Merge tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd

Pull MTD updates from Brian Norris:
 - refactor m25p80.c driver for use as a general SPI NOR framework for
   other drivers which may speak to SPI NOR flash without providing full
   SPI support (i.e., not part of drivers/spi/)
 - new Freescale QuadSPI driver (utilizing new SPI NOR framework)
 - updates for the STMicro "FSM" SPI NOR driver
 - fix sync/flush behavior on mtd_blkdevs
 - fixup subpage write support on a few NAND drivers
 - correct the MTD OOB test for odd-sized OOB areas
 - add BCH-16 support for OMAP NAND
 - fix warnings and trivial refactoring
 - utilize new ECC DT bindings in pxa3xx NAND driver
 - new LPDDR NVM driver
 - address a few assorted bugs caught by Coverity
 - add new imx6sx support for GPMI NAND
 - use a bounce buffer for NAND when non-DMA-able buffers are used

* tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd: (77 commits)
  mtd: gpmi: add gpmi support for imx6sx
  mtd: maps: remove check for CONFIG_MTD_SUPERH_RESERVE
  mtd: bf5xx_nand: use the managed version of kzalloc
  mtd: pxa3xx_nand: make the driver work on big-endian systems
  mtd: nand: omap: fix omap_calculate_ecc_bch() for-loop error
  mtd: nand: r852: correct write_buf loop bounds
  mtd: nand_bbt: handle error case for nand_create_badblock_pattern()
  mtd: nand_bbt: remove unused variable
  mtd: maps: sc520cdp: fix warnings
  mtd: slram: fix unused variable warning
  mtd: pfow: remove unused variable
  mtd: lpddr: fix Kconfig dependency, for I/O accessors
  mtd: nand: pxa3xx: Add supported ECC strength and step size to the DT binding
  mtd: nand: pxa3xx: Use ECC strength and step size devicetree binding
  mtd: nand: pxa3xx: Clean pxa_ecc_init() error handling
  mtd: nand: Warn the user if the selected ECC strength is too weak
  mtd: nand: omap: Documentation: How to select correct ECC scheme for your device ?
  mtd: nand: omap: add support for BCH16_ECC - NAND driver updates
  mtd: nand: omap: add support for BCH16_ECC - ELM driver updates
  mtd: nand: omap: add support for BCH16_ECC - GPMC driver updates
  ...

1 files changed, 11 insertions, 9 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 7d4e7b9..a0f54e8 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -568,13 +568,18 @@ static int mtdchar_write_ioctl(struct mtd_info *mtd,
 {
 	struct mtd_write_req req;
 	struct mtd_oob_ops ops;
-	void __user *usr_data, *usr_oob;
+	const void __user *usr_data, *usr_oob;
 	int ret;
 
-	if (copy_from_user(&req, argp, sizeof(req)) ||
-			!access_ok(VERIFY_READ, req.usr_data, req.len) ||
-			!access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
+	if (copy_from_user(&req, argp, sizeof(req)))
 		return -EFAULT;
+
+	usr_data = (const void __user *)(uintptr_t)req.usr_data;
+	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
+	if (!access_ok(VERIFY_READ, usr_data, req.len) ||
+	    !access_ok(VERIFY_READ, usr_oob, req.ooblen))
+		return -EFAULT;
+
 	if (!mtd->_write_oob)
 		return -EOPNOTSUPP;
 
@@ -583,10 +588,7 @@ static int mtdchar_write_ioctl(struct mtd_info *mtd,
 	ops.ooblen = (size_t)req.ooblen;
 	ops.ooboffs = 0;
 
-	usr_data = (void __user *)(uintptr_t)req.usr_data;
-	usr_oob = (void __user *)(uintptr_t)req.usr_oob;
-
-	if (req.usr_data) {
+	if (usr_data) {
 		ops.datbuf = memdup_user(usr_data, ops.len);
 		if (IS_ERR(ops.datbuf))
 			return PTR_ERR(ops.datbuf);
@@ -594,7 +596,7 @@ static int mtdchar_write_ioctl(struct mtd_info *mtd,
 		ops.datbuf = NULL;
 	}
 
-	if (req.usr_oob) {
+	if (usr_oob) {
 		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 		if (IS_ERR(ops.oobbuf)) {
 			kfree(ops.datbuf);