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author | Dongsheng Yang <yangds.fnst@cn.fujitsu.com> | 2015-07-21 08:30:20 (GMT) |
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committer | Brian Norris <computersforpeace@gmail.com> | 2015-09-29 22:43:15 (GMT) |
commit | 7827e3acad2df1c6537e5fe7211d216dabc60399 (patch) | |
tree | 7b38b2b3441409c8b882c40462a54608834fabeb /drivers/mtd/devices | |
parent | 8a799590005180b1010912be096c1302e2bd06da (diff) | |
download | linux-7827e3acad2df1c6537e5fe7211d216dabc60399.tar.xz |
mtd: mtdram: check offs and len in mtdram->erase
We should prevent user to erasing mtd device with
an unaligned offset or length.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/devices')
-rw-r--r-- | drivers/mtd/devices/mtdram.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c index 8e28508..73fa297 100644 --- a/drivers/mtd/devices/mtdram.c +++ b/drivers/mtd/devices/mtdram.c @@ -32,8 +32,29 @@ MODULE_PARM_DESC(erase_size, "Device erase block size in KiB"); // We could store these in the mtd structure, but we only support 1 device.. static struct mtd_info *mtd_info; +static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len) +{ + int ret = 0; + + /* Start address must align on block boundary */ + if (ofs % mtd->erasesize) { + pr_debug("%s: unaligned address\n", __func__); + ret = -EINVAL; + } + + /* Length must align on block boundary */ + if (len % mtd->erasesize) { + pr_debug("%s: length not block aligned\n", __func__); + ret = -EINVAL; + } + + return ret; +} + static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) { + if (check_offs_len(mtd, instr->addr, instr->len)) + return -EINVAL; memset((char *)mtd->priv + instr->addr, 0xff, instr->len); instr->state = MTD_ERASE_DONE; mtd_erase_callback(instr); |