+ mm-slub-fix-two-bugs-in-slab_debug_trace_open.patch added to -mm tree

+ mm-slub-fix-two-bugs-in-slab_debug_trace_open.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm, slub: fix two bugs in slab_debug_trace_open()
has been added to the -mm tree.  Its filename is
     mm-slub-fix-two-bugs-in-slab_debug_trace_open.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-slub-fix-two-bugs-in-slab_debug_trace_open.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-slub-fix-two-bugs-in-slab_debug_trace_open.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm, slub: fix two bugs in slab_debug_trace_open()

Patch series "Fixups for slub".

This series contains various bug fixes for slub.  We fix memoryleak,
use-afer-free, NULL pointer dereferencing and so on in slub.  More details
can be found in the respective changelogs.


This patch (of 5):

It's possible that __seq_open_private() will return NULL.  So we should
check t before using lest dereferencing NULL pointer.  And in error paths,
we forgot to release private buffer via seq_release_private().  Memory
will leak in these paths.

Link: https://lkml.kernel.org/r/20210916123920.48704-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210916123920.48704-2-linmiaohe@huawei.com
Fixes: 64dd68497be7 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/slub.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/mm/slub.c~mm-slub-fix-two-bugs-in-slab_debug_trace_open
+++ a/mm/slub.c
@@ -6108,9 +6108,14 @@ static int slab_debug_trace_open(struct
 	struct kmem_cache *s = file_inode(filep)->i_private;
 	unsigned long *obj_map;
 
+	if (!t)
+		return -ENOMEM;
+
 	obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
-	if (!obj_map)
+	if (!obj_map) {
+		seq_release_private(inode, filep);
 		return -ENOMEM;
+	}
 
 	if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0)
 		alloc = TRACK_ALLOC;
@@ -6119,6 +6124,7 @@ static int slab_debug_trace_open(struct
 
 	if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) {
 		bitmap_free(obj_map);
+		seq_release_private(inode, filep);
 		return -ENOMEM;
 	}
 
_

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