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authorWill Newton <will.newton@gmail.com>2012-03-30 11:51:02 +0100
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-05-07 20:29:50 +0100
commit7a84477c4acebf6299b6a8bd6a1d5894eb838ffa (patch)
tree7ead0857a87874bb3362953d5fb55749f88903de
parent66f75a5d028beaf67c931435fdc3e7823125730c (diff)
mtd: fix oops in dataflash driver
I'm seeing an oops in mtd_dataflash.c with Linux 3.3. What appears to be happening is that otp_select_filemode calls mtd_read_fact_prot_reg with -1 for offset and length and a NULL buffer to test if OTP operations are supported. This finds its way down to otp_read in mtd_dataflash.c and causes an oops when memcpying the returned data into the NULL buf. None of the checks in otp_read catches the negative length and offset. Changing the length of the dummy read to 0 prevents the oops. Cc: stable@kernel.org [3.3+] Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
-rw-r--r--drivers/mtd/mtdchar.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 58fc65f5c81..f2f482bec57 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -376,7 +376,7 @@ static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
* Make a fake call to mtd_read_fact_prot_reg() to check if OTP
* operations are supported.
*/
- if (mtd_read_fact_prot_reg(mtd, -1, -1, &retlen, NULL) == -EOPNOTSUPP)
+ if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) == -EOPNOTSUPP)
return -EOPNOTSUPP;
switch (mode) {