in smb2_query_path_info() smb: client: don't check for @leaf_fullpath in match_server() smb: client: get rid of TCP_Server_Info::refpath_lock cifs: Remove duplicate struct reparse_symlink_data and SYMLINK_FLAG_RELATIVE cifs: Do not attempt to call CIFSGetSrvInodeNumber() without CAP_INFOLEVEL_PASSTHRU cifs: Do not attempt to call CIFSSMBRenameOpenFile() without CAP_INFOLEVEL_PASSTHRU cifs: Remove declaration of dead CIFSSMBQuerySymLink function cifs: Fix printing Status code into dmesg cifs: Add missing NT_STATUS_* codes from nterr.h to nterr.c cifs: Fix endian types in struct rfc1002_session_packet cifs: Use cifs_autodisable_serverino() for disabling CIFS_MOUNT_SERVER_INUM in readdir.c smb3: add missing tracepoint for querying wsl EAs smb: client: fix order of arguments of tracepoints smb: client: fix oops due to unset link speed smb: client: correctly handle ErrorContextData as a flexible array smb: client: don't retry DFS targets on server shutdown smb: client: fix return value of parse_dfs_referrals() smb: client: optimize referral walk on failed link targets smb: client: provide dns_resolve_{unc,name} helpers smb: client: parse DNS domain name from domain= option ...
2025-01-22smb: client: handle lack of EA support in smb2_query_path_info()Paulo Alcantara
If the server doesn't support both EAs and reparse point in a file, the SMB2_QUERY_INFO request will fail with either STATUS_NO_EAS_ON_FILE or STATUS_EAS_NOT_SUPPORT in the compound chain, so ignore it as long as reparse point isn't IO_REPARSE_TAG_LX_(CHR|BLK), which would require the EAs to know about major/minor numbers. Reported-by: Pali Rohár <pali@kernel.org> Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-22smb: client: don't check for @leaf_fullpath in match_server()Paulo Alcantara
The matching of DFS connections is already handled by @dfs_conn, so remove @leaf_fullpath matching altogether. Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-22smb: client: get rid of TCP_Server_Info::refpath_lockPaulo Alcantara
TCP_Server_Info::leaf_fullpath is allocated in cifs_get_tcp_session() and never changed afterwards, so there is no need to serialize its access. Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2025-01-20cifs: Remove duplicate struct reparse_symlink_data and SYMLINK_FLAG_RELATIVEPali Rohár
In file common/smb2pdu.h is defined struct reparse_symlink_data_buffer which is same as struct reparse_symlink_data and is used in the whole code. So remove duplicate struct reparse_symlink_data from client/cifspdu.h. In file common/smb2pdu.h is defined also SYMLINK_FLAG_RELATIVE constant, so remove duplication from client/cifspdu.h. Signed-off-by: Pali Rohár <pali@kernel.org> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>