[ Upstream commit da99466ac2 ]
This fixes a global out-of-bounds read access in the copy_buffer
function of the floppy driver.
The FDDEFPRM ioctl allows one to set the geometry of a disk. The sect
and head fields (unsigned int) of the floppy_drive structure are used to
compute the max_sector (int) in the make_raw_rw_request function. It is
possible to overflow the max_sector. Next, max_sector is passed to the
copy_buffer function and used in one of the memcpy calls.
An unprivileged user could trigger the bug if the device is accessible,
but requires a floppy disk to be inserted.
The patch adds the check for the .sect * .head multiplication for not
overflowing in the set_geometry function.
The bug was found by syzkaller.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9b04609b78 ]
This fixes the invalid pointer dereference in the drive_name function of
the floppy driver.
The native_format field of the struct floppy_drive_params is used as
floppy_type array index in the drive_name function. Thus, the field
should be checked the same way as the autodetect field.
To trigger the bug, one could use a value out of range and set the drive
parameters with the FDSETDRVPRM ioctl. Next, FDGETDRVTYP ioctl should
be used to call the drive_name. A floppy disk is not required to be
inserted.
CAP_SYS_ADMIN is required to call FDSETDRVPRM.
The patch adds the check for a value of the native_format field to be in
the '0 <= x < ARRAY_SIZE(floppy_type)' range of the floppy_type array
indices.
The bug was found by syzkaller.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5635f897ed ]
This fixes a global out-of-bounds read access in the next_valid_format
function of the floppy driver.
The values from autodetect field of the struct floppy_drive_params are
used as indices for the floppy_type array in the next_valid_format
function 'floppy_type[DP->autodetect[probed_format]].sect'.
To trigger the bug, one could use a value out of range and set the drive
parameters with the FDSETDRVPRM ioctl. A floppy disk is not required to
be inserted.
CAP_SYS_ADMIN is required to call FDSETDRVPRM.
The patch adds the check for values of the autodetect field to be in the
'0 <= x < ARRAY_SIZE(floppy_type)' range of the floppy_type array indices.
The bug was found by syzkaller.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f3554aeb99 ]
This fixes a divide by zero error in the setup_format_params function of
the floppy driver.
Two consecutive ioctls can trigger the bug: The first one should set the
drive geometry with such .sect and .rate values for the F_SECT_PER_TRACK
to become zero. Next, the floppy format operation should be called.
A floppy disk is not required to be inserted. An unprivileged user
could trigger the bug if the device is accessible.
The patch checks F_SECT_PER_TRACK for a non-zero value in the
set_geometry function. The proper check should involve a reasonable
upper limit for the .sect and .rate fields, but it could change the
UAPI.
The patch also checks F_SECT_PER_TRACK in the setup_format_params, and
cancels the formatting operation in case of zero.
The bug was found by syzkaller.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bf348f9b78 ]
When tag_set->nr_maps is 1, the block layer limits the number of hw queues
by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it
has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues.
In addition, specifically for pci scenario, when the 'num-queues' specified
by qemu is more than maxcpus, virtio-blk would not be able to allocate more
than maxcpus vectors in order to have a vector for each queue. As a result,
it falls back into MSI-X with one vector for config and one shared for
queues.
Considering above reasons, this patch limits the number of hw queues used
by virtio-blk by nr_cpu_ids.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 96d7cb932e ]
floppy_check_events() is supposed to return bit flags to say which
events occured. We should return zero to say that no event flags are
set. Only BIT(0) and BIT(1) are used in the caller. And .check_events
interface also expect to return an unsigned int value.
However, after commit a0c80efe59, it may return -EINTR (-4u).
Here, both BIT(0) and BIT(1) are cleared. So this patch shouldn't
affect runtime, but it obviously is still worth fixing.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: a0c80efe59 ("floppy: fix lock_fdc() signal handling")
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 296dcc40f2 ]
When the block device is opened with FMODE_EXCL, ref_count is set to -1.
This value doesn't get reset when the device is closed which means the
device cannot be opened again. Fix this by checking for refcount <= 0
in the release method.
Reported-and-tested-by: Stan Johnson <userm57@yahoo.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9848b6ddd8 ]
If you try to promote a Secondary while connected to a Primary
and allow-two-primaries is NOT set, we will wait for "ping-timeout"
to give this node a chance to detect a dead primary,
in case the cluster manager noticed faster than we did.
But if we then are *still* connected to a Primary,
we fail (after an additional timeout of ping-timout).
This change skips the spurious second timeout.
Most people won't notice really,
since "ping-timeout" by default is half a second.
But in some installations, ping-timeout may be 10 or 20 seconds or more,
and spuriously delaying the error return becomes annoying.
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b17b59602b ]
With "on-no-data-accessible suspend-io", DRBD requires the next attach
or connect to be to the very same data generation uuid tag it lost last.
If we first lost connection to the peer,
then later lost connection to our own disk,
we would usually refuse to re-connect to the peer,
because it presents the wrong data set.
However, if the peer first connects without a disk,
and then attached its disk, we accepted that same wrong data set,
which would be "unexpected" by any user of that DRBD
and cause "undefined results" (read: very likely data corruption).
The fix is to forcefully disconnect as soon as we notice that the peer
attached to the "wrong" dataset.
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d29e89e349 ]
So far there was the possibility that we called
genlmsg_new(GFP_NOIO)/mutex_lock() while holding an rcu_read_lock().
This included cases like:
drbd_sync_handshake (acquire the RCU lock)
drbd_asb_recover_1p
drbd_khelper
drbd_bcast_event
genlmsg_new(GFP_NOIO) --> may sleep
drbd_sync_handshake (acquire the RCU lock)
drbd_asb_recover_1p
drbd_khelper
notify_helper
genlmsg_new(GFP_NOIO) --> may sleep
drbd_sync_handshake (acquire the RCU lock)
drbd_asb_recover_1p
drbd_khelper
notify_helper
mutex_lock --> may sleep
While using GFP_ATOMIC whould have been possible in the first two cases,
the real fix is to narrow the rcu_read_lock.
Reported-by: Jia-Ju Bai <baijiaju1990@163.com>
Reviewed-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a11f6ca9ae ]
__vdc_tx_trigger should only loop on EAGAIN a finite
number of times.
See commit adddc32d6f ("sunvnet: Do not spin in an
infinite loop when vio_ldc_send() returns EAGAIN") for detail.
Signed-off-by: Young Xiao <YangX92@hotmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c8a83a6b54 upstream.
NBD can update block device block size implicitely through
bd_set_size(). Make it explicitely set blocksize with set_blocksize() as
this behavior of bd_set_size() is going away.
CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e544541b07 upstream.
We noticed when trying to do O_DIRECT to an export on the server side
that we were getting requests smaller than the 4k sectorsize of the
device. This is because the client isn't setting the logical and
physical blocksizes properly for the underlying device. Fix this up by
setting the queue blocksizes and then calling bd_set_size.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0a42e99b58 upstream.
Now that loop_ctl_mutex is global, just get rid of loop_index_mutex as
there is no good reason to keep these two separate and it just
complicates the locking.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 967d1dc144 upstream.
__loop_release() has a single call site. Fold it there. This is
currently not a huge win but it will make following replacement of
loop_index_mutex more obvious.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 85f5a4d666 upstream.
There is a window between when RBD_DEV_FLAG_REMOVING is set and when
the device is removed from rbd_dev_list. During this window, we set
"already" and return 0.
Returning 0 from write(2) can confuse userspace tools because
0 indicates that nothing was written. In particular, "rbd unmap"
will retry the write multiple times a second:
10:28:05.463299 write(4, "0", 1) = 0
10:28:05.463509 write(4, "0", 1) = 0
10:28:05.463720 write(4, "0", 1) = 0
10:28:05.463942 write(4, "0", 1) = 0
10:28:05.464155 write(4, "0", 1) = 0
Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit de7b75d82f ]
LKP recently reported a hang at bootup in the floppy code:
[ 245.678853] INFO: task mount:580 blocked for more than 120 seconds.
[ 245.679906] Tainted: G T 4.19.0-rc6-00172-ga9f38e1 #1
[ 245.680959] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 245.682181] mount D 6372 580 1 0x00000004
[ 245.683023] Call Trace:
[ 245.683425] __schedule+0x2df/0x570
[ 245.683975] schedule+0x2d/0x80
[ 245.684476] schedule_timeout+0x19d/0x330
[ 245.685090] ? wait_for_common+0xa5/0x170
[ 245.685735] wait_for_common+0xac/0x170
[ 245.686339] ? do_sched_yield+0x90/0x90
[ 245.686935] wait_for_completion+0x12/0x20
[ 245.687571] __floppy_read_block_0+0xfb/0x150
[ 245.688244] ? floppy_resume+0x40/0x40
[ 245.688844] floppy_revalidate+0x20f/0x240
[ 245.689486] check_disk_change+0x43/0x60
[ 245.690087] floppy_open+0x1ea/0x360
[ 245.690653] __blkdev_get+0xb4/0x4d0
[ 245.691212] ? blkdev_get+0x1db/0x370
[ 245.691777] blkdev_get+0x1f3/0x370
[ 245.692351] ? path_put+0x15/0x20
[ 245.692871] ? lookup_bdev+0x4b/0x90
[ 245.693539] blkdev_get_by_path+0x3d/0x80
[ 245.694165] mount_bdev+0x2a/0x190
[ 245.694695] squashfs_mount+0x10/0x20
[ 245.695271] ? squashfs_alloc_inode+0x30/0x30
[ 245.695960] mount_fs+0xf/0x90
[ 245.696451] vfs_kern_mount+0x43/0x130
[ 245.697036] do_mount+0x187/0xc40
[ 245.697563] ? memdup_user+0x28/0x50
[ 245.698124] ksys_mount+0x60/0xc0
[ 245.698639] sys_mount+0x19/0x20
[ 245.699167] do_int80_syscall_32+0x61/0x130
[ 245.699813] entry_INT80_32+0xc7/0xc7
showing that we never complete that read request. The reason is that
the completion setup is racy - it initializes the completion event
AFTER submitting the IO, which means that the IO could complete
before/during the init. If it does, we are passing garbage to
complete() and we may sleep forever waiting for the event to
occur.
Fixes: 7b7b68bba5 ("floppy: bail out in open() if drive is not responding to block0 read")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit fef912bf86 upstream.
commit 98af4d4df8 upstream.
I got a report from Howard Chen that he saw zram and sysfs race(ie,
zram block device file is created but sysfs for it isn't yet)
when he tried to create new zram devices via hotadd knob.
v4.20 kernel fixes it by [1, 2] but it's too large size to merge
into -stable so this patch fixes the problem by registering defualt
group by Greg KH's approach[3].
This patch should be applied to every stable tree [3.16+] currently
existing from kernel.org because the problem was introduced at 2.6.37
by [4].
[1] fef912bf86, block: genhd: add 'groups' argument to device_add_disk
[2] 98af4d4df8, zram: register default groups with device_add_disk()
[3] http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/
[4] 33863c21e6, Staging: zram: Replace ioctls with sysfs interface
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Tested-by: Howard Chen <howardsoc@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f92898e7f3 upstream.
If a block device is hot-added when we are out of grants,
gnttab_grant_foreign_access fails with -ENOSPC (log message "28
granting access to ring page") in this code path:
talk_to_blkback ->
setup_blkring ->
xenbus_grant_ring ->
gnttab_grant_foreign_access
and the failing path in talk_to_blkback sets the driver_data to NULL:
destroy_blkring:
blkif_free(info, 0);
mutex_lock(&blkfront_mutex);
free_info(info);
mutex_unlock(&blkfront_mutex);
dev_set_drvdata(&dev->dev, NULL);
This results in a NULL pointer BUG when blkfront_remove and blkif_free
try to access the failing device's NULL struct blkfront_info.
Cc: stable@vger.kernel.org # 4.5 and later
Signed-off-by: Vasilis Liaskovitis <vliaskovitis@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1448a2a536 ]
If we fail to allocate the request queue for a disk, we still need to
free that disk, not just the previous ones. Additionally, we need to
cleanup the previous request queues.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 71327f547e ]
Move queue allocation next to disk allocation to fix a couple of issues:
- If add_disk() hasn't been called, we should clear disk->queue before
calling put_disk().
- If we fail to allocate a request queue, we still need to put all of
the disks, not just the ones that we allocated queues for.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d61b7f972d ]
A user noticed that write performance was horrible over loopback and we
traced it to an inversion of when we need to set MSG_MORE. It should be
set when we have more bvec's to send, not when we are on the last bvec.
This patch made the test go from 20 iops to 78k iops.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Fixes: 429a787be6 ("nbd: fix use-after-free of rq/bio in the xmit path")
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 65eea8edc3 upstream.
The final field of a floppy_struct is the field "name", which is a pointer
to a string in kernel memory. The kernel pointer should not be copied to
user memory. The FDGETPRM ioctl copies a floppy_struct to user memory,
including this "name" field. This pointer cannot be used by the user
and it will leak a kernel address to user-space, which will reveal the
location of kernel code and data and undermine KASLR protection.
Model this code after the compat ioctl which copies the returned data
to a previously cleared temporary structure on the stack (excluding the
name pointer) and copy out to userspace from there. As we already have
an inparam union with an appropriate member and that memory is already
cleared even for read only calls make use of that as a temporary store.
Based on an initial patch by Brian Belleville.
CVE-2018-7755
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Broke up long line.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 64dafbc953 upstream.
We have
struct drbd_requests { ... struct bio *private_bio; ... }
to hold a bio clone for local submission.
On local IO completion, we put that bio, and in case we want to use the
result later, we overload that member to hold the ERR_PTR() of the
completion result,
Which, before v4.3, used to be the passed in "int error",
so we could first bio_put(), then assign.
v4.3-rc1~100^2~21 4246a0b63b block: add a bi_error field to struct bio
changed that:
bio_put(req->private_bio);
- req->private_bio = ERR_PTR(error);
+ req->private_bio = ERR_PTR(bio->bi_error);
Which introduces an access after free,
because it was non obvious that req->private_bio == bio.
Impact of that was mostly unnoticable, because we only use that value
in a multiple-failure case, and even then map any "unexpected" error
code to EIO, so worst case we could potentially mask a more specific
error with EIO in a multiple failure case.
Unless the pointed to memory region was unmapped, as is the case with
CONFIG_DEBUG_PAGEALLOC, in which case this results in
BUG: unable to handle kernel paging request
v4.13-rc1~70^2~75 4e4cbee93d block: switch bios to blk_status_t
changes it further to
bio_put(req->private_bio);
req->private_bio = ERR_PTR(blk_status_to_errno(bio->bi_status));
And blk_status_to_errno() now contains a WARN_ON_ONCE() for unexpected
values, which catches this "sometimes", if the memory has been reused
quickly enough for other things.
Should also go into stable since 4.3, with the trivial change around 4.13.
Cc: stable@vger.kernel.org
Fixes: 4246a0b63b block: add a bi_error field to struct bio
Reported-by: Sarah Newman <srn@prgmr.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 23edca8649 upstream.
There is a problem if we are going to unmap a rbd device and the
watch_dwork is going to queue delayed work for watch:
unmap Thread watch Thread timer
do_rbd_remove
cancel_tasks_sync(rbd_dev)
queue_delayed_work for watch
destroy_workqueue(rbd_dev->task_wq)
drain_workqueue(wq)
destroy other resources in wq
call_timer_fn
__queue_work()
Then the delayed work escape the cancel_tasks_sync() and
destroy_workqueue() and we will get an user-after-free call trace:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
Modules linked in:
CPU: 7 PID: 0 Comm: swapper/7 Tainted: G OE 4.17.0-rc6+ #13
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:__queue_work+0x6a/0x3b0
RSP: 0018:ffff9427df1c3e90 EFLAGS: 00010086
RAX: ffff9427deca8400 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff9427deca8400 RSI: ffff9427df1c3e50 RDI: 0000000000000000
RBP: ffff942783e39e00 R08: ffff9427deca8400 R09: ffff9427df1c3f00
R10: 0000000000000004 R11: 0000000000000005 R12: ffff9427cfb85970
R13: 0000000000002000 R14: 000000000001eca0 R15: 0000000000000007
FS: 0000000000000000(0000) GS:ffff9427df1c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000004c900a005 CR4: 00000000000206e0
Call Trace:
<IRQ>
? __queue_work+0x3b0/0x3b0
call_timer_fn+0x2d/0x130
run_timer_softirq+0x16e/0x430
? tick_sched_timer+0x37/0x70
__do_softirq+0xd2/0x280
irq_exit+0xd5/0xe0
smp_apic_timer_interrupt+0x6c/0x130
apic_timer_interrupt+0xf/0x20
[ Move rbd_dev->watch_dwork cancellation so that rbd_reregister_watch()
either bails out early because the watch is UNREGISTERED at that point
or just gets cancelled. ]
Cc: stable@vger.kernel.org
Fixes: 99d1694310 ("rbd: retry watch re-registration periodically")
Signed-off-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2bbea6e117 ]
when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.
PID: 6766 TASK: ffff88007b2a6dd0 CPU: 0 COMMAND: "mount"
#0 [ffff880078447ae0] __schedule at ffffffff8168d605
#1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
#2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
#3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
#4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
#8 [ffff880078447da8] mount_bdev at ffffffff81202570
#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
RIP: 00007fd9ea914e9a RSP: 00007ffd5d9bf648 RFLAGS: 00010246
RAX: 00000000000000a5 RBX: ffffffff81698c49 RCX: 0000000000000010
RDX: 00007fd9ec2bc210 RSI: 00007fd9ec2bc290 RDI: 00007fd9ec2bcf30
RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000010
R10: 00000000c0ed0001 R11: 0000000000000206 R12: 00007fd9ec2bc040
R13: 00007fd9eb6b2380 R14: 00007fd9ec2bc210 R15: 00007fd9ec2bcf30
ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b
This task was trying to mount the cdrom. It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.
PID: 6785 TASK: ffff880078720fb0 CPU: 0 COMMAND: "systemd-udevd"
#0 [ffff880078417898] __schedule at ffffffff8168d605
#1 [ffff880078417900] schedule at ffffffff8168dc59
#2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
#3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
#4 [ffff8800784179d0] down_read at ffffffff8168cde0
#5 [ffff8800784179e8] get_super at ffffffff81201cc7
#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
#7 [ffff880078417a40] flush_disk at ffffffff8123a94b
#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
RIP: 00007f29438b0c20 RSP: 00007ffc76624b78 RFLAGS: 00010246
RAX: 0000000000000002 RBX: ffffffff81698c49 RCX: 0000000000000000
RDX: 00007f2944a5fa70 RSI: 00000000000a0800 RDI: 00007f2944a5fa70
RBP: 00007f2944a5f540 R8: 0000000000000000 R9: 0000000000000020
R10: 00007f2943614c40 R11: 0000000000000246 R12: ffffffff811fde4e
R13: ffff880078417f78 R14: 000000000000000c R15: 00007f2944a4b010
ORIG_RAX: 0000000000000002 CS: 0033 SS: 002b
This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.
The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.
This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6460495709 ]
While installing SLES-12 (based on v4.4), I found that the installer
will stall for 60+ seconds during LVM disk scan. The root cause was
determined to be the removal of a bound device check in loop_flush()
by commit b5dd2f6047 ("block: loop: improve performance via blk-mq").
Restoring this check, examining ->lo_state as set by loop_set_fd()
eliminates the bad behavior.
Test method:
modprobe loop max_loop=64
dd if=/dev/zero of=disk bs=512 count=200K
for((i=0;i<4;i++))do losetup -f disk; done
mkfs.ext4 -F /dev/loop0
for((i=0;i<4;i++))do mkdir t$i; mount /dev/loop$i t$i;done
for f in `ls /dev/loop[0-9]*|sort`; do \
echo $f; dd if=$f of=/dev/null bs=512 count=1; \
done
Test output: stock patched
/dev/loop0 18.1217e-05 8.3842e-05
/dev/loop1 6.1114e-05 0.000147979
/dev/loop10 0.414701 0.000116564
/dev/loop11 0.7474 6.7942e-05
/dev/loop12 0.747986 8.9082e-05
/dev/loop13 0.746532 7.4799e-05
/dev/loop14 0.480041 9.3926e-05
/dev/loop15 1.26453 7.2522e-05
Note that from loop10 onward, the device is not mounted, yet the
stock kernel consumes several orders of magnitude more wall time
than it does for a mounted device.
(Thanks for Mike Galbraith <efault@gmx.de>, give a changelog review.)
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: James Wang <jnwang@suse.com>
Fixes: b5dd2f6047 ("block: loop: improve performance via blk-mq")
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a4e84aae81 ]
mtip32xx supposes that 'request_idx' passed to .init_request()
is tag of the request, and use that as request's tag to initialize
command header.
After MQ IO scheduler is in, request tag assigned isn't same with
the request index anymore, so cause strange hardware failure on
mtip32xx, even whole system panic is triggered.
This patch fixes the issue by initializing command header via
request's real tag.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1d037577c3 upstream.
The following commit:
commit aa4d86163e ("block: loop: switch to VFS ITER_BVEC")
replaced __do_lo_send_write(), which used ITER_KVEC iterators, with
lo_write_bvec() which uses ITER_BVEC iterators. In this change, though,
the WRITE flag was lost:
- iov_iter_kvec(&from, ITER_KVEC | WRITE, &kvec, 1, len);
+ iov_iter_bvec(&i, ITER_BVEC, bvec, 1, bvec->bv_len);
This flag is necessary for the DAX case because we make decisions based on
whether or not the iterator is a READ or a WRITE in dax_iomap_actor() and
in dax_iomap_rw().
We end up going through this path in configurations where we combine a PMEM
device with 4k sectors, a loopback device and DAX. The consequence of this
missed flag is that what we intend as a write actually turns into a read in
the DAX code, so no data is ever written.
The very simplest test case is to create a loopback device and try and
write a small string to it, then hexdump a few bytes of the device to see
if the write took. Without this patch you read back all zeros, with this
you read back the string you wrote.
For XFS this causes us to fail or panic during the following xfstests:
xfs/074 xfs/078 xfs/216 xfs/217 xfs/250
For ext4 we have a similar issue where writes never happen, but we don't
currently have any xfstests that use loopback and show this issue.
Fix this by restoring the WRITE flag argument to iov_iter_bvec(). This
causes the xfstests to all pass.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Fixes: commit aa4d86163e ("block: loop: switch to VFS ITER_BVEC")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d4c2269b3d upstream.
drivers/block/rbd.c: In function ‘rbd_watch_cb’:
drivers/block/rbd.c:3690:5: error: ‘struct_v’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/block/rbd.c:3759:5: note: ‘struct_v’ was declared here
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a0ec388ef upstream.
Commit 523e1d399c ("block: make gendisk hold a reference to its queue")
modified add_disk() and disk_release() but did not update any of the
error paths that trigger a put_disk() call after disk->queue has been
assigned. That introduced the following behavior in the pktcdvd driver
if pkt_new_dev() fails:
Kernel BUG at 00000000e98fd882 [verbose debug info unavailable]
Since disk_release() calls blk_put_queue() anyway if disk->queue != NULL,
fix this by removing the blk_cleanup_queue() call from the pkt_setup_dev()
error path.
Fixes: commit 523e1d399c ("block: make gendisk hold a reference to its queue")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ae6650163c upstream.
范龙飞 reports that KASAN can report a use-after-free in __lock_acquire.
The reason is due to insufficient serialization in lo_release(), which
will continue to use the loop device even after it has decremented the
lo_refcnt to zero.
In the meantime, another process can come in, open the loop device
again as it is being shut down. Confusion ensues.
Reported-by: 范龙飞 <long7573@126.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 21acdf45f4 upstream.
Commit d3834fefcf ("rbd: bump queue_max_segments") bumped
max_segments (unsigned short) to max_hw_sectors (unsigned int).
max_hw_sectors is set to the number of 512-byte sectors in an object
and overflows unsigned short for 32M (largest possible) objects, making
the block layer resort to handing us single segment (i.e. single page
or even smaller) bios in that case.
Fixes: d3834fefcf ("rbd: bump queue_max_segments")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 429a787be6 upstream.
For writes, we can get a completion in while we're still iterating
the request and bio chain. If that happens, we're reading freed
memory and we can crash.
Break out after the last segment and avoid having the iterator
read freed memory.
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f858685503 ]
We can't just set the timeout on the tagset, we have to set it on the
queue as it would have been setup already at this point.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0bc315381f ]
zram can handle at most SECTORS_PER_PAGE sectors in a bio's bvec. When using
the NVMe over Fabrics loopback target which potentially sends a huge bulk of
pages attached to the bio's bvec this results in a kernel panic because of
array out of bounds accesses in zram_decompress_page().
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e37f2f846 upstream.
rbd_img_obj_exists_submit() and rbd_img_obj_parent_read_full() are on
the writeback path for cloned images -- we attempt a stat on the parent
object to see if it exists and potentially read it in to call copyup.
GFP_NOIO should be used instead of GFP_KERNEL here.
Link: http://tracker.ceph.com/issues/22014
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5fbd545cd3 upstream.
Ensure that the members of struct skd_msg_buf have been transferred
to the PCIe adapter before the doorbell is triggered. This patch
avoids that I/O fails sporadically and that the following error
message is reported:
(skd0:STM000196603:[0000:00:09.0]): Completion mismatch comp_id=0x0000 skreq=0x0400 new=0x0000
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
