From 86a6a0bdbe2beb4cc7bc80eccd835b62a1f0c364 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 16 Jun 2021 14:24:28 -0700 Subject: [PATCH] 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 Signed-off-by: Martin K. Petersen --- drivers/scsi/arcmsr/arcmsr_hba.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c index e5149c9fd4e6..ec1a834c922d 100644 --- a/drivers/scsi/arcmsr/arcmsr_hba.c +++ b/drivers/scsi/arcmsr/arcmsr_hba.c @@ -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; } -- 2.20.1