Commit Graph

145 Commits

Author SHA1 Message Date
Rabin Vincent 820962dc70 cifs: fix race between call_async() and reconnect()
cifs_call_async() queues the MID to the pending list and calls
smb_send_rqst().  If smb_send_rqst() performs a partial send, it sets
the tcpStatus to CifsNeedReconnect and returns an error code to
cifs_call_async().  In this case, cifs_call_async() removes the MID
from the list and returns to the caller.

However, cifs_call_async() releases the server mutex _before_ removing
the MID.  This means that a cifs_reconnect() can race with this function
and manage to remove the MID from the list and delete the entry before
cifs_call_async() calls cifs_delete_mid().  This leads to various
crashes due to the use after free in cifs_delete_mid().

Task1				Task2

cifs_call_async():
 - rc = -EAGAIN
 - mutex_unlock(srv_mutex)

				cifs_reconnect():
				 - mutex_lock(srv_mutex)
				 - mutex_unlock(srv_mutex)
				 - list_delete(mid)
				 - mid->callback()
				 	cifs_writev_callback():
				 		- mutex_lock(srv_mutex)
						- delete(mid)
				 		- mutex_unlock(srv_mutex)

 - cifs_delete_mid(mid) <---- use after free

Fix this by removing the MID in cifs_call_async() before releasing the
srv_mutex.  Also hold the srv_mutex in cifs_reconnect() until the MIDs
are moved out of the pending list.

Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <sfrench@localhost.localdomain>
2016-01-14 14:35:58 -06:00
Christopher Oo 5fb4e288a0 cifs: Fix use-after-free on mid_q_entry
With CIFS_DEBUG_2 enabled, additional debug information is tracked inside each
mid_q_entry struct, however cifs_save_when_sent may use the mid_q_entry after it
has been freed from the appropriate callback if the transport layer has very low
latency. Holding the srv_mutex fixes this use-after-free, as cifs_save_when_sent
is called while the srv_mutex is held while the request is sent.

Signed-off-by: Christopher Oo <t-chriso@microsoft.com>
2015-08-20 10:19:25 -05:00
Andy Shevchenko 0b456f04bc cifs: convert printk(LEVEL...) to pr_<level>
The useful macros embed message level in the name. Thus, it cleans up the code
a bit. In cases when it was plain printk() the conversion was done to info
level.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steve French <steve.french@primarydata.com>
2014-12-07 22:48:07 -06:00
Pavel Shilovsky cb7e9eabb2 CIFS: Use multicredits for SMB 2.1/3 writes
If we negotiate SMB 2.1 and higher version of the protocol and
a server supports large write buffer size, we need to consume 1
credit per 65536 bytes. So, we need to know how many credits
we have and obtain the required number of them before constructing
a writedata structure in writepages and iovec write.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 01:23:03 -05:00
Jeff Layton a26054d184 cifs: sanity check length of data to send before sending
We had a bug discovered recently where an upper layer function
(cifs_iovec_write) could pass down a smb_rqst with an invalid amount of
data in it. The length of the SMB frame would be correct, but the rqst
struct would cause smb_send_rqst to send nearly 4GB of data.

This should never be the case. Add some sanity checking to the beginning
of smb_send_rqst that ensures that the amount of data we're going to
send agrees with the length in the RFC1002 header. If it doesn't, WARN()
and return -EIO to the upper layers.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-02-23 20:55:07 -06:00
Shirish Pargaonkar 7f48558e64 cifs: Send a logoff request before removing a smb session
Send a smb session logoff request before removing smb session off of the list.
On a signed smb session, remvoing a session off of the list before sending
a logoff request results in server returning an error for lack of
smb signature.

Never seen an error during smb logoff, so as per MS-SMB2 3.2.5.1,
not sure how an error during logoff should be retried. So for now,
if a server returns an error to a logoff request, log the error and
remove the session off of the list.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-11-02 12:52:35 -05:00
Tim Gardner 3d378d3fd8 cifs: Make big endian multiplex ID sequences monotonic on the wire
The multiplex identifier (MID) in the SMB header is only
ever used by the client, in conjunction with PID, to match responses
from the server. As such, the endianess of the MID is not important.
However, When tracing packet sequences on the wire, protocol analyzers
such as wireshark display MID as little endian. It is much more informative
for the on-the-wire MID sequences to match debug information emitted by the
CIFS driver.  Therefore, one should write and read MID in the SMB header
assuming it is always little endian.

Observed from wireshark during the protocol negotiation
and session setup:

        Multiplex ID: 256
        Multiplex ID: 256
        Multiplex ID: 512
        Multiplex ID: 512
        Multiplex ID: 768
        Multiplex ID: 768

After this patch on-the-wire MID values begin at 1 and increase monotonically.

Introduce get_next_mid64() for the internal consumers that use the full 64 bit
multiplex identifier.

Introduce the helpers get_mid() and compare_mid() to make the endian
translation clear.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Tim Gardner <timg@tpi.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-11-02 12:51:53 -05:00
Shirish Pargaonkar eb4c7df6c2 cifs: Avoid umount hangs with smb2 when server is unresponsive
Do not send SMB2 Logoff command when reconnecting, the way smb1
code base works.

Also, no need to wait for a credit for an echo command when one is already
in flight.

Without these changes, umount command hangs if the server is unresponsive
e.g. hibernating.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@us.ibm.com>
2013-10-06 20:18:42 -05:00
Linus Torvalds f991fae5c6 Power management and ACPI updates for 3.11-rc1
- Hotplug changes allowing device hot-removal operations to fail
   gracefully (instead of crashing the kernel) if they cannot be
   carried out completely.  From Rafael J Wysocki and Toshi Kani.
 
 - Freezer update from Colin Cross and Mandeep Singh Baines targeted
   at making the freezing of tasks a bit less heavy weight operation.
 
 - cpufreq resume fix from Srivatsa S Bhat for a regression introduced
   during the 3.10 cycle causing some cpufreq sysfs attributes to
   return wrong values to user space after resume.
 
 - New freqdomain_cpus sysfs attribute for the acpi-cpufreq driver to
   provide information previously available via related_cpus from
   Lan Tianyu.
 
 - cpufreq fixes and cleanups from Viresh Kumar, Jacob Shin,
   Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia, Arnd Bergmann, and
   Tang Yuantian.
 
 - Fix for an ACPICA regression causing suspend/resume issues to
   appear on some systems introduced during the 3.4 development cycle
   from Lv Zheng.
 
 - ACPICA fixes and cleanups from Bob Moore, Tomasz Nowicki, Lv Zheng,
   Chao Guan, and Zhang Rui.
 
 - New cupidle driver for Xilinx Zynq processors from Michal Simek.
 
 - cpuidle fixes and cleanups from Daniel Lezcano.
 
 - Changes to make suspend/resume work correctly in Xen guests from
   Konrad Rzeszutek Wilk.
 
 - ACPI device power management fixes and cleanups from Fengguang Wu
   and Rafael J Wysocki.
 
 - ACPI documentation updates from Lv Zheng, Aaron Lu and Hanjun Guo.
 
 - Fix for the IA-64 issue that was the reason for reverting commit
   9f29ab1 and updates of the ACPI scan code from Rafael J Wysocki.
 
 - Mechanism for adding CMOS RTC address space handlers from Lan Tianyu
   (to allow some EC-related breakage to be fixed on some systems).
 
 - Spec-compliant implementation of acpi_os_get_timer() from
   Mika Westerberg.
 
 - Modification of do_acpi_find_child() to execute _STA in order to
   to avoid situations in which a pointer to a disabled device object
   is returned instead of an enabled one with the same _ADR value.
   From Jeff Wu.
 
 - Intel BayTrail PCH (Platform Controller Hub) support for the ACPI
   Intel Low-Power Subsystems (LPSS) driver and modificaions of that
   driver to work around a couple of known BIOS issues from
   Mika Westerberg and Heikki Krogerus.
 
 - EC driver fix from Vasiliy Kulikov to make it use get_user() and
   put_user() instead of dereferencing user space pointers blindly.
 
 - Assorted ACPI code cleanups from Bjorn Helgaas, Nicholas Mazzuca and
   Toshi Kani.
 
 - Modification of the "runtime idle" helper routine to take the return
   values of the callbacks executed by it into account and to call
   rpm_suspend() if they return 0, which allows some code bloat
   reduction to be done, from Rafael J Wysocki and Alan Stern.
 
 - New trace points for PM QoS from Sahara <keun-o.park@windriver.com>.
 
 - PM QoS documentation update from Lan Tianyu.
 
 - Assorted core PM code cleanups and changes from Bernie Thompson,
   Bjorn Helgaas, Julius Werner, and Shuah Khan.
 
 - New devfreq driver for the Exynos5-bus device from Abhilash Kesavan.
 
 - Minor devfreq cleanups, fixes and MAINTAINERS update from
   MyungJoo Ham, Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and
   Wei Yongjun.
 
 - OMAP Adaptive Voltage Scaling (AVS) SmartReflex voltage control
   driver updates from Andrii Tseglytskyi and Nishanth Menon.
 
 /
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Merge tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "This time the total number of ACPI commits is slightly greater than
  the number of cpufreq commits, but Viresh Kumar (who works on cpufreq)
  remains the most active patch submitter.

  To me, the most significant change is the addition of offline/online
  device operations to the driver core (with the Greg's blessing) and
  the related modifications of the ACPI core hotplug code.  Next are the
  freezer updates from Colin Cross that should make the freezing of
  tasks a bit less heavy weight.

  We also have a couple of regression fixes, a number of fixes for
  issues that have not been identified as regressions, two new drivers
  and a bunch of cleanups all over.

  Highlights:

   - Hotplug changes to support graceful hot-removal failures.

     It sometimes is necessary to fail device hot-removal operations
     gracefully if they cannot be carried out completely.  For example,
     if memory from a memory module being hot-removed has been allocated
     for the kernel's own use and cannot be moved elsewhere, it's
     desirable to fail the hot-removal operation in a graceful way
     rather than to crash the kernel, but currenty a success or a kernel
     crash are the only possible outcomes of an attempted memory
     hot-removal.  Needless to say, that is not a very attractive
     alternative and it had to be addressed.

     However, in order to make it work for memory, I first had to make
     it work for CPUs and for this purpose I needed to modify the ACPI
     processor driver.  It's been split into two parts, a resident one
     handling the low-level initialization/cleanup and a modular one
     playing the actual driver's role (but it binds to the CPU system
     device objects rather than to the ACPI device objects representing
     processors).  That's been sort of like a live brain surgery on a
     patient who's riding a bike.

     So this is a little scary, but since we found and fixed a couple of
     regressions it caused to happen during the early linux-next testing
     (a month ago), nobody has complained.

     As a bonus we remove some duplicated ACPI hotplug code, because the
     ACPI-based CPU hotplug is now going to use the common ACPI hotplug
     code.

   - Lighter weight freezing of tasks.

     These changes from Colin Cross and Mandeep Singh Baines are
     targeted at making the freezing of tasks a bit less heavy weight
     operation.  They reduce the number of tasks woken up every time
     during the freezing, by using the observation that the freezer
     simply doesn't need to wake up some of them and wait for them all
     to call refrigerator().  The time needed for the freezer to decide
     to report a failure is reduced too.

     Also reintroduced is the check causing a lockdep warining to
     trigger when try_to_freeze() is called with locks held (which is
     generally unsafe and shouldn't happen).

   - cpufreq updates

     First off, a commit from Srivatsa S Bhat fixes a resume regression
     introduced during the 3.10 cycle causing some cpufreq sysfs
     attributes to return wrong values to user space after resume.  The
     fix is kind of fresh, but also it's pretty obvious once Srivatsa
     has identified the root cause.

     Second, we have a new freqdomain_cpus sysfs attribute for the
     acpi-cpufreq driver to provide information previously available via
     related_cpus.  From Lan Tianyu.

     Finally, we fix a number of issues, mostly related to the
     CPUFREQ_POSTCHANGE notifier and cpufreq Kconfig options and clean
     up some code.  The majority of changes from Viresh Kumar with bits
     from Jacob Shin, Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia,
     Arnd Bergmann, and Tang Yuantian.

   - ACPICA update

     A usual bunch of updates from the ACPICA upstream.

     During the 3.4 cycle we introduced support for ACPI 5 extended
     sleep registers, but they are only supposed to be used if the
     HW-reduced mode bit is set in the FADT flags and the code attempted
     to use them without checking that bit.  That caused suspend/resume
     regressions to happen on some systems.  Fix from Lv Zheng causes
     those registers to be used only if the HW-reduced mode bit is set.

     Apart from this some other ACPICA bugs are fixed and code cleanups
     are made by Bob Moore, Tomasz Nowicki, Lv Zheng, Chao Guan, and
     Zhang Rui.

   - cpuidle updates

     New driver for Xilinx Zynq processors is added by Michal Simek.

     Multidriver support simplification, addition of some missing
     kerneldoc comments and Kconfig-related fixes come from Daniel
     Lezcano.

   - ACPI power management updates

     Changes to make suspend/resume work correctly in Xen guests from
     Konrad Rzeszutek Wilk, sparse warning fix from Fengguang Wu and
     cleanups and fixes of the ACPI device power state selection
     routine.

   - ACPI documentation updates

     Some previously missing pieces of ACPI documentation are added by
     Lv Zheng and Aaron Lu (hopefully, that will help people to
     uderstand how the ACPI subsystem works) and one outdated doc is
     updated by Hanjun Guo.

   - Assorted ACPI updates

     We finally nailed down the IA-64 issue that was the reason for
     reverting commit 9f29ab11dd ("ACPI / scan: do not match drivers
     against objects having scan handlers"), so we can fix it and move
     the ACPI scan handler check added to the ACPI video driver back to
     the core.

     A mechanism for adding CMOS RTC address space handlers is
     introduced by Lan Tianyu to allow some EC-related breakage to be
     fixed on some systems.

     A spec-compliant implementation of acpi_os_get_timer() is added by
     Mika Westerberg.

     The evaluation of _STA is added to do_acpi_find_child() to avoid
     situations in which a pointer to a disabled device object is
     returned instead of an enabled one with the same _ADR value.  From
     Jeff Wu.

     Intel BayTrail PCH (Platform Controller Hub) support is added to
     the ACPI driver for Intel Low-Power Subsystems (LPSS) and that
     driver is modified to work around a couple of known BIOS issues.
     Changes from Mika Westerberg and Heikki Krogerus.

     The EC driver is fixed by Vasiliy Kulikov to use get_user() and
     put_user() instead of dereferencing user space pointers blindly.

     Code cleanups are made by Bjorn Helgaas, Nicholas Mazzuca and Toshi
     Kani.

   - Assorted power management updates

     The "runtime idle" helper routine is changed to take the return
     values of the callbacks executed by it into account and to call
     rpm_suspend() if they return 0, which allows us to reduce the
     overall code bloat a bit (by dropping some code that's not
     necessary any more after that modification).

     The runtime PM documentation is updated by Alan Stern (to reflect
     the "runtime idle" behavior change).

     New trace points for PM QoS are added by Sahara
     (<keun-o.park@windriver.com>).

     PM QoS documentation is updated by Lan Tianyu.

     Code cleanups are made and minor issues are addressed by Bernie
     Thompson, Bjorn Helgaas, Julius Werner, and Shuah Khan.

   - devfreq updates

     New driver for the Exynos5-bus device from Abhilash Kesavan.

     Minor cleanups, fixes and MAINTAINERS update from MyungJoo Ham,
     Abhilash Kesavan, Paul Bolle, Rajagopal Venkat, and Wei Yongjun.

   - OMAP power management updates

     Adaptive Voltage Scaling (AVS) SmartReflex voltage control driver
     updates from Andrii Tseglytskyi and Nishanth Menon."

* tag 'pm+acpi-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits)
  cpufreq: Fix cpufreq regression after suspend/resume
  ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()
  PM / Sleep: Warn about system time after resume with pm_trace
  cpufreq: don't leave stale policy pointer in cdbs->cur_policy
  acpi-cpufreq: Add new sysfs attribute freqdomain_cpus
  cpufreq: make sure frequency transitions are serialized
  ACPI: implement acpi_os_get_timer() according the spec
  ACPI / EC: Add HP Folio 13 to ec_dmi_table in order to skip DSDT scan
  ACPI: Add CMOS RTC Operation Region handler support
  ACPI / processor: Drop unused variable from processor_perflib.c
  cpufreq: tegra: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: s3c64xx: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: omap: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: imx6q: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: exynos: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: dbx500: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: davinci: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: arm-big-little: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: powernow-k8: call CPUFREQ_POSTCHANGE notfier in error cases
  cpufreq: pcc: call CPUFREQ_POSTCHANGE notfier in error cases
  ...
2013-07-03 14:35:40 -07:00
Jeff Layton 38d77c50b4 cifs: track the enablement of signing in the TCP_Server_Info
Currently, we determine this according to flags in the sec_mode, flags
in the global_secflags and via other methods. That makes the semantics
very hard to follow and there are corner cases where we don't handle
this correctly.

Add a new bool to the TCP_Server_Info that acts as a simple flag to tell
us whether signing is enabled on this connection or not, and fix up the
places that need to determine this to use that flag.

This is a bit weird for the SMB2 case, where signing is per-session.
SMB2 needs work in this area already though. The existing SMB2 code has
similar logic to what we're using here, so there should be no real
change in behavior. These changes should make it easier to implement
per-session signing in the future though.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-24 01:56:43 -05:00
Colin Cross 5853cc2a89 freezer: add unsafe versions of freezable helpers for CIFS
CIFS calls wait_event_freezekillable_unsafe with a VFS lock held,
which is unsafe and will cause lockdep warnings when 6aa9707
"lockdep: check that no locks held at freeze time" is reapplied
(it was reverted in dbf520a).  CIFS shouldn't be doing this, but
it has long-running syscalls that must hold a lock but also
shouldn't block suspend.  Until CIFS freeze handling is rewritten
to use a signal to exit out of the critical section, add a new
wait_event_freezekillable_unsafe helper that will not run the
lockdep test when 6aa9707 is reapplied, and call it from CIFS.

In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock.  Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.

Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:21 +02:00
Jeff Layton 0124cc4511 cifs: store the real expected sequence number in the mid
Currently, the signing routines take a pointer to a place to store the
expected sequence number for the mid response. It then stores a value
that's one below what that sequence number should be, and then adds one
to it when verifying the signature on the response.

Increment the sequence number before storing the value in the mid, and
eliminate the "+1" when checking the signature.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:18:01 -05:00
Jeff Layton ad313cb86d cifs: on send failure, readjust server sequence number downward
If sending a call to the server fails for some reason (for instance, the
sending thread caught a signal), then we must readjust the sequence
number downward again or the next send will have it too high.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:17:56 -05:00
Jeff Layton ce6c44e44e cifs: remove ENOSPC handling in smb_sendv
To my knowledge, no one ever reported seeing this pop.

Acked-by: Suresh Jayaraman <sjayaraman@novell.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:17:51 -05:00
Joe Perches f96637be08 [CIFS] cifs: Rename cERROR and cFYI to cifs_dbg
It's not obvious from reading the macro names that these macros
are for debugging.  Convert the names to a single more typical
kernel style cifs_dbg macro.

	cERROR(1, ...)   -> cifs_dbg(VFS, ...)
	cFYI(1, ...)     -> cifs_dbg(FYI, ...)
	cFYI(DBG2, ...)  -> cifs_dbg(NOISY, ...)

Move the terminating format newline from the macro to the call site.

Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the
"CIFS VFS: " prefix for VFS messages.

Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y)

$ size fs/cifs/cifs.ko*
   text    data     bss     dec     hex filename
 265245	   2525	    132	 267902	  4167e	fs/cifs/cifs.ko.new
 268359    2525     132  271016   422a8 fs/cifs/cifs.ko.old

Other miscellaneous changes around these conversions:

o Miscellaneous typo fixes
o Add terminating \n's to almost all formats and remove them
  from the macros to be more kernel style like.  A few formats
  previously had defective \n's
o Remove unnecessary OOM messages as kmalloc() calls dump_stack
o Coalesce formats to make grep easier,
  added missing spaces when coalescing formats
o Use %s, __func__ instead of embedded function name
o Removed unnecessary "cifs: " prefixes
o Convert kzalloc with multiply to kcalloc
o Remove unused cifswarn macro

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:17:23 -05:00
Jeff Layton ea702b80e0 cifs: move check for NULL socket into smb_send_rqst
Cai reported this oops:

[90701.616664] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
[90701.625438] IP: [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.632167] PGD fea319067 PUD 103fda4067 PMD 0
[90701.637255] Oops: 0000 [#1] SMP
[90701.640878] Modules linked in: des_generic md4 nls_utf8 cifs dns_resolver binfmt_misc tun sg igb iTCO_wdt iTCO_vendor_support lpc_ich pcspkr i2c_i801 i2c_core i7core_edac edac_core ioatdma dca mfd_core coretemp kvm_intel kvm crc32c_intel microcode sr_mod cdrom ata_generic sd_mod pata_acpi crc_t10dif ata_piix libata megaraid_sas dm_mirror dm_region_hash dm_log dm_mod
[90701.677655] CPU 10
[90701.679808] Pid: 9627, comm: ls Tainted: G        W    3.7.1+ #10 QCI QSSC-S4R/QSSC-S4R
[90701.688950] RIP: 0010:[<ffffffff814a343e>]  [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.698383] RSP: 0018:ffff88177b431bb8  EFLAGS: 00010206
[90701.704309] RAX: ffff88177b431fd8 RBX: 00007ffffffff000 RCX: ffff88177b431bec
[90701.712271] RDX: 0000000000000003 RSI: 0000000000000006 RDI: 0000000000000000
[90701.720223] RBP: ffff88177b431bc8 R08: 0000000000000004 R09: 0000000000000000
[90701.728185] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
[90701.736147] R13: ffff88184ef92000 R14: 0000000000000023 R15: ffff88177b431c88
[90701.744109] FS:  00007fd56a1a47c0(0000) GS:ffff88105fc40000(0000) knlGS:0000000000000000
[90701.753137] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[90701.759550] CR2: 0000000000000028 CR3: 000000104f15f000 CR4: 00000000000007e0
[90701.767512] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[90701.775465] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[90701.783428] Process ls (pid: 9627, threadinfo ffff88177b430000, task ffff88185ca4cb60)
[90701.792261] Stack:
[90701.794505]  0000000000000023 ffff88177b431c50 ffff88177b431c38 ffffffffa014fcb1
[90701.802809]  ffff88184ef921bc 0000000000000000 00000001ffffffff ffff88184ef921c0
[90701.811123]  ffff88177b431c08 ffffffff815ca3d9 ffff88177b431c18 ffff880857758000
[90701.819433] Call Trace:
[90701.822183]  [<ffffffffa014fcb1>] smb_send_rqst+0x71/0x1f0 [cifs]
[90701.828991]  [<ffffffff815ca3d9>] ? schedule+0x29/0x70
[90701.834736]  [<ffffffffa014fe6d>] smb_sendv+0x3d/0x40 [cifs]
[90701.841062]  [<ffffffffa014fe96>] smb_send+0x26/0x30 [cifs]
[90701.847291]  [<ffffffffa015801f>] send_nt_cancel+0x6f/0xd0 [cifs]
[90701.854102]  [<ffffffffa015075e>] SendReceive+0x18e/0x360 [cifs]
[90701.860814]  [<ffffffffa0134a78>] CIFSFindFirst+0x1a8/0x3f0 [cifs]
[90701.867724]  [<ffffffffa013f731>] ? build_path_from_dentry+0xf1/0x260 [cifs]
[90701.875601]  [<ffffffffa013f731>] ? build_path_from_dentry+0xf1/0x260 [cifs]
[90701.883477]  [<ffffffffa01578e6>] cifs_query_dir_first+0x26/0x30 [cifs]
[90701.890869]  [<ffffffffa015480d>] initiate_cifs_search+0xed/0x250 [cifs]
[90701.898354]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.904486]  [<ffffffffa01554cb>] cifs_readdir+0x45b/0x8f0 [cifs]
[90701.911288]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.917410]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.923533]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.929657]  [<ffffffff81195848>] vfs_readdir+0xb8/0xe0
[90701.935490]  [<ffffffff81195b9f>] sys_getdents+0x8f/0x110
[90701.941521]  [<ffffffff815d3b99>] system_call_fastpath+0x16/0x1b
[90701.948222] Code: 66 90 55 65 48 8b 04 25 f0 c6 00 00 48 89 e5 53 48 83 ec 08 83 fe 01 48 8b 98 48 e0 ff ff 48 c7 80 48 e0 ff ff ff ff ff ff 74 22 <48> 8b 47 28 ff 50 68 65 48 8b 14 25 f0 c6 00 00 48 89 9a 48 e0
[90701.970313] RIP  [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.977125]  RSP <ffff88177b431bb8>
[90701.981018] CR2: 0000000000000028
[90701.984809] ---[ end trace 24bd602971110a43 ]---

This is likely due to a race vs. a reconnection event.

The current code checks for a NULL socket in smb_send_kvec, but that's
too late. By the time that check is done, the socket will already have
been passed to kernel_setsockopt. Move the check into smb_send_rqst, so
that it's checked earlier.

In truth, this is a bit of a half-assed fix. The -ENOTSOCK error
return here looks like it could bubble back up to userspace. The locking
rules around the ssocket pointer are really unclear as well. There are
cases where the ssocket pointer is changed without holding the srv_mutex,
but I'm not clear whether there's a potential race here yet or not.

This code seems like it could benefit from some fundamental re-think of
how the socket handling should behave. Until then though, this patch
should at least fix the above oops in most cases.

Cc: <stable@vger.kernel.org> # 3.7+
Reported-and-Tested-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-12-30 11:38:58 -06:00
Steve French b7a10626c8 [CIFS] WARN_ON_ONCE if kernel_sendmsg() returns -ENOSPC
kernel_sendmsg() is less likely to return -ENOSPC and it might be
a bug to do so. However, in the past there might have been cases
where a -ENOSPC was returned from a low level driver.

Add a WARN_ON_ONCE() to ensure that it is safe to assume that -ENOSPC
is no longer returned. This -ENOSPC specific handling will be removed
once we are sure it is no longer returned.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-10-07 20:00:47 -05:00
Jeff Layton fec344e3f3 cifs: change cifs_call_async to use smb_rqst structs
For now, none of the callers populate rq_pages. That will be done for
writes in a later patch. While we're at it, change the prototype of
setup_async_request not to need a return pointer argument. Just
return the pointer to the mid_q_entry or an ERR_PTR.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton fb308a6f22 cifs: teach signing routines how to deal with arrays of pages in a smb_rqst
Use the smb_send_rqst helper function to kmap each page in the array
and update the hash for that chunk.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton 97bc00b394 cifs: teach smb_send_rqst how to handle arrays of pages
Add code that allows smb_send_rqst to send an array of pages after the
initial kvec array has been sent. For now, we simply kmap the page
array and send it using the standard smb_send_kvec function. Eventually,
we may want to convert this code to use kernel_sendpage under the hood
and avoid the kmap altogether for the page data.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton b8eed28375 cifs: cork the socket before a send and uncork it afterward
We want to send SMBs as "atomically" as possible. Prior to sending any
data on the socket, cork it to make sure that no non-full frames go
out. Afterward, uncork it to make sure all of the data gets pushed out
to the wire.

Note that this more or less renders the socket=TCP_NODELAY mount option
obsolete. When TCP_CORK and TCP_NODELAY are used on the same socket,
TCP_NODELAY is essentially ignored.

Acked-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton 6f49f46b18 cifs: convert send code to use smb_rqst structs
Again, just a change in the arguments and some function renaming here.
In later patches, we'll change this code to deal with page arrays.

In this patch, we add a new smb_send_rqst wrapper and have smb_sendv
call that. Then we move most of the existing smb_sendv code into a new
function -- smb_send_kvec. This seems a little redundant, but later
we'll flesh this out to deal with arrays of pages.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton bf5ea0e2f2 cifs: change signing routines to deal with smb_rqst structs
We need a way to represent a call to be sent on the wire that does not
require having all of the page data kmapped. Behold the smb_rqst struct.
This new struct represents an array of kvecs immediately followed by an
array of pages.

Convert the signing routines to use these structs under the hood and
turn the existing functions for this into wrappers around that. For now,
we're just changing these functions to take different args. Later, we'll
teach them how to deal with arrays of pages.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:30 -05:00
Pavel Shilovsky 3c1bf7e48e CIFS: Enable signing in SMB2
Use hmac-sha256 and rather than hmac-md5 that is used for CIFS/SMB.

Signature field in SMB2 header is 16 bytes instead of 8 bytes.

Automatically enable signing by client when requested by the server
when signing ability is available to the client.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:28 -05:00
Steve French 985e4ff016 cifs: print error code if smb signature verification fails
While trying to debug a SMB signature related issue with Windows Servers
figured out it might be easier to debug if we print the error code from
cifs_verify_signature(). Also, fix indendation while at it.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-08-19 22:30:13 -05:00
Pavel Shilovsky 45740847e2 CIFS: Setup async request in ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:12 +04:00
Pavel Shilovsky 2dc7e1c033 CIFS: Make transport routines work with SMB2
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:20 -05:00
Pavel Shilovsky a891f0f895 CIFS: Extend credit mechanism to process request type
Split all requests to echos, oplocks and others - each group uses
its own credit slot. This is indicated by new flags

CIFS_ECHO_OP and CIFS_OBREAK_OP

that are not used now for CIFS. This change is required to support
SMB2 protocol because of different processing of these commands.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 00:32:48 -05:00
Jeff Layton 762a4206a3 cifs: rename cifs_sign_smb2 to cifs_sign_smbv
"smb2" makes me think of the SMB2.x protocol, which isn't at all what
this function is for...

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:34 -05:00
Jeff Layton d971e0656b cifs: remove bogus reset of smb_buf_length in smb_send routines
There's a comment here about how we don't want to modify this length,
but nothing in this function actually does.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:31 -05:00
Sachin Prabhu ffc61ccbb9 Initialise mid_q_entry before putting it on the pending queue
A user reported a crash in cifs_demultiplex_thread() caused by an
incorrectly set mid_q_entry->callback() function. It appears that the
callback assignment made in cifs_call_async() was not flushed back to
memory suggesting that a memory barrier was required here. Changing the
code to make sure that the mid_q_entry structure was completely
initialised before it was added to the pending queue fixes the problem.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16 23:57:02 -05:00
Pavel Shilovsky 8825736060 CIFS: Move get_next_mid to ops struct
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-06-01 12:35:19 -05:00
Pavel Shilovsky 452757897a CIFS: Move add/set_credits and get_credits_field to ops structure
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-05-23 12:33:12 +04:00
Pavel Shilovsky 082d0642c6 CIFS: Move protocol specific part from SendReceive2 to ops struct
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-05-23 12:32:57 +04:00
Jeff Layton 121b046af5 cifs: convert send_nt_cancel into a version specific op
For SMB2, this should be a no-op. Obviously if we wanted to do something
for the SMB2 case, we could also define an operation here for it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-05-16 20:13:34 -05:00
Pavel Shilovsky 7c9421e1a9 CIFS: Change mid_q_entry structure fields
to be protocol-unspecific and big enough to keep both CIFS
and SMB2 values.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:03 -04:00
Pavel Shilovsky d4e4854fd1 CIFS: Separate protocol-specific code from demultiplex code
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:02 -04:00
Pavel Shilovsky 792af7b05b CIFS: Separate protocol-specific code from transport routines
that lets us use this functions for SMB2.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:02 -04:00
Pavel Shilovsky bc205ed19b CIFS: Prepare credits code for a slot reservation
that is essential for CIFS/SMB/SMB2 oplock breaks and SMB2 echos.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-03-21 11:35:36 -05:00
Pavel Shilovsky 5bc594982f CIFS: Make wait_for_free_request killable
to let us kill the proccess if it hangs waiting for a credit when
the session is down and echo is disabled.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-03-21 11:35:32 -05:00
Pavel Shilovsky 2d86dbc970 CIFS: Introduce credit-based flow control
and send no more than credits value requests at once. For SMB/CIFS
it's trivial: increment this value by receiving any message and
decrement by sending one.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-03-21 11:35:03 -05:00
Pavel Shilovsky fc40f9cf82 CIFS: Simplify inFlight logic
by making it as unsigned integer and surround access with req_lock
from server structure.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-03-21 11:27:35 -05:00
Pavel Shilovsky 10b9b98e41 CIFS: Respect negotiated MaxMpxCount
Some servers sets this value less than 50 that was hardcoded and
we lost the connection if when we exceed this limit. Fix this by
respecting this value - not sending more than the server allows.

Cc: stable@kernel.org
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <stevef@smf-gateway.(none)>
2012-03-20 10:17:40 -05:00
Jeff Layton f06ac72e92 cifs, freezer: add wait_event_freezekillable and have cifs use it
CIFS currently uses wait_event_killable to put tasks to sleep while
they await replies from the server. That function though does not
allow the freezer to run. In many cases, the network interface may
be going down anyway, in which case the reply will never come. The
client then ends up blocking the computer from suspending.

Fix this by adding a new wait_event_freezable variant --
wait_event_freezekillable. The idea is to combine the behavior of
wait_event_killable and wait_event_freezable -- put the task to
sleep and only allow it to be awoken by fatal signals, but also
allow the freezer to do its job.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:30:40 -04:00
Jeff Layton 44d22d846f cifs: add a callback function to receive the rest of the frame
In order to handle larger SMBs for readpages and other calls, we want
to be able to read into a preallocated set of buffers. Rather than
changing all of the existing code to preallocate buffers however, we
instead add a receive callback function to the MID.

cifsd will call this function once the mid_q_entry has been identified
in order to receive the rest of the SMB. If the mid can't be identified
or the receive pointer is unset, then the standard 3rd phase receive
function will be called.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:49 -04:00
Jeff Layton 826a95e4a3 cifs: consolidate signature generating code
We have two versions of signature generating code. A vectorized and
non-vectorized version. Eliminate a large chunk of cut-and-paste
code by turning the non-vectorized version into a wrapper around the
vectorized one.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:41 -05:00
Steve French 789e666123 [CIFS] Cleanup use of CONFIG_CIFS_STATS2 ifdef to make transport routines more readable
Christoph had requested that the stats related code (in
CONFIG_CIFS_STATS2) be moved into helpers to make code flow more
readable.   This patch should help.   For example the following
section from transport.c

                       spin_unlock(&GlobalMid_Lock);
                       atomic_inc(&ses->server->num_waiters);
                       wait_event(ses->server->request_q,
                                  atomic_read(&ses->server->inFlight)
                                    < cifs_max_pending);
                       atomic_dec(&ses->server->num_waiters);
                       spin_lock(&GlobalMid_Lock);

becomes simpler (with the patch below):
                       spin_unlock(&GlobalMid_Lock);
                       cifs_num_waiters_inc(server);
                       wait_event(server->request_q,
                                  atomic_read(&server->inFlight)
                                    < cifs_max_pending);
                       cifs_num_waiters_dec(server);
                       spin_lock(&GlobalMid_Lock);

Reviewed-by: Jeff Layton <jlayton@redhat.com>
CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
2011-08-11 18:23:45 +00:00
Pavel Shilovsky 0193e07226 CIFS: Fix missing a decrement of inFlight value
if we failed on getting mid entry in cifs_call_async.

Cc: stable@kernel.org
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-08-03 19:42:12 +00:00
Steve French 96daf2b091 [CIFS] Rename three structures to avoid camel case
secMode to sec_mode
and
cifsTconInfo to cifs_tcon
and
cifsSesInfo to cifs_ses

Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-27 04:34:02 +00:00
Jeff Layton 3c1105df69 cifs: don't call mid_q_entry->callback under the Global_MidLock (try #5)
Minor revision to the last version of this patch -- the only difference
is the fix to the cFYI statement in cifs_reconnect.

Holding the spinlock while we call this function means that it can't
sleep, which really limits what it can do. Taking it out from under
the spinlock also means less contention for this global lock.

Change the semantics such that the Global_MidLock is not held when
the callback is called. To do this requires that we take extra care
not to have sync_mid_result remove the mid from the list when the
mid is in a state where that has already happened. This prevents
list corruption when the mid is sitting on a private list for
reconnect or when cifsd is coming down.

Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-24 03:11:33 +00:00