tools: Fix heap buffer overflow in ideviceimagemounter

1 files changed, 5 insertions, 2 deletions

diff --git a/tools/ideviceimagemounter.c b/tools/ideviceimagemounter.c
index 52b0666..511583e 100644
--- a/tools/ideviceimagemounter.c
+++ b/tools/ideviceimagemounter.c
@@ -377,8 +377,11 @@ int main(int argc, char **argv)
                                 fprintf(stderr, "Error opening signature file '%s': %s\n", image_sig_path, strerror(errno));
                                 goto leave;
                         }
-                        fstat(fileno(f), &fst);
-                        sig = malloc(sig_length);
+                        if (fstat(fileno(f), &fst) != 0) {
+                                fprintf(stderr, "Error: fstat: %s\n", strerror(errno));
+                                goto leave;
+                        }
+                        sig = malloc(fst.st_size);
                         sig_length = fread(sig, 1, fst.st_size, f);
                         fclose(f);
                         if (sig_length == 0) {