| Message ID | 20190730181757.248832-3-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix a race condition triggered by submit_bio() | expand |
> generic_make_request_checks() needs to be protected by a > blk_queue_enter() / blk_queue_exit() pair because it calls > blkcg_bio_issue_check() and because that last function calls > blkg_lookup(). > This patch fixes > https://syzkaller.appspot.com/bug?id=ff9ab4a23afa7553fb79f745a92be87ba4144508. > This patch also fixes the following kernel warning, triggered by > blktests: > WARNING: CPU: 5 PID: 10706 at block/blk-core.c:903 > generic_make_request_checks+0x9c6/0xe60 > RIP: 0010:generic_make_request_checks+0x9c6/0xe60 > Call Trace: > generic_make_request+0x7a/0x5c0 > submit_bio+0x92/0x280 > mpage_readpages+0x2b1/0x300 > blkdev_readpages+0x1d/0x20 > read_pages+0xd9/0x2c0 > __do_page_cache_readahead+0x2e0/0x310 > force_page_cache_readahead+0xfb/0x170 > page_cache_sync_readahead+0x28d/0x2a0 > generic_file_read_iter+0xc13/0x1530 > blkdev_read_iter+0x7d/0x90 > new_sync_read+0x2c5/0x3d0 > __vfs_read+0x7b/0x90 > vfs_read+0xc6/0x1f0 > ksys_read+0xc3/0x160 > __x64_sys_read+0x43/0x50 > do_syscall_64+0x71/0x270 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > Cc: Tejun Heo <tj@kernel.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Ming Lei <ming.lei@redhat.com> > Cc: Hannes Reinecke <hare@suse.com> > Cc: Johannes Thumshirn <jthumshirn@suse.de> > Cc: Alexandru Moise <00moses.alexander00@gmail.com> > Cc: Joseph Qi <joseph.qi@linux.alibaba.com> > Reported-by: syzbot+ff9ab4a23afa7553@syzkaller.appspotmail.com > Signed-off-by: Bart Van Assche <bvanassche@acm.org> > --- > block/blk-core.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > diff --git a/block/blk-core.c b/block/blk-core.c > index ff27c3080348..cd844c54e9f1 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1150,6 +1150,9 @@ EXPORT_SYMBOL_GPL(direct_make_request); > */ > blk_qc_t submit_bio(struct bio *bio) > { > + struct request_queue *q = bio->bi_disk->queue; > + blk_qc_t ret; > + > if (blkcg_punt_bio_submit(bio)) > return BLK_QC_T_NONE; > @@ -1182,7 +1185,15 @@ blk_qc_t submit_bio(struct bio *bio) > } > } > - return generic_make_request(bio); > + if (unlikely(blk_queue_enter(q, 0) < 0)) { > + bio->bi_status = BLK_STS_IOERR; > + bio->bi_end_io(bio); > + return BLK_QC_T_NONE; > + } > + ret = generic_make_request(bio); > + blk_queue_exit(q); > + > + return ret; > } > EXPORT_SYMBOL(submit_bio); > -- > 2.22.0.709.g102302147b-goog I see the command but can't find the corresponding bug. The email is sent to syzbot+HASH@syzkaller.appspotmail.com address but the HASH does not correspond to any known bug. Please double check the address.
On Tue, Jul 30, 2019 at 11:17:57AM -0700, Bart Van Assche wrote: > generic_make_request_checks() needs to be protected by a > blk_queue_enter() / blk_queue_exit() pair because it calls > blkcg_bio_issue_check() and because that last function calls > blkg_lookup(). > > This patch fixes https://syzkaller.appspot.com/bug?id=ff9ab4a23afa7553fb79f745a92be87ba4144508. > > This patch also fixes the following kernel warning, triggered by > blktests: > > WARNING: CPU: 5 PID: 10706 at block/blk-core.c:903 generic_make_request_checks+0x9c6/0xe60 > RIP: 0010:generic_make_request_checks+0x9c6/0xe60 > Call Trace: > generic_make_request+0x7a/0x5c0 > submit_bio+0x92/0x280 > mpage_readpages+0x2b1/0x300 > blkdev_readpages+0x1d/0x20 > read_pages+0xd9/0x2c0 > __do_page_cache_readahead+0x2e0/0x310 > force_page_cache_readahead+0xfb/0x170 > page_cache_sync_readahead+0x28d/0x2a0 > generic_file_read_iter+0xc13/0x1530 > blkdev_read_iter+0x7d/0x90 > new_sync_read+0x2c5/0x3d0 > __vfs_read+0x7b/0x90 > vfs_read+0xc6/0x1f0 > ksys_read+0xc3/0x160 > __x64_sys_read+0x43/0x50 > do_syscall_64+0x71/0x270 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Cc: Tejun Heo <tj@kernel.org> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Ming Lei <ming.lei@redhat.com> > Cc: Hannes Reinecke <hare@suse.com> > Cc: Johannes Thumshirn <jthumshirn@suse.de> > Cc: Alexandru Moise <00moses.alexander00@gmail.com> > Cc: Joseph Qi <joseph.qi@linux.alibaba.com> > Reported-by: syzbot+ff9ab4a23afa7553@syzkaller.appspotmail.com > Signed-off-by: Bart Van Assche <bvanassche@acm.org> > --- > block/blk-core.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index ff27c3080348..cd844c54e9f1 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1150,6 +1150,9 @@ EXPORT_SYMBOL_GPL(direct_make_request); > */ > blk_qc_t submit_bio(struct bio *bio) > { > + struct request_queue *q = bio->bi_disk->queue; > + blk_qc_t ret; > + > if (blkcg_punt_bio_submit(bio)) > return BLK_QC_T_NONE; > > @@ -1182,7 +1185,15 @@ blk_qc_t submit_bio(struct bio *bio) > } > } > > - return generic_make_request(bio); > + if (unlikely(blk_queue_enter(q, 0) < 0)) { > + bio->bi_status = BLK_STS_IOERR; > + bio->bi_end_io(bio); > + return BLK_QC_T_NONE; > + } > + ret = generic_make_request(bio); > + blk_queue_exit(q); No, nested blk_queue_enter() is easy to cause deadlock. Thanks, Ming
> On Tue, Jul 30, 2019 at 11:17:57AM -0700, Bart Van Assche wrote: >> generic_make_request_checks() needs to be protected by a >> blk_queue_enter() / blk_queue_exit() pair because it calls >> blkcg_bio_issue_check() and because that last function calls >> blkg_lookup(). >> This patch fixes >> https://syzkaller.appspot.com/bug?id=ff9ab4a23afa7553fb79f745a92be87ba4144508. >> This patch also fixes the following kernel warning, triggered by >> blktests: >> WARNING: CPU: 5 PID: 10706 at block/blk-core.c:903 >> generic_make_request_checks+0x9c6/0xe60 >> RIP: 0010:generic_make_request_checks+0x9c6/0xe60 >> Call Trace: >> generic_make_request+0x7a/0x5c0 >> submit_bio+0x92/0x280 >> mpage_readpages+0x2b1/0x300 >> blkdev_readpages+0x1d/0x20 >> read_pages+0xd9/0x2c0 >> __do_page_cache_readahead+0x2e0/0x310 >> force_page_cache_readahead+0xfb/0x170 >> page_cache_sync_readahead+0x28d/0x2a0 >> generic_file_read_iter+0xc13/0x1530 >> blkdev_read_iter+0x7d/0x90 >> new_sync_read+0x2c5/0x3d0 >> __vfs_read+0x7b/0x90 >> vfs_read+0xc6/0x1f0 >> ksys_read+0xc3/0x160 >> __x64_sys_read+0x43/0x50 >> do_syscall_64+0x71/0x270 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> Cc: Tejun Heo <tj@kernel.org> >> Cc: Christoph Hellwig <hch@lst.de> >> Cc: Ming Lei <ming.lei@redhat.com> >> Cc: Hannes Reinecke <hare@suse.com> >> Cc: Johannes Thumshirn <jthumshirn@suse.de> >> Cc: Alexandru Moise <00moses.alexander00@gmail.com> >> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> >> Reported-by: syzbot+ff9ab4a23afa7553@syzkaller.appspotmail.com >> Signed-off-by: Bart Van Assche <bvanassche@acm.org> >> --- >> block/blk-core.c | 13 ++++++++++++- >> 1 file changed, 12 insertions(+), 1 deletion(-) >> diff --git a/block/blk-core.c b/block/blk-core.c >> index ff27c3080348..cd844c54e9f1 100644 >> --- a/block/blk-core.c >> +++ b/block/blk-core.c >> @@ -1150,6 +1150,9 @@ EXPORT_SYMBOL_GPL(direct_make_request); >> */ >> blk_qc_t submit_bio(struct bio *bio) >> { >> + struct request_queue *q = bio->bi_disk->queue; >> + blk_qc_t ret; >> + >> if (blkcg_punt_bio_submit(bio)) >> return BLK_QC_T_NONE; >> @@ -1182,7 +1185,15 @@ blk_qc_t submit_bio(struct bio *bio) >> } >> } >> - return generic_make_request(bio); >> + if (unlikely(blk_queue_enter(q, 0) < 0)) { >> + bio->bi_status = BLK_STS_IOERR; >> + bio->bi_end_io(bio); >> + return BLK_QC_T_NONE; >> + } >> + ret = generic_make_request(bio); >> + blk_queue_exit(q); > No, nested blk_queue_enter() is easy to cause deadlock. > Thanks, > Ming I see the command but can't find the corresponding bug. The email is sent to syzbot+HASH@syzkaller.appspotmail.com address but the HASH does not correspond to any known bug. Please double check the address.
diff --git a/block/blk-core.c b/block/blk-core.c index ff27c3080348..cd844c54e9f1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1150,6 +1150,9 @@ EXPORT_SYMBOL_GPL(direct_make_request); */ blk_qc_t submit_bio(struct bio *bio) { + struct request_queue *q = bio->bi_disk->queue; + blk_qc_t ret; + if (blkcg_punt_bio_submit(bio)) return BLK_QC_T_NONE; @@ -1182,7 +1185,15 @@ blk_qc_t submit_bio(struct bio *bio) } } - return generic_make_request(bio); + if (unlikely(blk_queue_enter(q, 0) < 0)) { + bio->bi_status = BLK_STS_IOERR; + bio->bi_end_io(bio); + return BLK_QC_T_NONE; + } + ret = generic_make_request(bio); + blk_queue_exit(q); + + return ret; } EXPORT_SYMBOL(submit_bio);
generic_make_request_checks() needs to be protected by a blk_queue_enter() / blk_queue_exit() pair because it calls blkcg_bio_issue_check() and because that last function calls blkg_lookup(). This patch fixes https://syzkaller.appspot.com/bug?id=ff9ab4a23afa7553fb79f745a92be87ba4144508. This patch also fixes the following kernel warning, triggered by blktests: WARNING: CPU: 5 PID: 10706 at block/blk-core.c:903 generic_make_request_checks+0x9c6/0xe60 RIP: 0010:generic_make_request_checks+0x9c6/0xe60 Call Trace: generic_make_request+0x7a/0x5c0 submit_bio+0x92/0x280 mpage_readpages+0x2b1/0x300 blkdev_readpages+0x1d/0x20 read_pages+0xd9/0x2c0 __do_page_cache_readahead+0x2e0/0x310 force_page_cache_readahead+0xfb/0x170 page_cache_sync_readahead+0x28d/0x2a0 generic_file_read_iter+0xc13/0x1530 blkdev_read_iter+0x7d/0x90 new_sync_read+0x2c5/0x3d0 __vfs_read+0x7b/0x90 vfs_read+0xc6/0x1f0 ksys_read+0xc3/0x160 __x64_sys_read+0x43/0x50 do_syscall_64+0x71/0x270 entry_SYSCALL_64_after_hwframe+0x49/0xbe Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Alexandru Moise <00moses.alexander00@gmail.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Reported-by: syzbot+ff9ab4a23afa7553@syzkaller.appspotmail.com Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- block/blk-core.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)