History

mm/slab: make __free(kfree) accept error pointers

Currently, if an automatically freed allocation is an error pointer that will lead to a crash. An example of this is in wm831x_gpio_dbg_show(). 171 char *label __free(kfree) = gpiochip_dup_line_label(chip, i); 172 if (IS_ERR(label)) { 173 dev_err(wm831x->dev, "Failed to duplicate label\n"); 174 continue; 175 } The auto clean up function should check for error pointers as well, otherwise we're going to keep hitting issues like this.

Dan Carpenter committed 2 years ago

Commit cd7eb8f1 parent 8f828aa1 file · +2 −2Browse files

Unified · Split

include/linux/slab.h+2−2
@@ -266,7 +266,7 @@ void kfree(const void *objp); · 265 unmodified lines
266266 void kfree_sensitive(const void *objp);
267267 size_t __ksize(const void *objp);
268268
269−DEFINE_FREE(kfree, void *, if (_T) kfree(_T))
269+DEFINE_FREE(kfree, void *, if (!IS_ERR_OR_NULL(_T)) kfree(_T))
270270
271271 /**
272272 * ksize - Report actual allocation size of associated object
@@ -792,7 +792,7 @@ static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t fla · 519 unmodified lines
792792 extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
793793 __realloc_size(3);
794794 extern void kvfree(const void *addr);
795−DEFINE_FREE(kvfree, void *, if (_T) kvfree(_T))
795+DEFINE_FREE(kvfree, void *, if (!IS_ERR_OR_NULL(_T)) kvfree(_T))
796796
797797 extern void kvfree_sensitive(const void *addr, size_t len);
798798