scsi: arcmsr: Avoid over-read of sense buffer

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally reading across neighboring array fields.

pcmd->sense_buffer is 96 bytes, and was being manually zero-filled.
However, struct SENSE_DATA is 18 bytes, with ccb->arcmsr_cdb.SenseData only
being 15 bytes, resulting in a 3 byte over-read.

Copy only the contents of ccb->arcmsr_cdb.SenseData and zero fill the
remainder, avoiding potential over-reads.

Link: https://lore.kernel.org/r/20210616212428.1726958-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Kees Cook 2021-06-16 14:24:28 -07:00 committed by Martin K. Petersen
parent 4ab293c280
commit 86a6a0bdbe

View file

@ -1323,16 +1323,19 @@ static void arcmsr_ccb_complete(struct CommandControlBlock *ccb)
static void arcmsr_report_sense_info(struct CommandControlBlock *ccb)
{
struct scsi_cmnd *pcmd = ccb->pcmd;
struct SENSE_DATA *sensebuffer = (struct SENSE_DATA *)pcmd->sense_buffer;
pcmd->result = (DID_OK << 16) | SAM_STAT_CHECK_CONDITION;
if (sensebuffer) {
int sense_data_length =
sizeof(struct SENSE_DATA) < SCSI_SENSE_BUFFERSIZE
? sizeof(struct SENSE_DATA) : SCSI_SENSE_BUFFERSIZE;
memset(sensebuffer, 0, SCSI_SENSE_BUFFERSIZE);
memcpy(sensebuffer, ccb->arcmsr_cdb.SenseData, sense_data_length);
if (pcmd->sense_buffer) {
struct SENSE_DATA *sensebuffer;
memcpy_and_pad(pcmd->sense_buffer,
SCSI_SENSE_BUFFERSIZE,
ccb->arcmsr_cdb.SenseData,
sizeof(ccb->arcmsr_cdb.SenseData),
0);
sensebuffer = (struct SENSE_DATA *)pcmd->sense_buffer;
sensebuffer->ErrorCode = SCSI_SENSE_CURRENT_ERRORS;
sensebuffer->Valid = 1;
}