libkmod: return ENOMEM when strbuf_pushchar(s) fails

Currently get_strings() assumes that errno is set when either function
fails. This is not the case when our overflow checks kick in. The other
case where these functions fail is memory exhaustion.

In practice we cannot do anything if either of those trigger, plus I
don't see a compelling reason to set errno to EOVERFLOW... Something
which other parts of the codebase don't do.

So let's just return ENOMEM and avoid the corner case of returning
success from get_strings(), when it should be failing.

Fixes: 1005e99e ("libkmod: refactor builtin module handling")
Fixes: 952bf223 ("strbuf: Add strbuf_reserve_extra()")
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/368
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c
index 26c9e51c228a3f7e9255c27c8fca2d4fc6e6377f..f54d876b0fdb2298b226788bf460fdcbaf8f6ee9 100644 (file)
--- a/libkmod/libkmod-builtin.c
+++ b/libkmod/libkmod-builtin.c
@@ -99,7 +99,7 @@ static ssize_t get_strings(struct kmod_builtin_info *info, const char *modname,
                        break;
                }
                if (!strbuf_pushchars(buf, dot + 1) || !strbuf_pushchar(buf, '\0')) {
-                       count = -errno;
+                       count = -ENOMEM;
                        ERR(info->ctx, "get_strings: "
                                       "failed to append modinfo string\n");
                        return count;