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2026-09-24smb: client: use finish_no_open() for non-regular inodesNamjae Jeon1-13/+39
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 <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: stable@vger.kernel.org
2026-09-22smb: client: use GFP_KERNEL in get_targets()Fredric Cover1-2/+2
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 <fredric.cover.lkernel@gmail.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-22smb: client: update POSIX extension specification referencesZhangGuoDong1-3/+7
The POSIX extension specifications have now been published: https://smb3posix.org/ Suggested-by: Paulo Alcantara <pc@manguebit.org> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-21smb: client: preserve create-context parsing errorsZihan Xi1-1/+3
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 <vega@nebusec.ai> Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Tested-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-21smb: client: close completed creates on compound wait errorsZihan Xi3-17/+61
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 <vega@nebusec.ai> Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Tested-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-21smb: client: clean up failed cached directory opensZihan Xi1-10/+22
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 <vega@nebusec.ai> Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Tested-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-21smb: client: close handle after create-context parsing failureZihan Xi1-0/+3
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 <vega@nebusec.ai> Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Tested-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-21smb: client: validate POSIX create context lengthZihan Xi1-2/+5
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 <vega@nebusec.ai> Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Tested-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-21smb: client: fix create context out-of-bounds readsZihan Xi2-18/+54
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 <vega@nebusec.ai> Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Tested-by: Frank Sorenson <sorenson@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-20smb: client: delete compound mids on send failure before unlockAdarsh Das1-0/+4
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 <adarshdas950@gmail.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-18Merge tag 'cifs-fixes-7.3-rc4' of https://git.manguebit.org/linuxLinus Torvalds12-118/+223
Pull smb client fixes from Paulo Alcantara: "A batch of bug fixes for the smb client: - Fix multiple out-of-bounds reads and use-after-frees in the SMB2/3 receive path that are reachable from a malicious or compromised server: a stale next_buffer pointer and an integer overflow in compound encrypted frame handling, missing minimum-PDU-size and per-sub-PDU length validation before parsing command-specific response fields, missing bounds checks in DFS referral, server interface list, EA list, POSIX SID, snapshot enumeration and SMB1 reparse point parsing - Fix use-after-frees and races in multichannel and connection teardown, including an interface freed while still in use when adding channels, a server used after its channel reference was dropped, a reconnect work item left queued after the server is freed and an uninitialized reconnect list node - Fix a heap overflow in the native symlink parser: an absolute target without an NT drive prefix caused out-of-bounds writes and a u16 length underflow leading to a 64K memcpy into a small buffer, triggerable by a user with write access to a mounted share under default settings - Fix WSL reparse point parsing: use unaligned accessors for the packed extended-attribute payload to avoid alignment faults on some architectures and stop leaving partially mutated fattr fields on parse failure - Fix lease break ACKs being sent through the wrong session on multiuser mounts, which caused read failures (e.g. on NetApp ONTAP/Azure Files) when copying files - Fix an smbd_connection leak when cifs_get_tcp_session() fails after an RDMA connection was already established" * tag 'cifs-fixes-7.3-rc4' of https://git.manguebit.org/linux: cifs: Fix server use-after-free in cifs_chan_skip_or_disable() smb: client: fix reparse buffer bounds in cifs_query_reparse_point() smb: client: fix potential OOB read in smb3_enum_snapshots() smb: client: fix missing iov bounds check in parse_posix_sids() smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs() smb: client: reject short Next offsets in parse_server_interfaces() smb: client: fix missing lower-bound check on DFS referral string offsets smb: client: fix server->total_read for compound encrypted PDUs smb: client: validate minimum PDU size before smb2_get_data_area_len() smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs smb: client: fix use-after-free of iface in cifs_try_adding_channels() smb: client: fix fattr leaking on wsl_to_fattr() failure smb: client: fix unaligned access in WSL reparse point parser smb: client: fix smbd_connection leak on cifs_get_tcp_session() error smb: client: fix rlist race and missing initialization smb: client: cancel reconnect work in clean_demultiplex_info() smb/client: send lease break ACKs thru correct session for multiuser mounts smb: client: validate absolute native symlink targets before NT fixups
2026-09-18Merge tag 'ksmbd-for-7.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smbLinus Torvalds9-43/+243
Pull smb server fixes from Namjae Jeon: - Fix session expiration so that valid sessions are no longer removed after ten seconds of inactivity when a new session setup request is received. Sessions now expire only after credential expiration, while stale unauthenticated sessions are cleaned up after a 45-second timeout. - Keep earlier responses in compound requests when Query Info fails because the output buffer is too small. The error response is appended without truncating preceding responses. - Return STATUS_BUFFER_OVERFLOW for partial FILE_NORMALIZED_NAME_INFORMATION responses instead of incorrectly returning STATUS_INFO_LENGTH_MISMATCH. * tag 'ksmbd-for-7.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smb: ksmbd: keep compound responses on query info errors ksmbd: fix partial normalized name responses ksmbd: follow SMB2 session expiration semantics
2026-09-17cifs: Fix server use-after-free in cifs_chan_skip_or_disable()Wentao Liang1-6/+7
When a secondary channel is no longer supported by the server, cifs_chan_skip_or_disable() drops the channel reference with cifs_put_tcp_session() and then continues to use the server pointer by calling cifs_signal_cifsd_for_reconnect() on it and reading its primary_server pointer. cifs_put_tcp_session() can drop the last reference of the channel and tear it down, so both the channel and the primary server (whose reference is also dropped by cifs_put_tcp_session()) can be freed before they are signaled for reconnect. Signal the channel and the primary server and capture the primary server pointer before dropping the channel reference with cifs_put_tcp_session(). Fixes: f591062bdbf4 ("cifs: handle servers that still advertise multichannel after disabling") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang <vulab@iscas.ac.cn> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix reparse buffer bounds in cifs_query_reparse_point()Frank Sorenson1-1/+1
In cifs_query_reparse_point(), the start >= end check before casting to struct reparse_data_buffer * only ensures the start pointer is within the response. It fails to verify that there is enough space remaining for the fixed 8-byte header of the structure. If a server provides a DataOffset that leaves less than 8 bytes remaining, the check passes, but subsequent reads of ReparseTag and ReparseDataLength will occur out-of-bounds. Fix this by ensuring the remaining space is at least the size of the reparse_data_buffer structure before accessing its fields. Fixes: 56e84c64fc25 ("cifs: Fix validation of SMB1 query reparse point response") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix potential OOB read in smb3_enum_snapshots()Frank Sorenson1-1/+7
If snapshot_array_size is smaller than GMT_TOKEN_SIZE, smb3_enum_snapshots() sets ret_data_len to sizeof(struct smb_snapshot_array) without verifying the actual length of the server's reply. Because SMB2_ioctl() places no lower bound on the server-supplied OutputCount and allocates retbuf to exactly that length, a short reply results in ret_data_len exceeding the size of retbuf. The subsequent copy_to_user() then reads past the end of retbuf, leaking adjacent slab memory to userspace. The subsequent clamp check is ineffective as it only reduces ret_data_len. Fix this by rejecting replies shorter than sizeof(struct smb_snapshot_array) with -EIO. Note that the bound is set to the 12-byte struct size rather than the 16-byte MIN_SNAPSHOT_ARRAY_SIZE defined in MS-SMB2 3.3.5.15.1, because 12 bytes is exactly what copy_to_user() attempts to read. Fixes: e02789a53d71 ("smb3: enumerating snapshots was leaving part of the data off end") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix missing iov bounds check in parse_posix_sids()Frank Sorenson1-0/+11
In parse_posix_sids(), sidsbuf_end is calculated using the server-supplied out_len without being validated against the actual length of the received iov (iov_len). If a server provides an inflated out_len, sidsbuf_end will point past the end of the iov. This defeats the bounds guards in posix_info_sid_size(), allowing out-of-bounds reads into adjacent kernel memory. Fix this by rejecting responses where the calculated sidsbuf_end would exceed the received iov boundaries or cause pointer wraparound. Fixes: a90f37e3d7ac ("smb: client: parse owner/group when creating reparse points") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs()Frank Sorenson2-8/+18
In move_smb2_ea_to_cifs(), the while (src_size > 0) loop condition is insufficient. It allows iteration to continue even if the remaining src_size is too small to contain a complete smb2_ea_info structure. Consequently, reads of ea_name_length and ea_value_length can occur out-of-bounds. Fix this by ensuring src_size >= sizeof(*src) before attempting to read any structure fields. Additionally, reject any next_entry_offset that is smaller than sizeof(*src) or that would advance the pointer beyond the available buffer. Note that for calls where the server returns a malformed EA list, the error returned to userspace changes from -ENODATA (getxattr) or -ERANGE (listxattr) to -EIO. This correctly signals a server protocol error rather than misleadingly indicating "attribute not present" or "output buffer too small". Fixes: 95907fea4fd8 ("cifs: Add support for reading attributes on SMB2+") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: reject short Next offsets in parse_server_interfaces()Frank Sorenson1-3/+3
In parse_server_interfaces(), the server-supplied Next offset is validated against bytes_left, but not against the size of the interface structure itself. A small, non-zero Next value can pass the bounds check but advance the pointer by less than sizeof(*p). This causes the next iteration of the loop to read misaligned, overlapping structure fields. Fix this by ensuring the Next offset is at least sizeof(*p). Fixes: 7d34ec36abb8 ("smb3: fix for slab out of bounds on mount to ksmbd") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix missing lower-bound check on DFS referral string offsetsFrank Sorenson1-2/+10
parse_dfs_referrals() checks that DfsPathOffset and NetworkAddressOffset do not exceed the buffer end, but fails to check that they don't point inside the referral header itself. If a server provides an offset smaller than sizeof(struct dfs_referral_level_3), the derived string pointer overlaps with the struct fields, causing cifs_strndup_from_utf16() to interpret header data as UTF-16 strings. Fix this by enforcing that string offsets are at least sizeof(*ref). Fixes: 4ecce920e13a ("CIFS: move DFS response parsing out of SMB1 code") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix server->total_read for compound encrypted PDUsFrank Sorenson1-0/+1
In receive_encrypted_standard(), server->total_read is left at the full decrypted frame size when walking sub-PDUs of a compound encrypted frame. As a result, cifs_handle_standard() passes this full size to smb2_check_message(), causing the PDU length guards to incorrectly validate the entire compound frame instead of the current sub-PDU. This allows truncated non-last sub-PDUs to bypass length validation, leading to out-of-bounds reads in smb2_get_data_area_len(). Fix this by setting server->total_read to the true length of the current sub-PDU: next_cmd for non-last sub-PDUs, and the remaining pdu_length for the last one. Fixes: b24df3e30cbf ("cifs: update receive_encrypted_standard to handle compounded responses") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: validate minimum PDU size before smb2_get_data_area_len()Frank Sorenson1-28/+41
__smb2_calc_size() calls smb2_get_data_area_len(), which reads command-specific struct fields to locate the data area. However, smb2_check_message() only validates StructureSize2, meaning a truncated response could cause smb2_get_data_area_len() to read out-of-bounds. Replace has_smb2_data_area[] with smb2_min_pdu_len[], which is now used to indicate both whether a command's response has a data area and the size of that fixed response struct. A non-zero entry means the command has a data area, and is the minimum length required before the struct is read. For each command with a data area, PDUs shorter than this minimum size are rejected instead of parsed. The minimum is not applied to SMB2 error responses, which carry only the 9-byte error body, the same exemption the StructureSize2 check above it already makes. STATUS_MORE_PROCESSING_REQUIRED is treated as a normal reply, since an in-progress SESSION_SETUP response carries a full body and a security blob. Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-17smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUsFrank Sorenson1-1/+10
Fix several related bounds checking and pointer lifecycle issues in receive_encrypted_standard()'s handling of compound encrypted frames: - Clear next_buffer after assigning it to server->bigbuf. A stale next_buffer pointer can lead to a use-after-free on subsequent error paths. - Update pdu_length to the decrypted plaintext size (buf_size). Using the pre-decryption length allows NextCommand to point into stale ciphertext residue. - Reject next_cmd values smaller than MID_HEADER_SIZE(server). - Fix an integer overflow in the upper bound check by verifying pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the trailing slice is large enough for a header. Fixes: b24df3e30cbf ("cifs: update receive_encrypted_standard to handle compounded responses") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-16smb: client: fix use-after-free of iface in cifs_try_adding_channels()Joseph Qi1-41/+63
cifs_try_adding_channels() iterates ses->iface_list with list_for_each_entry_safe_from(), which captures the next entry (niface) under iface_lock. The loop body then drops iface_lock for the whole duration of cifs_ses_add_channel(). A concurrent interface refresh (SMB3_request_interfaces() -> parse_server_interfaces()) marks all ifaces inactive and removes and frees any that are not re-advertised via list_del() + kref_put(), where release_iface() is a bare kfree(). Since niface typically has no channel holding a reference, the list reference is its last and it can be freed inside the unlocked window. On continue, the iterator advance step then dereferences niface->iface_head.next, and the loop body reads iface->rdma_capable/is_active, both on freed memory. Fix this by never keeping an unreferenced list pointer across the unlocked window. Each channel attempt now re-scans the list from the head under iface_lock, takes a kref on the selected candidate, and passes only that referenced candidate to cifs_ses_add_channel(). weight_fulfilled still tracks selection progress, so restarting the scan preserves the original weighted distribution and the weight_fulfilled-before-kref_put ordering on the failure path. Add a per-pass attempts cap so a flapping interface refresh cannot keep the inner loop spinning within a single tries increment. Fixes: aa45dadd34e4 ("cifs: change iface_list from array to sorted linked list") Cc: stable@vger.kernel.org Assisted-by: Qoder:Qwen3.8-Max Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Acked-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-15ksmbd: keep compound responses on query info errorsNamjae Jeon1-19/+12
Do not reset the RFC1002 length of the complete response when a query info buffer is too small. The current command will add its error response through ksmbd_iov_pin_rsp(), while resetting the base length can truncate earlier responses in a compound request. This lets ksmbd return the earlier responses and the query-info error response together. Remove the now-unused rsp_org parameter from the pipe query-info helpers. Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound") Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-15ksmbd: fix partial normalized name responsesNamjae Jeon2-0/+4
Windows may request FILE_NORMALIZED_NAME_INFORMATION with an output buffer that only fits the fixed portion of the variable-length response. Treat the fixed portion as FILE_NORMALIZED_NAME_INFORMATION_SIZE so ksmbd returns STATUS_BUFFER_OVERFLOW instead of STATUS_INFO_LENGTH_MISMATCH. This avoids rejecting valid partial normalized-name responses. Fixes: 6b8b79226bc3 ("ksmbd: fix partial file information responses") Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-14smb: client: fix fattr leaking on wsl_to_fattr() failurePaulo Alcantara1-15/+19
wsl_to_fattr() mutates fattr fields as it parses each WSL EA. If validation later fails, the function returns false with partially mutated fattr fields that callers do not reset. Fix this by parsing into local variables and only committing them to fattr on success. Closes: https://sashiko.dev/#/patchset/20260906200517.725015-1-pc%40manguebit.org Fixes: 78e26bec4d6d ("smb: client: parse uid, gid, mode and dev from WSL reparse points") Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: David Howells <dhowells@redhat.com> Cc: Tom Talpey <tom@talpey.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org
2026-09-14smb: client: fix unaligned access in WSL reparse point parserPaulo Alcantara2-5/+6
When wsl_to_fattr() parses WSL extended attributes, it computes a payload pointer from ea->ea_data + ea_name_length + 1. Since the smb2_file_full_ea_info struct is __packed and all WSL xattr names are 6 bytes long, the value pointer always lands at an odd byte offset, never satisfying __le32 or __le64 alignment requirements. The code then casts this pointer to __le32 * or __le64 * and dereferences it directly, which may cause alignment faults on some architectures. Replace all such casts with get_unaligned_le32() and get_unaligned_le64() in reparse_mkdev(), wsl_make_kuid(), wsl_make_kgid() and wsl_to_fattr(). Closes: https://sashiko.dev/#/patchset/20260906200517.725015-1-pc%40manguebit.org Fixes: 78e26bec4d6d ("smb: client: parse uid, gid, mode and dev from WSL reparse points") Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: David Howells <dhowells@redhat.com> Cc: Tom Talpey <tom@talpey.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org
2026-09-14ksmbd: follow SMB2 session expiration semanticsNamjae Jeon9-24/+227
ksmbd_session_register() destroys valid sessions after ten seconds of inactivity whenever a client starts another SessionSetup exchange. This confuses Session.IdleTime with Session.ExpirationTime. Windows can create additional authenticated sessions on an existing connection, so deleting the older session invalidates its tree connects and makes mapped drives fail with STATUS_NETWORK_NAME_DELETED. The session expiration rules require the server to change a valid session to expired only after its credential expiration time passes. A valid or expired session otherwise keeps its connection from being scavenged. Connections that have not negotiated a dialect, have no sessions, or have only InProgress sessions are disconnected after an implementation-specific timeout. Use the Windows-compatible 45 second value and run the expiration check periodically for both TCP and SMB Direct. Keep zero as an infinite credential expiration time, and count each Valid-to-Expired transition. Set expired sessions to InProgress when they reauthenticate. If authentication fails, remove the session from the global and per-connection tables immediately, including SMB3 multichannel connections. Retain protection against abandoned SessionId-zero exchanges by allowing only one InProgress authentication per connection. Additional exchanges fail with STATUS_INSUFFICIENT_RESOURCES, and stale InProgress sessions are reaped after the same 45 second setup timeout. This bounds the original unauthenticated memory-exhaustion path without evicting established sessions. Fixes: ea174a918939 ("ksmbd: destroy expired sessions") Reported-by: Mobin Aydinfar <mobin@mobintestserver.ir> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-13smb: client: fix smbd_connection leak on cifs_get_tcp_session() errorPaulo Alcantara1-0/+1
When an RDMA connection is successfully established via smbd_get_connection() but cifs_get_tcp_session() later fails (e.g. kthread_create() returns an error), the error path frees tcp_ses without first destroying the smbd_connection. Fix this by calling smbd_destroy() in the out_err cleanup path before kfree(tcp_ses). smbd_destroy() safely handles the case where smbd_conn is NULL, so it can be called unconditionally. Closes: https://sashiko.dev/#/patchset/20260912165503.521597-1-pc%40manguebit.org Fixes: 2f8946464b11 ("CIFS: SMBD: Upper layer connects to SMBDirect session") Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Tom Talpey <tom@talpey.com> Cc: Stefan Metzmacher <metze@samba.org> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org
2026-09-13smb: client: fix rlist race and missing initializationPaulo Alcantara1-0/+7
TCP_Server_Info.rlist is allocated via kzalloc which zeros both ->next and ->prev to NULL instead of pointing to itself, making list_empty() always return false and list_add() dereference a NULL ->prev pointer. Also, cifs_signal_cifsd_for_reconnect() can be called concurrently from multiple cifsd threads, allowing the same server's rlist node to be added twice into the local list, corrupting it. Closes: https://sashiko.dev/#/patchset/20260911204446.1719356-1-pc%40manguebit.org Fixes: df0e03a4fb94 ("smb: client: fix potential deadlock when reconnecting channels") Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: David Howells <dhowells@redhat.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org
2026-09-13smb: client: cancel reconnect work in clean_demultiplex_info()Paulo Alcantara1-0/+1
clean_demultiplex_info() cancels server->echo delayed work but not server->reconnect, which can cause a use-after-free when the demultiplex thread exits while a reconnect work is still queued: cifs_demultiplex_thread() cifs_readv_from_socket() cifs_reconnect() __cifs_reconnect() cifs_queue_server_reconn() mod_delayed_work(cifsiod_wq, &server->reconnect, 0) clean_demultiplex_info() cancel_delayed_work_sync(&server->echo) // echo canceled // reconnect NOT canceled kfree_sensitive(server) // server freed ...later, on cifsiod_wq: smb2_reconnect_server() server->srv_count // UAF read of freed server Fix this by canceling server->reconnect delayed work in clean_demultiplex_info() before the server is freed, the same way cifs_put_tcp_session() already does. Reported-by: syzbot+5003556314abc915a71f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/6aa4a12d.f81106d8.2ab401.0023.GAE@google.com Fixes: 53e0e11efe92 ("CIFS: Fix a possible memory corruption during reconnect") Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: David Howells <dhowells@redhat.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org
2026-09-11smb/client: send lease break ACKs thru correct session for multiuser mountsApril Cardenas1-2/+2
Currently, when cifs_oplock_break handles a break request from the server it searches for the appropriate tlink to handle the request but incorrectly uses the current fsuid as the search key, eventually causing read errors for users with multiuser mounts on NetApp. Fix this by using the tlink from the cfile struct instead to respond through the correct session. As breaks are handled in a worker thread, the current fsuid isn't guaranteed to match the session that the break is intended for. This means that cifs_sb_tlink may search the rbtree using the wrong fsuid, and return a tlink with an incorrect session than the lease break was intended for. As a result, the breaks may be ACKed through an incorrect session. While it seems that Samba/Windows Servers 2016-2025 ignore this as long as the lease key is correct, we ran into a case where if you're using NetApp ONTAP or Azure NetApp Files they will reject the ACK and return `STATUS_LOCK_NOT_GRANTED` errors on any future read requests a user may initiate through their still held open file handle, and the server will eventually close the file. In the dmesg logs, the user may see errors like these: CIFS: Status code returned 0xc0000128 STATUS_FILE_CLOSED CIFS: VFS: Send error in read = -9 With a multiuser mount using NetApp, this issue is really easy for users to hit on a wide variety of kernel versions by attempting to copy a file from the share to the local machine through GNOME Files/Nautilus. This copy will always result in Nautilus throwing a `Bad File Descriptor` error to the user and fail. With this fix, you can copy files through Nautilus without issue. >From looking at the traces, it seems that glib will open the file first, and call listxattr before actually attempting to copy the file data. The listxattr call always triggers a break, causing the copy to fail. The proposed fix returns to the way the client grabbed the tlink before commit e8f5f849ffce2 ("cifs: fix potential oops in cifs_oplock_break"). The bulk of that commit (checking for list empty) remains untouched, and I think the change to using cifs_sb_tlink was intended to avoid a NULL/ERR deference on the tlink as well as update the reference count. I believe this fix should preserve those safety properties, but of course I'd appreciate any corrections here. Fixes: e8f5f849ffce2 ("cifs: fix potential oops in cifs_oplock_break") Cc: stable@vger.kernel.org Signed-off-by: April Cardenas <april.cardenas@canonical.com> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Reviewed-by: Bharath S M <bharathsm@microsoft.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-11smb: client: validate absolute native symlink targets before NT fixupsJérémy Jean1-7/+17
With symlinkroot unset, an absolute target is copied without conversion to an NT drive path. Later code still assumes an NT prefix is present when modifying the target and calculating the print name length. For "/ab", this causes two failures: sym[5] and path[5] are written past their allocations, and plen -= 2 * poff subtracts an assumed 8-byte prefix from a 6-byte UTF-16 target, wrapping u16 plen to 65534. That underflow causes another overflow: memcpy() copies 65534 bytes into a 24-byte buffer. A user with write access to a mounted share can trigger these bugs with default settings. Validate the NT drive prefix, including an ASCII drive letter, before accessing fixed offsets or subtracting the prefix length. Fixes: 3363da82e02f ("smb: client: fix native SMB symlink traversal") Assisted-by: Codex:gpt-5 Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-10Merge tag 'cifs-fixes-7.3-rc3' of https://git.manguebit.org/linuxLinus Torvalds9-81/+172
Pull smb client fixes from Paulo Alcantara: - File type corruption fixes in reparse point handling: setting S_IFMT bits without clearing the existing type first corrupted the file mode (e.g. S_IFREG | S_IFCHR == S_IFLNK). Fixed in the WSL, POSIX and native symlink reparse parsers. Also fixes an uninitialized SID structure in the POSIX readdir path when parsing fails. - Ownership mapping fixes: forceuid/forcegid mount options were ignored in several code paths (SID-to-id mapping, WSL extended attributes, POSIX extensions getattr), allowing an untrusted server to dictate local file ownership despite explicit mount overrides. - Heap overflow and overflow fixes in DACL rewriting: replacing short SIDs with long ones could overflow the DACL buffer, and the u16 accumulator for DACL size could wrap around with enough ACEs. - Reference count leak fixes in oplock break and deferred close: duplicate oplock breaks on a queued work item leaked a cifsFileInfo reference, and deferred close had a similar leak when requeueing a running work item. Both cause busy-inode oopses on unmount. - DFS superblock use-after-free fix: the iterator callback stored a raw superblock pointer without pinning it, racing with automount expiry. - One-byte slab OOB read in the native symlink parser when handling share-root relative paths. - Hardening of legacy SMB1 input: reject userspace-crafted cifs.idmap key descriptions that bypass kernel origin checks, and validate DataOffset in CIFSSMBRead() to prevent heap info disclosure from a malicious server. - DFS cache fix: defer metadata updates until target copying succeeds to prevent partial-state cache entries on allocation failure. * tag 'cifs-fixes-7.3-rc3' of https://git.manguebit.org/linux: smb: client: fix one-byte OOB read in smb2_parse_native_symlink() smb: client: fail DACL rewrite when the new DACL exceeds 64K smb: client: fix heap overflow in DACL owner/group rewrite smb: client: fix file type corruption in cifs_reparse_point_to_fattr() smb: client: fix file type corruption in posix_reparse_to_fattr() smb: client: fix file type corruption in wsl_to_fattr() smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr() smb: client: fix WSL reparse point uid/gid override smb: client: honor forceuid/forcegid when mapping SIDs to uid/gid smb: client: fix uid/gid override in getattr with posix extensions smb: client: fix cifsFileInfo reference leak in deferred close smb: client: avoid leaking refcount when cifs_sb_tlink() fails smb: client: avoid leaking refcount in cifs_queue_oplock_break() smb: client: fill cache fields after populating cache in copy_ref_data() smb: client: pin DFS superblock in iterator callback smb: client: reject userspace cifs.idmap descriptions smb: client: reject out-of-bounds DataOffset in CIFSSMBRead() smb: client: reject short READ responses in CIFSSMBRead()
2026-09-09smb: client: fix one-byte OOB read in smb2_parse_native_symlink()Paulo Alcantara1-1/+2
When parsing a share-root relative native symlink, memcpy copies smb_target+1 (skipping the leading separator) but uses strlen(smb_target)+1 as the length, reading one byte past the allocated buffer. This fixes the following KASAN splat when accessing an SMB symlink with a target of '\a\b': BUG: KASAN: slab-out-of-bounds in smb2_parse_native_symlink+0x4f5/0xca0 Read of size 5 at addr ffff88800878fe21 by task netfsfuzz-execu/1 CPU: 1 UID: 0 PID: 1 Comm: netfsfuzz-execu Tainted: G N 7.2.0-11943-g2709dd5ae32f-dirty #1 PREEMPT(lazy) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996) Call Trace: <TASK> dump_stack_lvl+0x7b/0xa0 print_report+0xd0/0x630 kasan_report+0xe5/0x120 kasan_check_range+0x105/0x1b0 __asan_memcpy+0x23/0x60 smb2_parse_native_symlink+0x4f5/0xca0 parse_reparse_point+0x68a/0x1530 reparse_info_to_fattr+0x752/0xa20 cifs_get_fattr+0x873/0x15b0 cifs_get_inode_info+0xc0/0x310 cifs_lookup+0x308/0xa70 __lookup_slow+0x122/0x2b0 lookup_slow+0x50/0x70 path_lookupat+0x525/0xaf0 filename_lookup+0x1f2/0x550 vfs_statx+0xd1/0x1a0 vfs_fstatat+0x65/0xc0 __do_sys_newfstatat+0x9a/0x120 do_syscall_64+0xdd/0x4a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-by: Yuanfu Xie <yuanfuxie@stu.pku.edu.cn> Fixes: 723f4ef90452 ("cifs: Fix parsing native symlinks relative to the export") Suggested-by: Pali Rohar <pali@kernel.org> Reviewed-by: Pali Rohar <pali@kernel.org> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-09smb: client: fail DACL rewrite when the new DACL exceeds 64KBjoern Doebel1-13/+26
replace_sids_and_copy_aces() and set_chmod_dacl() accumulate the size of the DACL they build in a u16. That accumulator can wrap. validate_dacl() caps num_aces at (dacl_size - sizeof(struct smb_acl)) / 20, i.e. 3276 for a maximally sized DACL, while each rewritten ACE can grow to sizeof(struct smb_ace) (76 bytes) once its SID is replaced with one carrying SID_MAX_SUB_AUTHORITIES sub-authorities. The worst case is therefore sizeof(struct smb_acl) + 3276 * 76 = 248984 bytes, far beyond what a u16 can hold. A wraparound is reached with 863 ACEs. After the wraparound, ndacl_ptr->size becomes meaningless and the offset will point anywhere in the ACE array. As a result, we will see corruption of the DACL, which then gets sent to the server. This is not an out-of-bounds write as the allocation now covers the worst-case expansion, so writes will always go into the buffer. Adjust the code to use a u32 internally and return -EOVERFLOW in the overflow case. The operation must be refused, because a DACL can only hold 2^16-1 bytes on the wire and larger DACLs cannot be represented. set_chmod_dacl() carries the same pattern and is fixed the same way. It only wraps once the source DACL comes within roughly 380 bytes of the 64K ceiling, but the failure mode is identical. Suggested-by: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org Fixes: f5065508897a ("cifs: Retain old ACEs when converting between mode bits and ACL.") Assisted-by: Kiro:claude-opus-5 Signed-off-by: Bjoern Doebel <doebel@amazon.de> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-09smb: client: fix heap overflow in DACL owner/group rewriteBjoern Doebel1-5/+7
When id_mode_to_cifs_acl rewrites an existing DACL, it allocates a buffer sized according to the on-disk DACL length reported by dacl_ptr->size. However, replace_sids_and_copy_aces may rewrite each ACE with a new owner/group SID obtained from the cifs.idmap upcall. Those SIDs can have up to SID_MAX_SUB_AUTHORITIES (15) sub-authorities, making each ACE up to 76 bytes (sizeof(struct smb_ace)). If the original DACL contains short SIDs (e.g., 1 sub-authority) while the replacement SIDs are long, the rewritten ACEs overflow the allocation. Fix this by always budgeting for worst-case SID expansion: allocate sizeof(struct smb_acl) plus num_aces * sizeof(struct smb_ace), which covers the smb_acl header and room for every ACE at maximum SID size. This replaces the previous split logic that used dacl_ptr->size for cifsacl mounts but num_aces * sizeof(struct smb_ace) for mode_from_sid mounts: both paths can trigger the same rewrite and need the same headroom. KASAN reports this as: BUG: KASAN: slab-out-of-bounds in build_sec_desc+0x1e8a/0x2680 [cifs] Write of size 4 at addr ffff8881a5e25374 by task chown/5298 ... The buggy address is located 0 bytes to the right of allocated 884-byte region [ffff8881a5e25000, ffff8881a5e25374) Cc: stable@vger.kernel.org Fixes: bc3e9dd9d104 ("cifs: Change SIDs in ACEs while transferring file ownership.") Assisted-by: Kiro:claude-opus-4.6 Signed-off-by: Bjoern Doebel <doebel@amazon.de> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Fixes: 5c3564852c58 ("cifs: Minimize the number of cifs_acl memory allocations") Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-08smb: client: fix file type corruption in cifs_reparse_point_to_fattr()Paulo Alcantara1-0/+1
Setting the file type in cf_mode without clearing the existing S_IFMT bits first is wrong as it corrupts the file type when cf_mode already has type bits set (e.g. S_IFREG | S_IFLNK == S_IFDIR | S_IFREG). Clear S_IFMT before setting S_IFLNK for native and SMB1 symlinks. Closes: https://sashiko.dev/#/patchset/20260906181540.647469-1-pc%40manguebit.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-08smb: client: fix file type corruption in posix_reparse_to_fattr()Paulo Alcantara1-5/+7
Setting the file type in cf_mode without clearing the existing S_IFMT bits first is wrong as it corrupts the file type when cf_mode already has type bits set (e.g. S_IFREG | S_IFCHR == S_IFLNK). Use a local ftype variable to collect the new file type and apply it after validation succeeds, clearing S_IFMT and setting the new type in a single assignment. This avoids stripping cf_mode on malformed reparse points where the function returns false early. Closes: https://sashiko.dev/#/patchset/20260906172005.627163-1-pc%40manguebit.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-08smb: client: fix file type corruption in wsl_to_fattr()Paulo Alcantara1-0/+1
Setting the file type in cf_mode without clearing the existing S_IFMT bits first is wrong as it corrupts the file type when cf_mode already has type bits set (e.g. S_IFREG | S_IFCHR == S_IFLNK). Clear S_IFMT before the switch statement. Closes: https://sashiko.dev/#/patchset/20260906172005.627163-1-pc%40manguebit.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-08smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr()Paulo Alcantara1-5/+11
cifs_posix_to_fattr() ignores the return value of posix_info_parse(). When a malformed POSIX directory entry is encountered (e.g. invalid SID lengths from an untrusted server), posix_info_parse() returns -1 without populating the 'parsed' struct. The uninitialized stack memory in parsed.owner and parsed.group is then passed to sid_to_id(), which processes the garbage bytes and passes them to request_key() to construct a SID string, potentially leaking kernel stack contents to the userspace idmap daemon. Fix this by checking the return value and skipping the SID-to-id mapping when parsing fails. The remaining fattr fields (timestamps, mode, etc.) are populated directly from the 'info' pointer so they are unaffected. Closes: https://sashiko.dev/#/patchset/20260906172005.627163-1-pc%40manguebit.org Closes: https://sashiko.dev/#/patchset/20260906181540.647469-1-pc%40manguebit.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-08smb: client: fix WSL reparse point uid/gid overridePaulo Alcantara1-5/+11
wsl_to_fattr() unconditionally overwrites cf_uid/cf_gid with values from WSL extended attributes ($LXUID/$LXGID), ignoring the forceuid and forcegid mount options. Fix this by initializing cf_uid/cf_gid to the mount defaults and gating the $LXUID/$LXGID EA parsing on forceuid/forcegid. Closes: https://sashiko.dev/#/patchset/20260906190803.667489-1-pc%40manguebit.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-08smb: client: honor forceuid/forcegid when mapping SIDs to uid/gidPaulo Alcantara3-15/+32
When the administrator mounts with forceuid or forcegid (uid=/gid= mount options), they expect all files to appear owned by the specified user/group. However, several code paths unconditionally called sid_to_id() to overwrite cf_uid/cf_gid with server-provided values, ignoring the administrator's explicit override: - smb311_posix_info_to_fattr() (stat via POSIX extensions) - cifs_posix_to_fattr() (readdir via POSIX extensions) - parse_sec_desc() (CIFS ACL ownership mapping) This allowed an untrusted server to dictate local file ownership even when the mount was configured to force specific uid/gid values. Fix all three call sites to check CIFS_MOUNT_OVERR_UID and CIFS_MOUNT_OVERR_GID before calling sid_to_id(), following the same pattern already used by cifs_unix_basic_to_fattr() for unix extensions. Closes: https://sashiko.dev/#/patchset/20260906155816.603278-1-pc%40manguebit.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-08smb: client: fix uid/gid override in getattr with posix extensionsPaulo Alcantara1-4/+4
When mounting with 'multiuser,posix' options, cifs_getattr() overrides the server-provided uid/gid with the current process's fsuid/fsgid. This is because the condition only checks for unix extensions (tcon->unix_ext) but not posix extensions (tcon->posix_extensions). With SMB3 POSIX extensions, the server provides real uid/gid values just like with unix extensions, so they should be preserved rather than replaced with the caller's credentials. Add a tcon->posix_extensions check to the condition so that uid/gid from the server are properly reported in stat results. Reported-by: Arthur Lesuisse <arthur.lesuisse@ulb.be> Closes: https://lore.kernel.org/r/DB9P190MB2012266F6B8DECBE5D26A1798DB52@DB9P190MB2012.EURP190.PROD.OUTLOOK.COM Suggested-by: Arthur Lesuisse <arthur.lesuisse@ulb.be> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org
2026-09-05smb: client: fix cifsFileInfo reference leak in deferred closeFan Wu1-5/+12
When cifs_close() defers a close, it hands the cifsFileInfo reference of the closing struct file to the queued work. Each execution of smb2_deferred_work_close() drops one such reference. deferred_close_scheduled can be false while the work is pending: the workqueue clears PENDING when the callback starts to run, before the callback clears the flag under deferred_lock. A close in that interval requeues the running work, and the callback then clears the flag, leaving the requeued work pending with the flag down. A later cifs_open() can reuse the handle and its cifs_close() reaches the same branch: queue_delayed_work() fails because the work is still pending, but cifs_close() returns without dropping the closing file's reference. The cifsFileInfo count stays pinned and its tlink, dentry and server handle are leaked. Check the return value and hand off the reference only when work was actually queued. Otherwise, use the shared _cifsFileInfo_put(), like the mod_delayed_work() branch above: the pending execution already owns its reference. This issue was found by an in-house static analysis tool. Fixes: c3f207ab29f7 ("cifs: Deferred close for files") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6 Co-developed-by: Song Li <songl@zju.edu.cn> Signed-off-by: Song Li <songl@zju.edu.cn> Signed-off-by: Fan Wu <fanwu01@zju.edu.cn> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-05smb: client: avoid leaking refcount when cifs_sb_tlink() failsBjoern Doebel1-1/+4
cifs_oplock_break() takes over the reference that cifs_queue_oplock_break() acquired when it queued the work, and drops it with _cifsFileInfo_put() once the break has been processed. Only in setups with "-o multiuser", cifs_sb_tlink() may fail, at which point cifs_oplock_break() returns without putting the file reference, mirroring the reference leak we already fixed in the companion patch to cifs_queue_oplock_break(). This would trigger a crash due to busy inodes on the next unmount: BUG: Dentry ... still in use (1) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) Drop the reference on that path as well. Doing so before the out label mirrors the normal path, which also puts the reference before cifs_done_oplock_break(). Found by Sashiko code review. The failure path was not exercised at runtime. Fixes: e8f5f849ffce2 ("cifs: fix potential oops in cifs_oplock_break") Cc: stable@vger.kernel.org Assisted-by: Kiro:claude-opus-5 Signed-off-by: Bjoern Doebel <doebel@amazon.de> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-05smb: client: avoid leaking refcount in cifs_queue_oplock_break()Bjoern Doebel1-3/+4
cifs_queue_oplock_break() unconditionally takes a reference on the target file before queueing cifs_oplock_break(). Only that work item decreases the reference counter again. If another oplock break arrives while that work is still queued, queue_work() will return false and not queue this second work item. As a result, we will never reach the point to drop the file reference again and are leaking this reference. This can be triggered when interacting with a slow-responding server. As a result, later unmount operations for this file system will fail with BUG: Dentry ... still in use (1) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) kernel BUG at fs/super.c:777! Fix this by only incrementing the reference count if the work has been queued successfully. Taking it after queue_work() is safe because all three callers hold tcon->open_file_lock across the call and _cifsFileInfo_put() decrements under that same lock, so a worker that starts the handler in the window cannot drop the reference before it has been taken. Fixes: b98749cac4a69 ("CIFS: keep FileInfo handle live during oplock break") Cc: stable@vger.kernel.org Assisted-by: Kiro:claude-opus-5 Signed-off-by: Bjoern Doebel <doebel@amazon.de> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-04treewide: refresh kmalloc_obj() conversionsKees Cook5-5/+5
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
2026-09-03smb: client: fill cache fields after populating cache in copy_ref_data()Fredric Cover1-9/+9
In copy_ref_data(), struct cache_entry *ce has its fields populated at the beginning of the function. Later, if alloc_target fails with an ERR_PTR, free_tgts() is called on the cache, leaving the cache metadata populated without any targets. Critically, this extends ce->etime, making the cache appear valid for longer without any targets. Also, free_tgts() does not set ce->numtgts to zero. On error, when the cache is freed, ce->numtgts is not zeroed, and other cache users may attempt to access nonexistent entries. Update fields after copying targets to prevent partial-state updates. Set ce->numtgts to zero at the end of free_tgts(). Signed-off-by: Fredric Cover <fredric.cover.lkernel@gmail.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-02smb: client: pin DFS superblock in iterator callbackKarl Mehltretter1-9/+8
tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super() takes its active reference only after iterate_supers_type() has dropped s_umount and its passive reference. Concurrent DFS automount expiry can therefore free the superblock before cifs_sb_active() uses it. A deterministic KASAN test reproduces the race as: BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80 The same test passes with this change applied. Take the active reference in the callback while iterate_supers_type() still holds s_umount shared. cifs_put_tcp_super() remains the matching release. Fixes: bacd704a95ad ("cifs: handle prefix paths in reconnect") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>