From cc90bc68422318eb8e75b15cd74bc8d538a7df29 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Mon, 9 Dec 2019 20:11:14 +0100 Subject: block: fix "check bi_size overflow before merge" This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06. Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full check to __bio_try_merge_page. This will cause __bio_try_merge_page to fail when the last bi_io_vec has been reached. Instead, what we want here is only the bi_size overflow check. Fixes: e3a5d8e386c3 ("block: check bi_size overflow before merge") Cc: stable@vger.kernel.org # v5.4+ Reviewed-by: Ming Lei Signed-off-by: Andreas Gruenbacher Signed-off-by: Jens Axboe --- block/bio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/bio.c b/block/bio.c index 9d54aa37ce6c..a5d75f6bf4c7 100644 --- a/block/bio.c +++ b/block/bio.c @@ -754,10 +754,12 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) return false; - if (bio->bi_vcnt > 0 && !bio_full(bio, len)) { + if (bio->bi_vcnt > 0) { struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; if (page_is_mergeable(bv, page, len, off, same_page)) { + if (bio->bi_iter.bi_size > UINT_MAX - len) + return false; bv->bv_len += len; bio->bi_iter.bi_size += len; return true; -- cgit v1.2.3 From ecb6186cf78803663cbd7c70241bfe1af439ca03 Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Tue, 10 Dec 2019 11:47:04 -0700 Subject: block: fix NULL pointer dereference in account statistics with IDE The IDE driver creates some passthru requests which never get submitted to the block layer in such a way that blk_account_io_start() gets called. However, the driver still calls __blk_mq_end_request() in ide_end_rq() which will call blk_account_io_completion() which tries to dereferences req->part which is never set. See ide_prep_sense() for an example of where these requests come from. To fix this, blk_account_io_completion() and blk_account_io_done() should do nothing if req->part is not set. The back trace of this bug is: BUG: kernel NULL pointer dereference, address: 000002ac #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page *pde = 00000000 Oops: 0002 [#1] CPU: 0 PID: 237 Comm: kworker/0:1H Not tainted 5.4.0-rc2-00011-g48d9b0d43105e #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Workqueue: kblockd drive_rq_insert_work EIP: blk_account_io_completion+0x7a/0xf0 Code: 89 54 24 08 31 d2 89 4c 24 04 31 c9 c7 04 24 02 00 00 00 c1 ee 09 e8 f5 21 a6 ff e8 70 5c a7 ff 8b 53 60 8d 04 bd 00 00 00 00 <01> b4 02 ac 02 00 00 8b 9a 88 02 00 00 85 db 74 11 85 d2 74 51 8b EAX: 00000000 EBX: f5b80000 ECX: 00000000 EDX: 00000000 ESI: 00000000 EDI: 00000000 EBP: f3031e70 ESP: f3031e54 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010046 CR0: 80050033 CR2: 000002ac CR3: 03c25000 CR4: 000406d0 Call Trace: blk_update_request+0x85/0x420 ide_end_rq+0x38/0xa0 ide_complete_rq+0x3d/0x70 cdrom_newpc_intr+0x258/0xba0 ide_intr+0x135/0x250 __handle_irq_event_percpu+0x3e/0x250 handle_irq_event_percpu+0x1f/0x50 handle_irq_event+0x32/0x60 handle_level_irq+0x6c/0x110 handle_irq+0x72/0xa0 do_IRQ+0x45/0xad common_interrupt+0x115/0x11c Fixes: 48d9b0d43105 ("block: account statistics for passthrough requests") Reported-by: kernel test robot Signed-off-by: Logan Gunthorpe Signed-off-by: Jens Axboe --- block/blk-core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index a1e228752083..68c309ce6735 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1310,7 +1310,7 @@ EXPORT_SYMBOL_GPL(blk_rq_err_bytes); void blk_account_io_completion(struct request *req, unsigned int bytes) { - if (blk_do_io_stat(req)) { + if (req->part && blk_do_io_stat(req)) { const int sgrp = op_stat_group(req_op(req)); struct hd_struct *part; @@ -1328,7 +1328,8 @@ void blk_account_io_done(struct request *req, u64 now) * normal IO on queueing nor completion. Accounting the * containing request is enough. */ - if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) { + if (req->part && blk_do_io_stat(req) && + !(req->rq_flags & RQF_FLUSH_SEQ)) { const int sgrp = op_stat_group(req_op(req)); struct hd_struct *part; -- cgit v1.2.3 From 5addeae1bedc4c126b179f61e43e039bb373581f Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Thu, 12 Dec 2019 16:52:00 +0100 Subject: blk-cgroup: remove blkcg_drain_queue Since blk_drain_queue had already been removed, so this function is not needed anymore. Signed-off-by: Guoqing Jiang Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 20 -------------------- 1 file changed, 20 deletions(-) (limited to 'block') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 708dea92dac8..a229b94d5390 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1061,26 +1061,6 @@ err_unlock: return PTR_ERR(blkg); } -/** - * blkcg_drain_queue - drain blkcg part of request_queue - * @q: request_queue to drain - * - * Called from blk_drain_queue(). Responsible for draining blkcg part. - */ -void blkcg_drain_queue(struct request_queue *q) -{ - lockdep_assert_held(&q->queue_lock); - - /* - * @q could be exiting and already have destroyed all blkgs as - * indicated by NULL root_blkg. If so, don't confuse policies. - */ - if (!q->root_blkg) - return; - - blk_throtl_drain(q); -} - /** * blkcg_exit_queue - exit and release blkcg part of request_queue * @q: request_queue being released -- cgit v1.2.3