wireguard-linux/fs/smb/client, branch stable

smb: client: use finish_no_open() for non-regular inodes

2026-09-24T13:50:39Z

An O_CREAT open can find an existing symlink or another non-regular inode. cifs_atomic_open() calls finish_open() on it and attaches a cifsFileInfo. Symlink inodes have no CIFS release operation, so the dentry reference held by cifsFileInfo is leaked. FMODE_OPENED also prevents the VFS from following the symlink. Track whether cifs_do_create() returned an open server handle. For non-regular inodes, close the handle if present, remove the pending open, and call finish_no_open() so the VFS can continue the lookup. Do not set FMODE_CREATED unless a regular file was opened. For O_NOFOLLOW with __O_REGULAR, return -ELOOP before the VFS's -EFTYPE check. Defer closing a legacy POSIX handle on a non-regular inode until after inode lookup. This avoids closing it again if lookup fails. Fixes: d2c127197dfc ("cifs: implement i_op->atomic_open()") Signed-off-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: stable@vger.kernel.org

smb: client: use GFP_KERNEL in get_targets()

2026-09-23T01:20:18Z

Currently, get_targets() uses GFP_ATOMIC to allocate the cache target iterator and to duplicate t->name. The callers of get_targets() are in a sleepable context; therefore, switch to GFP_KERNEL to reduce risk of failure and reduce pressure on emergency pools in low-memory scenarios. Signed-off-by: Fredric Cover Signed-off-by: Paulo Alcantara

smb: client: update POSIX extension specification references

2026-09-23T01:12:10Z

The POSIX extension specifications have now been published: https://smb3posix.org/ Suggested-by: Paulo Alcantara Reviewed-by: ChenXiaoSong Signed-off-by: ZhangGuoDong Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara

smb: client: preserve create-context parsing errors

2026-09-22T00:40:17Z

smb2_compound_op() saves the result from compound_send_recv() in tmp_rc. For SMB2_OP_OPEN_QUERY it then parses the CREATE contexts, but the final assignment of rc from tmp_rc discards a parsing error. A malformed create-context response can therefore be reported as successful to smb2_query_path_info(). Keep a create-context parsing error in tmp_rc so it survives per-command response processing and is returned to the caller. Fixes: b07687edee99 ("cifs: Improve SMB2+ stat() to work also without FILE_READ_ATTRIBUTES") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Tested-by: Frank Sorenson Signed-off-by: Paulo Alcantara

smb: client: close completed creates on compound wait errors

2026-09-22T00:40:17Z

compound_send_recv() waits for responses in order. If a later wait is interrupted, or if a later MID fails during response synchronization, an earlier CREATE may already have opened a remote handle. The earlier mid is then released without invoking handle_cancelled_mid(), leaving the remote handle open because no FID was copied to the caller. Mark completed earlier mids as cancelled when a compound wait or MID synchronization aborts. Keep their response buffers attached while the MIDs are synchronized, and transfer them only after synchronization of the processed responses, so the release path can inspect successful CREATE responses and queue SMB2_close() after a later failure. Account for a remote open only after the close work is allocated and before it is queued, since the caller has not yet updated num_remote_opens. Mark the create+close compound used by smb2_unlink() so it is not closed again. Non-CREATE responses and compounds that already include a close keep their existing behavior. Fixes: e0bba0b85481 ("cifs: add compound_send_recv()") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Tested-by: Frank Sorenson Signed-off-by: Paulo Alcantara

smb: client: clean up failed cached directory opens

2026-09-22T00:40:17Z

open_cached_dir() sends CREATE and QUERY_INFO as a compound request. If the CREATE succeeds but a later command returns an error, the function must retain the CREATE FID so common cleanup can issue SMB2_close(). It also must not treat a response error as a valid CREATE. Validate the CREATE response before using its fields, record the FIDs, and mark the handle open before handling errors from later compound commands. Move the -EREMCHG reconnect handling before response validation so a missing response does not hide the reconnect request. Count the handle when it is marked open; confirmed close responses decrement the counter, while existing close retry behavior remains best effort on transport failures. Fixes: b0f6df737a1c ("cifs: cache FILE_ALL_INFO for the shared root handle") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Tested-by: Frank Sorenson Signed-off-by: Paulo Alcantara

smb: client: close handle after create-context parsing failure

2026-09-22T00:40:17Z

SMB2_open() accounts a successful CREATE response as a remote open before parsing its create contexts. If smb2_parse_contexts() rejects malformed context data, SMB2_open() returns without closing the handle, leaving the server-side handle open and num_remote_opens elevated. Close the handle after a post-CREATE context parsing failure so the error path releases the remote resource and balances the open count. Fixes: af1689a9b770 ("smb: client: fix potential OOBs in smb2_parse_contexts()") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Tested-by: Frank Sorenson Signed-off-by: Paulo Alcantara

smb: client: validate POSIX create context length

2026-09-22T00:40:17Z

parse_posix_ctxt() reads the fixed nlink, reparse_tag, and mode fields before checking that the POSIX create context contains them. A short context can pass the generic checks and still make these fixed-width reads run past its declared data. The current in-tree smb2_open_file() path passes a NULL posix pointer, so this handler is not reached on the ordinary open path. Still require the POSIX data to cover all three fields before reading them because the helper performs those unguarded reads. Keep the existing soft-failure behavior so malformed optional metadata does not fail the open. Fixes: 69dda3059e7a ("cifs: add SMB2_open() arg to return POSIX data") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Tested-by: Frank Sorenson Signed-off-by: Paulo Alcantara

smb: client: fix create context out-of-bounds reads

2026-09-22T00:40:17Z

smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open. Fixes: b8c32dbb0deb ("CIFS: Request SMB2.1 leases") Fixes: f047390a097e ("CIFS: Add create lease v2 context for SMB3") Fixes: 89a5bfa350fa ("smb3: optimize open to not send query file internal info") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Tested-by: Frank Sorenson Signed-off-by: Paulo Alcantara

smb: client: delete compound mids on send failure before unlock

2026-09-20T03:58:39Z

When sending a compound request fails, smb_send_rqst() kicks off a reconnect. compound_send_recv() still has those mids on pending_mid_q, but it unlocks the server without removing them first. During reconnect, cifs_abort_connection() walks pending_mid_q and runs each mid callback. With no response yet, those callbacks return credits and drop in_flight. Then compound_send_recv()'s send-error path returns the same credits again. in_flight ends up decremented twice and smb2_add_credits() WARNs. syzbot hits this during SMB2_negotiate when the socket send fails. cifs_call_async() already calls delete_mid() before unlock on send failure. Do the same for compound chains and set cancelled_mid[] so the out: path does not delete them again. Fixes: ee258d79159a ("CIFS: Move credit processing to mid callbacks for SMB3") Reported-by: syzbot+eeb58d2197d88720a228@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/6a727d22.40259c87.584f4.04ce.GAE@google.com Tested-by: syzbot+eeb58d2197d88720a228@syzkaller.appspotmail.com Assisted-by: LLM Cc: stable@vger.kernel.org Signed-off-by: Adarsh Das Signed-off-by: Paulo Alcantara