diff options
| author |   Gustavo A. R. Silva <garsilva@embeddedor.com> | 2018-03-07 20:27:56 -0600 |
|---|---|---|
| committer |   Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-03-17 14:20:56 +0100 |
| commit | fed9b18611f75110d5b26d650819665d528038da (patch) | |
| tree | bca711325de4c186d2e3d42320211fc758b828e8 | |
| parent | rtc: Add useful timestamp definitions (diff) | |
| download | linux-dev-fed9b18611f75110d5b26d650819665d528038da.tar.xz linux-dev-fed9b18611f75110d5b26d650819665d528038da.zip | |
rtc: remove VLA usage
In preparation to enabling -Wvla, remove VLA and replace it
with a fixed-length array instead.
>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.
Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/rtc/rtc-bq32k.c | 6 | ||||
| -rw-r--r-- | drivers/rtc/rtc-mcp795.c | 2 |
2 files changed, 6 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c index e8698e9870fe..ef52741000a8 100644 --- a/drivers/rtc/rtc-bq32k.c +++ b/drivers/rtc/rtc-bq32k.c @@ -36,6 +36,10 @@ #define BQ32K_CFG2 0x09 /* Trickle charger control */ #define BQ32K_TCFE BIT(6) /* Trickle charge FET bypass */ +#define MAX_LEN 10 /* Maximum number of consecutive + * register for this particular RTC. + */ + struct bq32k_regs { uint8_t seconds; uint8_t minutes; @@ -74,7 +78,7 @@ static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len) static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len) { struct i2c_client *client = to_i2c_client(dev); - uint8_t buffer[len + 1]; + uint8_t buffer[MAX_LEN + 1]; buffer[0] = off; memcpy(&buffer[1], data, len); diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c index 79e24eadbe99..00e11c1b2186 100644 --- a/drivers/rtc/rtc-mcp795.c +++ b/drivers/rtc/rtc-mcp795.c @@ -82,7 +82,7 @@ static int mcp795_rtcc_write(struct device *dev, u8 addr, u8 *data, u8 count) { struct spi_device *spi = to_spi_device(dev); int ret; - u8 tx[2 + count]; + u8 tx[257]; tx[0] = MCP795_WRITE; tx[1] = addr; |