6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook <keescook@xxxxxxxxxxxx> commit 35235e19b393b54db0e0d7c424d658ba45f20468 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 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@xxxxxxxxx> Cc: Paulo Alcantara <pc@xxxxxx> Cc: Ronnie Sahlberg <lsahlber@xxxxxxxxxx> Cc: Shyam Prasad N <sprasad@xxxxxxxxxxxxx> Cc: linux-cifs@xxxxxxxxxxxxxxx Cc: samba-technical@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> [ Salvatore Bonaccorso: Patch does not apply cleanly only due to a whitespace difference in fs/smb/client/cifspdu.h . Fixed up manually. ] Signed-off-by: Salvatore Bonaccorso <carnil@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/smb/client/cifs_spnego.h | 2 fs/smb/client/cifspdu.h | 96 +++++++++++++++++++++----------------------- fs/smb/client/readdir.c | 6 +- fs/smb/client/smb2pdu.c | 4 - fs/smb/client/smb2pdu.h | 2 5 files changed, 53 insertions(+), 57 deletions(-) --- a/fs/smb/client/cifs_spnego.h +++ b/fs/smb/client/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__ --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/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 { /* als __le32 ImpersonationLevel; __u8 SecurityFlags; __le16 ByteCount; - char fileName[1]; + char fileName[]; } __attribute__((packed)) OPEN_REQ; /* open response: oplock levels */ @@ -939,7 +939,7 @@ 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 { @@ -1087,7 +1087,7 @@ 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 */ @@ -1116,7 +1116,7 @@ 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; @@ -1136,7 +1136,7 @@ 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; @@ -1146,7 +1146,7 @@ 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 @@ -1160,7 +1160,7 @@ typedef struct smb_com_nt_rename_req { / __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; @@ -1175,7 +1175,7 @@ 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 { @@ -1187,7 +1187,7 @@ typedef struct smb_com_delete_directory_ 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 { @@ -1199,7 +1199,7 @@ typedef struct smb_com_create_directory_ 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 { @@ -1211,7 +1211,7 @@ typedef struct smb_com_query_information 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 { @@ -1231,7 +1231,7 @@ 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 { @@ -1313,7 +1313,7 @@ typedef struct smb_com_transaction_ioctl __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 { @@ -1431,8 +1431,8 @@ typedef struct smb_com_transaction_chang __u8 WatchTree; /* 1 = Monitor subdirectories */ __u8 Reserved2; __le16 ByteCount; -/* __u8 Pad[3];*/ -/* __u8 Data[1];*/ +/* __u8 Pad[3];*/ +/* __u8 Data[];*/ } __attribute__((packed)) TRANSACT_CHANGE_NOTIFY_REQ; /* BB eventually change to use generic ntransact rsp struct @@ -1521,7 +1521,7 @@ 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 */ @@ -1673,7 +1673,7 @@ typedef struct smb_com_transaction2_qpi_ __u8 Pad; __le16 InformationLevel; __u32 Reserved4; - char FileName[1]; + char FileName[]; } __attribute__((packed)) TRANSACTION2_QPI_REQ; typedef struct smb_com_transaction2_qpi_rsp { @@ -1706,7 +1706,7 @@ typedef struct smb_com_transaction2_spi_ __u16 Pad1; __le16 InformationLevel; __u32 Reserved4; - char FileName[1]; + char FileName[]; } __attribute__((packed)) TRANSACTION2_SPI_REQ; typedef struct smb_com_transaction2_spi_rsp { @@ -1813,7 +1813,7 @@ typedef struct smb_com_transaction2_ffir __le16 SearchFlags; __le16 InformationLevel; __le32 SearchStorageType; - char FileName[1]; + char FileName[]; } __attribute__((packed)) TRANSACTION2_FFIRST_REQ; typedef struct smb_com_transaction2_ffirst_rsp { @@ -2024,7 +2024,7 @@ typedef struct smb_com_transaction2_get_ 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) @@ -2053,7 +2053,7 @@ 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; @@ -2292,7 +2292,10 @@ typedef struct { /* data block encoding __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 { @@ -2330,7 +2333,7 @@ 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 @@ -2380,7 +2383,7 @@ 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 { @@ -2490,7 +2493,10 @@ 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 { @@ -2504,7 +2510,7 @@ 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 { @@ -2519,7 +2525,7 @@ 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 { @@ -2536,7 +2542,7 @@ 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 { @@ -2554,7 +2560,7 @@ 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 { @@ -2569,7 +2575,7 @@ 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 */ @@ -2579,16 +2585,6 @@ 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; --- a/fs/smb/client/readdir.c +++ b/fs/smb/client/readdir.c @@ -497,7 +497,7 @@ static char *nxt_dir_entry(char *old_ent 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); @@ -515,9 +515,9 @@ static char *nxt_dir_entry(char *old_ent 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; --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -5073,10 +5073,10 @@ smb2_parse_query_directory(struct cifs_t 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 */ --- a/fs/smb/client/smb2pdu.h +++ b/fs/smb/client/smb2pdu.h @@ -373,7 +373,7 @@ 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];