1. 27 Oct, 2015 8 commits
    • Shaohua Li's avatar
      x86/apic: Serialize LVTT and TSC_DEADLINE writes · 17d85849
      Shaohua Li authored
      commit 5d7c631d upstream.
      
      The APIC LVTT register is MMIO mapped but the TSC_DEADLINE register is an
      MSR. The write to the TSC_DEADLINE MSR is not serializing, so it's not
      guaranteed that the write to LVTT has reached the APIC before the
      TSC_DEADLINE MSR is written. In such a case the write to the MSR is
      ignored and as a consequence the local timer interrupt never fires.
      
      The SDM decribes this issue for xAPIC and x2APIC modes. The
      serialization methods recommended by the SDM differ.
      
      xAPIC:
       "1. Memory-mapped write to LVT Timer Register, setting bits 18:17 to 10b.
        2. WRMSR to the IA32_TSC_DEADLINE MSR a value much larger than current time-stamp counter.
        3. If RDMSR of the IA32_TSC_DEADLINE MSR returns zero, go to step 2.
        4. WRMSR to the IA32_TSC_DEADLINE MSR the desired deadline."
      
      x2APIC:
       "To allow for efficient access to the APIC registers in x2APIC mode,
        the serializing semantics of WRMSR are relaxed when writing to the
        APIC registers. Thus, system software should not use 'WRMSR to APIC
        registers in x2APIC mode' as a serializing instruction. Read and write
        accesses to the APIC registers will occur in program order. A WRMSR to
        an APIC register may complete before all preceding stores are globally
        visible; software can prevent this by inserting a serializing
        instruction, an SFENCE, or an MFENCE before the WRMSR."
      
      The xAPIC method is to just wait for the memory mapped write to hit
      the LVTT by checking whether the MSR write has reached the hardware.
      There is no reason why a proper MFENCE after the memory mapped write would
      not do the same. Andi Kleen confirmed that MFENCE is sufficient for the
      xAPIC case as well.
      
      Issue MFENCE before writing to the TSC_DEADLINE MSR. This can be done
      unconditionally as all CPUs which have TSC_DEADLINE also have MFENCE
      support.
      
      [ tglx: Massaged the changelog ]
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: <Kernel-team@fb.com>
      Cc: <lenb@kernel.org>
      Cc: <fenghua.yu@intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Link: http://lkml.kernel.org/r/20150909041352.GA2059853@devbig257.prn2.facebook.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      17d85849
    • Liu.Zhao's avatar
      USB: option: add ZTE PIDs · 77a428ad
      Liu.Zhao authored
      commit 19ab6bc5 upstream.
      
      This is intended to add ZTE device PIDs on kernel.
      Signed-off-by: default avatarLiu.Zhao <lzsos369@163.com>
      [johan: sort the new entries ]
      Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      77a428ad
    • Guenter Roeck's avatar
      hwmon: (nct6775) Swap STEP_UP_TIME and STEP_DOWN_TIME registers for most chips · a34de469
      Guenter Roeck authored
      commit 728d2940 upstream.
      
      The STEP_UP_TIME and STEP_DOWN_TIME registers are swapped for all chips but
      NCT6775.
      Reported-by: default avatarGrazvydas Ignotas <notasas@gmail.com>
      Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      a34de469
    • Jann Horn's avatar
      CIFS: fix type confusion in copy offload ioctl · 3249f58a
      Jann Horn authored
      commit 4c17a6d5 upstream.
      
      This might lead to local privilege escalation (code execution as
      kernel) for systems where the following conditions are met:
      
       - CONFIG_CIFS_SMB2 and CONFIG_CIFS_POSIX are enabled
       - a cifs filesystem is mounted where:
        - the mount option "vers" was used and set to a value >=2.0
        - the attacker has write access to at least one file on the filesystem
      
      To attack this, an attacker would have to guess the target_tcon
      pointer (but guessing wrong doesn't cause a crash, it just returns an
      error code) and win a narrow race.
      Signed-off-by: default avatarJann Horn <jann@thejh.net>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      3249f58a
    • Paul Mackerras's avatar
      powerpc/MSI: Fix race condition in tearing down MSI interrupts · e6d78946
      Paul Mackerras authored
      commit e297c939 upstream.
      
      This fixes a race which can result in the same virtual IRQ number
      being assigned to two different MSI interrupts.  The most visible
      consequence of that is usually a warning and stack trace from the
      sysfs code about an attempt to create a duplicate entry in sysfs.
      
      The race happens when one CPU (say CPU 0) is disposing of an MSI
      while another CPU (say CPU 1) is setting up an MSI.  CPU 0 calls
      (for example) pnv_teardown_msi_irqs(), which calls
      msi_bitmap_free_hwirqs() to indicate that the MSI (i.e. its
      hardware IRQ number) is no longer in use.  Then, before CPU 0 gets
      to calling irq_dispose_mapping() to free up the virtal IRQ number,
      CPU 1 comes in and calls msi_bitmap_alloc_hwirqs() to allocate an
      MSI, and gets the same hardware IRQ number that CPU 0 just freed.
      CPU 1 then calls irq_create_mapping() to get a virtual IRQ number,
      which sees that there is currently a mapping for that hardware IRQ
      number and returns the corresponding virtual IRQ number (which is
      the same virtual IRQ number that CPU 0 was using).  CPU 0 then
      calls irq_dispose_mapping() and frees that virtual IRQ number.
      Now, if another CPU comes along and calls irq_create_mapping(), it
      is likely to get the virtual IRQ number that was just freed,
      resulting in the same virtual IRQ number apparently being used for
      two different hardware interrupts.
      
      To fix this race, we just move the call to msi_bitmap_free_hwirqs()
      to after the call to irq_dispose_mapping().  Since virq_to_hw()
      doesn't work for the virtual IRQ number after irq_dispose_mapping()
      has been called, we need to call it before irq_dispose_mapping() and
      remember the result for the msi_bitmap_free_hwirqs() call.
      
      The pattern of calling msi_bitmap_free_hwirqs() before
      irq_dispose_mapping() appears in 5 places under arch/powerpc, and
      appears to have originated in commit 05af7bd2 ("[POWERPC] MPIC
      U3/U4 MSI backend") from 2007.
      
      Fixes: 05af7bd2 ("[POWERPC] MPIC U3/U4 MSI backend")
      Reported-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      [ kamal: backport to 3.19-stable: pasemi/msi.c -->
        arch/powerpc/sysdev/mpic_pasemi_msi.c ]
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      e6d78946
    • Ard Biesheuvel's avatar
      ARM: 8429/1: disable GCC SRA optimization · 1c2898b2
      Ard Biesheuvel authored
      commit a077224f upstream.
      
      While working on the 32-bit ARM port of UEFI, I noticed a strange
      corruption in the kernel log. The following snprintf() statement
      (in drivers/firmware/efi/efi.c:efi_md_typeattr_format())
      
      	snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
      
      was producing the following output in the log:
      
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|RUN|   |   |   |    |WB|WT|WC|UC]*
      	|RUN|   |   |   |    |WB|WT|WC|UC]*
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|RUN|   |   |   |    |WB|WT|WC|UC]*
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|RUN|   |   |   |    |   |   |   |UC]
      	|RUN|   |   |   |    |   |   |   |UC]
      
      As it turns out, this is caused by incorrect code being emitted for
      the string() function in lib/vsprintf.c. The following code
      
      	if (!(spec.flags & LEFT)) {
      		while (len < spec.field_width--) {
      			if (buf < end)
      				*buf = ' ';
      			++buf;
      		}
      	}
      	for (i = 0; i < len; ++i) {
      		if (buf < end)
      			*buf = *s;
      		++buf; ++s;
      	}
      	while (len < spec.field_width--) {
      		if (buf < end)
      			*buf = ' ';
      		++buf;
      	}
      
      when called with len == 0, triggers an issue in the GCC SRA optimization
      pass (Scalar Replacement of Aggregates), which handles promotion of signed
      struct members incorrectly. This is a known but as yet unresolved issue.
      (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932). In this particular
      case, it is causing the second while loop to be executed erroneously a
      single time, causing the additional space characters to be printed.
      
      So disable the optimization by passing -fno-ipa-sra.
      Acked-by: default avatarNicolas Pitre <nico@linaro.org>
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      [ luis: backported to 3.16: adjusted context ]
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      1c2898b2
    • Guenter Roeck's avatar
      spi: Fix documentation of spi_alloc_master() · fda98848
      Guenter Roeck authored
      commit a394d635 upstream.
      
      Actually, spi_master_put() after spi_alloc_master() must _not_ be followed
      by kfree(). The memory is already freed with the call to spi_master_put()
      through spi_master_class, which registers a release function. Calling both
      spi_master_put() and kfree() results in often nasty (and delayed) crashes
      elsewhere in the kernel, often in the networking stack.
      
      This reverts commit eb4af0f5.
      
      Link to patch and concerns: https://lkml.org/lkml/2012/9/3/269
      or
      http://lkml.iu.edu/hypermail/linux/kernel/1209.0/00790.html
      
      Alexey Klimov: This revert becomes valid after
      94c69f76 when spi-imx.c
      has been fixed and there is no need to call kfree() so comment
      for spi_alloc_master() should be fixed.
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarAlexey Klimov <alexey.klimov@linaro.org>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      fda98848
    • Tan, Jui Nee's avatar
      spi: spi-pxa2xx: Check status register to determine if SSSR_TINT is disabled · 69a4d746
      Tan, Jui Nee authored
      commit 02bc933e upstream.
      
      On Intel Baytrail, there is case when interrupt handler get called, no SPI
      message is captured. The RX FIFO is indeed empty when RX timeout pending
      interrupt (SSSR_TINT) happens.
      
      Use the BIOS version where both HSUART and SPI are on the same IRQ. Both
      drivers are using IRQF_SHARED when calling the request_irq function. When
      running two separate and independent SPI and HSUART application that
      generate data traffic on both components, user will see messages like
      below on the console:
      
        pxa2xx-spi pxa2xx-spi.0: bad message state in interrupt handler
      
      This commit will fix this by first checking Receiver Time-out Interrupt,
      if it is disabled, ignore the request and return without servicing.
      Signed-off-by: default avatarTan, Jui Nee <jui.nee.tan@intel.com>
      Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      69a4d746
  2. 26 Oct, 2015 4 commits
    • Sabrina Dubroca's avatar
      [stable-only] net: add length argument to skb_copy_and_csum_datagram_iovec · 1837825e
      Sabrina Dubroca authored
      Without this length argument, we can read past the end of the iovec in
      memcpy_toiovec because we have no way of knowing the total length of the
      iovec's buffers.
      
      This is needed for stable kernels where 89c22d8c ("net: Fix skb
      csum races when peeking") has been backported but that don't have the
      ioviter conversion, which is almost all the stable trees <= 3.18.
      
      This also fixes a kernel crash for NFS servers when the client uses
       -onfsvers=3,proto=udp to mount the export.
      Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
      Reviewed-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      1837825e
    • David Howells's avatar
      KEYS: Don't permit request_key() to construct a new keyring · 35552610
      David Howells authored
      commit 911b79cd upstream.
      
      If request_key() is used to find a keyring, only do the search part - don't
      do the construction part if the keyring was not found by the search.  We
      don't really want keyrings in the negative instantiated state since the
      rejected/negative instantiation error value in the payload is unioned with
      keyring metadata.
      
      Now the kernel gives an error:
      
      	request_key("keyring", "#selinux,bdekeyring", "keyring", KEY_SPEC_USER_SESSION_KEYRING) = -1 EPERM (Operation not permitted)
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      35552610
    • David Howells's avatar
      KEYS: Fix crash when attempt to garbage collect an uninstantiated keyring · 1881b6b8
      David Howells authored
      commit f05819df upstream.
      
      The following sequence of commands:
      
          i=`keyctl add user a a @s`
          keyctl request2 keyring foo bar @t
          keyctl unlink $i @s
      
      tries to invoke an upcall to instantiate a keyring if one doesn't already
      exist by that name within the user's keyring set.  However, if the upcall
      fails, the code sets keyring->type_data.reject_error to -ENOKEY or some
      other error code.  When the key is garbage collected, the key destroy
      function is called unconditionally and keyring_destroy() uses list_empty()
      on keyring->type_data.link - which is in a union with reject_error.
      Subsequently, the kernel tries to unlink the keyring from the keyring names
      list - which oopses like this:
      
      	BUG: unable to handle kernel paging request at 00000000ffffff8a
      	IP: [<ffffffff8126e051>] keyring_destroy+0x3d/0x88
      	...
      	Workqueue: events key_garbage_collector
      	...
      	RIP: 0010:[<ffffffff8126e051>] keyring_destroy+0x3d/0x88
      	RSP: 0018:ffff88003e2f3d30  EFLAGS: 00010203
      	RAX: 00000000ffffff82 RBX: ffff88003bf1a900 RCX: 0000000000000000
      	RDX: 0000000000000000 RSI: 000000003bfc6901 RDI: ffffffff81a73a40
      	RBP: ffff88003e2f3d38 R08: 0000000000000152 R09: 0000000000000000
      	R10: ffff88003e2f3c18 R11: 000000000000865b R12: ffff88003bf1a900
      	R13: 0000000000000000 R14: ffff88003bf1a908 R15: ffff88003e2f4000
      	...
      	CR2: 00000000ffffff8a CR3: 000000003e3ec000 CR4: 00000000000006f0
      	...
      	Call Trace:
      	 [<ffffffff8126c756>] key_gc_unused_keys.constprop.1+0x5d/0x10f
      	 [<ffffffff8126ca71>] key_garbage_collector+0x1fa/0x351
      	 [<ffffffff8105ec9b>] process_one_work+0x28e/0x547
      	 [<ffffffff8105fd17>] worker_thread+0x26e/0x361
      	 [<ffffffff8105faa9>] ? rescuer_thread+0x2a8/0x2a8
      	 [<ffffffff810648ad>] kthread+0xf3/0xfb
      	 [<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
      	 [<ffffffff815f2ccf>] ret_from_fork+0x3f/0x70
      	 [<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
      
      Note the value in RAX.  This is a 32-bit representation of -ENOKEY.
      
      The solution is to only call ->destroy() if the key was successfully
      instantiated.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      1881b6b8
    • David Howells's avatar
      KEYS: Fix race between key destruction and finding a keyring by name · 348fce88
      David Howells authored
      commit 94c4554b upstream.
      
      There appears to be a race between:
      
       (1) key_gc_unused_keys() which frees key->security and then calls
           keyring_destroy() to unlink the name from the name list
      
       (2) find_keyring_by_name() which calls key_permission(), thus accessing
           key->security, on a key before checking to see whether the key usage is 0
           (ie. the key is dead and might be cleaned up).
      
      Fix this by calling ->destroy() before cleaning up the core key data -
      including key->security.
      Reported-by: default avatarPetr Matousek <pmatouse@redhat.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      348fce88
  3. 23 Oct, 2015 2 commits
  4. 21 Oct, 2015 26 commits