smb3: Replace smb2pdu 1-element arrays with flex-arrays

commit eb3e28c1e89b4984308777231887e41aa8a0151f upstream.

The kernel is globally removing the ambiguous 0-length and 1-element
arrays in favor of flexible arrays, so that we can gain both compile-time
and run-time array bounds checking[1].

Replace the trailing 1-element array with a flexible array in the
following structures:

        struct smb2_err_rsp
        struct smb2_tree_connect_req
        struct smb2_negotiate_rsp
        struct smb2_sess_setup_req
        struct smb2_sess_setup_rsp
        struct smb2_read_req
        struct smb2_read_rsp
        struct smb2_write_req
        struct smb2_write_rsp
        struct smb2_query_directory_req
        struct smb2_query_directory_rsp
        struct smb2_set_info_req
        struct smb2_change_notify_rsp
        struct smb2_create_rsp
        struct smb2_query_info_req
        struct smb2_query_info_rsp

Replace the trailing 1-element array with a flexible array, but leave
the existing structure padding:

        struct smb2_file_all_info
        struct smb2_lock_req

Adjust all related size calculations to match the changes to sizeof().

No machine code output or .data section differences are produced after
these changes.

[1] For lots of details, see both:
    https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays
    https://people.kernel.org/kees/bounded-flexible-arrays-in-c

Cc: Steve French <sfrench@samba.org>
Cc: Paulo Alcantara <pc@cjr.nz>
Cc: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kees Cook 2024-01-26 22:31:43 +03:00 committed by Greg Kroah-Hartman
parent 443b16ee3d
commit 02f629bb46
4 changed files with 38 additions and 33 deletions

View File

@ -117,7 +117,7 @@ static __u32 get_neg_ctxt_len(struct smb2_sync_hdr *hdr, __u32 len,
} else if (nc_offset + 1 == non_ctxlen) { } else if (nc_offset + 1 == non_ctxlen) {
cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n"); cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
size_of_pad_before_neg_ctxts = 0; size_of_pad_before_neg_ctxts = 0;
} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE) } else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
/* has padding, but no SPNEGO blob */ /* has padding, but no SPNEGO blob */
size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1; size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
else else

View File

@ -5561,7 +5561,7 @@ struct smb_version_values smb20_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,
@ -5583,7 +5583,7 @@ struct smb_version_values smb21_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,
@ -5604,7 +5604,7 @@ struct smb_version_values smb3any_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,
@ -5625,7 +5625,7 @@ struct smb_version_values smbdefault_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,
@ -5646,7 +5646,7 @@ struct smb_version_values smb30_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,
@ -5667,7 +5667,7 @@ struct smb_version_values smb302_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,
@ -5688,7 +5688,7 @@ struct smb_version_values smb311_values = {
.header_size = sizeof(struct smb2_sync_hdr), .header_size = sizeof(struct smb2_sync_hdr),
.header_preamble_size = 0, .header_preamble_size = 0,
.max_header_size = MAX_SMB2_HDR_SIZE, .max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1, .read_rsp_size = sizeof(struct smb2_read_rsp),
.lock_cmd = SMB2_LOCK, .lock_cmd = SMB2_LOCK,
.cap_unix = 0, .cap_unix = 0,
.cap_nt_find = SMB2_NT_FIND, .cap_nt_find = SMB2_NT_FIND,

View File

@ -1261,7 +1261,7 @@ SMB2_sess_sendreceive(struct SMB2_sess_data *sess_data)
/* Testing shows that buffer offset must be at location of Buffer[0] */ /* Testing shows that buffer offset must be at location of Buffer[0] */
req->SecurityBufferOffset = req->SecurityBufferOffset =
cpu_to_le16(sizeof(struct smb2_sess_setup_req) - 1 /* pad */); cpu_to_le16(sizeof(struct smb2_sess_setup_req));
req->SecurityBufferLength = cpu_to_le16(sess_data->iov[1].iov_len); req->SecurityBufferLength = cpu_to_le16(sess_data->iov[1].iov_len);
memset(&rqst, 0, sizeof(struct smb_rqst)); memset(&rqst, 0, sizeof(struct smb_rqst));
@ -1760,8 +1760,7 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
iov[0].iov_len = total_len - 1; iov[0].iov_len = total_len - 1;
/* Testing shows that buffer offset must be at location of Buffer[0] */ /* Testing shows that buffer offset must be at location of Buffer[0] */
req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req) req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req));
- 1 /* pad */);
req->PathLength = cpu_to_le16(unc_path_len - 2); req->PathLength = cpu_to_le16(unc_path_len - 2);
iov[1].iov_base = unc_path; iov[1].iov_base = unc_path;
iov[1].iov_len = unc_path_len; iov[1].iov_len = unc_path_len;
@ -4676,7 +4675,7 @@ int SMB2_query_directory_init(const unsigned int xid,
memcpy(bufptr, &asteriks, len); memcpy(bufptr, &asteriks, len);
req->FileNameOffset = req->FileNameOffset =
cpu_to_le16(sizeof(struct smb2_query_directory_req) - 1); cpu_to_le16(sizeof(struct smb2_query_directory_req));
req->FileNameLength = cpu_to_le16(len); req->FileNameLength = cpu_to_le16(len);
/* /*
* BB could be 30 bytes or so longer if we used SMB2 specific * BB could be 30 bytes or so longer if we used SMB2 specific
@ -4873,7 +4872,7 @@ SMB2_set_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
req->AdditionalInformation = cpu_to_le32(additional_info); req->AdditionalInformation = cpu_to_le32(additional_info);
req->BufferOffset = req->BufferOffset =
cpu_to_le16(sizeof(struct smb2_set_info_req) - 1); cpu_to_le16(sizeof(struct smb2_set_info_req));
req->BufferLength = cpu_to_le32(*size); req->BufferLength = cpu_to_le32(*size);
memcpy(req->Buffer, *data, *size); memcpy(req->Buffer, *data, *size);
@ -5105,9 +5104,9 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon,
req->VolatileFileId = volatile_fid; req->VolatileFileId = volatile_fid;
/* 1 for pad */ /* 1 for pad */
req->InputBufferOffset = req->InputBufferOffset =
cpu_to_le16(sizeof(struct smb2_query_info_req) - 1); cpu_to_le16(sizeof(struct smb2_query_info_req));
req->OutputBufferLength = cpu_to_le32( req->OutputBufferLength = cpu_to_le32(
outbuf_len + sizeof(struct smb2_query_info_rsp) - 1); outbuf_len + sizeof(struct smb2_query_info_rsp));
iov->iov_base = (char *)req; iov->iov_base = (char *)req;
iov->iov_len = total_len; iov->iov_len = total_len;

View File

@ -220,7 +220,7 @@ struct smb2_err_rsp {
__le16 StructureSize; __le16 StructureSize;
__le16 Reserved; /* MBZ */ __le16 Reserved; /* MBZ */
__le32 ByteCount; /* even if zero, at least one byte follows */ __le32 ByteCount; /* even if zero, at least one byte follows */
__u8 ErrorData[1]; /* variable length */ __u8 ErrorData[]; /* variable length */
} __packed; } __packed;
#define SYMLINK_ERROR_TAG 0x4c4d5953 #define SYMLINK_ERROR_TAG 0x4c4d5953
@ -464,7 +464,7 @@ struct smb2_negotiate_rsp {
__le16 SecurityBufferOffset; __le16 SecurityBufferOffset;
__le16 SecurityBufferLength; __le16 SecurityBufferLength;
__le32 NegotiateContextOffset; /* Pre:SMB3.1.1 was reserved/ignored */ __le32 NegotiateContextOffset; /* Pre:SMB3.1.1 was reserved/ignored */
__u8 Buffer[1]; /* variable length GSS security buffer */ __u8 Buffer[]; /* variable length GSS security buffer */
} __packed; } __packed;
/* Flags */ /* Flags */
@ -481,7 +481,7 @@ struct smb2_sess_setup_req {
__le16 SecurityBufferOffset; __le16 SecurityBufferOffset;
__le16 SecurityBufferLength; __le16 SecurityBufferLength;
__u64 PreviousSessionId; __u64 PreviousSessionId;
__u8 Buffer[1]; /* variable length GSS security buffer */ __u8 Buffer[]; /* variable length GSS security buffer */
} __packed; } __packed;
/* Currently defined SessionFlags */ /* Currently defined SessionFlags */
@ -494,7 +494,7 @@ struct smb2_sess_setup_rsp {
__le16 SessionFlags; __le16 SessionFlags;
__le16 SecurityBufferOffset; __le16 SecurityBufferOffset;
__le16 SecurityBufferLength; __le16 SecurityBufferLength;
__u8 Buffer[1]; /* variable length GSS security buffer */ __u8 Buffer[]; /* variable length GSS security buffer */
} __packed; } __packed;
struct smb2_logoff_req { struct smb2_logoff_req {
@ -520,7 +520,7 @@ struct smb2_tree_connect_req {
__le16 Flags; /* Reserved MBZ for dialects prior to SMB3.1.1 */ __le16 Flags; /* Reserved MBZ for dialects prior to SMB3.1.1 */
__le16 PathOffset; __le16 PathOffset;
__le16 PathLength; __le16 PathLength;
__u8 Buffer[1]; /* variable length */ __u8 Buffer[]; /* variable length */
} __packed; } __packed;
/* See MS-SMB2 section 2.2.9.2 */ /* See MS-SMB2 section 2.2.9.2 */
@ -828,7 +828,7 @@ struct smb2_create_rsp {
__u64 VolatileFileId; /* opaque endianness */ __u64 VolatileFileId; /* opaque endianness */
__le32 CreateContextsOffset; __le32 CreateContextsOffset;
__le32 CreateContextsLength; __le32 CreateContextsLength;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
struct create_context { struct create_context {
@ -1289,7 +1289,7 @@ struct smb2_read_plain_req {
__le32 RemainingBytes; __le32 RemainingBytes;
__le16 ReadChannelInfoOffset; __le16 ReadChannelInfoOffset;
__le16 ReadChannelInfoLength; __le16 ReadChannelInfoLength;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
/* Read flags */ /* Read flags */
@ -1304,7 +1304,7 @@ struct smb2_read_rsp {
__le32 DataLength; __le32 DataLength;
__le32 DataRemaining; __le32 DataRemaining;
__u32 Flags; __u32 Flags;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
/* For write request Flags field below the following flags are defined: */ /* For write request Flags field below the following flags are defined: */
@ -1324,7 +1324,7 @@ struct smb2_write_req {
__le16 WriteChannelInfoOffset; __le16 WriteChannelInfoOffset;
__le16 WriteChannelInfoLength; __le16 WriteChannelInfoLength;
__le32 Flags; __le32 Flags;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
struct smb2_write_rsp { struct smb2_write_rsp {
@ -1335,7 +1335,7 @@ struct smb2_write_rsp {
__le32 DataLength; __le32 DataLength;
__le32 DataRemaining; __le32 DataRemaining;
__u32 Reserved2; __u32 Reserved2;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
/* notify flags */ /* notify flags */
@ -1371,7 +1371,7 @@ struct smb2_change_notify_rsp {
__le16 StructureSize; /* Must be 9 */ __le16 StructureSize; /* Must be 9 */
__le16 OutputBufferOffset; __le16 OutputBufferOffset;
__le32 OutputBufferLength; __le32 OutputBufferLength;
__u8 Buffer[1]; /* array of file notify structs */ __u8 Buffer[]; /* array of file notify structs */
} __packed; } __packed;
#define SMB2_LOCKFLAG_SHARED_LOCK 0x0001 #define SMB2_LOCKFLAG_SHARED_LOCK 0x0001
@ -1394,7 +1394,10 @@ struct smb2_lock_req {
__u64 PersistentFileId; /* opaque endianness */ __u64 PersistentFileId; /* opaque endianness */
__u64 VolatileFileId; /* opaque endianness */ __u64 VolatileFileId; /* opaque endianness */
/* Followed by at least one */ /* Followed by at least one */
struct smb2_lock_element locks[1]; union {
struct smb2_lock_element lock;
DECLARE_FLEX_ARRAY(struct smb2_lock_element, locks);
};
} __packed; } __packed;
struct smb2_lock_rsp { struct smb2_lock_rsp {
@ -1434,7 +1437,7 @@ struct smb2_query_directory_req {
__le16 FileNameOffset; __le16 FileNameOffset;
__le16 FileNameLength; __le16 FileNameLength;
__le32 OutputBufferLength; __le32 OutputBufferLength;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
struct smb2_query_directory_rsp { struct smb2_query_directory_rsp {
@ -1442,7 +1445,7 @@ struct smb2_query_directory_rsp {
__le16 StructureSize; /* Must be 9 */ __le16 StructureSize; /* Must be 9 */
__le16 OutputBufferOffset; __le16 OutputBufferOffset;
__le32 OutputBufferLength; __le32 OutputBufferLength;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
/* Possible InfoType values */ /* Possible InfoType values */
@ -1483,7 +1486,7 @@ struct smb2_query_info_req {
__le32 Flags; __le32 Flags;
__u64 PersistentFileId; /* opaque endianness */ __u64 PersistentFileId; /* opaque endianness */
__u64 VolatileFileId; /* opaque endianness */ __u64 VolatileFileId; /* opaque endianness */
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
struct smb2_query_info_rsp { struct smb2_query_info_rsp {
@ -1491,7 +1494,7 @@ struct smb2_query_info_rsp {
__le16 StructureSize; /* Must be 9 */ __le16 StructureSize; /* Must be 9 */
__le16 OutputBufferOffset; __le16 OutputBufferOffset;
__le32 OutputBufferLength; __le32 OutputBufferLength;
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
/* /*
@ -1514,7 +1517,7 @@ struct smb2_set_info_req {
__le32 AdditionalInformation; __le32 AdditionalInformation;
__u64 PersistentFileId; /* opaque endianness */ __u64 PersistentFileId; /* opaque endianness */
__u64 VolatileFileId; /* opaque endianness */ __u64 VolatileFileId; /* opaque endianness */
__u8 Buffer[1]; __u8 Buffer[];
} __packed; } __packed;
struct smb2_set_info_rsp { struct smb2_set_info_rsp {
@ -1716,7 +1719,10 @@ struct smb2_file_all_info { /* data block encoding of response to level 18 */
__le32 Mode; __le32 Mode;
__le32 AlignmentRequirement; __le32 AlignmentRequirement;
__le32 FileNameLength; __le32 FileNameLength;
char FileName[1]; union {
char __pad; /* Legacy structure padding */
DECLARE_FLEX_ARRAY(char, FileName);
};
} __packed; /* level 18 Query */ } __packed; /* level 18 Query */
struct smb2_file_eof_info { /* encoding of request for level 10 */ struct smb2_file_eof_info { /* encoding of request for level 10 */