One-element arrays are deprecated, and we are replacing them with flexible array members instead. So, replace one-element arrays with flexible-array member in structs negotiate_req and extended_response, and refactor the rest of the code, accordingly. Also, make use of the DECLARE_FLEX_ARRAY() helper to declare flexible array member EncryptionKey in union u. This new helper allows for flexible-array members in unions. Change pointer notation to proper array notation in a call to memcpy() where flexible-array member DialectsArray is being used as destination argument. Important to mention is that doing a build before/after this patch results in no binary output differences. This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/229 Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836 [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> --- fs/cifs/cifspdu.h | 7 ++++--- fs/cifs/cifssmb.c | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h index aeba371c4c70..d1abaeea974a 100644 --- a/fs/cifs/cifspdu.h +++ b/fs/cifs/cifspdu.h @@ -483,7 +483,7 @@ put_bcc(__u16 count, struct smb_hdr *hdr) typedef struct negotiate_req { struct smb_hdr hdr; /* wct = 0 */ __le16 ByteCount; - unsigned char DialectsArray[1]; + unsigned char DialectsArray[]; } __attribute__((packed)) NEGOTIATE_REQ; #define MIN_TZ_ADJ (15 * 60) /* minimum grid for timezones in seconds */ @@ -508,13 +508,14 @@ typedef struct negotiate_rsp { __u8 EncryptionKeyLength; __u16 ByteCount; union { - unsigned char EncryptionKey[1]; /* cap extended security off */ + /* cap extended security off */ + DECLARE_FLEX_ARRAY(unsigned char, EncryptionKey); /* followed by Domain name - if extended security is off */ /* followed by 16 bytes of server GUID */ /* then security blob if cap_extended_security negotiated */ struct { unsigned char GUID[SMB1_CLIENT_GUID_SIZE]; - unsigned char SecurityBlob[1]; + unsigned char SecurityBlob[]; } __attribute__((packed)) extended_response; } __attribute__((packed)) u; } __attribute__((packed)) NEGOTIATE_RSP; diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 7aa91e272027..7a808e41b1b8 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -465,7 +465,7 @@ CIFSSMBNegotiate(const unsigned int xid, for (i = 0; i < CIFS_NUM_PROT; i++) { size_t len = strlen(protocols[i].name) + 1; - memcpy(pSMB->DialectsArray+count, protocols[i].name, len); + memcpy(&pSMB->DialectsArray[count], protocols[i].name, len); count += len; } inc_rfc1001_len(pSMB, count); -- 2.34.1
