kernel/git/stable/linux.git/fs/smb/server/server.c, branch master

ksmbd: use the session dialect for rejected binding signatures

2026-07-06T12:55:41+00:00

When an SMB3 session is referenced by a binding request on an SMB2.1 connection, the request is signed with the existing session's SMB3 signing algorithm. ksmbd instead verifies it with the new connection's SMB2.1 HMAC algorithm, so verification fails and the client receives STATUS_ACCESS_DENIED instead of STATUS_REQUEST_NOT_ACCEPTED. Select the signing verifier from the referenced session dialect. Permit a signed SESSION_SETUP without an established channel to use the SMB3 session signing key for verification. This is limited to SESSION_SETUP so other unbound requests remain rejected. The rejected response must use the same existing session algorithm. When an SMB3 session is referenced on an SMB2.1 connection, sign the SESSION_SETUP response with the SMB3 signing path rather than the connection's SMB2.1 path. This fixes smb2.session.bind_negative_smb3to2s. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: mark invalid session responses as signed

2026-07-06T12:55:41+00:00

When a signed request uses a session that is not registered on the connection, ksmbd returns STATUS_USER_SESSION_DELETED before reaching the normal response signing path. The response therefore lacks SMB2_FLAGS_SIGNED. Clients that require signing check this flag before handling STATUS_USER_SESSION_DELETED and replace the server status with STATUS_ACCESS_DENIED when it is absent. The protocol permits this error response to skip signature verification because the connection has no matching session key. Preserve SMB2_FLAGS_SIGNED on the early error response when the request was signed. This lets the client propagate STATUS_USER_SESSION_DELETED. It fixes smb2.session.bind2. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: fix outstanding credit leak on abort and error paths

2026-07-01T02:29:46+00:00

smb2_validate_credit_charge() adds the request's CreditCharge to conn->outstanding_credits when an SMB2 PDU is received, and smb2_set_rsp_credits() subtracts it again when the response is built. However smb2_set_rsp_credits() only runs on the normal response path: - __process_request() returning SERVER_HANDLER_ABORT (unimplemented command, command index out of range, signature check failure, or a handler that sets send_no_response such as a cancelled blocking lock) breaks out of the processing loop before set_rsp_credits() is called; - smb2_set_rsp_credits() itself returns early with -EINVAL (total credit overflow or insufficient credits) before the subtraction. On all of these paths the charge added at receive time is never returned, so conn->outstanding_credits only grows. Because a client can repeatedly trigger them (e.g. by sending unimplemented commands or by issuing and cancelling blocking locks), outstanding_credits eventually reaches total_credits and smb2_validate_credit_charge() then rejects every subsequent request, wedging the connection. Record the charge that was added in work->credit_charge and release any charge still pending at the single send. exit point of __handle_ksmbd_work(), which all abort and error paths fall through to. smb2_set_rsp_credits() clears work->credit_charge once it has returned the charge so the response path is unchanged and the credit is never released twice. Paths that never charged a credit (no multi-credit support, validation failure) leave work->credit_charge at zero and are unaffected. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: compress SMB2 READ responses

2026-06-16T23:57:22+00:00

Handle SMB2_READFLAG_REQUEST_COMPRESSED for non-RDMA reads. Flatten the response iov, emit chained or unchained LZ77 transforms when compression is beneficial, and retain the generated buffer until the work item is released. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: centralize ksmbd_conn final release to plug transport leak

2026-05-02T02:49:35+00:00

ksmbd_conn_free() is one of four sites that can observe the last refcount drop of a struct ksmbd_conn. The other three fs/smb/server/connection.c ksmbd_conn_r_count_dec() fs/smb/server/oplock.c __free_opinfo() fs/smb/server/vfs_cache.c session_fd_check() end the conn with a bare kfree(), skipping ida_destroy(&conn->async_ida) and conn->transport->ops->free_transport(conn->transport). Whenever one of them is the last putter, the embedded async_ida and the entire transport struct leak -- for TCP, that is also the struct socket and the kvec iov. __free_opinfo() being a final putter is not theoretical. opinfo_put() queues the callback via call_rcu(&opinfo->rcu, free_opinfo_rcu), so ksmbd_server_terminate_conn() can deposit N opinfo releases in RCU and have ksmbd_conn_free() run in the handler thread before any of them fire. ksmbd_conn_free() then observes refcnt > 0 and short-circuits; the last RCU-delivered __free_opinfo() falls onto its bare kfree(conn) branch and the transport is lost. A/B validation in a QEMU/virtme guest, mounting //127.0.0.1/testshare: each iteration holds 8 files open via sleep processes, force-closes TCP with "ss -K sport = :445", kills the holders, lazy-umounts; repeated 10 times, then ksmbd shutdown and kmemleak scan. state conn_alloc conn_free tcp_free opi_rcu kmemleak ---------- ---------- --------- -------- ------- -------- pre-patch 20 20 10 160 7 with patch 20 20 20 160 0 Pre-patch conn_free=20 with tcp_free=10 directly demonstrates the bare-kfree paths skipping transport cleanup; kmemleak backtraces point into struct tcp_transport / iov. With this patch tcp_free matches conn_free at 20/20 and kmemleak is clean. Move the per-struct final release into __ksmbd_conn_release_work() and route the three bare-kfree final-put sites through a new ksmbd_conn_put(). Those sites now pair ida_destroy() and free_transport() with kfree(conn) regardless of which holder happens to release the last reference. stop_sessions() only triggers the transport shutdown and does not itself drop the last conn reference, so it is unaffected. The centralized release reaches sock_release() -> tcp_close() -> lock_sock_nested() (might_sleep) from every final putter, including __free_opinfo() invoked from an RCU softirq callback, which trips CONFIG_DEBUG_ATOMIC_SLEEP. Defer the release to a dedicated ksmbd_conn_wq workqueue so ksmbd_conn_put() is safe from any non-sleeping context. Make ksmbd_file own a strong connection reference while fp->conn is non-NULL so durable-preserve and final-close paths cannot dereference a stale connection. ksmbd_open_fd() and ksmbd_reopen_durable_fd() take the reference via ksmbd_conn_get() (the latter also reorders the fp->conn / fp->tcon assignments before __open_id() so the published fp is never observed with fp->conn == NULL); session_fd_check() and __ksmbd_close_fd() drop it via ksmbd_conn_put(). With that invariant, session_fd_check() can take a local conn pointer once and use it across the m_op_list and lock_list iterations even though op->conn puts may otherwise drop the last reference. At module exit the workqueue is flushed and destroyed after rcu_barrier(), so any release queued by a trailing RCU callback is drained before the inode hash and module text go away. Fixes: ee426bfb9d09 ("ksmbd: add refcnt to ksmbd_conn struct") Signed-off-by: DaeMyung Kang Acked-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: Use AES-CMAC library for SMB3 signature calculation

2026-04-22T13:11:23+00:00

Now that AES-CMAC has a library API, convert ksmbd_sign_smb3_pdu() to use it instead of a "cmac(aes)" crypto_shash. The result is simpler and faster code. With the library there's no need to dynamically allocate memory, no need to handle errors, and the AES-CMAC code is accessed directly without inefficient indirect calls and other unnecessary API overhead. Acked-by: Namjae Jeon Reviewed-by: Ard Biesheuvel Signed-off-by: Eric Biggers Signed-off-by: Steve French

ksmbd: Remove unnecessary selection of CRYPTO_ECB

2026-04-12T23:07:55+00:00

Since the SMB server never uses any ecb(...) algorithm from the crypto_skcipher API, selecting CRYPTO_ECB is unnecessary. Remove it along with the unused CRYPTO_BLK_* constants. Signed-off-by: Eric Biggers Acked-by: Namjae Jeon Signed-off-by: Steve French

Merge tag 'kmalloc_obj-treewide-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2026-02-21T19:02:58+00:00

Pull kmalloc_obj conversion from Kees Cook: "This does the tree-wide conversion to kmalloc_obj() and friends using coccinelle, with a subsequent small manual cleanup of whitespace alignment that coccinelle does not handle. This uncovered a clang bug in __builtin_counted_by_ref(), so the conversion is preceded by disabling that for current versions of clang. The imminent clang 22.1 release has the fix. I've done allmodconfig build tests for x86_64, arm64, i386, and arm. I did defconfig builds for alpha, m68k, mips, parisc, powerpc, riscv, s390, sparc, sh, arc, csky, xtensa, hexagon, and openrisc" * tag 'kmalloc_obj-treewide-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kmalloc_obj: Clean up after treewide replacements treewide: Replace kmalloc with kmalloc_obj for non-scalar types compiler_types: Disable __builtin_counted_by_ref for Clang

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

smb: server: Remove duplicate include of misc.h

2026-02-15T01:26:26+00:00

Remove duplicate inclusion of misc.h in server.c to clean up redundant code. Signed-off-by: Chen Ni Acked-by: Namjae Jeon Signed-off-by: Steve French