From: Gabriel Ravier gabravier@gmail.com
[ Upstream commit d1ee7e1f5c9191afb69ce46cc7752e4257340a31 ]
If '-o' was used more than 64 times in a single invocation of gpio-hammer, this could lead to an overflow of the 'lines' array. This commit fixes this by avoiding the overflow and giving a proper diagnostic back to the user
Signed-off-by: Gabriel Ravier gabravier@gmail.com Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/gpio/gpio-hammer.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c index 4bcb234c0fcab..3da5462a0c7d3 100644 --- a/tools/gpio/gpio-hammer.c +++ b/tools/gpio/gpio-hammer.c @@ -138,7 +138,14 @@ int main(int argc, char **argv) device_name = optarg; break; case 'o': - lines[i] = strtoul(optarg, NULL, 10); + /* + * Avoid overflow. Do not immediately error, we want to + * be able to accurately report on the amount of times + * '-o' was given to give an accurate error message + */ + if (i < GPIOHANDLES_MAX) + lines[i] = strtoul(optarg, NULL, 10); + i++; break; case '?': @@ -146,6 +153,14 @@ int main(int argc, char **argv) return -1; } } + + if (i >= GPIOHANDLES_MAX) { + fprintf(stderr, + "Only %d occurences of '-o' are allowed, %d were found\n", + GPIOHANDLES_MAX, i + 1); + return -1; + } + nlines = i;
if (!device_name || !nlines) {