Message ID | 20210728145655.274476-1-wanghai38@huawei.com (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | [v2] mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook() | expand |
On Wed, Jul 28, 2021 at 7:57 AM Wang Hai <wanghai38@huawei.com> wrote: > > When I use kfree_rcu() to free a large memory allocated by > kmalloc_node(), the following dump occurs. > > BUG: kernel NULL pointer dereference, address: 0000000000000020 > [...] > Oops: 0000 [#1] SMP > [...] > Workqueue: events kfree_rcu_work > RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] > RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] > RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 > [...] > Call Trace: > kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 > kfree_bulk include/linux/slab.h:413 [inline] > kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 > process_one_work+0x207/0x530 kernel/workqueue.c:2276 > worker_thread+0x320/0x610 kernel/workqueue.c:2422 > kthread+0x13d/0x160 kernel/kthread.c:313 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > When kmalloc_node() a large memory, page is allocated, not slab, > so when freeing memory via kfree_rcu(), this large memory should not > be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is > is used for slab. > > Using page_objcgs_check() instead of page_objcgs() in > memcg_slab_free_hook() to fix this bug. > > Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") > Signed-off-by: Wang Hai <wanghai38@huawei.com> Reviewed-by: Shakeel Butt <shakeelb@google.com>
On Wed 28-07-21 22:56:55, Wang Hai wrote: > When I use kfree_rcu() to free a large memory allocated by > kmalloc_node(), the following dump occurs. > > BUG: kernel NULL pointer dereference, address: 0000000000000020 > [...] > Oops: 0000 [#1] SMP > [...] > Workqueue: events kfree_rcu_work > RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] > RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] > RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 > [...] > Call Trace: > kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 > kfree_bulk include/linux/slab.h:413 [inline] > kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 > process_one_work+0x207/0x530 kernel/workqueue.c:2276 > worker_thread+0x320/0x610 kernel/workqueue.c:2422 > kthread+0x13d/0x160 kernel/kthread.c:313 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > When kmalloc_node() a large memory, page is allocated, not slab, > so when freeing memory via kfree_rcu(), this large memory should not > be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is > is used for slab. > > Using page_objcgs_check() instead of page_objcgs() in > memcg_slab_free_hook() to fix this bug. > > Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") > Signed-off-by: Wang Hai <wanghai38@huawei.com> This looks like a much better fix. Thanks! Acked-by: Michal Hocko <mhocko@suse.com> > --- > v1->v2: Use page_objcgs_check() to fix this bug > mm/slab.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/slab.h b/mm/slab.h > index 67e06637ff2e..59db4797acd4 100644 > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -339,7 +339,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, > continue; > > page = virt_to_head_page(p[i]); > - objcgs = page_objcgs(page); > + objcgs = page_objcgs_check(page); > if (!objcgs) > continue; > > -- > 2.17.1
On Wed, Jul 28, 2021 at 06:44:03PM +0200, Michal Hocko wrote: > On Wed 28-07-21 22:56:55, Wang Hai wrote: > > When I use kfree_rcu() to free a large memory allocated by > > kmalloc_node(), the following dump occurs. > > > > BUG: kernel NULL pointer dereference, address: 0000000000000020 > > [...] > > Oops: 0000 [#1] SMP > > [...] > > Workqueue: events kfree_rcu_work > > RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] > > RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] > > RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 > > [...] > > Call Trace: > > kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 > > kfree_bulk include/linux/slab.h:413 [inline] > > kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 > > process_one_work+0x207/0x530 kernel/workqueue.c:2276 > > worker_thread+0x320/0x610 kernel/workqueue.c:2422 > > kthread+0x13d/0x160 kernel/kthread.c:313 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > > > When kmalloc_node() a large memory, page is allocated, not slab, > > so when freeing memory via kfree_rcu(), this large memory should not > > be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is > > is used for slab. > > > > Using page_objcgs_check() instead of page_objcgs() in > > memcg_slab_free_hook() to fix this bug. > > > > Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") > > Signed-off-by: Wang Hai <wanghai38@huawei.com> > > This looks like a much better fix. Thanks! +1 Acked-by: Roman Gushchin <guro@fb.com> Thank you, Wang!
On Wed, Jul 28, 2021 at 10:57 PM Wang Hai <wanghai38@huawei.com> wrote: > > When I use kfree_rcu() to free a large memory allocated by > kmalloc_node(), the following dump occurs. > > BUG: kernel NULL pointer dereference, address: 0000000000000020 > [...] > Oops: 0000 [#1] SMP > [...] > Workqueue: events kfree_rcu_work > RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] > RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] > RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 > [...] > Call Trace: > kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 > kfree_bulk include/linux/slab.h:413 [inline] > kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 > process_one_work+0x207/0x530 kernel/workqueue.c:2276 > worker_thread+0x320/0x610 kernel/workqueue.c:2422 > kthread+0x13d/0x160 kernel/kthread.c:313 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > When kmalloc_node() a large memory, page is allocated, not slab, > so when freeing memory via kfree_rcu(), this large memory should not > be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is > is used for slab. > > Using page_objcgs_check() instead of page_objcgs() in > memcg_slab_free_hook() to fix this bug. > > Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") > Signed-off-by: Wang Hai <wanghai38@huawei.com> More simpler than v1. Thanks. Reviewed-by: Muchun Song <songmuchun@bytedance.com>
On 2021/7/28 22:56, Wang Hai wrote: > When I use kfree_rcu() to free a large memory allocated by > kmalloc_node(), the following dump occurs. > > BUG: kernel NULL pointer dereference, address: 0000000000000020 > [...] > Oops: 0000 [#1] SMP > [...] > Workqueue: events kfree_rcu_work > RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] > RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] > RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 > [...] > Call Trace: > kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 > kfree_bulk include/linux/slab.h:413 [inline] > kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 > process_one_work+0x207/0x530 kernel/workqueue.c:2276 > worker_thread+0x320/0x610 kernel/workqueue.c:2422 > kthread+0x13d/0x160 kernel/kthread.c:313 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > When kmalloc_node() a large memory, page is allocated, not slab, > so when freeing memory via kfree_rcu(), this large memory should not > be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is > is used for slab. > > Using page_objcgs_check() instead of page_objcgs() in > memcg_slab_free_hook() to fix this bug. > > Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") > Signed-off-by: Wang Hai <wanghai38@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > v1->v2: Use page_objcgs_check() to fix this bug > mm/slab.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/slab.h b/mm/slab.h > index 67e06637ff2e..59db4797acd4 100644 > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -339,7 +339,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, > continue; > > page = virt_to_head_page(p[i]); > - objcgs = page_objcgs(page); > + objcgs = page_objcgs_check(page); > if (!objcgs) > continue; >
diff --git a/mm/slab.h b/mm/slab.h index 67e06637ff2e..59db4797acd4 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -339,7 +339,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, continue; page = virt_to_head_page(p[i]); - objcgs = page_objcgs(page); + objcgs = page_objcgs_check(page); if (!objcgs) continue;
When I use kfree_rcu() to free a large memory allocated by kmalloc_node(), the following dump occurs. BUG: kernel NULL pointer dereference, address: 0000000000000020 [...] Oops: 0000 [#1] SMP [...] Workqueue: events kfree_rcu_work RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 [...] Call Trace: kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 kfree_bulk include/linux/slab.h:413 [inline] kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 process_one_work+0x207/0x530 kernel/workqueue.c:2276 worker_thread+0x320/0x610 kernel/workqueue.c:2422 kthread+0x13d/0x160 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 When kmalloc_node() a large memory, page is allocated, not slab, so when freeing memory via kfree_rcu(), this large memory should not be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is is used for slab. Using page_objcgs_check() instead of page_objcgs() in memcg_slab_free_hook() to fix this bug. Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") Signed-off-by: Wang Hai <wanghai38@huawei.com> --- v1->v2: Use page_objcgs_check() to fix this bug mm/slab.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)