linux-stable.git/drivers/block, branch v4.14.136

floppy: fix out-of-bounds read in copy_buffer

2019-07-31T05:28:34+00:00

[ Upstream commit da99466ac243f15fbba65bd261bfc75ffa1532b6 ]

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 
Tested-by: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

floppy: fix invalid pointer dereference in drive_name

2019-07-31T05:28:34+00:00

[ Upstream commit 9b04609b784027968348796a18f601aed9db3789 ]

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 
Tested-by: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

floppy: fix out-of-bounds read in next_valid_format

2019-07-31T05:28:34+00:00

[ Upstream commit 5635f897ed83fd539df78e98ba69ee91592f9bb8 ]

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 
Tested-by: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

floppy: fix div-by-zero in setup_format_params

2019-07-31T05:28:34+00:00

[ Upstream commit f3554aeb991214cbfafd17d55e2bfddb50282e32 ]

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 
Tested-by: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

virtio-blk: limit number of hw queues by nr_cpu_ids

2019-05-10T15:53:12+00:00

[ Upstream commit bf348f9b78d413e75bb079462751a1d86b6de36c ]

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 
Signed-off-by: Dongli Zhang 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

xsysace: Fix error handling in ace_setup

2019-05-08T05:20:51+00:00

[ Upstream commit 47b16820c490149c2923e8474048f2c6e7557cab ]

If xace hardware reports a bad version number, the error handling code
in ace_setup() calls put_disk(), followed by queue cleanup. However, since
the disk data structure has the queue pointer set, put_disk() also
cleans and releases the queue. This results in blk_cleanup_queue()
accessing an already released data structure, which in turn may result
in a crash such as the following.

[   10.681671] BUG: Kernel NULL pointer dereference at 0x00000040
[   10.681826] Faulting instruction address: 0xc0431480
[   10.682072] Oops: Kernel access of bad area, sig: 11 [#1]
[   10.682251] BE PAGE_SIZE=4K PREEMPT Xilinx Virtex440
[   10.682387] Modules linked in:
[   10.682528] CPU: 0 PID: 1 Comm: swapper Tainted: G        W         5.0.0-rc6-next-20190218+ #2
[   10.682733] NIP:  c0431480 LR: c043147c CTR: c0422ad8
[   10.682863] REGS: cf82fbe0 TRAP: 0300   Tainted: G        W          (5.0.0-rc6-next-20190218+)
[   10.683065] MSR:  00029000   CR: 22000222  XER: 00000000
[   10.683236] DEAR: 00000040 ESR: 00000000
[   10.683236] GPR00: c043147c cf82fc90 cf82ccc0 00000000 00000000 00000000 00000002 00000000
[   10.683236] GPR08: 00000000 00000000 c04310bc 00000000 22000222 00000000 c0002c54 00000000
[   10.683236] GPR16: 00000000 00000001 c09aa39c c09021b0 c09021dc 00000007 c0a68c08 00000000
[   10.683236] GPR24: 00000001 ced6d400 ced6dcf0 c0815d9c 00000000 00000000 00000000 cedf0800
[   10.684331] NIP [c0431480] blk_mq_run_hw_queue+0x28/0x114
[   10.684473] LR [c043147c] blk_mq_run_hw_queue+0x24/0x114
[   10.684602] Call Trace:
[   10.684671] [cf82fc90] [c043147c] blk_mq_run_hw_queue+0x24/0x114 (unreliable)
[   10.684854] [cf82fcc0] [c04315bc] blk_mq_run_hw_queues+0x50/0x7c
[   10.685002] [cf82fce0] [c0422b24] blk_set_queue_dying+0x30/0x68
[   10.685154] [cf82fcf0] [c0423ec0] blk_cleanup_queue+0x34/0x14c
[   10.685306] [cf82fd10] [c054d73c] ace_probe+0x3dc/0x508
[   10.685445] [cf82fd50] [c052d740] platform_drv_probe+0x4c/0xb8
[   10.685592] [cf82fd70] [c052abb0] really_probe+0x20c/0x32c
[   10.685728] [cf82fda0] [c052ae58] driver_probe_device+0x68/0x464
[   10.685877] [cf82fdc0] [c052b500] device_driver_attach+0xb4/0xe4
[   10.686024] [cf82fde0] [c052b5dc] __driver_attach+0xac/0xfc
[   10.686161] [cf82fe00] [c0528428] bus_for_each_dev+0x80/0xc0
[   10.686314] [cf82fe30] [c0529b3c] bus_add_driver+0x144/0x234
[   10.686457] [cf82fe50] [c052c46c] driver_register+0x88/0x15c
[   10.686610] [cf82fe60] [c09de288] ace_init+0x4c/0xac
[   10.686742] [cf82fe80] [c0002730] do_one_initcall+0xac/0x330
[   10.686888] [cf82fee0] [c09aafd0] kernel_init_freeable+0x34c/0x478
[   10.687043] [cf82ff30] [c0002c6c] kernel_init+0x18/0x114
[   10.687188] [cf82ff40] [c000f2f0] ret_from_kernel_thread+0x14/0x1c
[   10.687349] Instruction dump:
[   10.687435] 3863ffd4 4bfffd70 9421ffd0 7c0802a6 93c10028 7c9e2378 93e1002c 38810008
[   10.687637] 7c7f1b78 90010034 4bfffc25 813f008c <81290040> 75290100 4182002c 80810008
[   10.688056] ---[ end trace 13c9ff51d41b9d40 ]---

Fix the problem by setting the disk queue pointer to NULL before calling
put_disk(). A more comprehensive fix might be to rearrange the code
to check the hardware version before initializing data structures,
but I don't know if this would have undesirable side effects, and
it would increase the complexity of backporting the fix to older kernels.

Fixes: 74489a91dd43a ("Add support for Xilinx SystemACE CompactFlash interface")
Acked-by: Michal Simek 
Signed-off-by: Guenter Roeck 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

Revert "block/loop: Use global lock for ioctl() operation."

2019-05-02T07:40:33+00:00

This reverts commit 57da9a9742200f391d1cf93fea389f7ddc25ec9a which is
commit 310ca162d779efee8a2dc3731439680f3e9c1e86 upstream.

Jan Kara has reported seeing problems with this patch applied, as has
Salvatore Bonaccorso, so let's drop it for now.

Reported-by: Salvatore Bonaccorso 
Reported-by: Jan Kara 
Cc: Tetsuo Handa 
Cc: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

zram: pass down the bvec we need to read into in the work struct

2019-05-02T07:40:28+00:00

commit e153abc0739ff77bd89c9ba1688cdb963464af97 upstream.

When scheduling work item to read page we need to pass down the proper
bvec struct which points to the page to read into.  Before this patch it
uses a randomly initialized bvec (only if PAGE_SIZE != 4096) which is
wrong.

Note that without this patch on arch/kernel where PAGE_SIZE != 4096
userspace could read random memory through a zram block device (thought
userspace probably would have no control on the address being read).

Link: http://lkml.kernel.org/r/20190408183219.26377-1-jglisse@redhat.com
Signed-off-by: Jérôme Glisse 
Reviewed-by: Andrew Morton 
Reviewed-by: Sergey Senozhatsky 
Acked-by: Minchan Kim 
Cc: Nitin Gupta 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

floppy: check_events callback should not return a negative number

2019-03-23T13:35:12+00:00

[ Upstream commit 96d7cb932e826219ec41ac02e5af037ffae6098c ]

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 a0c80efe5956, 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 
Fixes: a0c80efe5956 ("floppy: fix lock_fdc() signal handling")
Signed-off-by: Yufen Yu 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

Revert "loop: Fold __loop_release into loop_release"

2019-03-05T16:57:58+00:00

This reverts commit f1e81ba8a3fa56dcc48828869b392b29559a0ac3 which is
commit 967d1dc144b50ad005e5eecdfadfbcfb399ffff6 upstream.

It does not work properly in the 4.14.y tree and causes more problems
than it fixes, so revert it.

Reported-by: Thomas Lindroth 
Reported-by: Jan Kara 
Cc: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman