blob: 455591dc9a7af891ddf6019857a9b25344292449 [file] [log] [blame]
From c5588929a64ca65b0d596d496c04105e67dce509 Mon Sep 17 00:00:00 2001
From: Eugeniu Rosca <erosca@de.adit-jv.com>
Date: Fri, 4 Sep 2020 16:35:30 -0700
Subject: [PATCH] mm: slub: fix conversion of freelist_corrupted()
commit dc07a728d49cf025f5da2c31add438d839d076c0 upstream.
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]. In addition, make freelist_corrupted()
immune to passing NULL instead of &freelist.
The issue has been spotted via static analysis and code review.
[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()")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dongli Zhang <dongli.zhang@oracle.com>
Cc: Joe Jin <joe.jin@oracle.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: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200824130643.10291-1-erosca@de.adit-jv.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/mm/slub.c b/mm/slub.c
index 9e7da3b8bd0a..04a46eaea862 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -645,12 +645,12 @@ static void slab_fix(struct kmem_cache *s, char *fmt, ...)
}
static bool freelist_corrupted(struct kmem_cache *s, struct page *page,
- void *freelist, void *nextfree)
+ void **freelist, void *nextfree)
{
if ((s->flags & SLAB_CONSISTENCY_CHECKS) &&
- !check_valid_pointer(s, page, nextfree)) {
- object_err(s, page, freelist, "Freechain corrupt");
- freelist = NULL;
+ !check_valid_pointer(s, page, nextfree) && freelist) {
+ object_err(s, page, *freelist, "Freechain corrupt");
+ *freelist = NULL;
slab_fix(s, "Isolate corrupted freechain");
return true;
}
@@ -1391,7 +1391,7 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node,
int objects) {}
static bool freelist_corrupted(struct kmem_cache *s, struct page *page,
- void *freelist, void *nextfree)
+ void **freelist, void *nextfree)
{
return false;
}
@@ -2089,7 +2089,7 @@ 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))
break;
do {
--
2.27.0