From: David Scidmore Date: Tue, 11 Dec 2007 23:44:30 +0000 (-0600) Subject: [MTD] mtdchar.c: ioctl always returns 0 as size written for ppc64 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e9d8d48253c50106d85b288939e5227083360863;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git [MTD] mtdchar.c: ioctl always returns 0 as size written for ppc64 "include/linux/mtd/mtd.h" declares "mtd_oob_ops.retlen" as size_t, which is 64 bits on targets with a 64 bit addressing. The MEMWRITEOOB ioctl calls copy_to_user() to write it back to "mtd_oob_buf.length", which is declared in "include/linux/mtd-abi.h" as uint32_t. Since powerpc is a big endian architecture, this only copies the upper 32 bits of the address, which is always 0. Signed-off-by: David Scidmore Signed-off-by: David Woodhouse --- diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 22ed96c4b7b..b42553cd9af 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -483,6 +483,7 @@ static int mtd_ioctl(struct inode *inode, struct file *file, { struct mtd_oob_buf buf; struct mtd_oob_ops ops; + uint32_t retlen; if(!(file->f_mode & 2)) return -EPERM; @@ -522,8 +523,11 @@ static int mtd_ioctl(struct inode *inode, struct file *file, buf.start &= ~(mtd->oobsize - 1); ret = mtd->write_oob(mtd, buf.start, &ops); - if (copy_to_user(argp + sizeof(uint32_t), &ops.oobretlen, - sizeof(uint32_t))) + if (ops.oobretlen > 0xFFFFFFFFU) + ret = -EOVERFLOW; + retlen = ops.oobretlen; + if (copy_to_user(&((struct mtd_oob_buf *)argp)->length, + &retlen, sizeof(buf.length))) ret = -EFAULT; kfree(ops.oobbuf);