On 3/12/20 3:40 PM, Gabriel Ravier wrote:
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@xxxxxxxxx>
---
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 0e0060a6e..d0be21af1 100644
--- a/tools/gpio/gpio-hammer.c
+++ b/tools/gpio/gpio-hammer.c
@@ -135,7 +135,14 @@ 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 '?':
@@ -143,6 +150,14 @@ 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) {
Just noticed that there isn't a space before the "'-o'" in the third
line of the explanatory comment in the first part of the patch, will
send a third version of the patch with a space before the "'-o'"
