The main problem is that this copy can overflow:
if (copy_from_user(mf, mfPtr, karg.dataSgeOffset * 4)) {
We try to prevent an overflow by checking "if (sz > ioc->req_sz) {" but
the problem is that "sz" is signed so the test can underflow or their
could be an integer overflow.
A second problem was this check which could underflow if "maxSenseBytes"
was negative.
if (karg.maxSenseBytes > MPT_SENSE_BUFFER_SIZE)
I made the variables unsigned to prevent underflow and I added a new
test to prevent integer overflows. I had to update a call to printk()
and change some min() usages to min_t() as part of the fallout from the
type changes.
Signed-off-by: Dan Carpenter <[email protected]>
---
Static checker stuff, and not tested but I think it is safe.
diff --git a/drivers/message/fusion/mptctl.h b/drivers/message/fusion/mptctl.h
index d564cc9..117fe89 100644
--- a/drivers/message/fusion/mptctl.h
+++ b/drivers/message/fusion/mptctl.h
@@ -324,11 +324,11 @@ struct mpt_ioctl_command {
char __user *dataInBufPtr;
char __user *dataOutBufPtr;
char __user *senseDataPtr;
- int maxReplyBytes;
- int dataInSize;
- int dataOutSize;
- int maxSenseBytes;
- int dataSgeOffset;
+ unsigned int maxReplyBytes;
+ unsigned int dataInSize;
+ unsigned int dataOutSize;
+ unsigned int maxSenseBytes;
+ unsigned int dataSgeOffset;
char MF[1];
};
diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index 70bb753..5646830 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -1829,7 +1829,8 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg,
void __user *mfPtr)
dma_addr_t dma_addr_out;
int sgSize = 0; /* Num SG elements */
int iocnum, flagsLength;
- int sz, rc = 0;
+ size_t sz;
+ int rc = 0;
int msgContext;
u16 req_idx;
ulong timeout;
@@ -1861,6 +1862,9 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg,
void __user *mfPtr)
/* Verify that the final request frame will not be too large.
*/
+ if (karg.dataSgeOffset > ioc->req_sz)
+ return -EFAULT;
+
sz = karg.dataSgeOffset * 4;
if (karg.dataInSize > 0)
sz += ioc->SGE_size;
@@ -1869,7 +1873,7 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg,
void __user *mfPtr)
if (sz > ioc->req_sz) {
printk(MYIOC_s_ERR_FMT "%s@%d::mptctl_do_mpt_command - "
- "Request frame too large (%d) maximum (%d)\n",
+ "Request frame too large (%ld) maximum (%d)\n",
ioc->name, __FILE__, __LINE__, sz, ioc->req_sz);
return -EFAULT;
}
@@ -2316,8 +2320,8 @@ retry_wait:
*/
if (ioc->ioctl_cmds.status & MPT_MGMT_STATUS_RF_VALID) {
if (karg.maxReplyBytes < ioc->reply_sz) {
- sz = min(karg.maxReplyBytes,
- 4*ioc->ioctl_cmds.reply[2]);
+ sz = min_t(size_t, karg.maxReplyBytes,
+ 4*ioc->ioctl_cmds.reply[2]);
} else {
sz = min(ioc->reply_sz, 4*ioc->ioctl_cmds.reply[2]);
}
@@ -2337,7 +2341,7 @@ retry_wait:
/* If valid sense data, copy to user.
*/
if (ioc->ioctl_cmds.status & MPT_MGMT_STATUS_SENSE_VALID) {
- sz = min(karg.maxSenseBytes, MPT_SENSE_BUFFER_SIZE);
+ sz = min_t(size_t, karg.maxSenseBytes, MPT_SENSE_BUFFER_SIZE);
if (sz > 0) {
if (copy_to_user(karg.senseDataPtr,
ioc->ioctl_cmds.sense, sz)) {
--
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