kernel/linux.git/fs/smb/client/ioctl.c, branch linux-7.0.y

smb: client: Use FullSessionKey for AES-256 encryption key derivation

2026-05-23T11:09:43+00:00

[ Upstream commit 5be7a0cef3229fb3b63a07c0d289daf752545424 ] When Kerberos authentication is used with AES-256 encryption (AES-256-CCM or AES-256-GCM), the SMB3 encryption and decryption keys must be derived using the full session key (Session.FullSessionKey) rather than just the first 16 bytes (Session.SessionKey). Per MS-SMB2 section 3.2.5.3.1, when Connection.Dialect is "3.1.1" and Connection.CipherId is AES-256-CCM or AES-256-GCM, Session.FullSessionKey must be set to the full cryptographic key from the GSS authentication context. The encryption and decryption key derivation (SMBC2SCipherKey, SMBS2CCipherKey) must use this FullSessionKey as the KDF input. The signing key derivation continues to use Session.SessionKey (first 16 bytes) in all cases. Previously, generate_key() hardcoded SMB2_NTLMV2_SESSKEY_SIZE (16) as the HMAC-SHA256 key input length for all derivations. When Kerberos with AES-256 provides a 32-byte session key, the KDF for encryption/decryption was using only the first 16 bytes, producing keys that did not match the server's, causing mount failures with sec=krb5 and require_gcm_256=1. Add a full_key_size parameter to generate_key() and pass the appropriate size from generate_smb3signingkey(): - Signing: always SMB2_NTLMV2_SESSKEY_SIZE (16 bytes) - Encryption/Decryption: ses->auth_key.len when AES-256, otherwise 16 Also fix cifs_dump_full_key() to report the actual session key length for AES-256 instead of hardcoded CIFS_SESS_KEY_SIZE, so that userspace tools like Wireshark receive the correct key for decryption. Cc: Reviewed-by: Bharath SM Signed-off-by: Piyush Sachdeva Signed-off-by: Piyush Sachdeva Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

smb: client: use atomic_t for mnt_cifs_flags

2026-02-27T00:17:08+00:00

Use atomic_t for cifs_sb_info::mnt_cifs_flags as it's currently accessed locklessly and may be changed concurrently in mount/remount and reconnect paths. Signed-off-by: Paulo Alcantara (Red Hat) Reviewed-by: David Howells Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

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

cifs: SMB1 split: Split SMB1 protocol defs into smb1pdu.h

2026-02-08T23:07:45+00:00

Split SMB1 protocol defs into smb1pdu.h. This should perhaps go in the common/ directory. Signed-off-by: David Howells cc: Steve French cc: Paulo Alcantara cc: Enzo Matsumiya cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-kernel@vger.kernel.org Acked-by: Enzo Matsumiya Signed-off-by: Steve French

smb3 client: add missing tracepoint for unsupported ioctls

2025-12-30T15:16:45+00:00

In debugging a recent problem with an xfstest, noticed that we weren't tracing cases where the ioctl was not supported. Add dynamic tracepoint: "trace-cmd record -e smb3_unsupported_ioctl" and then after running an app which calls unsupported ioctl, "trace-cmd show"would display e.g. xfs_io-7289 [012] ..... 1205.137765: smb3_unsupported_ioctl: xid=19 fid=0x4535bb84 ioctl cmd=0x801c581f Acked-by: Bharath SM Signed-off-by: Steve French

smb: minor fix to use SMB2_NTLMV2_SESSKEY_SIZE for auth_key size

2025-06-21T16:03:25+00:00

Replaced hardcoded value 16 with SMB2_NTLMV2_SESSKEY_SIZE in the auth_key definition and memcpy call. Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Bharath SM Signed-off-by: Steve French

convert cifs_ioctl_copychunk()

2024-11-03T06:28:07+00:00

fdput() moved past mnt_drop_file_write(); harmless, if somewhat cringeworthy. Reordering could be avoided either by adding an explicit scope or by making mnt_drop_file_write() called via __cleanup. Reviewed-by: Christian Brauner Signed-off-by: Al Viro

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36+00:00

Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.

smb3: fix problem unloading module due to leaked refcount on shutdown

2024-08-22T17:36:57+00:00

The shutdown ioctl can leak a refcount on the tlink which can prevent rmmod (unloading the cifs.ko) module from working. Found while debugging xfstest generic/043 Fixes: 69ca1f57555f ("smb3: add dynamic tracepoints for shutdown ioctl") Reviewed-by: Meetakshi Setiya Reviewed-by: Shyam Prasad N Signed-off-by: Steve French