linux-stable.git/drivers/target/target_core_user.c, branch linux-5.7.y

scsi: target: tcmu: Fix crash in tcmu_flush_dcache_range on ARM

2020-08-26T09:42:09+00:00

[ Upstream commit 3145550a7f8b08356c8ff29feaa6c56aca12901d ]

This patch fixes the following crash (see
https://bugzilla.kernel.org/show_bug.cgi?id=208045)

 Process iscsi_trx (pid: 7496, stack limit = 0x0000000010dd111a)
 CPU: 0 PID: 7496 Comm: iscsi_trx Not tainted 4.19.118-0419118-generic
        #202004230533
 Hardware name: Greatwall QingTian DF720/F601, BIOS 601FBE20 Sep 26 2019
 pstate: 80400005 (Nzcv daif +PAN -UAO)
 pc : flush_dcache_page+0x18/0x40
 lr : is_ring_space_avail+0x68/0x2f8 [target_core_user]
 sp : ffff000015123a80
 x29: ffff000015123a80 x28: 0000000000000000
 x27: 0000000000001000 x26: ffff000023ea5000
 x25: ffffcfa25bbe08b8 x24: 0000000000000078
 x23: ffff7e0000000000 x22: ffff000023ea5001
 x21: ffffcfa24b79c000 x20: 0000000000000fff
 x19: ffff7e00008fa940 x18: 0000000000000000
 x17: 0000000000000000 x16: ffff2d047e709138
 x15: 0000000000000000 x14: 0000000000000000
 x13: 0000000000000000 x12: ffff2d047fbd0a40
 x11: 0000000000000000 x10: 0000000000000030
 x9 : 0000000000000000 x8 : ffffc9a254820a00
 x7 : 00000000000013b0 x6 : 000000000000003f
 x5 : 0000000000000040 x4 : ffffcfa25bbe08e8
 x3 : 0000000000001000 x2 : 0000000000000078
 x1 : ffffcfa25bbe08b8 x0 : ffff2d040bc88a18
 Call trace:
  flush_dcache_page+0x18/0x40
  is_ring_space_avail+0x68/0x2f8 [target_core_user]
  queue_cmd_ring+0x1f8/0x680 [target_core_user]
  tcmu_queue_cmd+0xe4/0x158 [target_core_user]
  __target_execute_cmd+0x30/0xf0 [target_core_mod]
  target_execute_cmd+0x294/0x390 [target_core_mod]
  transport_generic_new_cmd+0x1e8/0x358 [target_core_mod]
  transport_handle_cdb_direct+0x50/0xb0 [target_core_mod]
  iscsit_execute_cmd+0x2b4/0x350 [iscsi_target_mod]
  iscsit_sequence_cmd+0xd8/0x1d8 [iscsi_target_mod]
  iscsit_process_scsi_cmd+0xac/0xf8 [iscsi_target_mod]
  iscsit_get_rx_pdu+0x404/0xd00 [iscsi_target_mod]
  iscsi_target_rx_thread+0xb8/0x130 [iscsi_target_mod]
  kthread+0x130/0x138
  ret_from_fork+0x10/0x18
 Code: f9000bf3 aa0003f3 aa1e03e0 d503201f (f9400260)
 ---[ end trace 1e451c73f4266776 ]---

The solution is based on patch:

  "scsi: target: tcmu: Optimize use of flush_dcache_page"

which restricts the use of tcmu_flush_dcache_range() to addresses from
vmalloc'ed areas only.

This patch now replaces the virt_to_page() call in
tcmu_flush_dcache_range() - which is wrong for vmalloced addrs - by
vmalloc_to_page().

The patch was tested on ARM with kernel 4.19.118 and 5.7.2

Link: https://lore.kernel.org/r/20200618131632.32748-3-bstroesser@ts.fujitsu.com
Tested-by: JiangYu 
Tested-by: Daniel Meyerholt 
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: tcmu: Fix a use after free in tcmu_check_expired_queue_cmd()

2020-06-24T15:48:57+00:00

[ Upstream commit 9d7464b18892332e35ff37f0b024429a1a9835e6 ]

The pr_debug() dereferences "cmd" after we already freed it by calling
tcmu_free_cmd(cmd).  The debug printk needs to be done earlier.

Link: https://lore.kernel.org/r/20200523101129.GB98132@mwanda
Fixes: 61fb24822166 ("scsi: target: tcmu: Userspace must not complete queued commands")
Reviewed-by: Mike Christie 
Reviewed-by: David Disseldorp 
Signed-off-by: Dan Carpenter 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: tcmu: Userspace must not complete queued commands

2020-06-24T15:48:51+00:00

[ Upstream commit 61fb2482216679b9e1e797440c148bb143a5040a ]

When tcmu queues a new command - no matter whether in command ring or in
qfull_queue - a cmd_id from IDR udev->commands is assigned to the command.

If userspace sends a wrong command completion containing the cmd_id of a
command on the qfull_queue, tcmu_handle_completions() finds the command in
the IDR and calls tcmu_handle_completion() for it. This might do some nasty
things because commands in qfull_queue do not have a valid dbi list.

To fix this bug, we no longer add queued commands to the idr.  Instead the
cmd_id is assign when a command is written to the command ring.

Due to this change I had to adapt the source code at several places where
up to now an idr_for_each had been done.

[mkp: fix checkpatch warnings]

Link: https://lore.kernel.org/r/20200518164833.12775-1-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: tcmu: reset_ring should reset TCMU_DEV_BIT_BROKEN

2020-04-13T18:03:20+00:00

In case command ring buffer becomes inconsistent, tcmu sets device flag
TCMU_DEV_BIT_BROKEN.  If the bit is set, tcmu rejects new commands from LIO
core with TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, and no longer processes
completions from the ring.  The reset_ring attribute can be used to
completely clean up the command ring, so after reset_ring the ring no
longer is inconsistent.

Therefore reset_ring also should reset bit TCMU_DEV_BIT_BROKEN to allow
normal processing.

Link: https://lore.kernel.org/r/20200409101026.17872-1-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen

scsi: target: tcmu: Prevent memory reclaim recursion

2019-11-09T02:37:24+00:00

Prevent recursion into the IO path under low memory conditions by using
GFP_NOIO in place of GFP_KERNEL when allocating a new command with
tcmu_alloc_cmd() and user ring space with tcmu_get_empty_block().

Link: https://lore.kernel.org/r/20191108082901.417950-1-damien.lemoal@wdc.com
Reported-by: Masato Suzuki 
Signed-off-by: Damien Le Moal 
Acked-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2019-09-21T17:50:15+00:00

Pull SCSI updates from James Bottomley:
 "This is mostly update of the usual drivers: qla2xxx, ufs, smartpqi,
  lpfc, hisi_sas, qedf, mpt3sas; plus a whole load of minor updates. The
  only core change this time around is the addition of request batching
  for virtio. Since batching requires an additional flag to use, it
  should be invisible to the rest of the drivers"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (264 commits)
  scsi: hisi_sas: Fix the conflict between device gone and host reset
  scsi: hisi_sas: Add BIST support for phy loopback
  scsi: hisi_sas: Add hisi_sas_debugfs_alloc() to centralise allocation
  scsi: hisi_sas: Remove some unused function arguments
  scsi: hisi_sas: Remove redundant work declaration
  scsi: hisi_sas: Remove hisi_sas_hw.slot_complete
  scsi: hisi_sas: Assign NCQ tag for all NCQ commands
  scsi: hisi_sas: Update all the registers after suspend and resume
  scsi: hisi_sas: Retry 3 times TMF IO for SAS disks when init device
  scsi: hisi_sas: Remove sleep after issue phy reset if sas_smp_phy_control() fails
  scsi: hisi_sas: Directly return when running I_T_nexus reset if phy disabled
  scsi: hisi_sas: Use true/false as input parameter of sas_phy_reset()
  scsi: hisi_sas: add debugfs auto-trigger for internal abort time out
  scsi: virtio_scsi: unplug LUNs when events missed
  scsi: scsi_dh_rdac: zero cdb in send_mode_select()
  scsi: fcoe: fix null-ptr-deref Read in fc_release_transport
  scsi: ufs-hisi: use devm_platform_ioremap_resource() to simplify code
  scsi: ufshcd: use devm_platform_ioremap_resource() to simplify code
  scsi: hisi_sas: use devm_platform_ioremap_resource() to simplify code
  scsi: ufs: Use kmemdup in ufshcd_read_string_desc()
  ...

scsi: target: tcmu: avoid use-after-free after command timeout

2019-08-15T01:58:55+00:00

In tcmu_handle_completion() function, the variable called read_len is
always initialized with a value taken from se_cmd structure. If this
function is called to complete an expired (timed out) out command, the
session command pointed by se_cmd is likely to be already deallocated by
the target core at that moment. As the result, this access triggers a
use-after-free warning from KASAN.

This patch fixes the code not to touch se_cmd when completing timed out
TCMU commands. It also resets the pointer to se_cmd at the time when the
TCMU_CMD_BIT_EXPIRED flag is set because it is going to become invalid
after calling target_complete_cmd() later in the same function,
tcmu_check_expired_cmd().

Signed-off-by: Dmitry Fomichev 
Acked-by: Mike Christie 
Reviewed-by: Damien Le Moal 
Signed-off-by: Martin K. Petersen

scsi: target: tcmu: clean the nl_cmd of the udev when nl send fails

2019-08-08T01:52:01+00:00

If the userspace process crashes while we send the nl msg, it is possible
that the cmd in curr_nl_cmd of tcmu_dev never gets reset to 0, and and
returns busy for other commands after the userspace process is restartd.

More details below:

/backstores/user:file/file> set attribute dev_size=2048
Cannot set attribute dev_size: [Errno 3] No such process
/backstores/user:file/file> set attribute dev_size=2048
Cannot set attribute dev_size: [Errno 16] Device or resource busy

with following kernel messages:
[173605.747169] Unable to reconfigure device
[173616.686674] tcmu daemon: command reply support 1.
[173623.866978] netlink cmd 3 already executing on file
[173623.866984] Unable to reconfigure device

Also, it is not safe to leave the nl_cmd in the list, and not get deleted.

This patch removes the nl_cmd from the list, and clear its data if it is
not sent successfully.

Signed-off-by: Li Zhong 
Acked-by: Mike Christie 
Signed-off-by: Martin K. Petersen

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2019-07-11T22:14:01+00:00

Pull SCSI updates from James Bottomley:
 "This is mostly update of the usual drivers: qla2xxx, hpsa, lpfc, ufs,
  mpt3sas, ibmvscsi, megaraid_sas, bnx2fc and hisi_sas as well as the
  removal of the osst driver (I heard from Willem privately that he
  would like the driver removed because all his test hardware has
  failed). Plus number of minor changes, spelling fixes and other
  trivia.

  The big merge conflict this time around is the SPDX licence tags.
  Following discussion on linux-next, we believe our version to be more
  accurate than the one in the tree, so the resolution is to take our
  version for all the SPDX conflicts"

Note on the SPDX license tag conversion conflicts: the SCSI tree had
done its own SPDX conversion, which in some cases conflicted with the
treewide ones done by Thomas & co.

In almost all cases, the conflicts were purely syntactic: the SCSI tree
used the old-style SPDX tags ("GPL-2.0" and "GPL-2.0+") while the
treewide conversion had used the new-style ones ("GPL-2.0-only" and
"GPL-2.0-or-later").

In these cases I picked the new-style one.

In a few cases, the SPDX conversion was actually different, though.  As
explained by James above, and in more detail in a pre-pull-request
thread:

 "The other problem is actually substantive: In the libsas code Luben
  Tuikov originally specified gpl 2.0 only by dint of stating:

  * This file is licensed under GPLv2.

  In all the libsas files, but then muddied the water by quoting GPLv2
  verbatim (which includes the or later than language). So for these
  files Christoph did the conversion to v2 only SPDX tags and Thomas
  converted to v2 or later tags"

So in those cases, where the spdx tag substantially mattered, I took the
SCSI tree conversion of it, but then also took the opportunity to turn
the old-style "GPL-2.0" into a new-style "GPL-2.0-only" tag.

Similarly, when there were whitespace differences or other differences
to the comments around the copyright notices, I took the version from
the SCSI tree as being the more specific conversion.

Finally, in the spdx conversions that had no conflicts (because the
treewide ones hadn't been done for those files), I just took the SCSI
tree version as-is, even if it was old-style.  The old-style conversions
are perfectly valid, even if the "-only" and "-or-later" versions are
perhaps more descriptive.

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (185 commits)
  scsi: qla2xxx: move IO flush to the front of NVME rport unregistration
  scsi: qla2xxx: Fix NVME cmd and LS cmd timeout race condition
  scsi: qla2xxx: on session delete, return nvme cmd
  scsi: qla2xxx: Fix kernel crash after disconnecting NVMe devices
  scsi: megaraid_sas: Update driver version to 07.710.06.00-rc1
  scsi: megaraid_sas: Introduce various Aero performance modes
  scsi: megaraid_sas: Use high IOPS queues based on IO workload
  scsi: megaraid_sas: Set affinity for high IOPS reply queues
  scsi: megaraid_sas: Enable coalescing for high IOPS queues
  scsi: megaraid_sas: Add support for High IOPS queues
  scsi: megaraid_sas: Add support for MPI toolbox commands
  scsi: megaraid_sas: Offload Aero RAID5/6 division calculations to driver
  scsi: megaraid_sas: RAID1 PCI bandwidth limit algorithm is applicable for only Ventura
  scsi: megaraid_sas: megaraid_sas: Add check for count returned by HOST_DEVICE_LIST DCMD
  scsi: megaraid_sas: Handle sequence JBOD map failure at driver level
  scsi: megaraid_sas: Don't send FPIO to RL Bypass queue
  scsi: megaraid_sas: In probe context, retry IOC INIT once if firmware is in fault
  scsi: megaraid_sas: Release Mutex lock before OCR in case of DCMD timeout
  scsi: megaraid_sas: Call disable_irq from process IRQ poll
  scsi: megaraid_sas: Remove few debug counters from IO path
  ...

scsi: tcmu: Simplify tcmu_update_uio_info()

2019-06-20T19:37:02+00:00

Use 'kasprintf()' instead of:
   - snprintf(NULL, 0...
   - kmalloc(...
   - snprintf(...

This is less verbose and saves 7 bytes (i.e. the space for '/(null)') if
'udev->dev_config' is NULL.

Signed-off-by: Christophe JAILLET 
Acked-by: Mike Christie 
Signed-off-by: Martin K. Petersen