From: Masami Hiramatsu (Google) <[email protected]> In paths where tracing_map_elt_alloc() failed to allocate objects, the map->ops->elt_alloc() call was never successful. In this case, map->ops->elt_free() should not be called.
This bug was found by Sashiko. Link: https://sashiko.dev/#/patchset/20260520223101.34710-1-rosenp%40gmail.com Fixes: 2734b629525a ("tracing: Add per-element variable support to tracing_map") Signed-off-by: Masami Hiramatsu (Google) <[email protected]> Cc: [email protected] --- kernel/trace/tracing_map.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index bf1a507695b6..0dd7927df22a 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c @@ -386,13 +386,11 @@ static void tracing_map_elt_init_fields(struct tracing_map_elt *elt) } } -static void tracing_map_elt_free(struct tracing_map_elt *elt) +static void __tracing_map_elt_free(struct tracing_map_elt *elt) { if (!elt) return; - if (elt->map->ops && elt->map->ops->elt_free) - elt->map->ops->elt_free(elt); kfree(elt->fields); kfree(elt->vars); kfree(elt->var_set); @@ -400,6 +398,17 @@ static void tracing_map_elt_free(struct tracing_map_elt *elt) kfree(elt); } +static void tracing_map_elt_free(struct tracing_map_elt *elt) +{ + if (!elt) + return; + + /* Only objects initialized with alloc_elt() should be passed to free_elt().*/ + if (elt->map->ops && elt->map->ops->elt_free) + elt->map->ops->elt_free(elt); + __tracing_map_elt_free(elt); +} + static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map) { struct tracing_map_elt *elt; @@ -444,7 +453,7 @@ static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map) } return elt; free: - tracing_map_elt_free(elt); + __tracing_map_elt_free(elt); return ERR_PTR(err); }
