+ mm-slub-fix-potential-use-after-free-in-slab_debugfs_fops.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm, slub: fix potential use-after-free in slab_debugfs_fops
has been added to the -mm tree.  Its filename is
     mm-slub-fix-potential-use-after-free-in-slab_debugfs_fops.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-slub-fix-potential-use-after-free-in-slab_debugfs_fops.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-slub-fix-potential-use-after-free-in-slab_debugfs_fops.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm, slub: fix potential use-after-free in slab_debugfs_fops

When sysfs_slab_add failed, we shouldn't call debugfs_slab_add() for s
because s will be freed soon.  And slab_debugfs_fops will use s later
leading to a use-after-free.

Link: https://lkml.kernel.org/r/20210916123920.48704-5-linmiaohe@huawei.com
Fixes: 64dd68497be7 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/slub.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/mm/slub.c~mm-slub-fix-potential-use-after-free-in-slab_debugfs_fops
+++ a/mm/slub.c
@@ -4887,13 +4887,15 @@ int __kmem_cache_create(struct kmem_cach
 		return 0;
 
 	err = sysfs_slab_add(s);
-	if (err)
+	if (err) {
 		__kmem_cache_release(s);
+		return err;
+	}
 
 	if (s->flags & SLAB_STORE_USER)
 		debugfs_slab_add(s);
 
-	return err;
+	return 0;
 }
 
 void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-slub-fix-two-bugs-in-slab_debug_trace_open.patch
mm-slub-fix-mismatch-between-reconstructed-freelist-depth-and-cnt.patch
mm-slub-fix-potential-memoryleak-in-kmem_cache_open.patch
mm-slub-fix-potential-use-after-free-in-slab_debugfs_fops.patch
mm-slub-fix-incorrect-memcg-slab-count-for-bulk-free.patch
mm-page_allocc-remove-meaningless-vm_bug_on-in-pindex_to_order.patch
mm-page_allocc-simplify-the-code-by-using-macro-k.patch
mm-page_allocc-fix-obsolete-comment-in-free_pcppages_bulk.patch
mm-page_allocc-use-helper-function-zone_spans_pfn.patch
mm-page_allocc-avoid-allocating-highmem-pages-via-alloc_pages_exact.patch
mm-page_isolation-fix-potential-missing-call-to-unset_migratetype_isolate.patch
mm-page_isolation-guard-against-possible-putback-unisolated-page.patch
mm-memory_hotplug-make-hwpoisoned-dirty-swapcache-pages-unmovable.patch
mm-zsmallocc-close-race-window-between-zs_pool_dec_isolated-and-zs_unregister_migration.patch
mm-zsmallocc-combine-two-atomic-ops-in-zs_pool_dec_isolated.patch