diff options
| author | Muchun Song <songmuchun@bytedance.com> | 2023-03-20 06:00:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-04-13 17:55:30 +0300 |
| commit | 476699a8a7397bb5a147d256ed0c848d4e26b318 (patch) | |
| tree | 0f89e2da859a0b0c46986da3762520333e975afe /mm | |
| parent | dc54e4ea3190e953920be207d5fbf0371a683af5 (diff) | |
| download | linux-476699a8a7397bb5a147d256ed0c848d4e26b318.tar.xz | |
mm: kfence: fix PG_slab and memcg_data clearing
commit 3ee2d7471fa4963a2ced0a84f0653ce88b43c5b2 upstream.
It does not reset PG_slab and memcg_data when KFENCE fails to initialize
kfence pool at runtime. It is reporting a "Bad page state" message when
kfence pool is freed to buddy. The checking of whether it is a compound
head page seems unnecessary since we already guarantee this when
allocating kfence pool. Remove the check to simplify the code.
Link: https://lkml.kernel.org/r/20230320030059.20189-1-songmuchun@bytedance.com
Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/kfence/core.c | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c index c3d04753806a..5e4c1abc794f 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -562,10 +562,6 @@ static unsigned long kfence_init_pool(void) if (!i || (i % 2)) continue; - /* Verify we do not have a compound head page. */ - if (WARN_ON(compound_head(&pages[i]) != &pages[i])) - return addr; - __folio_set_slab(slab_folio(slab)); #ifdef CONFIG_MEMCG slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg | @@ -598,12 +594,26 @@ static unsigned long kfence_init_pool(void) /* Protect the right redzone. */ if (unlikely(!kfence_protect(addr + PAGE_SIZE))) - return addr; + goto reset_slab; addr += 2 * PAGE_SIZE; } return 0; + +reset_slab: + for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) { + struct slab *slab = page_slab(&pages[i]); + + if (!i || (i % 2)) + continue; +#ifdef CONFIG_MEMCG + slab->memcg_data = 0; +#endif + __folio_clear_slab(slab_folio(slab)); + } + + return addr; } static bool __init kfence_init_pool_early(void) @@ -633,16 +643,6 @@ static bool __init kfence_init_pool_early(void) * fails for the first page, and therefore expect addr==__kfence_pool in * most failure cases. */ - for (char *p = (char *)addr; p < __kfence_pool + KFENCE_POOL_SIZE; p += PAGE_SIZE) { - struct slab *slab = virt_to_slab(p); - - if (!slab) - continue; -#ifdef CONFIG_MEMCG - slab->memcg_data = 0; -#endif - __folio_clear_slab(slab_folio(slab)); - } memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool)); __kfence_pool = NULL; return false; |