From: Arnd Bergmann arnd@arndb.de
stable inclusion from stable-5.10.3 commit 79ab763e574fde60d35ee818e90261fdd7907f7c bugzilla: 46871
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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: stable@vger.kernel.org # v2.6.15+ Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
Signed-off-by: Chen Jun chenjun102@huawei.com --- 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 e158d3d62056..9ebeb031329d 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -8095,7 +8095,7 @@ 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; int ret = DCMD_SUCCESS;
@@ -8218,6 +8218,13 @@ 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) { @@ -8225,12 +8232,11 @@ 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); }
/*