From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: Block IO issue in kernel-v4.17 To: Chunyu Hu Cc: Kent Overstreet , Li Wang , Coly Li , hch@lst.de, darrick.wong@oracle.com, snitzer@redhat.com, linux-block@vger.kernel.org, linux-kernel References: <20180606084105.GA10720@kmo-pixel> <015f6160-216a-31ba-e251-11336e7ff5d6@kernel.dk> From: Jens Axboe Message-ID: <39e797fa-b24c-d122-c06b-196ba2a2d395@kernel.dk> Date: Thu, 7 Jun 2018 08:46:22 -0600 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 List-ID: On 6/7/18 12:33 AM, Chunyu Hu wrote: > kasan reported a user-after-free. I'm using a kvm machine, it panic > during boot. I'm using the latest linux tree. which contains below. > > commit d377535405686f735b90a8ad4ba269484cd7c96e > Author: Kent Overstreet > Date: Tue Jun 5 05:26:33 2018 -0400 > > dm: Use kzalloc for all structs with embedded biosets/mempools Can you try with the below? Li Wang, would be great if you could too. diff --git a/block/bio.c b/block/bio.c index 595663e0281a..45bdee67d28b 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1967,6 +1967,27 @@ int bioset_init(struct bio_set *bs, } EXPORT_SYMBOL(bioset_init); +void bioset_move(struct bio_set *dst, struct bio_set *src) +{ + dst->bio_slab = src->bio_slab; + dst->front_pad = src->front_pad; + mempool_move(&dst->bio_pool, &src->bio_pool); + mempool_move(&dst->bvec_pool, &src->bvec_pool); +#if defined(CONFIG_BLK_DEV_INTEGRITY) + mempool_move(&dst->bio_integrity_pool, &src->bio_integrity_pool); + mempool_move(&dst->bvec_integrity_pool, &src->bvec_integrity_pool); +#endif + BUG_ON(!bio_list_empty(&src->rescue_list)); + BUG_ON(work_pending(&src->rescue_work)); + spin_lock_init(&dst->rescue_lock); + bio_list_init(&dst->rescue_list); + INIT_WORK(&dst->rescue_work, bio_alloc_rescue); + dst->rescue_workqueue = src->rescue_workqueue; + + memset(src, 0, sizeof(*src)); +} +EXPORT_SYMBOL(bioset_move); + #ifdef CONFIG_BLK_CGROUP /** diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 98dff36b89a3..87f636815baf 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1982,10 +1982,8 @@ static void __bind_mempools(struct mapped_device *md, struct dm_table *t) bioset_initialized(&md->bs) || bioset_initialized(&md->io_bs)); - md->bs = p->bs; - memset(&p->bs, 0, sizeof(p->bs)); - md->io_bs = p->io_bs; - memset(&p->io_bs, 0, sizeof(p->io_bs)); + bioset_move(&md->bs, &p->bs); + bioset_move(&md->io_bs, &p->io_bs); out: /* mempool bind completed, no longer need any mempools in the table */ dm_table_free_md_mempools(t); diff --git a/include/linux/bio.h b/include/linux/bio.h index 810a8bee8f85..7581231dd0a3 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -417,6 +417,7 @@ enum { extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags); extern void bioset_exit(struct bio_set *); extern int biovec_init_pool(mempool_t *pool, int pool_entries); +extern void bioset_move(struct bio_set *dst, struct bio_set *src); extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *); extern void bio_put(struct bio *); diff --git a/include/linux/mempool.h b/include/linux/mempool.h index 0c964ac107c2..20818919180c 100644 --- a/include/linux/mempool.h +++ b/include/linux/mempool.h @@ -47,6 +47,7 @@ extern int mempool_resize(mempool_t *pool, int new_min_nr); extern void mempool_destroy(mempool_t *pool); extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc; extern void mempool_free(void *element, mempool_t *pool); +extern void mempool_move(mempool_t *dst, mempool_t *src); /* * A mempool_alloc_t and mempool_free_t that get the memory from diff --git a/mm/mempool.c b/mm/mempool.c index b54f2c20e5e0..dd402653367b 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -181,6 +181,8 @@ int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn, mempool_free_t *free_fn, void *pool_data, gfp_t gfp_mask, int node_id) { + memset(pool, 0, sizeof(*pool)); + spin_lock_init(&pool->lock); pool->min_nr = min_nr; pool->pool_data = pool_data; @@ -546,3 +548,19 @@ void mempool_free_pages(void *element, void *pool_data) __free_pages(element, order); } EXPORT_SYMBOL(mempool_free_pages); + +void mempool_move(mempool_t *dst, mempool_t *src) +{ + BUG_ON(waitqueue_active(&src->wait)); + + spin_lock_init(&dst->lock); + dst->min_nr = src->min_nr; + dst->curr_nr = src->curr_nr; + memcpy(dst->elements, src->elements, sizeof(void *) * src->curr_nr); + dst->pool_data = src->pool_data; + dst->alloc = src->alloc; + dst->free = src->free; + init_waitqueue_head(&dst->wait); + + memset(src, 0, sizeof(*src)); +} -- Jens Axboe