* nvmem: mxs-ocotp read problem
@ 2016-04-26 11:45 Stanislav Meduna
2016-04-26 12:59 ` Stefan Wahren
0 siblings, 1 reply; 2+ messages in thread
From: Stanislav Meduna @ 2016-04-26 11:45 UTC (permalink / raw)
To: linux-arm-kernel
Hi,
the mxs_ocotp_read seems to incorrectly iterate through
the memory to be read, resulting in a buffer overflow/off-area
access and sometimes oops. The following patch seems to fix
the problem
Regards
Stano
diff --git a/drivers/nvmem/mxs-ocotp.c b/drivers/nvmem/mxs-ocotp.c
index 8ba19bb..914a4fa 100644
--- a/drivers/nvmem/mxs-ocotp.c
+++ b/drivers/nvmem/mxs-ocotp.c
@@ -94,7 +94,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
if (ret)
goto close_banks;
- while (val_size) {
+ while (val_size >= reg_size) {
if ((offset < OCOTP_DATA_OFFSET) || (offset % 16)) {
/* fill up non-data register */
*buf = 0;
@@ -103,7 +103,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
}
buf++;
- val_size--;
+ val_size -= reg_size;
offset += reg_size;
}
^ permalink raw reply related [flat|nested] 2+ messages in thread* nvmem: mxs-ocotp read problem
2016-04-26 11:45 nvmem: mxs-ocotp read problem Stanislav Meduna
@ 2016-04-26 12:59 ` Stefan Wahren
0 siblings, 0 replies; 2+ messages in thread
From: Stefan Wahren @ 2016-04-26 12:59 UTC (permalink / raw)
To: linux-arm-kernel
Hi Stano,
Am 26.04.2016 um 13:45 schrieb Stanislav Meduna:
> Hi,
>
> the mxs_ocotp_read seems to incorrectly iterate through
> the memory to be read, resulting in a buffer overflow/off-area
> access and sometimes oops.
could you please provide me scenario, so i can test it.
Regards
Stefan
> The following patch seems to fix
> the problem
>
> Regards
> Stano
>
>
> diff --git a/drivers/nvmem/mxs-ocotp.c b/drivers/nvmem/mxs-ocotp.c
> index 8ba19bb..914a4fa 100644
> --- a/drivers/nvmem/mxs-ocotp.c
> +++ b/drivers/nvmem/mxs-ocotp.c
> @@ -94,7 +94,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
> if (ret)
> goto close_banks;
>
> - while (val_size) {
> + while (val_size >= reg_size) {
> if ((offset < OCOTP_DATA_OFFSET) || (offset % 16)) {
> /* fill up non-data register */
> *buf = 0;
> @@ -103,7 +103,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
> }
>
> buf++;
> - val_size--;
> + val_size -= reg_size;
> offset += reg_size;
> }
^ permalink raw reply [flat|nested] 2+ messages in thread
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2016-04-26 11:45 nvmem: mxs-ocotp read problem Stanislav Meduna
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