[PATCH] mm: slub: fix conversion of freelist_corrupted()

[Eugeniu Rosca <erosca@de.adit-jv.com>]

Commit 52f23478081ae0 ("mm/slub.c: fix corrupted freechain in
deactivate_slab()") suffered an update when picked up from LKML [1].

Specifically, relocating 'freelist = NULL' into 'freelist_corrupted()'
created a no-op statement. Fix it by sticking to the behavior intended
in the original patch [1]. Prefer the lowest-line-count solution.

[1] https://lore.kernel.org/linux-mm/20200331031450.12182-1-dongli.zhang@oracle.com/

Fixes: 52f23478081ae0 ("mm/slub.c: fix corrupted freechain in deactivate_slab()")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dongli Zhang <dongli.zhang@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
---
 mm/slub.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 68c02b2eecd9..9a3e963b02a3 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -677,7 +677,6 @@ static bool freelist_corrupted(struct kmem_cache *s, struct page *page,
 	if ((s->flags & SLAB_CONSISTENCY_CHECKS) &&
 	    !check_valid_pointer(s, page, nextfree)) {
 		object_err(s, page, freelist, "Freechain corrupt");
-		freelist = NULL;
 		slab_fix(s, "Isolate corrupted freechain");
 		return true;
 	}
@@ -2184,8 +2183,10 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page,
 		 * 'freelist' is already corrupted.  So isolate all objects
 		 * starting at 'freelist'.
 		 */
-		if (freelist_corrupted(s, page, freelist, nextfree))
+		if (freelist_corrupted(s, page, freelist, nextfree)) {
+			freelist = NULL;
 			break;
+		}
 
 		do {
 			prior = page->freelist;
-- 
2.28.0