diff options
| author | Masahiro Yamada <masahiroy@kernel.org> | 2025-01-03 16:30:39 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-08 09:58:09 +0100 |
| commit | 52f0a28e17f711d7567605f1de6d1d48c6069f99 (patch) | |
| tree | 59c8ccd41a372c48a508d169798c6f25574ec695 | |
| parent | a23834b782777ce0704b7622725b8b6da5b043f5 (diff) | |
genksyms: fix memory leak when the same symbol is read from *.symref file
[ Upstream commit be2fa44b5180a1f021efb40c55fdf63c249c3209 ]
When a symbol that is already registered is read again from *.symref
file, __add_symbol() removes the previous one from the hash table without
freeing it.
[Test Case]
$ cat foo.c
#include <linux/export.h>
void foo(void);
void foo(void) {}
EXPORT_SYMBOL(foo);
$ cat foo.symref
foo void foo ( void )
foo void foo ( void )
When a symbol is removed from the hash table, it must be freed along
with its ->name and ->defn members. However, sym->name cannot be freed
because it is sometimes shared with node->string, but not always. If
sym->name and node->string share the same memory, free(sym->name) could
lead to a double-free bug.
To resolve this issue, always assign a strdup'ed string to sym->name.
Fixes: 64e6c1e12372 ("genksyms: track symbol checksum changes")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | scripts/genksyms/genksyms.c | 8 | ||||
| -rw-r--r-- | scripts/genksyms/genksyms.h | 2 | ||||
| -rw-r--r-- | scripts/genksyms/parse.y | 4 |
3 files changed, 9 insertions, 5 deletions
diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c index 0077c96e526f..bbc6b7d3088c 100644 --- a/scripts/genksyms/genksyms.c +++ b/scripts/genksyms/genksyms.c @@ -272,11 +272,15 @@ static struct symbol *__add_symbol(const char *name, enum symbol_type type, break; } } + + free_list(sym->defn, NULL); + free(sym->name); + free(sym); --nsyms; } sym = xmalloc(sizeof(*sym)); - sym->name = name; + sym->name = xstrdup(name); sym->type = type; sym->defn = defn; sym->expansion_trail = NULL; @@ -483,7 +487,7 @@ static void read_reference(FILE *f) defn = def; def = read_node(f); } - subsym = add_reference_symbol(xstrdup(sym->string), sym->tag, + subsym = add_reference_symbol(sym->string, sym->tag, defn, is_extern); subsym->is_override = is_override; free_node(sym); diff --git a/scripts/genksyms/genksyms.h b/scripts/genksyms/genksyms.h index 21ed2ec2d98c..5621533dcb8e 100644 --- a/scripts/genksyms/genksyms.h +++ b/scripts/genksyms/genksyms.h @@ -32,7 +32,7 @@ struct string_list { struct symbol { struct symbol *hash_next; - const char *name; + char *name; enum symbol_type type; struct string_list *defn; struct symbol *expansion_trail; diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y index 840371d01bf4..689cb6bb40b6 100644 --- a/scripts/genksyms/parse.y +++ b/scripts/genksyms/parse.y @@ -482,12 +482,12 @@ enumerator_list: enumerator: IDENT { - const char *name = strdup((*$1)->string); + const char *name = (*$1)->string; add_symbol(name, SYM_ENUM_CONST, NULL, 0); } | IDENT '=' EXPRESSION_PHRASE { - const char *name = strdup((*$1)->string); + const char *name = (*$1)->string; struct string_list *expr = copy_list_range(*$3, *$2); add_symbol(name, SYM_ENUM_CONST, expr, 0); } |