linux-stable.git/drivers/block, branch v3.16.80 Linux kernel stable tree block: drbd: remove a stray unlock in __drbd_send_protocol() 2019-12-19T15:58:58+00:00 Dan Carpenter dan.carpenter@oracle.com 2019-11-07T07:48:47+00:00 fbb4995c67ac32830d7c9519150a8623ecf18fdc commit 8e9c523016cf9983b295e4bc659183d1fa6ef8e0 upstream. There are two callers of this function and they both unlock the mutex so this ends up being a double unlock. Fixes: 44ed167da748 ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 8e9c523016cf9983b295e4bc659183d1fa6ef8e0 upstream.

There are two callers of this function and they both unlock the mutex so
this ends up being a double unlock.

Fixes: 44ed167da748 ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
floppy: fix out-of-bounds read in copy_buffer 2019-08-13T11:39:27+00:00 Denis Efremov efremov@ispras.ru 2019-07-12T18:55:23+00:00 05429983fa0fa3bfa1b8436beb63913d9d4aad1a commit da99466ac243f15fbba65bd261bfc75ffa1532b6 upstream. 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: Ben Hutchings <ben@decadent.org.uk> 
commit da99466ac243f15fbba65bd261bfc75ffa1532b6 upstream.

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: Ben Hutchings <ben@decadent.org.uk>
floppy: fix invalid pointer dereference in drive_name 2019-08-13T11:39:26+00:00 Denis Efremov efremov@ispras.ru 2019-07-12T18:55:22+00:00 fbf6a95d0a3d410ee2f4530e243b77beee87c76a commit 9b04609b784027968348796a18f601aed9db3789 upstream. 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> [bwh: Backported to 3.16: Drop changes in compat_setdrvprm(), as compat ioctls go via fd_ioctl_locked() after translation in compat_ioctl.c.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 9b04609b784027968348796a18f601aed9db3789 upstream.

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>
[bwh: Backported to 3.16: Drop changes in compat_setdrvprm(), as compat
 ioctls go via fd_ioctl_locked() after translation in compat_ioctl.c.]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
floppy: fix out-of-bounds read in next_valid_format 2019-08-13T11:39:26+00:00 Denis Efremov efremov@ispras.ru 2019-07-12T18:55:21+00:00 59fbdf8b65a4f09d8043dded8a4b8e0d603eee27 commit 5635f897ed83fd539df78e98ba69ee91592f9bb8 upstream. 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> [bwh: Backported to 3.16: Drop changes in compat_setdrvprm(), as compat ioctls go via fd_ioctl_locked() after translation in compat_ioctl.c.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 5635f897ed83fd539df78e98ba69ee91592f9bb8 upstream.

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>
[bwh: Backported to 3.16: Drop changes in compat_setdrvprm(), as compat
 ioctls go via fd_ioctl_locked() after translation in compat_ioctl.c.]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
floppy: fix div-by-zero in setup_format_params 2019-08-13T11:39:26+00:00 Denis Efremov efremov@ispras.ru 2019-07-12T18:55:20+00:00 a36b6459cbff32a0ef228241c99d6586ca7e944c commit f3554aeb991214cbfafd17d55e2bfddb50282e32 upstream. 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: Ben Hutchings <ben@decadent.org.uk> 
commit f3554aeb991214cbfafd17d55e2bfddb50282e32 upstream.

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: Ben Hutchings <ben@decadent.org.uk>
xsysace: Fix error handling in ace_setup 2019-08-13T11:39:03+00:00 Guenter Roeck linux@roeck-us.net 2019-02-19T16:49:56+00:00 30e591c61a4801318b82875c7aa84ee61a0e59a6 commit 47b16820c490149c2923e8474048f2c6e7557cab upstream. 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 <CE,EE,ME> 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 <michal.simek@xilinx.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 47b16820c490149c2923e8474048f2c6e7557cab upstream.

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 <CE,EE,ME>  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 <michal.simek@xilinx.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
rbd: don't return 0 on unmap if RBD_DEV_FLAG_REMOVING is set 2019-05-02T20:41:17+00:00 Ilya Dryomov idryomov@gmail.com 2019-01-08T18:47:38+00:00 e7254cb5da9aee39e160870499f816f782e28019 commit 85f5a4d666fd9be73856ed16bb36c5af5b406b29 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 Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Tested-by: Dongsheng Yang <dongsheng.yang@easystack.cn> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 85f5a4d666fd9be73856ed16bb36c5af5b406b29 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

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
block/swim3: Fix -EBUSY error when re-opening device after unmount 2019-04-04T15:14:09+00:00 Finn Thain fthain@telegraphics.com.au 2018-12-31T05:44:09+00:00 c4712cd74e68cd49c55b07b3648af2f20fe2938f commit 296dcc40f2f2e402facf7cd26cf3f2c8f4b17d47 upstream. 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: 1da177e4c3f4 ("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: Ben Hutchings <ben@decadent.org.uk> 
commit 296dcc40f2f2e402facf7cd26cf3f2c8f4b17d47 upstream.

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: 1da177e4c3f4 ("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: Ben Hutchings <ben@decadent.org.uk>
floppy: fix race condition in __floppy_read_block_0() 2019-02-11T17:53:59+00:00 Jens Axboe axboe@kernel.dk 2018-11-09T22:58:40+00:00 ddce3611490c679877f4609d0ae1ce1221a157c2 commit de7b75d82f70c5469675b99ad632983c50b6f7e7 upstream. 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: 7b7b68bba5ef ("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> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit de7b75d82f70c5469675b99ad632983c50b6f7e7 upstream.

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: 7b7b68bba5ef ("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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nbd: don't allow invalid blocksize settings 2018-12-16T22:09:02+00:00 Jens Axboe axboe@kernel.dk 2018-09-04T17:52:34+00:00 b1713a2e188d7912c7b5543755b0479ad75c8e11 commit bc811f05d77f47059c197a98b6ad242eb03999cb upstream. syzbot reports a divide-by-zero off the NBD_SET_BLKSIZE ioctl. We need proper validation of the input here. Not just if it's zero, but also if the value is a power-of-2 and in a valid range. Add that. Reported-by: syzbot <syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit bc811f05d77f47059c197a98b6ad242eb03999cb upstream.

syzbot reports a divide-by-zero off the NBD_SET_BLKSIZE ioctl.
We need proper validation of the input here. Not just if it's
zero, but also if the value is a power-of-2 and in a valid
range. Add that.

Reported-by: syzbot <syzbot+25dbecbec1e62c6b0dd4@syzkaller.appspotmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>