Commit c5c1e313 authored by Ihor Solodrai's avatar Ihor Solodrai Committed by Alexei Starovoitov
Browse files

resolve_btfids: Fix memory leaks reported by ASAN 



Running resolve_btfids with ASAN reveals memory leaks in btf_id
handling.

- Change get_id() to use a local buffer
- Make btf_id__add() strdup the name internally
- Add btf_id__free_all() that frees all nodese of a tree
- Call the cleanup function on exit for every tree

Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarIhor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20260223190736.649171-8-ihor.solodrai@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 4021848a

tools/bpf/resolve_btfids/main.c

+54 −27
Original line number Diff line number Diff line
@@ -226,7 +226,7 @@ static struct btf_id *btf_id__find(struct rb_root *root, const char *name) 
}



static struct btf_id *__btf_id__add(struct rb_root *root,

				    char *name,

				    const char *name,

				    enum btf_id_kind kind,

				    bool unique)

{
@@ -250,7 +250,11 @@ static struct btf_id *__btf_id__add(struct rb_root *root, 
	id = zalloc(sizeof(*id));

	if (id) {

		pr_debug("adding symbol %s\n", name);

		id->name = name;

		id->name = strdup(name);

		if (!id->name) {

			free(id);

			return NULL;

		}

		id->kind = kind;

		rb_link_node(&id->rb_node, parent, p);

		rb_insert_color(&id->rb_node, root);
@@ -258,17 +262,21 @@ static struct btf_id *__btf_id__add(struct rb_root *root, 
	return id;

}



static inline struct btf_id *btf_id__add(struct rb_root *root, char *name, enum btf_id_kind kind)

static inline struct btf_id *btf_id__add(struct rb_root *root,

					 const char *name,

					 enum btf_id_kind kind)

{

	return __btf_id__add(root, name, kind, false);

}



static inline struct btf_id *btf_id__add_unique(struct rb_root *root, char *name, enum btf_id_kind kind)

static inline struct btf_id *btf_id__add_unique(struct rb_root *root,

						const char *name,

						enum btf_id_kind kind)

{

	return __btf_id__add(root, name, kind, true);

}



static char *get_id(const char *prefix_end)

static int get_id(const char *prefix_end, char *buf, size_t buf_sz)

{

	/*

	 * __BTF_ID__func__vfs_truncate__0
@@ -277,28 +285,28 @@ static char *get_id(const char *prefix_end) 
	 */

	int len = strlen(prefix_end);

	int pos = sizeof("__") - 1;

	char *p, *id;

	char *p;



	if (pos >= len)

		return NULL;

		return -1;



	id = strdup(prefix_end + pos);

	if (id) {

	if (len - pos >= buf_sz)

		return -1;



	strcpy(buf, prefix_end + pos);

	/*

	 * __BTF_ID__func__vfs_truncate__0

		 * id =            ^

	 * buf =           ^

	 *

	 * cut the unique id part

	 */

		p = strrchr(id, '_');

	p = strrchr(buf, '_');

	p--;

		if (*p != '_') {

			free(id);

			return NULL;

		}

	if (*p != '_')

		return -1;

	*p = '\0';

	}

	return id;



	return 0;

}



static struct btf_id *add_set(struct object *obj, char *name, enum btf_id_kind kind)
@@ -335,10 +343,9 @@ static struct btf_id *add_set(struct object *obj, char *name, enum btf_id_kind k 


static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)

{

	char *id;

	char id[KSYM_NAME_LEN];



	id = get_id(name + size);

	if (!id) {

	if (get_id(name + size, id, sizeof(id))) {

		pr_err("FAILED to parse symbol name: %s\n", name);

		return NULL;

	}
@@ -346,6 +353,21 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size) 
	return btf_id__add(root, id, BTF_ID_KIND_SYM);

}



static void btf_id__free_all(struct rb_root *root)

{

	struct rb_node *next;

	struct btf_id *id;



	next = rb_first(root);

	while (next) {

		id = rb_entry(next, struct btf_id, rb_node);

		next = rb_next(&id->rb_node);

		rb_erase(&id->rb_node, root);

		free(id->name);

		free(id);

	}

}



static void bswap_32_data(void *data, u32 nr_bytes)

{

	u32 cnt, i;
@@ -1547,6 +1569,11 @@ int main(int argc, const char **argv) 
out:

	btf__free(obj.base_btf);

	btf__free(obj.btf);

	btf_id__free_all(&obj.structs);

	btf_id__free_all(&obj.unions);

	btf_id__free_all(&obj.typedefs);

	btf_id__free_all(&obj.funcs);

	btf_id__free_all(&obj.sets);

	if (obj.efile.elf) {

		elf_end(obj.efile.elf);

		close(obj.efile.fd);