<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/block, branch v6.0.7</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drbd: only clone bio if we have a backing device</title>
<updated>2022-10-29T08:08:35+00:00</updated>
<author>
<name>Christoph Böhmwalder</name>
<email>christoph.boehmwalder@linbit.com</email>
</author>
<published>2022-10-20T08:52:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=05580a3bbf3cec677cb00a85dfeb21d6a9b48eaf'/>
<id>05580a3bbf3cec677cb00a85dfeb21d6a9b48eaf</id>
<content type='text'>
[ Upstream commit 6d42ddf7f27b6723549ee6d4c8b1b418b59bf6b5 ]

Commit c347a787e34cb (drbd: set -&gt;bi_bdev in drbd_req_new) moved a
bio_set_dev call (which has since been removed) to "earlier", from
drbd_request_prepare to drbd_req_new.

The problem is that this accesses device-&gt;ldev-&gt;backing_bdev, which is
not NULL-checked at this point. When we don't have an ldev (i.e. when
the DRBD device is diskless), this leads to a null pointer deref.

So, only allocate the private_bio if we actually have a disk. This is
also a small optimization, since we don't clone the bio to only to
immediately free it again in the diskless case.

Fixes: c347a787e34cb ("drbd: set -&gt;bi_bdev in drbd_req_new")
Co-developed-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt;
Signed-off-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt;
Co-developed-by: Joel Colledge &lt;joel.colledge@linbit.com&gt;
Signed-off-by: Joel Colledge &lt;joel.colledge@linbit.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20221020085205.129090-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6d42ddf7f27b6723549ee6d4c8b1b418b59bf6b5 ]

Commit c347a787e34cb (drbd: set -&gt;bi_bdev in drbd_req_new) moved a
bio_set_dev call (which has since been removed) to "earlier", from
drbd_request_prepare to drbd_req_new.

The problem is that this accesses device-&gt;ldev-&gt;backing_bdev, which is
not NULL-checked at this point. When we don't have an ldev (i.e. when
the DRBD device is diskless), this leads to a null pointer deref.

So, only allocate the private_bio if we actually have a disk. This is
also a small optimization, since we don't clone the bio to only to
immediately free it again in the diskless case.

Fixes: c347a787e34cb ("drbd: set -&gt;bi_bdev in drbd_req_new")
Co-developed-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt;
Signed-off-by: Christoph Böhmwalder &lt;christoph.boehmwalder@linbit.com&gt;
Co-developed-by: Joel Colledge &lt;joel.colledge@linbit.com&gt;
Signed-off-by: Joel Colledge &lt;joel.colledge@linbit.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20221020085205.129090-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nbd: Fix hung when signal interrupts nbd_start_device_ioctl()</title>
<updated>2022-10-21T10:39:21+00:00</updated>
<author>
<name>Shigeru Yoshida</name>
<email>syoshida@redhat.com</email>
</author>
<published>2022-09-07T16:35:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=35fb7d4a53d9e36d1b91161ea9870d9c6d57dccf'/>
<id>35fb7d4a53d9e36d1b91161ea9870d9c6d57dccf</id>
<content type='text'>
[ Upstream commit 1de7c3cf48fc41cd95adb12bd1ea9033a917798a ]

syzbot reported hung task [1].  The following program is a simplified
version of the reproducer:

int main(void)
{
	int sv[2], fd;

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) &lt; 0)
		return 1;
	if ((fd = open("/dev/nbd0", 0)) &lt; 0)
		return 1;
	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, 0x81) &lt; 0)
		return 1;
	if (ioctl(fd, NBD_SET_SOCK, sv[0]) &lt; 0)
		return 1;
	if (ioctl(fd, NBD_DO_IT) &lt; 0)
		return 1;
	return 0;
}

When signal interrupt nbd_start_device_ioctl() waiting the condition
atomic_read(&amp;config-&gt;recv_threads) == 0, the task can hung because it
waits the completion of the inflight IOs.

This patch fixes the issue by clearing queue, not just shutdown, when
signal interrupt nbd_start_device_ioctl().

Link: https://syzkaller.appspot.com/bug?id=7d89a3ffacd2b83fdd39549bc4d8e0a89ef21239 [1]
Reported-by: syzbot+38e6c55d4969a14c1534@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida &lt;syoshida@redhat.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Link: https://lore.kernel.org/r/20220907163502.577561-1-syoshida@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1de7c3cf48fc41cd95adb12bd1ea9033a917798a ]

syzbot reported hung task [1].  The following program is a simplified
version of the reproducer:

int main(void)
{
	int sv[2], fd;

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) &lt; 0)
		return 1;
	if ((fd = open("/dev/nbd0", 0)) &lt; 0)
		return 1;
	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, 0x81) &lt; 0)
		return 1;
	if (ioctl(fd, NBD_SET_SOCK, sv[0]) &lt; 0)
		return 1;
	if (ioctl(fd, NBD_DO_IT) &lt; 0)
		return 1;
	return 0;
}

When signal interrupt nbd_start_device_ioctl() waiting the condition
atomic_read(&amp;config-&gt;recv_threads) == 0, the task can hung because it
waits the completion of the inflight IOs.

This patch fixes the issue by clearing queue, not just shutdown, when
signal interrupt nbd_start_device_ioctl().

Link: https://syzkaller.appspot.com/bug?id=7d89a3ffacd2b83fdd39549bc4d8e0a89ef21239 [1]
Reported-by: syzbot+38e6c55d4969a14c1534@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida &lt;syoshida@redhat.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Link: https://lore.kernel.org/r/20220907163502.577561-1-syoshida@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>virtio-blk: Fix WARN_ON_ONCE in virtio_queue_rq()</title>
<updated>2022-09-27T22:30:49+00:00</updated>
<author>
<name>Suwan Kim</name>
<email>suwan.kim027@gmail.com</email>
</author>
<published>2022-08-30T15:01:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=37fafe6b61e4f15d977982635bb785f4e605f7cd'/>
<id>37fafe6b61e4f15d977982635bb785f4e605f7cd</id>
<content type='text'>
If a request fails at virtio_queue_rqs(), it is inserted to requeue_list
and passed to virtio_queue_rq(). Then blk_mq_start_request() can be called
again at virtio_queue_rq() and trigger WARN_ON_ONCE like below trace because
request state was already set to MQ_RQ_IN_FLIGHT in virtio_queue_rqs()
despite the failure.

[    1.890468] ------------[ cut here ]------------
[    1.890776] WARNING: CPU: 2 PID: 122 at block/blk-mq.c:1143
blk_mq_start_request+0x8a/0xe0
[    1.891045] Modules linked in:
[    1.891250] CPU: 2 PID: 122 Comm: journal-offline Not tainted 5.19.0+ #44
[    1.891504] Hardware name: ChromiumOS crosvm, BIOS 0
[    1.891739] RIP: 0010:blk_mq_start_request+0x8a/0xe0
[    1.891961] Code: 12 80 74 22 48 8b 4b 10 8b 89 64 01 00 00 8b 53
20 83 fa ff 75 08 ba 00 00 00 80 0b 53 24 c1 e1 10 09 d1 89 48 34 5b
41 5e c3 &lt;0f&gt; 0b eb b8 65 8b 05 2b 39 b6 7e 89 c0 48 0f a3 05 39 77 5b
01 0f
[    1.892443] RSP: 0018:ffffc900002777b0 EFLAGS: 00010202
[    1.892673] RAX: 0000000000000000 RBX: ffff888004bc0000 RCX: 0000000000000000
[    1.892952] RDX: 0000000000000000 RSI: ffff888003d7c200 RDI: ffff888004bc0000
[    1.893228] RBP: 0000000000000000 R08: 0000000000000001 R09: ffff888004bc0100
[    1.893506] R10: ffffffffffffffff R11: ffffffff8185ca10 R12: ffff888004bc0000
[    1.893797] R13: ffffc90000277900 R14: ffff888004ab2340 R15: ffff888003d86e00
[    1.894060] FS:  00007ffa143a4640(0000) GS:ffff88807dd00000(0000)
knlGS:0000000000000000
[    1.894412] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.894682] CR2: 00005648577d9088 CR3: 00000000053da004 CR4: 0000000000170ee0
[    1.894953] Call Trace:
[    1.895139]  &lt;TASK&gt;
[    1.895303]  virtblk_prep_rq+0x1e5/0x280
[    1.895509]  virtio_queue_rq+0x5c/0x310
[    1.895710]  ? virtqueue_add_sgs+0x95/0xb0
[    1.895905]  ? _raw_spin_unlock_irqrestore+0x16/0x30
[    1.896133]  ? virtio_queue_rqs+0x340/0x390
[    1.896453]  ? sbitmap_get+0xfa/0x220
[    1.896678]  __blk_mq_issue_directly+0x41/0x180
[    1.896906]  blk_mq_plug_issue_direct+0xd8/0x2c0
[    1.897115]  blk_mq_flush_plug_list+0x115/0x180
[    1.897342]  blk_add_rq_to_plug+0x51/0x130
[    1.897543]  blk_mq_submit_bio+0x3a1/0x570
[    1.897750]  submit_bio_noacct_nocheck+0x418/0x520
[    1.897985]  ? submit_bio_noacct+0x1e/0x260
[    1.897989]  ext4_bio_write_page+0x222/0x420
[    1.898000]  mpage_process_page_bufs+0x178/0x1c0
[    1.899451]  mpage_prepare_extent_to_map+0x2d2/0x440
[    1.899603]  ext4_writepages+0x495/0x1020
[    1.899733]  do_writepages+0xcb/0x220
[    1.899871]  ? __seccomp_filter+0x171/0x7e0
[    1.900006]  file_write_and_wait_range+0xcd/0xf0
[    1.900167]  ext4_sync_file+0x72/0x320
[    1.900308]  __x64_sys_fsync+0x66/0xa0
[    1.900449]  do_syscall_64+0x31/0x50
[    1.900595]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[    1.900747] RIP: 0033:0x7ffa16ec96ea
[    1.900883] Code: b8 4a 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3
48 83 ec 18 89 7c 24 0c e8 e3 02 f8 ff 8b 7c 24 0c 89 c2 b8 4a 00 00
00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 43 03 f8 ff 8b
44 24
[    1.901302] RSP: 002b:00007ffa143a3ac0 EFLAGS: 00000293 ORIG_RAX:
000000000000004a
[    1.901499] RAX: ffffffffffffffda RBX: 0000560277ec6fe0 RCX: 00007ffa16ec96ea
[    1.901696] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000016
[    1.901884] RBP: 0000560277ec5910 R08: 0000000000000000 R09: 00007ffa143a4640
[    1.902082] R10: 00007ffa16e4d39e R11: 0000000000000293 R12: 00005602773f59e0
[    1.902459] R13: 0000000000000000 R14: 00007fffbfc007ff R15: 00007ffa13ba4000
[    1.902763]  &lt;/TASK&gt;
[    1.902877] ---[ end trace 0000000000000000 ]---

To avoid calling blk_mq_start_request() twice, This patch moves the
execution of blk_mq_start_request() to the end of virtblk_prep_rq().
And instead of requeuing failed request to plug list in the error path of
virtblk_add_req_batch(), it uses blk_mq_requeue_request() to change failed
request state to MQ_RQ_IDLE. Then virtblk can safely handle the request
on the next trial.

Fixes: 0e9911fa768f ("virtio-blk: support mq_ops-&gt;queue_rqs()")
Reported-by: Alexandre Courbot &lt;acourbot@chromium.org&gt;
Tested-by: Alexandre Courbot &lt;acourbot@chromium.org&gt;
Signed-off-by: Suwan Kim &lt;suwan.kim027@gmail.com&gt;
Message-Id: &lt;20220830150153.12627-1-suwan.kim027@gmail.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Acked-by: Stefan Hajnoczi &lt;stefanha@redhat.com&gt;
Reviewed-by: Pankaj Raghav &lt;p.raghav@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If a request fails at virtio_queue_rqs(), it is inserted to requeue_list
and passed to virtio_queue_rq(). Then blk_mq_start_request() can be called
again at virtio_queue_rq() and trigger WARN_ON_ONCE like below trace because
request state was already set to MQ_RQ_IN_FLIGHT in virtio_queue_rqs()
despite the failure.

[    1.890468] ------------[ cut here ]------------
[    1.890776] WARNING: CPU: 2 PID: 122 at block/blk-mq.c:1143
blk_mq_start_request+0x8a/0xe0
[    1.891045] Modules linked in:
[    1.891250] CPU: 2 PID: 122 Comm: journal-offline Not tainted 5.19.0+ #44
[    1.891504] Hardware name: ChromiumOS crosvm, BIOS 0
[    1.891739] RIP: 0010:blk_mq_start_request+0x8a/0xe0
[    1.891961] Code: 12 80 74 22 48 8b 4b 10 8b 89 64 01 00 00 8b 53
20 83 fa ff 75 08 ba 00 00 00 80 0b 53 24 c1 e1 10 09 d1 89 48 34 5b
41 5e c3 &lt;0f&gt; 0b eb b8 65 8b 05 2b 39 b6 7e 89 c0 48 0f a3 05 39 77 5b
01 0f
[    1.892443] RSP: 0018:ffffc900002777b0 EFLAGS: 00010202
[    1.892673] RAX: 0000000000000000 RBX: ffff888004bc0000 RCX: 0000000000000000
[    1.892952] RDX: 0000000000000000 RSI: ffff888003d7c200 RDI: ffff888004bc0000
[    1.893228] RBP: 0000000000000000 R08: 0000000000000001 R09: ffff888004bc0100
[    1.893506] R10: ffffffffffffffff R11: ffffffff8185ca10 R12: ffff888004bc0000
[    1.893797] R13: ffffc90000277900 R14: ffff888004ab2340 R15: ffff888003d86e00
[    1.894060] FS:  00007ffa143a4640(0000) GS:ffff88807dd00000(0000)
knlGS:0000000000000000
[    1.894412] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.894682] CR2: 00005648577d9088 CR3: 00000000053da004 CR4: 0000000000170ee0
[    1.894953] Call Trace:
[    1.895139]  &lt;TASK&gt;
[    1.895303]  virtblk_prep_rq+0x1e5/0x280
[    1.895509]  virtio_queue_rq+0x5c/0x310
[    1.895710]  ? virtqueue_add_sgs+0x95/0xb0
[    1.895905]  ? _raw_spin_unlock_irqrestore+0x16/0x30
[    1.896133]  ? virtio_queue_rqs+0x340/0x390
[    1.896453]  ? sbitmap_get+0xfa/0x220
[    1.896678]  __blk_mq_issue_directly+0x41/0x180
[    1.896906]  blk_mq_plug_issue_direct+0xd8/0x2c0
[    1.897115]  blk_mq_flush_plug_list+0x115/0x180
[    1.897342]  blk_add_rq_to_plug+0x51/0x130
[    1.897543]  blk_mq_submit_bio+0x3a1/0x570
[    1.897750]  submit_bio_noacct_nocheck+0x418/0x520
[    1.897985]  ? submit_bio_noacct+0x1e/0x260
[    1.897989]  ext4_bio_write_page+0x222/0x420
[    1.898000]  mpage_process_page_bufs+0x178/0x1c0
[    1.899451]  mpage_prepare_extent_to_map+0x2d2/0x440
[    1.899603]  ext4_writepages+0x495/0x1020
[    1.899733]  do_writepages+0xcb/0x220
[    1.899871]  ? __seccomp_filter+0x171/0x7e0
[    1.900006]  file_write_and_wait_range+0xcd/0xf0
[    1.900167]  ext4_sync_file+0x72/0x320
[    1.900308]  __x64_sys_fsync+0x66/0xa0
[    1.900449]  do_syscall_64+0x31/0x50
[    1.900595]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[    1.900747] RIP: 0033:0x7ffa16ec96ea
[    1.900883] Code: b8 4a 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3
48 83 ec 18 89 7c 24 0c e8 e3 02 f8 ff 8b 7c 24 0c 89 c2 b8 4a 00 00
00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 43 03 f8 ff 8b
44 24
[    1.901302] RSP: 002b:00007ffa143a3ac0 EFLAGS: 00000293 ORIG_RAX:
000000000000004a
[    1.901499] RAX: ffffffffffffffda RBX: 0000560277ec6fe0 RCX: 00007ffa16ec96ea
[    1.901696] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000016
[    1.901884] RBP: 0000560277ec5910 R08: 0000000000000000 R09: 00007ffa143a4640
[    1.902082] R10: 00007ffa16e4d39e R11: 0000000000000293 R12: 00005602773f59e0
[    1.902459] R13: 0000000000000000 R14: 00007fffbfc007ff R15: 00007ffa13ba4000
[    1.902763]  &lt;/TASK&gt;
[    1.902877] ---[ end trace 0000000000000000 ]---

To avoid calling blk_mq_start_request() twice, This patch moves the
execution of blk_mq_start_request() to the end of virtblk_prep_rq().
And instead of requeuing failed request to plug list in the error path of
virtblk_add_req_batch(), it uses blk_mq_requeue_request() to change failed
request state to MQ_RQ_IDLE. Then virtblk can safely handle the request
on the next trial.

Fixes: 0e9911fa768f ("virtio-blk: support mq_ops-&gt;queue_rqs()")
Reported-by: Alexandre Courbot &lt;acourbot@chromium.org&gt;
Tested-by: Alexandre Courbot &lt;acourbot@chromium.org&gt;
Signed-off-by: Suwan Kim &lt;suwan.kim027@gmail.com&gt;
Message-Id: &lt;20220830150153.12627-1-suwan.kim027@gmail.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Acked-by: Stefan Hajnoczi &lt;stefanha@redhat.com&gt;
Reviewed-by: Pankaj Raghav &lt;p.raghav@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-6.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip</title>
<updated>2022-09-03T20:23:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-09-03T20:23:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=65eea2c060aee3bf6d27ea365360059fbd4eeff4'/>
<id>65eea2c060aee3bf6d27ea365360059fbd4eeff4</id>
<content type='text'>
Pull xen fixes from Juergen Gross:

 - a minor fix for the Xen grant driver

 - a small series fixing a recently introduced problem in the Xen
   blkfront/blkback drivers with negotiation of feature usage

* tag 'for-linus-6.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/grants: prevent integer overflow in gnttab_dma_alloc_pages()
  xen-blkfront: Cache feature_persistent value before advertisement
  xen-blkfront: Advertise feature-persistent as user requested
  xen-blkback: Advertise feature-persistent as user requested
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull xen fixes from Juergen Gross:

 - a minor fix for the Xen grant driver

 - a small series fixing a recently introduced problem in the Xen
   blkfront/blkback drivers with negotiation of feature usage

* tag 'for-linus-6.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/grants: prevent integer overflow in gnttab_dma_alloc_pages()
  xen-blkfront: Cache feature_persistent value before advertisement
  xen-blkfront: Advertise feature-persistent as user requested
  xen-blkback: Advertise feature-persistent as user requested
</pre>
</div>
</content>
</entry>
<entry>
<title>xen-blkfront: Cache feature_persistent value before advertisement</title>
<updated>2022-09-02T09:05:15+00:00</updated>
<author>
<name>SeongJae Park</name>
<email>sj@kernel.org</email>
</author>
<published>2022-08-31T16:58:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fe8f65b018effbf473f53af3538d0c1878b8b329'/>
<id>fe8f65b018effbf473f53af3538d0c1878b8b329</id>
<content type='text'>
Xen blkfront advertises its support of the persistent grants feature
when it first setting up and when resuming in 'talk_to_blkback()'.
Then, blkback reads the advertised value when it connects with blkfront
and decides if it will use the persistent grants feature or not, and
advertises its decision to blkfront.  Blkfront reads the blkback's
decision and it also makes the decision for the use of the feature.

Commit 402c43ea6b34 ("xen-blkfront: Apply 'feature_persistent' parameter
when connect"), however, made the blkfront's read of the parameter for
disabling the advertisement, namely 'feature_persistent', to be done
when it negotiate, not when advertise.  Therefore blkfront advertises
without reading the parameter.  As the field for caching the parameter
value is zero-initialized, it always advertises as the feature is
disabled, so that the persistent grants feature becomes always disabled.

This commit fixes the issue by making the blkfront does parmeter caching
just before the advertisement.

Fixes: 402c43ea6b34 ("xen-blkfront: Apply 'feature_persistent' parameter when connect")
Cc: &lt;stable@vger.kernel.org&gt; # 5.10.x
Reported-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Signed-off-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20220831165824.94815-4-sj@kernel.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Xen blkfront advertises its support of the persistent grants feature
when it first setting up and when resuming in 'talk_to_blkback()'.
Then, blkback reads the advertised value when it connects with blkfront
and decides if it will use the persistent grants feature or not, and
advertises its decision to blkfront.  Blkfront reads the blkback's
decision and it also makes the decision for the use of the feature.

Commit 402c43ea6b34 ("xen-blkfront: Apply 'feature_persistent' parameter
when connect"), however, made the blkfront's read of the parameter for
disabling the advertisement, namely 'feature_persistent', to be done
when it negotiate, not when advertise.  Therefore blkfront advertises
without reading the parameter.  As the field for caching the parameter
value is zero-initialized, it always advertises as the feature is
disabled, so that the persistent grants feature becomes always disabled.

This commit fixes the issue by making the blkfront does parmeter caching
just before the advertisement.

Fixes: 402c43ea6b34 ("xen-blkfront: Apply 'feature_persistent' parameter when connect")
Cc: &lt;stable@vger.kernel.org&gt; # 5.10.x
Reported-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Signed-off-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20220831165824.94815-4-sj@kernel.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen-blkfront: Advertise feature-persistent as user requested</title>
<updated>2022-09-02T09:05:12+00:00</updated>
<author>
<name>SeongJae Park</name>
<email>sj@kernel.org</email>
</author>
<published>2022-08-31T16:58:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9f5e0fe5d05f7e8de7f39b2b10089834eb0ff787'/>
<id>9f5e0fe5d05f7e8de7f39b2b10089834eb0ff787</id>
<content type='text'>
The advertisement of the persistent grants feature (writing
'feature-persistent' to xenbus) should mean not the decision for using
the feature but only the availability of the feature.  However, commit
74a852479c68 ("xen-blkfront: add a parameter for disabling of persistent
grants") made a field of blkfront, which was a place for saving only the
negotiation result, to be used for yet another purpose: caching of the
'feature_persistent' parameter value.  As a result, the advertisement,
which should follow only the parameter value, becomes inconsistent.

This commit fixes the misuse of the semantic by making blkfront saves
the parameter value in a separate place and advertises the support based
on only the saved value.

Fixes: 74a852479c68 ("xen-blkfront: add a parameter for disabling of persistent grants")
Cc: &lt;stable@vger.kernel.org&gt; # 5.10.x
Suggested-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20220831165824.94815-3-sj@kernel.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The advertisement of the persistent grants feature (writing
'feature-persistent' to xenbus) should mean not the decision for using
the feature but only the availability of the feature.  However, commit
74a852479c68 ("xen-blkfront: add a parameter for disabling of persistent
grants") made a field of blkfront, which was a place for saving only the
negotiation result, to be used for yet another purpose: caching of the
'feature_persistent' parameter value.  As a result, the advertisement,
which should follow only the parameter value, becomes inconsistent.

This commit fixes the misuse of the semantic by making blkfront saves
the parameter value in a separate place and advertises the support based
on only the saved value.

Fixes: 74a852479c68 ("xen-blkfront: add a parameter for disabling of persistent grants")
Cc: &lt;stable@vger.kernel.org&gt; # 5.10.x
Suggested-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20220831165824.94815-3-sj@kernel.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen-blkback: Advertise feature-persistent as user requested</title>
<updated>2022-09-02T09:05:06+00:00</updated>
<author>
<name>SeongJae Park</name>
<email>sj@kernel.org</email>
</author>
<published>2022-08-31T16:58:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=06ba5d2e943e97bb66e75c152e87f1d2c7027a67'/>
<id>06ba5d2e943e97bb66e75c152e87f1d2c7027a67</id>
<content type='text'>
The advertisement of the persistent grants feature (writing
'feature-persistent' to xenbus) should mean not the decision for using
the feature but only the availability of the feature.  However, commit
aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent
grants") made a field of blkback, which was a place for saving only the
negotiation result, to be used for yet another purpose: caching of the
'feature_persistent' parameter value.  As a result, the advertisement,
which should follow only the parameter value, becomes inconsistent.

This commit fixes the misuse of the semantic by making blkback saves the
parameter value in a separate place and advertises the support based on
only the saved value.

Fixes: aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants")
Cc: &lt;stable@vger.kernel.org&gt; # 5.10.x
Suggested-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20220831165824.94815-2-sj@kernel.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The advertisement of the persistent grants feature (writing
'feature-persistent' to xenbus) should mean not the decision for using
the feature but only the availability of the feature.  However, commit
aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent
grants") made a field of blkback, which was a place for saving only the
negotiation result, to be used for yet another purpose: caching of the
'feature_persistent' parameter value.  As a result, the advertisement,
which should follow only the parameter value, becomes inconsistent.

This commit fixes the misuse of the semantic by making blkback saves the
parameter value in a separate place and advertises the support based on
only the saved value.

Fixes: aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants")
Cc: &lt;stable@vger.kernel.org&gt; # 5.10.x
Suggested-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Marek Marczykowski-Górecki &lt;marmarek@invisiblethingslab.com&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Link: https://lore.kernel.org/r/20220831165824.94815-2-sj@kernel.org
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'block-6.0-2022-08-26' of git://git.kernel.dk/linux-block</title>
<updated>2022-08-26T18:05:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-26T18:05:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3e5c673f0d75bc22b3c26eade87e4db4f374cd34'/>
<id>3e5c673f0d75bc22b3c26eade87e4db4f374cd34</id>
<content type='text'>
Pull block fixes from Jens Axboe:

 - MD pull request via Song:
      - Fix for clustered raid (Guoqing Jiang)
      - req_op fix (Bart Van Assche)
      - Fix race condition in raid recreate (David Sloan)

 - loop configuration overflow fix (Siddh)

 - Fix missing commit_rqs call for certain conditions (Yu)

* tag 'block-6.0-2022-08-26' of git://git.kernel.dk/linux-block:
  md: call __md_stop_writes in md_stop
  Revert "md-raid: destroy the bitmap after destroying the thread"
  md: Flush workqueue md_rdev_misc_wq in md_alloc()
  md/raid10: Fix the data type of an r10_sync_page_io() argument
  loop: Check for overflow while configuring loop
  blk-mq: fix io hung due to missing commit_rqs
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block fixes from Jens Axboe:

 - MD pull request via Song:
      - Fix for clustered raid (Guoqing Jiang)
      - req_op fix (Bart Van Assche)
      - Fix race condition in raid recreate (David Sloan)

 - loop configuration overflow fix (Siddh)

 - Fix missing commit_rqs call for certain conditions (Yu)

* tag 'block-6.0-2022-08-26' of git://git.kernel.dk/linux-block:
  md: call __md_stop_writes in md_stop
  Revert "md-raid: destroy the bitmap after destroying the thread"
  md: Flush workqueue md_rdev_misc_wq in md_alloc()
  md/raid10: Fix the data type of an r10_sync_page_io() argument
  loop: Check for overflow while configuring loop
  blk-mq: fix io hung due to missing commit_rqs
</pre>
</div>
</content>
</entry>
<entry>
<title>loop: Check for overflow while configuring loop</title>
<updated>2022-08-24T12:52:52+00:00</updated>
<author>
<name>Siddh Raman Pant</name>
<email>code@siddh.me</email>
</author>
<published>2022-08-23T16:08:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c490a0b5a4f36da3918181a8acdc6991d967c5f3'/>
<id>c490a0b5a4f36da3918181a8acdc6991d967c5f3</id>
<content type='text'>
The userspace can configure a loop using an ioctl call, wherein
a configuration of type loop_config is passed (see lo_ioctl()'s
case on line 1550 of drivers/block/loop.c). This proceeds to call
loop_configure() which in turn calls loop_set_status_from_info()
(see line 1050 of loop.c), passing &amp;config-&gt;info which is of type
loop_info64*. This function then sets the appropriate values, like
the offset.

loop_device has lo_offset of type loff_t (see line 52 of loop.c),
which is typdef-chained to long long, whereas loop_info64 has
lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h).

The function directly copies offset from info to the device as
follows (See line 980 of loop.c):
	lo-&gt;lo_offset = info-&gt;lo_offset;

This results in an overflow, which triggers a warning in iomap_iter()
due to a call to iomap_iter_done() which has:
	WARN_ON_ONCE(iter-&gt;iomap.offset &gt; iter-&gt;pos);

Thus, check for negative value during loop_set_status_from_info().

Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e

Reported-and-tested-by: syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Siddh Raman Pant &lt;code@siddh.me&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20220823160810.181275-1-code@siddh.me
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The userspace can configure a loop using an ioctl call, wherein
a configuration of type loop_config is passed (see lo_ioctl()'s
case on line 1550 of drivers/block/loop.c). This proceeds to call
loop_configure() which in turn calls loop_set_status_from_info()
(see line 1050 of loop.c), passing &amp;config-&gt;info which is of type
loop_info64*. This function then sets the appropriate values, like
the offset.

loop_device has lo_offset of type loff_t (see line 52 of loop.c),
which is typdef-chained to long long, whereas loop_info64 has
lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h).

The function directly copies offset from info to the device as
follows (See line 980 of loop.c):
	lo-&gt;lo_offset = info-&gt;lo_offset;

This results in an overflow, which triggers a warning in iomap_iter()
due to a call to iomap_iter_done() which has:
	WARN_ON_ONCE(iter-&gt;iomap.offset &gt; iter-&gt;pos);

Thus, check for negative value during loop_set_status_from_info().

Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e

Reported-and-tested-by: syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Siddh Raman Pant &lt;code@siddh.me&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20220823160810.181275-1-code@siddh.me
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-hotfixes-stable-2022-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2022-08-23T20:33:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-23T20:33:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=95607ad99b5a4e3e69e025621165753718a6ea98'/>
<id>95607ad99b5a4e3e69e025621165753718a6ea98</id>
<content type='text'>
Pull misc fixes from Andrew Morton:
 "Thirteen fixes, almost all for MM.

  Seven of these are cc:stable and the remainder fix up the changes
  which went into this -rc cycle"

* tag 'mm-hotfixes-stable-2022-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  kprobes: don't call disarm_kprobe() for disabled kprobes
  mm/shmem: shmem_replace_page() remember NR_SHMEM
  mm/shmem: tmpfs fallocate use file_modified()
  mm/shmem: fix chattr fsflags support in tmpfs
  mm/hugetlb: support write-faults in shared mappings
  mm/hugetlb: fix hugetlb not supporting softdirty tracking
  mm/uffd: reset write protection when unregister with wp-mode
  mm/smaps: don't access young/dirty bit if pte unpresent
  mm: add DEVICE_ZONE to FOR_ALL_ZONES
  kernel/sys_ni: add compat entry for fadvise64_64
  mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW
  Revert "zram: remove double compression logic"
  get_maintainer: add Alan to .get_maintainer.ignore
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull misc fixes from Andrew Morton:
 "Thirteen fixes, almost all for MM.

  Seven of these are cc:stable and the remainder fix up the changes
  which went into this -rc cycle"

* tag 'mm-hotfixes-stable-2022-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  kprobes: don't call disarm_kprobe() for disabled kprobes
  mm/shmem: shmem_replace_page() remember NR_SHMEM
  mm/shmem: tmpfs fallocate use file_modified()
  mm/shmem: fix chattr fsflags support in tmpfs
  mm/hugetlb: support write-faults in shared mappings
  mm/hugetlb: fix hugetlb not supporting softdirty tracking
  mm/uffd: reset write protection when unregister with wp-mode
  mm/smaps: don't access young/dirty bit if pte unpresent
  mm: add DEVICE_ZONE to FOR_ALL_ZONES
  kernel/sys_ni: add compat entry for fadvise64_64
  mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW
  Revert "zram: remove double compression logic"
  get_maintainer: add Alan to .get_maintainer.ignore
</pre>
</div>
</content>
</entry>
</feed>
