mm/zsmalloc: do not attempt to free IS_ERR handle

sergey-senozhatsky · akpm00 · commit a5d2172180e8 · 2022-08-28T14:02:44.000-07:00
zsmalloc() now returns ERR_PTR values as handles, which zram accidentally can pass to zs_free(). Another bad scenario is when zcomp_compress() fails - handle has default -ENOMEM value, and zs_free() will try to free that "pointer value". Add the missing check and make sure that zs_free() bails out when ERR_PTR() is passed to it. Link: https://lkml.kernel.org/r/20220816050906.2583956-1-senozhatsky@chromium.org Fixes: c7e6f17 ("zsmalloc: zs_malloc: return ERR_PTR on failure") Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
@@ -1487,7 +1487,7 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
 	struct size_class *class;
 	enum fullness_group fullness;
 
-	if (unlikely(!handle))
+	if (IS_ERR_OR_NULL((void *)handle))
 		return;
 
 	/*
