From: Changhui Zhong <czhong@redhat.com>
To: Yu Kuai <yukuai1@huaweicloud.com>
Cc: Ming Lei <ming.lei@redhat.com>,
linux-block@vger.kernel.org, "yukuai (C)" <yukuai3@huawei.com>
Subject: Re: [bug report] BUG: kernel NULL pointer dereference, address: 00000000000000fc
Date: Wed, 26 Apr 2023 14:20:56 +0800 [thread overview]
Message-ID: <CAGVVp+W9SnHaEyi7o2Pkh6XEJsWL1E7W7esHvyXfXed8DFjt8g@mail.gmail.com> (raw)
In-Reply-To: <f5d3b05b-33a6-818f-6476-c3993f9d4e87@huaweicloud.com>
On Wed, Apr 26, 2023 at 2:06 PM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> Hi,
>
> 在 2023/04/26 13:56, Changhui Zhong 写道:
> > On Tue, Apr 25, 2023 at 11:27 AM Ming Lei <ming.lei@redhat.com> wrote:
> >>
> >> On Tue, Apr 25, 2023 at 10:37:05AM +0800, Changhui Zhong wrote:
> >>> Hello,
> >>>
> >>> Below issue was triggered in my test,it caused system panic ,please
> >>> help check it.
> >>> branch: for-6.4/block
> >>> https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
> >>>
> >>> mdadm -CR /dev/md0 -l 1 -n 2 /dev/sda /dev/sdb -e 1.0
> >>> sgdisk -n 0:0:+100MiB /dev/md0
> >>> cat /proc/partitions
> >>> mdadm -S /dev/md0
> >>> mdadm -A /dev/md0 /dev/sda /dev/sdb
> >>> cat /proc/partitions
> >>>
> >>>
> >>> [ 34.219123] BUG: kernel NULL pointer dereference, address: 00000000000000fc
> >>> [ 34.219507] #PF: supervisor read access in kernel mode
> >>> [ 34.219784] #PF: error_code(0x0000) - not-present page
> >>> [ 34.220039] PGD 0 P4D 0
> >>> [ 34.220176] Oops: 0000 [#1] PREEMPT SMP PTI
> >>> [ 34.220374] CPU: 8 PID: 1956 Comm: systemd-udevd Kdump: loaded Not
> >>> tainted 6.3.0-rc2+ #1
> >>> [ 34.220787] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360
> >>> Gen9, BIOS P89 05/21/2018
> >>> [ 34.221188] RIP: 0010:blk_mq_sched_bio_merge+0x6d/0xf0
> >>
> >> Hi Changhui,
> >>
> >> Please try the following fix:
> >>
> >> diff --git a/block/bdev.c b/block/bdev.c
> >> index 850852fe4b78..fa2838ca2e6d 100644
> >> --- a/block/bdev.c
> >> +++ b/block/bdev.c
> >> @@ -419,7 +419,11 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
> >> bdev->bd_inode = inode;
> >> bdev->bd_queue = disk->queue;
> >> bdev->bd_stats = alloc_percpu(struct disk_stats);
> >> - bdev->bd_has_submit_bio = false;
> >> +
> >> + if (partno)
> >> + bdev->bd_has_submit_bio = disk->part0->bd_has_submit_bio;
> >> + else
> >> + bdev->bd_has_submit_bio = false;
> >> if (!bdev->bd_stats) {
> >> iput(inode);
> >> return NULL;
> >>
> >> Fixes: 9f4107b07b17 ("block: store bdev->bd_disk->fops->submit_bio state in bdev")
> >>
> >
> > Hi,Ming
> >
> > I retest the latest updated branch for-6.4/block
> > (https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/log/?h=for-6.4/block),
> > which contain your fix patch "block: sync part's ->bd_has_submit_bio
> > with disk's".
> > the kernel panic no longer happen, but the test will failed, the
> > system will reread partition table on exclusively open device,
>
> Is this patch in the branch for-6.4/block?
>
> 3723091ea188 ("block: don't set GD_NEED_PART_SCAN if scan partition failed")
> >
Hi, Yu Kuai
this patch was not found in the for-6.4/block branch, and found it
exist in the master branch
> > :: [ 01:50:05 ] :: [ BEGIN ] :: Running 'mdadm -S /dev/md0'
> > mdadm: stopped /dev/md0
> > :: [ 01:50:06 ] :: [ PASS ] :: Command 'mdadm -S /dev/md0'
> > (Expected 0, got 0)
> > :: [ 01:50:06 ] :: [ BEGIN ] :: Running 'mdadm -A /dev/md0
> > /dev/"$dev0" /dev/"$dev1"'
> > mdadm: /dev/md0 has been started with 2 drives.
> > :: [ 01:50:06 ] :: [ PASS ] :: Command 'mdadm -A /dev/md0
> > /dev/"$dev0" /dev/"$dev1"' (Expected 0, got 0)
> > :: [ 01:50:09 ] :: [ BEGIN ] :: Running 'lsblk'
> > NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
> > sda 8:0 1 447.1G 0 disk
> > ├─sda1 8:1 1 1G 0 part /boot
> > └─sda2 8:2 1 446.1G 0 part
> > ├─rhel_storageqe--104-root 253:0 0 70G 0 lvm /
> > ├─rhel_storageqe--104-swap 253:1 0 7.7G 0 lvm [SWAP]
> > └─rhel_storageqe--104-home 253:2 0 368.4G 0 lvm /home
> > sdb 8:16 1 447.1G 0 disk
> > ├─sdb1 8:17 1 100M 0 part
> > └─md0 9:0 0 447.1G 0 raid1
> > └─md0p1 259:0 0 100M 0 part
> > sdc 8:32 1 447.1G 0 disk
> > ├─sdc1 8:33 1 100M 0 part
> > └─md0 9:0 0 447.1G 0 raid1
> > └─md0p1 259:0 0 100M 0 part
> > sdd 8:48 1 447.1G 0 disk
> > :: [ 01:50:09 ] :: [ PASS ] :: Command 'lsblk' (Expected 0, got 0)
> > :: [ 01:50:09 ] :: [ BEGIN ] :: Running 'cat /proc/partitions'
> > major minor #blocks name
> >
> > 8 0 468851544 sda
> > 8 1 1048576 sda1
> > 8 2 467801088 sda2
> > 8 48 468851544 sdd
> > 8 32 468851544 sdc
> > 8 33 102400 sdc1
> > 8 16 468851544 sdb
> > 8 17 102400 sdb1
> > 253 0 73400320 dm-0
> > 253 1 8060928 dm-1
> > 253 2 386338816 dm-2
> > 9 0 468851392 md0
> > 259 0 102400 md0p1
> >
> > Thanks，
> >
> > .
> >
>
next prev parent reply other threads:[~2023-04-26 6:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-25 2:37 [bug report] BUG: kernel NULL pointer dereference, address: 00000000000000fc Changhui Zhong
2023-04-25 3:27 ` Ming Lei
2023-04-26 5:56 ` Changhui Zhong
2023-04-26 6:05 ` Yu Kuai
2023-04-26 6:20 ` Changhui Zhong [this message]
2023-04-26 6:24 ` Yu Kuai
2023-04-26 6:32 ` Changhui Zhong
2023-04-26 8:38 ` Changhui Zhong
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