On Wed, Jul 30, 2025 at 09:46:09AM +0800, liqiong wrote:
在 2025/7/29 21:41, Harry Yoo 写道:
On Tue, Jul 29, 2025 at 04:14:55PM +0800, Li Qiong wrote:
Fixes: bb192ed9aa71 ("mm/slub: Convert most struct page to struct slab by spatch")
As Vlastimil mentioned in previous version, this is not the first commit that introduced this problem.
Please don't forget to update Fixes: tag :)
Cc: stable@vger.kernel.org Signed-off-by: Li Qiong liqiong@nfschina.com
v2:
- rephrase the commit message, add comment for object_err().
v3:
- check object pointer in object_err().
mm/slub.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c index 31e11ef256f9..d3abae5a2193 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1104,7 +1104,11 @@ static void object_err(struct kmem_cache *s, struct slab *slab, return; slab_bug(s, reason);
- print_trailer(s, slab, object);
- if (!check_valid_pointer(s, slab, object)) {
print_slab_info(slab);pr_err("invalid object 0x%p\n", object);Can we just handle this inside print_trailer() because that's the function that prints the object's free pointer, metadata, etc.?
Maybe it's clearer , if object pointer being invalid, don't enter print_trailer()， print_trailer() prints valid object.
You're probably right. No strong opinion. object_err() is the only user anyway.
- } else
print_trailer(s, slab, object);WARN_ON(1); @@ -1587,7 +1591,7 @@ static inline int alloc_consistency_checks(struct kmem_cache *s, return 0; if (!check_valid_pointer(s, slab, object)) {
object_err(s, slab, object, "Freelist Pointer check fails");
slab_err(s, slab, "Freelist Pointer(0x%p) check fails", object);Do we really need this hunk after making object_err() resiliant against wild pointers?
That's the origin issue, it may be inappropriate to use object_err(), if check_valid_pointer being false.
That was the original issue, but you're making it not crash even if with bad pointers are passed?
}