From b67c5f87c13f398ec3f4d6b455cb0bbeda8d7ac0 Mon Sep 17 00:00:00 2001 From: Zev Weiss Date: Mon, 1 Sep 2008 05:02:12 -0700 Subject: [PATCH] [MTD] mtdchar.c: Fix regression in MEMGETREGIONINFO ioctl() The MEMGETREGIONINFO ioctl() in mtdchar.c was clobbering user memory by overwriting more than intended, due the size of struct mtd_erase_region_info changing in commit 0ecbc81adfcb9f15f86b05ff576b342ce81bbef8 ('Support for auto locking flash on power up'). Fix avoids this by copying struct members one by one with put_user(), as there is no longer a convenient struct to use the size of as the length argument to copy_to_user(). Signed-off-by: Zev Weiss Signed-off-by: David Woodhouse --- drivers/mtd/mtdchar.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index d2f3318..e00d424 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -410,16 +410,20 @@ static int mtd_ioctl(struct inode *inode, struct file *file, case MEMGETREGIONINFO: { - struct region_info_user ur; + uint32_t ur_idx; + struct mtd_erase_region_info *kr; + struct region_info_user *ur = (struct region_info_user *) argp; - if (copy_from_user(&ur, argp, sizeof(struct region_info_user))) + if (get_user(ur_idx, &(ur->regionindex))) return -EFAULT; - if (ur.regionindex >= mtd->numeraseregions) - return -EINVAL; - if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]), - sizeof(struct mtd_erase_region_info))) + kr = &(mtd->eraseregions[ur_idx]); + + if (put_user(kr->offset, &(ur->offset)) + || put_user(kr->erasesize, &(ur->erasesize)) + || put_user(kr->numblocks, &(ur->numblocks))) return -EFAULT; + break; } -- 2.7.4