From fd819f54065c590308a5ff24d50d4f7500b87101 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 30 Oct 2020 17:44:20 +0100 Subject: [PATCH] scsi: megaraid_sas: Check user-provided offsets commit 381d34e376e3d9d27730fda8a0e870600e6c8196 upstream. It sounds unwise to let user space pass an unchecked 32-bit offset into a kernel structure in an ioctl. This is an unsigned variable, so checking the upper bound for the size of the structure it points into is sufficient to avoid data corruption, but as the pointer might also be unaligned, it has to be written carefully as well. While I stumbled over this problem by reading the code, I did not continue checking the function for further problems like it. Link: https://lore.kernel.org/r/20201030164450.1253641-2-arnd@kernel.org Fixes: c4a3e0a529ab ("[SCSI] MegaRAID SAS RAID: new driver") Cc: # v2.6.15+ Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/megaraid/megaraid_sas_base.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index 2c2966a297c77..4a23dd8b7f9aa 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -8038,7 +8038,7 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance, int error = 0, i; void *sense = NULL; dma_addr_t sense_handle; - unsigned long *sense_ptr; + void *sense_ptr; u32 opcode = 0; memset(kbuff_arr, 0, sizeof(kbuff_arr)); @@ -8160,6 +8160,13 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance, } if (ioc->sense_len) { + /* make sure the pointer is part of the frame */ + if (ioc->sense_off > + (sizeof(union megasas_frame) - sizeof(__le64))) { + error = -EINVAL; + goto out; + } + sense = dma_alloc_coherent(&instance->pdev->dev, ioc->sense_len, &sense_handle, GFP_KERNEL); if (!sense) { @@ -8167,12 +8174,11 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance, goto out; } - sense_ptr = - (unsigned long *) ((unsigned long)cmd->frame + ioc->sense_off); + sense_ptr = (void *)cmd->frame + ioc->sense_off; if (instance->consistent_mask_64bit) - *sense_ptr = cpu_to_le64(sense_handle); + put_unaligned_le64(sense_handle, sense_ptr); else - *sense_ptr = cpu_to_le32(sense_handle); + put_unaligned_le32(sense_handle, sense_ptr); } /*