cifs: Replace remaining 1-element arrays

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 cifs_spnego_msg
	struct cifs_quota_data
	struct get_dfs_referral_rsp
	struct file_alt_name_info
	NEGOTIATE_RSP
	SESSION_SETUP_ANDX
	TCONX_REQ
	TCONX_RSP
	TCONX_RSP_EXT
	ECHO_REQ
	ECHO_RSP
	OPEN_REQ
	OPENX_REQ
	LOCK_REQ
	RENAME_REQ
	COPY_REQ
	COPY_RSP
	NT_RENAME_REQ
	DELETE_FILE_REQ
	DELETE_DIRECTORY_REQ
	CREATE_DIRECTORY_REQ
	QUERY_INFORMATION_REQ
	SETATTR_REQ
	TRANSACT_IOCTL_REQ
	TRANSACT_CHANGE_NOTIFY_REQ
	TRANSACTION2_QPI_REQ
	TRANSACTION2_SPI_REQ
	TRANSACTION2_FFIRST_REQ
	TRANSACTION2_GET_DFS_REFER_REQ
	FILE_UNIX_LINK_INFO
	FILE_DIRECTORY_INFO
	FILE_FULL_DIRECTORY_INFO
	SEARCH_ID_FULL_DIR_INFO
	FILE_BOTH_DIRECTORY_INFO
	FIND_FILE_STANDARD_INFO

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

	FILE_ALL_INFO
	FILE_UNIX_INFO

Remove unused structures:

	struct gea
	struct gealist

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

No machine code output 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: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/cifs_spnego.h b/fs/cifs/cifs_spnego.h
index 7f102ff..e4d751b 100644 (file)
--- a/fs/cifs/cifs_spnego.h
+++ b/fs/cifs/cifs_spnego.h
@@ -24,7 +24,7 @@ struct cifs_spnego_msg {
        uint32_t        flags;
        uint32_t        sesskey_len;
        uint32_t        secblob_len;
-       uint8_t         data[1];
+       uint8_t         data[];
 };
 
 #ifdef __KERNEL__

diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index add73be..445e3ea 100644 (file)
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -562,7 +562,7 @@ typedef union smb_com_session_setup_andx {
                __u32 Reserved;
                __le32 Capabilities;    /* see below */
                __le16 ByteCount;
-               unsigned char SecurityBlob[1];  /* followed by */
+               unsigned char SecurityBlob[];   /* followed by */
                /* STRING NativeOS */
                /* STRING NativeLanMan */
        } __attribute__((packed)) req;  /* NTLM request format (with
@@ -582,7 +582,7 @@ typedef union smb_com_session_setup_andx {
                __u32 Reserved; /* see below */
                __le32 Capabilities;
                __le16 ByteCount;
-               unsigned char CaseInsensitivePassword[1];     /* followed by: */
+               unsigned char CaseInsensitivePassword[];     /* followed by: */
                /* unsigned char * CaseSensitivePassword; */
                /* STRING AccountName */
                /* STRING PrimaryDomain */
@@ -599,7 +599,7 @@ typedef union smb_com_session_setup_andx {
                __le16 Action;  /* see below */
                __le16 SecurityBlobLength;
                __u16 ByteCount;
-               unsigned char SecurityBlob[1];  /* followed by */
+               unsigned char SecurityBlob[];   /* followed by */
 /*      unsigned char  * NativeOS;      */
 /*     unsigned char  * NativeLanMan;  */
 /*      unsigned char  * PrimaryDomain; */
@@ -618,7 +618,7 @@ typedef union smb_com_session_setup_andx {
                __le16 PasswordLength;
                __u32 Reserved; /* encrypt key len and offset */
                __le16 ByteCount;
-               unsigned char AccountPassword[1];       /* followed by */
+               unsigned char AccountPassword[];        /* followed by */
                /* STRING AccountName */
                /* STRING PrimaryDomain */
                /* STRING NativeOS */
@@ -632,7 +632,7 @@ typedef union smb_com_session_setup_andx {
                __le16 AndXOffset;
                __le16 Action;  /* see below */
                __u16 ByteCount;
-               unsigned char NativeOS[1];      /* followed by */
+               unsigned char NativeOS[];       /* followed by */
 /*     unsigned char * NativeLanMan; */
 /*      unsigned char * PrimaryDomain; */
        } __attribute__((packed)) old_resp; /* pre-NTLM (LANMAN2.1) response */
@@ -693,7 +693,7 @@ typedef struct smb_com_tconx_req {
        __le16 Flags;           /* see below */
        __le16 PasswordLength;
        __le16 ByteCount;
-       unsigned char Password[1];      /* followed by */
+       unsigned char Password[];       /* followed by */
 /* STRING Path    *//* \\server\share name */
        /* STRING Service */
 } __attribute__((packed)) TCONX_REQ;
@@ -705,7 +705,7 @@ typedef struct smb_com_tconx_rsp {
        __le16 AndXOffset;
        __le16 OptionalSupport; /* see below */
        __u16 ByteCount;
-       unsigned char Service[1];       /* always ASCII, not Unicode */
+       unsigned char Service[];        /* always ASCII, not Unicode */
        /* STRING NativeFileSystem */
 } __attribute__((packed)) TCONX_RSP;
 
@@ -718,7 +718,7 @@ typedef struct smb_com_tconx_rsp_ext {
        __le32 MaximalShareAccessRights;
        __le32 GuestMaximalShareAccessRights;
        __u16 ByteCount;
-       unsigned char Service[1];       /* always ASCII, not Unicode */
+       unsigned char Service[];        /* always ASCII, not Unicode */
        /* STRING NativeFileSystem */
 } __attribute__((packed)) TCONX_RSP_EXT;
 
@@ -755,14 +755,14 @@ typedef struct smb_com_echo_req {
        struct  smb_hdr hdr;
        __le16  EchoCount;
        __le16  ByteCount;
-       char    Data[1];
+       char    Data[];
 } __attribute__((packed)) ECHO_REQ;
 
 typedef struct smb_com_echo_rsp {
        struct  smb_hdr hdr;
        __le16  SequenceNumber;
        __le16  ByteCount;
-       char    Data[1];
+       char    Data[];
 } __attribute__((packed)) ECHO_RSP;
 
 typedef struct smb_com_logoff_andx_req {
@@ -862,7 +862,7 @@ typedef struct smb_com_open_req {   /* also handles create */
        __le32 ImpersonationLevel;
        __u8 SecurityFlags;
        __le16 ByteCount;
-       char fileName[1];
+       char fileName[];
 } __attribute__((packed)) OPEN_REQ;
 
 /* open response: oplock levels */
@@ -937,7 +937,7 @@ typedef struct smb_com_openx_req {
        __le32 Timeout;
        __le32 Reserved;
        __le16  ByteCount;  /* file name follows */
-       char   fileName[1];
+       char   fileName[];
 } __attribute__((packed)) OPENX_REQ;
 
 typedef struct smb_com_openx_rsp {
@@ -1085,7 +1085,7 @@ typedef struct smb_com_lock_req {
        __le16 NumberOfUnlocks;
        __le16 NumberOfLocks;
        __le16 ByteCount;
-       LOCKING_ANDX_RANGE Locks[1];
+       LOCKING_ANDX_RANGE Locks[];
 } __attribute__((packed)) LOCK_REQ;
 
 /* lock type */
@@ -1114,7 +1114,7 @@ typedef struct smb_com_rename_req {
        __le16 SearchAttributes;        /* target file attributes */
        __le16 ByteCount;
        __u8 BufferFormat;      /* 4 = ASCII or Unicode */
-       unsigned char OldFileName[1];
+       unsigned char OldFileName[];
        /* followed by __u8 BufferFormat2 */
        /* followed by NewFileName */
 } __attribute__((packed)) RENAME_REQ;
@@ -1134,7 +1134,7 @@ typedef struct smb_com_copy_req {
        __le16 Flags;
        __le16 ByteCount;
        __u8 BufferFormat;      /* 4 = ASCII or Unicode */
-       unsigned char OldFileName[1];
+       unsigned char OldFileName[];
        /* followed by __u8 BufferFormat2 */
        /* followed by NewFileName string */
 } __attribute__((packed)) COPY_REQ;
@@ -1144,7 +1144,7 @@ typedef struct smb_com_copy_rsp {
        __le16 CopyCount;    /* number of files copied */
        __u16 ByteCount;    /* may be zero */
        __u8 BufferFormat;  /* 0x04 - only present if errored file follows */
-       unsigned char ErrorFileName[1]; /* only present if error in copy */
+       unsigned char ErrorFileName[]; /* only present if error in copy */
 } __attribute__((packed)) COPY_RSP;
 
 #define CREATE_HARD_LINK               0x103
@@ -1158,7 +1158,7 @@ typedef struct smb_com_nt_rename_req {    /* A5 - also used for create hardlink */
        __le32 ClusterCount;
        __le16 ByteCount;
        __u8 BufferFormat;      /* 4 = ASCII or Unicode */
-       unsigned char OldFileName[1];
+       unsigned char OldFileName[];
        /* followed by __u8 BufferFormat2 */
        /* followed by NewFileName */
 } __attribute__((packed)) NT_RENAME_REQ;
@@ -1173,7 +1173,7 @@ typedef struct smb_com_delete_file_req {
        __le16 SearchAttributes;
        __le16 ByteCount;
        __u8 BufferFormat;      /* 4 = ASCII */
-       unsigned char fileName[1];
+       unsigned char fileName[];
 } __attribute__((packed)) DELETE_FILE_REQ;
 
 typedef struct smb_com_delete_file_rsp {
@@ -1185,7 +1185,7 @@ typedef struct smb_com_delete_directory_req {
        struct smb_hdr hdr;     /* wct = 0 */
        __le16 ByteCount;
        __u8 BufferFormat;      /* 4 = ASCII */
-       unsigned char DirName[1];
+       unsigned char DirName[];
 } __attribute__((packed)) DELETE_DIRECTORY_REQ;
 
 typedef struct smb_com_delete_directory_rsp {
@@ -1197,7 +1197,7 @@ typedef struct smb_com_create_directory_req {
        struct smb_hdr hdr;     /* wct = 0 */
        __le16 ByteCount;
        __u8 BufferFormat;      /* 4 = ASCII */
-       unsigned char DirName[1];
+       unsigned char DirName[];
 } __attribute__((packed)) CREATE_DIRECTORY_REQ;
 
 typedef struct smb_com_create_directory_rsp {
@@ -1209,7 +1209,7 @@ typedef struct smb_com_query_information_req {
        struct smb_hdr hdr;     /* wct = 0 */
        __le16 ByteCount;       /* 1 + namelen + 1 */
        __u8 BufferFormat;      /* 4 = ASCII */
-       unsigned char FileName[1];
+       unsigned char FileName[];
 } __attribute__((packed)) QUERY_INFORMATION_REQ;
 
 typedef struct smb_com_query_information_rsp {
@@ -1229,7 +1229,7 @@ typedef struct smb_com_setattr_req {
        __le16 reserved[5]; /* must be zero */
        __u16  ByteCount;
        __u8   BufferFormat; /* 4 = ASCII */
-       unsigned char fileName[1];
+       unsigned char fileName[];
 } __attribute__((packed)) SETATTR_REQ;
 
 typedef struct smb_com_setattr_rsp {
@@ -1311,7 +1311,7 @@ typedef struct smb_com_transaction_ioctl_req {
        __u8 IsRootFlag; /* 1 = apply command to root of share (must be DFS) */
        __le16 ByteCount;
        __u8 Pad[3];
-       __u8 Data[1];
+       __u8 Data[];
 } __attribute__((packed)) TRANSACT_IOCTL_REQ;
 
 typedef struct smb_com_transaction_compr_ioctl_req {
@@ -1430,7 +1430,7 @@ typedef struct smb_com_transaction_change_notify_req {
        __u8 Reserved2;
        __le16 ByteCount;
 /*     __u8 Pad[3];*/
-/*     __u8 Data[1];*/
+/*     __u8 Data[];*/
 } __attribute__((packed)) TRANSACT_CHANGE_NOTIFY_REQ;
 
 /* BB eventually change to use generic ntransact rsp struct
@@ -1519,7 +1519,7 @@ struct cifs_quota_data {
        __u64   space_used;
        __u64   soft_limit;
        __u64   hard_limit;
-       char    sid[1];  /* variable size? */
+       char    sid[];  /* variable size? */
 } __attribute__((packed));
 
 /* quota sub commands */
@@ -1671,7 +1671,7 @@ typedef struct smb_com_transaction2_qpi_req {
        __u8 Pad;
        __le16 InformationLevel;
        __u32 Reserved4;
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) TRANSACTION2_QPI_REQ;
 
 typedef struct smb_com_transaction2_qpi_rsp {
@@ -1704,7 +1704,7 @@ typedef struct smb_com_transaction2_spi_req {
        __u16 Pad1;
        __le16 InformationLevel;
        __u32 Reserved4;
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) TRANSACTION2_SPI_REQ;
 
 typedef struct smb_com_transaction2_spi_rsp {
@@ -1809,7 +1809,7 @@ typedef struct smb_com_transaction2_ffirst_req {
        __le16 SearchFlags;
        __le16 InformationLevel;
        __le32 SearchStorageType;
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) TRANSACTION2_FFIRST_REQ;
 
 typedef struct smb_com_transaction2_ffirst_rsp {
@@ -2020,7 +2020,7 @@ typedef struct smb_com_transaction2_get_dfs_refer_req {
                                   perhaps?) followed by one byte pad - doesn't
                                   seem to matter though */
        __le16 MaxReferralLevel;
-       char RequestFileName[1];
+       char RequestFileName[];
 } __attribute__((packed)) TRANSACTION2_GET_DFS_REFER_REQ;
 
 #define DFS_VERSION cpu_to_le16(0x0003)
@@ -2049,7 +2049,7 @@ struct get_dfs_referral_rsp {
        __le16 PathConsumed;
        __le16 NumberOfReferrals;
        __le32 DFSFlags;
-       REFERRAL3 referrals[1]; /* array of level 3 dfs_referral structures */
+       REFERRAL3 referrals[];  /* array of level 3 dfs_referral structures */
        /* followed by the strings pointed to by the referral structures */
 } __packed;
 
@@ -2284,7 +2284,10 @@ typedef struct { /* data block encoding of response to level 263 QPathInfo */
        __le32 Mode;
        __le32 AlignmentRequirement;
        __le32 FileNameLength;
-       char FileName[1];
+       union {
+               char __pad;
+               DECLARE_FLEX_ARRAY(char, FileName);
+       };
 } __attribute__((packed)) FILE_ALL_INFO;       /* level 0x107 QPathInfo */
 
 typedef struct {
@@ -2322,7 +2325,7 @@ typedef struct {
 } __attribute__((packed)) FILE_UNIX_BASIC_INFO;        /* level 0x200 QPathInfo */
 
 typedef struct {
-       char LinkDest[1];
+       DECLARE_FLEX_ARRAY(char, LinkDest);
 } __attribute__((packed)) FILE_UNIX_LINK_INFO; /* level 0x201 QPathInfo */
 
 /* The following three structures are needed only for
@@ -2371,7 +2374,7 @@ struct file_end_of_file_info {
 } __attribute__((packed)); /* size info, level 0x104 for set, 0x106 for query */
 
 struct file_alt_name_info {
-       __u8   alt_name[1];
+       DECLARE_FLEX_ARRAY(__u8, alt_name);
 } __attribute__((packed));      /* level 0x0108 */
 
 struct file_stream_info {
@@ -2480,7 +2483,10 @@ typedef struct {
        __le32 NextEntryOffset;
        __u32 ResumeKey; /* as with FileIndex - no need to convert */
        FILE_UNIX_BASIC_INFO basic;
-       char FileName[1];
+       union {
+               char __pad;
+               DECLARE_FLEX_ARRAY(char, FileName);
+       };
 } __attribute__((packed)) FILE_UNIX_INFO; /* level 0x202 */
 
 typedef struct {
@@ -2494,7 +2500,7 @@ typedef struct {
        __le64 AllocationSize;
        __le32 ExtFileAttributes;
        __le32 FileNameLength;
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) FILE_DIRECTORY_INFO;   /* level 0x101 FF resp data */
 
 typedef struct {
@@ -2509,7 +2515,7 @@ typedef struct {
        __le32 ExtFileAttributes;
        __le32 FileNameLength;
        __le32 EaSize; /* length of the xattrs */
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) FILE_FULL_DIRECTORY_INFO; /* level 0x102 rsp data */
 
 typedef struct {
@@ -2526,7 +2532,7 @@ typedef struct {
        __le32 EaSize; /* EA size */
        __le32 Reserved;
        __le64 UniqueId; /* inode num - le since Samba puts ino in low 32 bit*/
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) SEARCH_ID_FULL_DIR_INFO; /* level 0x105 FF rsp data */
 
 typedef struct {
@@ -2544,7 +2550,7 @@ typedef struct {
        __u8   ShortNameLength;
        __u8   Reserved;
        __u8   ShortName[24];
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) FILE_BOTH_DIRECTORY_INFO; /* level 0x104 FFrsp data */
 
 typedef struct {
@@ -2559,7 +2565,7 @@ typedef struct {
        __le32 AllocationSize;
        __le16 Attributes; /* verify not u32 */
        __u8   FileNameLength;
-       char FileName[1];
+       char FileName[];
 } __attribute__((packed)) FIND_FILE_STANDARD_INFO; /* level 0x1 FF resp data */
 
 
@@ -2569,16 +2575,6 @@ struct win_dev {
        __le64 minor;
 } __attribute__((packed));
 
-struct gea {
-       unsigned char name_len;
-       char name[1];
-} __attribute__((packed));
-
-struct gealist {
-       unsigned long list_len;
-       struct gea list[1];
-} __attribute__((packed));
-
 struct fea {
        unsigned char EA_flags;
        __u8 name_len;

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 2d75ba5..ef63808 100644 (file)
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -495,7 +495,7 @@ static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
                FIND_FILE_STANDARD_INFO *pfData;
                pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 
-               new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
+               new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 +
                                pfData->FileNameLength;
        } else {
                u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
@@ -513,9 +513,9 @@ static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
                         new_entry, end_of_smb, old_entry);
                return NULL;
        } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
-                   (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
+                   (new_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 > end_of_smb))
                  || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
-                  (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
+                  (new_entry + sizeof(FILE_DIRECTORY_INFO) + 1 > end_of_smb)))  {
                cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
                         new_entry, end_of_smb);
                return NULL;

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index b16b41d..3bc0aa8 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -5011,10 +5011,10 @@ smb2_parse_query_directory(struct cifs_tcon *tcon,
 
        switch (srch_inf->info_level) {
        case SMB_FIND_FILE_DIRECTORY_INFO:
-               info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
+               info_buf_size = sizeof(FILE_DIRECTORY_INFO);
                break;
        case SMB_FIND_FILE_ID_FULL_DIR_INFO:
-               info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
+               info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO);
                break;
        case SMB_FIND_FILE_POSIX_INFO:
                /* note that posix payload are variable size */

diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 1237bb8..3ad7ec4 100644 (file)
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -371,7 +371,7 @@ struct smb2_file_id_extd_directory_info {
        __le32 EaSize; /* EA size */
        __le32 ReparsePointTag; /* valid if FILE_ATTR_REPARSE_POINT set in FileAttributes */
        __le64 UniqueId; /* inode num - le since Samba puts ino in low 32 bit */
-       char FileName[1];
+       char FileName[];
 } __packed; /* level 60 */
 
 extern char smb2_padding[7];