kernel/linux.git/fs/smb/server, branch v7.2-rc1

ksmbd: fix kernel-doc warnings in smb2_lease_break_noti()

2026-06-23T22:52:42+00:00

kernel test robot report missing kernel-doc descriptions for the 'wait_ack' and 'inc_epoch' parameters of smb2_lease_break_noti(): Warning: fs/smb/server/oplock.c:937 function parameter 'wait_ack' not described in 'smb2_lease_break_noti' Warning: fs/smb/server/oplock.c:937 function parameter 'inc_epoch' not described in 'smb2_lease_break_noti' Document both parameters to silence the warnings. Reported-by: kernel test robot Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: fix inconsistent indenting warnings

2026-06-23T22:52:42+00:00

Detected by Smatch. fs/smb/server/oplock.c:1446 smb_grant_oplock() warn: inconsistent indenting Reported-by: Dan Carpenter Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: validate NTLMv2 response before updating session key

2026-06-23T22:52:42+00:00

ksmbd_auth_ntlmv2() derives the NTLMv2 session key into sess->sess_key before it verifies the NTLMv2 response. ksmbd_decode_ntlmssp_auth_blob() then continues into KEY_XCH even when ksmbd_auth_ntlmv2() failed. With SMB3 multichannel binding, the failed authentication operates on an existing session and the session setup error path does not expire binding sessions. A client can send a binding session setup with a bad NT proof and KEY_XCH and still modify sess->sess_key before STATUS_LOGON_FAILURE is returned. Relevant path: smb2_sess_setup() -> conn->binding = true -> ntlm_authenticate() -> session_user() -> ksmbd_decode_ntlmssp_auth_blob() -> ksmbd_auth_ntlmv2() -> calc_ntlmv2_hash() -> hmac_md5_usingrawkey(..., sess->sess_key) -> crypto_memneq() returns mismatch -> KEY_XCH arc4_crypt(..., sess->sess_key, ...) -> out_err without expiring the binding session Derive the base session key into a local buffer and copy it to sess->sess_key only after the proof matches. Return immediately on authentication failure so KEY_XCH is only processed after successful authentication. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Fixes: f9929ef6a2a5 ("ksmbd: add support for key exchange") Cc: stable@vger.kernel.org Signed-off-by: Haofeng Li Reviewed-by: ChenXiaoSong Acked-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: increase SMB3_DEFAULT_TRANS_SIZE from 1MB to 4MB

2026-06-23T01:15:06+00:00

This patch raises `SMB3_DEFAULT_TRANS_SIZE` to 4MB to align it with `smb2 max read/write`. This allows better I/O negotiation with modern clients and improves sequential read/write performance on high-speed networks. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: fix UBSAN array-index-out-of-bounds in decode_compress_ctxt()

2026-06-23T01:15:06+00:00

decode_compress_ctxt() walks CompressionAlgorithms[] using the client supplied CompressionAlgorithmCount. That field is declared in struct smb2_compression_capabilities_context as a fixed 4-element array, but the number of algorithms is actually variable and clients such as Windows advertise more than four (e.g. LZ77, LZ77+Huffman, LZNT1, Pattern_V1 and LZ4). The on-wire context length is already validated, so the access is within the received buffer, but indexing the statically sized [4] array makes UBSAN report an out-of-bounds access: UBSAN: array-index-out-of-bounds in smb2pdu.c:1122:48 index 4 is out of range for type '__le16 [4]' Call Trace: smb2_handle_negotiate+0xda7/0xde0 [ksmbd] ksmbd_smb_negotiate_common+0x27b/0x3e0 [ksmbd] smb2_negotiate_request+0x14/0x20 [ksmbd] handle_ksmbd_work+0x181/0x500 [ksmbd] Walk the algorithms through a pointer so the fixed-array bounds check is not applied, while keeping the existing length validation that bounds the loop to the data actually received. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: sleep interruptibly in the durable handle scavenger

2026-06-23T01:15:06+00:00

The durable handle scavenger kthread waits up to DURABLE_HANDLE_MAX_TIMEOUT (300 seconds) between scans using wait_event_timeout(), which sleeps in TASK_UNINTERRUPTIBLE. When there are no durable handles pending expiry the task stays in D state far longer than 120 seconds, so the hung task detector prints a bogus "task ksmbd-durable-s blocked for more than 120 seconds" warning with a backtrace, even though the thread is only idle. Use wait_event_interruptible_timeout() so the thread sleeps in TASK_INTERRUPTIBLE, which the hung task detector ignores. This also suits the already-freezable kthread. Treat a negative return (e.g. -ERESTARTSYS) like a timeout when recomputing the next wake interval. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: start file id allocation at 1

2026-06-23T01:15:06+00:00

ksmbd allocates both the volatile id (per-session file table) and the persistent id (global file table) with idr_alloc_cyclic() starting at 0. The first open after the module loads therefore gets volatile id 0 and persistent id 0, and ksmbd returns an SMB2 FileId of {0, 0} in the create response. Clients treat an all-zero FileId as a null handle. smbtorture's smb2_util_handle_empty() considers {0, 0} empty, so tests that guard the close with it (e.g. smb2.oplock.statopen1, smb2.lease.statopen*) never close that first handle. The leaked open keeps the inode's oplock count non-zero, so a later batch oplock request on the same file is downgraded to level II and the test fails. Start the id allocation at 1 (KSMBD_START_FID) so no handle is ever assigned a {0, 0} FileId, matching the behaviour of other SMB servers. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: treat read-control opens as stat opens only for leases

2026-06-23T01:15:06+00:00

A second open that requests only metadata-level access must not break the existing caching state. ksmbd already skips the break for such opens via fp->attrib_only (FILE_READ_ATTRIBUTES, FILE_WRITE_ATTRIBUTES and FILE_SYNCHRONIZE). An open requesting only READ_CONTROL (reading the security descriptor) must be treated differently depending on the existing caching state. smbtorture smb2.lease.statopen4 expects a read-control open NOT to break a caching lease, while smb2.oplock.statopen1 expects the same open to break a batch oplock. So READ_CONTROL is a stat open for leases but not for oplocks. Extend the stat-open break-skip in smb_grant_oplock() to also cover a read-control-only open, but only when the existing holder is a lease. The global fp->attrib_only flag (used for share-mode, rename and truncate decisions) is left unchanged so oplock behaviour is preserved. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: validate :: stream type against directory create

2026-06-23T01:15:06+00:00

smb2.streams.dir opens ::$DATA with FILE_DIRECTORY_FILE and expects STATUS_NOT_A_DIRECTORY, then opens ::$DATA without it and expects STATUS_FILE_IS_A_DIRECTORY. Commit "treat unnamed DATA stream as base file" canonicalizes the ::$DATA suffix to a NULL stream name so the open continues through the base-file path. That skipped the stream/directory type validation, which was guarded by "if (stream_name)", so opening a directory's ::$DATA stream with FILE_DIRECTORY_FILE incorrectly returned STATUS_OK and a plain open of it no longer reported STATUS_FILE_IS_A_DIRECTORY. parse_stream_name() still records the explicit $DATA type in s_type even when it clears stream_name. Run the data-stream vs directory validation whenever s_type is DATA_STREAM, not only when stream_name is set, so the canonicalized ::$DATA open is rejected with the correct status. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: break conflicting-open leases only as far as needed

2026-06-23T01:15:06+00:00

smb2.lease.oplock and smb2.lease.breaking1 hold a lease and then issue a single conflicting open on the same file. The held lease must break one step to drop write caching (RWH->RH, RW->R) and then stop, so lease_break_info.count is 1 and the lease keeps its read/handle caching. ksmbd instead cascaded the break all the way down to none (e.g. RWH->RH->R->none), so the break count was 2 or 3 and the reported lease state ended at 0. Commit "chain pending lease breaks before waking waiters" forces break_level to SMB2_OPLOCK_LEVEL_NONE for any non-lease open against a handle-caching lease, which drives oplock_break()'s retry loop down to none even when only one open is contending. Drop that break_level override so a conflicting open breaks a lease only to its own compatible level (level II, i.e. RH/R). A deeper break is still required when a truncating open is also waiting behind the same lease break. smb2.lease.breaking3 keeps a normal open pending through RWH->RH and an overwrite open pending behind it, and expects the lease to continue RH->R->none before either open completes. The overwrite waiter sets open_trunc on the lease while it blocks on the pending break, so extend the retry loop to chain another break while that truncating waiter still needs the lease at none. The per-break open_trunc snapshot stays cleared, so the cascade steps down (RH->R->none) instead of collapsing straight to none, and the normal open stays pending until the lease is fully broken. Signed-off-by: Namjae Jeon Signed-off-by: Steve French