Re: [vbabka:b4/sheaves-for-all] [slab] 16e7d1ea82: BUG:kernel_NULL_pointer_dereference,address

[Vlastimil Babka <vbabka@suse.cz>]

On 10/16/25 08:02, kernel test robot wrote:
> 
> 
> Hello,
> 
> kernel test robot noticed "BUG:kernel_NULL_pointer_dereference,address" on:
> 
> commit: 16e7d1ea820782b8335c2a52052e4a0d9ca0d4b0 ("slab: add sheaves to most caches")
> https://git.kernel.org/cgit/linux/kernel/git/vbabka/linux.git b4/sheaves-for-all
> 
> in testcase: boot
> 
> config: x86_64-randconfig-004-20251015
> compiler: clang-20
> test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> 
> (please refer to attached dmesg/kmsg for entire log/backtrace)
> 
> 
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202510161341.61ccb50f-lkp@intel.com
> 

Thanks, most likely this, will update the branch.
----8<----
diff --git a/include/linux/slab.h b/include/linux/slab.h
index cf443f064a66..e42aa6a3d202 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -57,9 +57,7 @@ enum _slab_flag_bits {
 #endif
 	_SLAB_OBJECT_POISON,
 	_SLAB_CMPXCHG_DOUBLE,
-#ifdef CONFIG_SLAB_OBJ_EXT
 	_SLAB_NO_OBJ_EXT,
-#endif
 	_SLAB_FLAGS_LAST_BIT
 };
 
@@ -238,11 +236,7 @@ enum _slab_flag_bits {
 #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */
 
 /* Slab created using create_boot_cache */
-#ifdef CONFIG_SLAB_OBJ_EXT
 #define SLAB_NO_OBJ_EXT		__SLAB_FLAG_BIT(_SLAB_NO_OBJ_EXT)
-#else
-#define SLAB_NO_OBJ_EXT		__SLAB_FLAG_UNUSED
-#endif
 
 /*
  * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.