GCC 8.2 gives this warning:
builtin-run.c: In function ‘kvm_run_write_sandbox_cmd.isra.1’:
builtin-run.c:417:28: error: ‘%s’ directive output may be truncated writing up to 4095 bytes into a region of size 4091 [-Werror=format-truncation=]
snprintf(dst, len, "/host%s", resolved_path);
^~ ~~~~~~~~~~~~~
It's because it understands that len is PATH_MAX, the same as
resolved_path's size. This patch handles the case where the string is
truncated, and fixes the warning.
Signed-off-by: Anisse Astier <aastier@xxxxxxxxxx>
---
builtin-run.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/builtin-run.c b/builtin-run.c
index 82e2b2e..463a481 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -414,7 +414,9 @@ static void resolve_program(const char *src, char *dst, size_t len)
if (!realpath(src, resolved_path))
die("Unable to resolve program %s: %s\n", src, strerror(errno));
- snprintf(dst, len, "/host%s", resolved_path);
+ if (snprintf(dst, len, "/host%s", resolved_path) >= (int)len)
+ die("Pathname too long: %s -> %s\n", src, resolved_path);
+
} else
strncpy(dst, src, len);
}
--
2.19.1
