1. 29 Jun, 2017 16 commits
    • Jason A. Donenfeld's avatar
      mac80211/wpa: use constant time memory comparison for MACs · 6bc55148
      Jason A. Donenfeld authored
      commit 98c67d18 upstream.
      
      Otherwise, we enable all sorts of forgeries via timing attack.
      Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
      Cc: Johannes Berg <johannes@sipsolutions.net>
      Cc: linux-wireless@vger.kernel.org
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      6bc55148
    • Russell King's avatar
      net: phy: fix marvell phy status reading · 131e696c
      Russell King authored
      commit 898805e0 upstream.
      
      The Marvell driver incorrectly provides phydev->lp_advertising as the
      logical and of the link partner's advert and our advert.  This is
      incorrect - this field is supposed to store the link parter's unmodified
      advertisment.
      
      This allows ethtool to report the correct link partner auto-negotiation
      status.
      
      Fixes: be937f1f ("Marvell PHY m88e1111 driver fix")
      Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
      Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarAmit Pundir <amit.pundir@linaro.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      131e696c
    • William Wu's avatar
      usb: gadget: f_fs: avoid out of bounds access on comp_desc · e1957b18
      William Wu authored
      commit b7f73850 upstream.
      
      Companion descriptor is only used for SuperSpeed endpoints,
      if the endpoints are HighSpeed or FullSpeed, the Companion
      descriptor will not allocated, so we can only access it if
      gadget is SuperSpeed.
      
      I can reproduce this issue on Rockchip platform rk3368 SoC
      which supports USB 2.0, and use functionfs for ADB. Kernel
      build with CONFIG_KASAN=y and CONFIG_SLUB_DEBUG=y report
      the following BUG:
      
      ==================================================================
      BUG: KASAN: slab-out-of-bounds in ffs_func_set_alt+0x224/0x3a0 at addr ffffffc0601f6509
      Read of size 1 by task swapper/0/0
      ============================================================================
      BUG kmalloc-256 (Not tainted): kasan: bad access detected
      ----------------------------------------------------------------------------
      
      Disabling lock debugging due to kernel taint
      INFO: Allocated in ffs_func_bind+0x52c/0x99c age=1275 cpu=0 pid=1
      alloc_debug_processing+0x128/0x17c
      ___slab_alloc.constprop.58+0x50c/0x610
      __slab_alloc.isra.55.constprop.57+0x24/0x34
      __kmalloc+0xe0/0x250
      ffs_func_bind+0x52c/0x99c
      usb_add_function+0xd8/0x1d4
      configfs_composite_bind+0x48c/0x570
      udc_bind_to_driver+0x6c/0x170
      usb_udc_attach_driver+0xa4/0xd0
      gadget_dev_desc_UDC_store+0xcc/0x118
      configfs_write_file+0x1a0/0x1f8
      __vfs_write+0x64/0x174
      vfs_write+0xe4/0x200
      SyS_write+0x68/0xc8
      el0_svc_naked+0x24/0x28
      INFO: Freed in inode_doinit_with_dentry+0x3f0/0x7c4 age=1275 cpu=7 pid=247
      ...
      Call trace:
      [<ffffff900808aab4>] dump_backtrace+0x0/0x230
      [<ffffff900808acf8>] show_stack+0x14/0x1c
      [<ffffff90084ad420>] dump_stack+0xa0/0xc8
      [<ffffff90082157cc>] print_trailer+0x188/0x198
      [<ffffff9008215948>] object_err+0x3c/0x4c
      [<ffffff900821b5ac>] kasan_report+0x324/0x4dc
      [<ffffff900821aa38>] __asan_load1+0x24/0x50
      [<ffffff90089eb750>] ffs_func_set_alt+0x224/0x3a0
      [<ffffff90089d3760>] composite_setup+0xdcc/0x1ac8
      [<ffffff90089d7394>] android_setup+0x124/0x1a0
      [<ffffff90089acd18>] _setup+0x54/0x74
      [<ffffff90089b6b98>] handle_ep0+0x3288/0x4390
      [<ffffff90089b9b44>] dwc_otg_pcd_handle_out_ep_intr+0x14dc/0x2ae4
      [<ffffff90089be85c>] dwc_otg_pcd_handle_intr+0x1ec/0x298
      [<ffffff90089ad680>] dwc_otg_pcd_irq+0x10/0x20
      [<ffffff9008116328>] handle_irq_event_percpu+0x124/0x3ac
      [<ffffff9008116610>] handle_irq_event+0x60/0xa0
      [<ffffff900811af30>] handle_fasteoi_irq+0x10c/0x1d4
      [<ffffff9008115568>] generic_handle_irq+0x30/0x40
      [<ffffff90081159b4>] __handle_domain_irq+0xac/0xdc
      [<ffffff9008080e9c>] gic_handle_irq+0x64/0xa4
      ...
      Memory state around the buggy address:
        ffffffc0601f6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
        ffffffc0601f6480: 00 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc
       >ffffffc0601f6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                             ^
        ffffffc0601f6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
        ffffffc0601f6600: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
      ==================================================================
      Signed-off-by: default avatarWilliam Wu <william.wu@rock-chips.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Cc: Jerry Zhang <zhangjerry@google.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e1957b18
    • Michael Ellerman's avatar
      powerpc/slb: Force a full SLB flush when we insert for a bad EA · 668e0da8
      Michael Ellerman authored
      [Note this patch is not upstream. The bug fix was fixed differently in
      upstream prior to the bug being identified.]
      
      The SLB miss handler calls slb_allocate_realmode() in order to create an
      SLB entry for the faulting address. At the very start of that function
      we check that the faulting Effective Address (EA) is less than
      PGTABLE_RANGE (ignoring the region), ie. is it an address which could
      possibly fit in the virtual address space.
      
      For an EA which fails that test, we branch out of line (to label 8), but
      we still go on to create an SLB entry for the address. The SLB entry we
      create has a VSID of 0, which means it will never match anything in the
      hash table and so can't actually translate to a physical address.
      
      However that SLB entry will be inserted in the SLB, and so needs to be
      managed properly like any other SLB entry. In particular we need to
      insert the SLB entry in the SLB cache, so that it will be flushed when
      the process is descheduled.
      
      And that is where the bugs begin. The first bug is that slb_finish_load()
      uses cr7 to decide if it should insert the SLB entry into the SLB cache.
      When we come from the invalid EA case we don't set cr7, it just has some
      junk value from userspace. So we may or may not insert the SLB entry in
      the SLB cache. If we fail to insert it, we may then incorrectly leave it
      in the SLB when the process is descheduled.
      
      The second bug is that even if we do happen to add the entry to the SLB
      cache, we do not have enough bits in the SLB cache to remember the full
      ESID value for very large EAs.
      
      For example if a process branches to 0x788c545a18000000, that results in
      a 256MB SLB entry with an ESID of 0x788c545a1. But each entry in the SLB
      cache is only 32-bits, meaning we truncate the ESID to 0x88c545a1. This
      has the same effect as the first bug, we incorrectly leave the SLB entry
      in the SLB when the process is descheduled.
      
      When a process accesses an invalid EA it results in a SEGV signal being
      sent to the process, which typically results in the process being
      killed. Process death isn't instantaneous however, the process may catch
      the SEGV signal and continue somehow, or the kernel may start writing a
      core dump for the process, either of which means it's possible for the
      process to be preempted while its processing the SEGV but before it's
      been killed.
      
      If that happens, when the process is scheduled back onto the CPU we will
      allocate a new SLB entry for the NIP, which will insert a second entry
      into the SLB for the bad EA. Because we never flushed the original
      entry, due to either bug one or two, we now have two SLB entries that
      match the same EA.
      
      If another access is made to that EA, either by the process continuing
      after catching the SEGV, or by a second process accessing the same bad
      EA on the same CPU, we will trigger an SLB multi-hit machine check
      exception. This has been observed happening in the wild.
      
      The fix is when we hit the invalid EA case, we mark the SLB cache as
      being full. This causes us to not insert the truncated ESID into the SLB
      cache, and means when the process is switched out we will flush the
      entire SLB. Note that this works both for the original fault and for a
      subsequent call to slb_allocate_realmode() from switch_slb().
      
      Because we mark the SLB cache as full, it doesn't really matter what
      value is in cr7, but rather than leaving it as something random we set
      it to indicate the address was a kernel address. That also skips the
      attempt to insert it in the SLB cache which is a nice side effect.
      
      Another way to fix the bug would be to make the entries in the SLB cache
      wider, so that we don't truncate the ESID. However this would be a more
      intrusive change as it alters the size and layout of the paca.
      
      This bug was fixed in upstream by commit f0f558b1 ("powerpc/mm:
      Preserve CFAR value on SLB miss caused by access to bogus address"),
      which changed the way we handle a bad EA entirely removing this bug in
      the process.
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Reviewed-by: default avatarPaul Mackerras <paulus@ozlabs.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      668e0da8
    • Joël Esponde's avatar
      mtd: spi-nor: fix spansion quad enable · 2eb4011c
      Joël Esponde authored
      commit 807c1625 upstream.
      
      With the S25FL127S nor flash part, each writing to the configuration
      register takes hundreds of ms. During that  time, no more accesses to
      the flash should be done (even reads).
      
      This commit adds a wait loop after the register writing until the flash
      finishes its work.
      
      This issue could make rootfs mounting fail when the latter was done too
      much closely to this quad enable bit setting step. And in this case, a
      driver as UBIFS may try to recover the filesystem and may broke it
      completely.
      Signed-off-by: default avatarJoël Esponde <joel.esponde@honeywell.com>
      Signed-off-by: default avatarCyrille Pitchen <cyrille.pitchen@atmel.com>
      Signed-off-by: default avatarAmit Pundir <amit.pundir@linaro.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2eb4011c
    • Tobias Wolf's avatar
      of: Add check to of_scan_flat_dt() before accessing initial_boot_params · db89d5c7
      Tobias Wolf authored
      commit 3ec75441 upstream.
      
      An empty __dtb_start to __dtb_end section might result in
      initial_boot_params being null for arch/mips/ralink. This showed that the
      boot process hangs indefinitely in of_scan_flat_dt().
      Signed-off-by: default avatarTobias Wolf <dev-NTEO@vplace.de>
      Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/14605/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarAmit Pundir <amit.pundir@linaro.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      db89d5c7
    • David Howells's avatar
      rxrpc: Fix several cases where a padded len isn't checked in ticket decode · 9c3a8a0f
      David Howells authored
      commit 5f2f9765 upstream.
      
      This fixes CVE-2017-7482.
      
      When a kerberos 5 ticket is being decoded so that it can be loaded into an
      rxrpc-type key, there are several places in which the length of a
      variable-length field is checked to make sure that it's not going to
      overrun the available data - but the data is padded to the nearest
      four-byte boundary and the code doesn't check for this extra.  This could
      lead to the size-remaining variable wrapping and the data pointer going
      over the end of the buffer.
      
      Fix this by making the various variable-length data checks use the padded
      length.
      Reported-by: default avatar石磊 <shilei-c@360.cn>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Reviewed-by: default avatarMarc Dionne <marc.c.dionne@auristor.com>
      Reviewed-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9c3a8a0f
    • Nicholas Bellinger's avatar
      target: Fix kref->refcount underflow in transport_cmd_finish_abort · 0b7db7b0
      Nicholas Bellinger authored
      commit 73d4e580 upstream.
      
      This patch fixes a se_cmd->cmd_kref underflow during CMD_T_ABORTED
      when a fabric driver drops it's second reference from below the
      target_core_tmr.c based callers of transport_cmd_finish_abort().
      
      Recently with the conversion of kref to refcount_t, this bug was
      manifesting itself as:
      
      [705519.601034] refcount_t: underflow; use-after-free.
      [705519.604034] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 20116.512 msecs
      [705539.719111] ------------[ cut here ]------------
      [705539.719117] WARNING: CPU: 3 PID: 26510 at lib/refcount.c:184 refcount_sub_and_test+0x33/0x51
      
      Since the original kref atomic_t based kref_put() didn't check for
      underflow and only invoked the final callback when zero was reached,
      this bug did not manifest in practice since all se_cmd memory is
      using preallocated tags.
      
      To address this, go ahead and propigate the existing return from
      transport_put_cmd() up via transport_cmd_finish_abort(), and
      change transport_cmd_finish_abort() + core_tmr_handle_tas_abort()
      callers to only do their local target_put_sess_cmd() if necessary.
      Reported-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
      Tested-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
      Cc: Mike Christie <mchristi@redhat.com>
      Cc: Hannes Reinecke <hare@suse.de>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Tested-by: default avatarGary Guo <ghg@datera.io>
      Tested-by: default avatarChu Yuan Lin <cyl@datera.io>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0b7db7b0
    • Daniel Drake's avatar
      Input: i8042 - add Fujitsu Lifebook AH544 to notimeout list · 90e149d0
      Daniel Drake authored
      commit 817ae460 upstream.
      
      Without this quirk, the touchpad is not responsive on this product, with
      the following message repeated in the logs:
      
       psmouse serio1: bad data from KBC - timeout
      
      Add it to the notimeout list alongside other similar Fujitsu laptops.
      Signed-off-by: default avatarDaniel Drake <drake@endlessm.com>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      90e149d0
    • Naveen N. Rao's avatar
      powerpc/kprobes: Pause function_graph tracing during jprobes handling · 96ed79b5
      Naveen N. Rao authored
      commit a9f8553e upstream.
      
      This fixes a crash when function_graph and jprobes are used together.
      This is essentially commit 237d28db ("ftrace/jprobes/x86: Fix
      conflict between jprobes and function graph tracing"), but for powerpc.
      
      Jprobes breaks function_graph tracing since the jprobe hook needs to use
      jprobe_return(), which never returns back to the hook, but instead to
      the original jprobe'd function. The solution is to momentarily pause
      function_graph tracing before invoking the jprobe hook and re-enable it
      when returning back to the original jprobe'd function.
      
      Fixes: 6794c782 ("powerpc64: port of the function graph tracer")
      Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Acked-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      96ed79b5
    • Eric W. Biederman's avatar
      signal: Only reschedule timers on signals timers have sent · 0ddaca0a
      Eric W. Biederman authored
      commit 57db7e4a upstream.
      
      Thomas Gleixner  wrote:
      > The CRIU support added a 'feature' which allows a user space task to send
      > arbitrary (kernel) signals to itself. The changelog says:
      >
      >   The kernel prevents sending of siginfo with positive si_code, because
      >   these codes are reserved for kernel.  I think we can allow a task to
      >   send such a siginfo to itself.  This operation should not be dangerous.
      >
      > Quite contrary to that claim, it turns out that it is outright dangerous
      > for signals with info->si_code == SI_TIMER. The following code sequence in
      > a user space task allows to crash the kernel:
      >
      >    id = timer_create(CLOCK_XXX, ..... signo = SIGX);
      >    timer_set(id, ....);
      >    info->si_signo = SIGX;
      >    info->si_code = SI_TIMER:
      >    info->_sifields._timer._tid = id;
      >    info->_sifields._timer._sys_private = 2;
      >    rt_[tg]sigqueueinfo(..., SIGX, info);
      >    sigemptyset(&sigset);
      >    sigaddset(&sigset, SIGX);
      >    rt_sigtimedwait(sigset, info);
      >
      > For timers based on CLOCK_PROCESS_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID this
      > results in a kernel crash because sigwait() dequeues the signal and the
      > dequeue code observes:
      >
      >   info->si_code == SI_TIMER && info->_sifields._timer._sys_private != 0
      >
      > which triggers the following callchain:
      >
      >  do_schedule_next_timer() -> posix_cpu_timer_schedule() -> arm_timer()
      >
      > arm_timer() executes a list_add() on the timer, which is already armed via
      > the timer_set() syscall. That's a double list add which corrupts the posix
      > cpu timer list. As a consequence the kernel crashes on the next operation
      > touching the posix cpu timer list.
      >
      > Posix clocks which are internally implemented based on hrtimers are not
      > affected by this because hrtimer_start() can handle already armed timers
      > nicely, but it's a reliable way to trigger the WARN_ON() in
      > hrtimer_forward(), which complains about calling that function on an
      > already armed timer.
      
      This problem has existed since the posix timer code was merged into
      2.5.63. A few releases earlier in 2.5.60 ptrace gained the ability to
      inject not just a signal (which linux has supported since 1.0) but the
      full siginfo of a signal.
      
      The core problem is that the code will reschedule in response to
      signals getting dequeued not just for signals the timers sent but
      for other signals that happen to a si_code of SI_TIMER.
      
      Avoid this confusion by testing to see if the queued signal was
      preallocated as all timer signals are preallocated, and so far
      only the timer code preallocates signals.
      
      Move the check for if a timer needs to be rescheduled up into
      collect_signal where the preallocation check must be performed,
      and pass the result back to dequeue_signal where the code reschedules
      timers.   This makes it clear why the code cares about preallocated
      timers.
      Reported-by: default avatarThomas Gleixner <tglx@linutronix.de>
      History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
      Reference: 66dd34ad ("signal: allow to send any siginfo to itself")
      Reference: 1669ce53 ("Add PTRACE_GETSIGINFO and PTRACE_SETSIGINFO")
      Fixes: db8b50ba ("[PATCH] POSIX clocks & timers")
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0ddaca0a
    • Pavel Shilovsky's avatar
      CIFS: Improve readdir verbosity · 5290a58f
      Pavel Shilovsky authored
      commit dcd87838 upstream.
      
      Downgrade the loglevel for SMB2 to prevent filling the log
      with messages if e.g. readdir was interrupted. Also make SMB2
      and SMB1 codepaths do the same logging during readdir.
      Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5290a58f
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Preserve userspace HTM state properly · 0b423dab
      Paul Mackerras authored
      commit 46a704f8 upstream.
      
      If userspace attempts to call the KVM_RUN ioctl when it has hardware
      transactional memory (HTM) enabled, the values that it has put in the
      HTM-related SPRs TFHAR, TFIAR and TEXASR will get overwritten by
      guest values.  To fix this, we detect this condition and save those
      SPR values in the thread struct, and disable HTM for the task.  If
      userspace goes to access those SPRs or the HTM facility in future,
      a TM-unavailable interrupt will occur and the handler will reload
      those SPRs and re-enable HTM.
      
      If userspace has started a transaction and suspended it, we would
      currently lose the transactional state in the guest entry path and
      would almost certainly get a "TM Bad Thing" interrupt, which would
      cause the host to crash.  To avoid this, we detect this case and
      return from the KVM_RUN ioctl with an EINVAL error, with the KVM
      exit reason set to KVM_EXIT_FAIL_ENTRY.
      
      Fixes: b005255e ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
      Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0b423dab
    • Ilya Matveychikov's avatar
      lib/cmdline.c: fix get_options() overflow while parsing ranges · 4d6142de
      Ilya Matveychikov authored
      commit a91e0f68 upstream.
      
      When using get_options() it's possible to specify a range of numbers,
      like 1-100500.  The problem is that it doesn't track array size while
      calling internally to get_range() which iterates over the range and
      fills the memory with numbers.
      
      Link: http://lkml.kernel.org/r/2613C75C-B04D-4BFF-82A6-12F97BA0F620@gmail.comSigned-off-by: default avatarIlya V. Matveychikov <matvejchikov@gmail.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4d6142de
    • NeilBrown's avatar
      autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL · 75735be7
      NeilBrown authored
      commit 9fa4eb8e upstream.
      
      If a positive status is passed with the AUTOFS_DEV_IOCTL_FAIL ioctl,
      autofs4_d_automount() will return
      
         ERR_PTR(status)
      
      with that status to follow_automount(), which will then dereference an
      invalid pointer.
      
      So treat a positive status the same as zero, and map to ENOENT.
      
      See comment in systemd src/core/automount.c::automount_send_ready().
      
      Link: http://lkml.kernel.org/r/871sqwczx5.fsf@notabene.neil.brown.nameSigned-off-by: default avatarNeilBrown <neilb@suse.com>
      Cc: Ian Kent <raven@themaw.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      75735be7
    • Kees Cook's avatar
      fs/exec.c: account for argv/envp pointers · 2dff2164
      Kees Cook authored
      commit 98da7d08 upstream.
      
      When limiting the argv/envp strings during exec to 1/4 of the stack limit,
      the storage of the pointers to the strings was not included.  This means
      that an exec with huge numbers of tiny strings could eat 1/4 of the stack
      limit in strings and then additional space would be later used by the
      pointers to the strings.
      
      For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721
      single-byte strings would consume less than 2MB of stack, the max (8MB /
      4) amount allowed, but the pointers to the strings would consume the
      remaining additional stack space (1677721 * 4 == 6710884).
      
      The result (1677721 + 6710884 == 8388605) would exhaust stack space
      entirely.  Controlling this stack exhaustion could result in
      pathological behavior in setuid binaries (CVE-2017-1000365).
      
      [akpm@linux-foundation.org: additional commenting from Kees]
      Fixes: b6a2fea3 ("mm: variable length argument support")
      Link: http://lkml.kernel.org/r/20170622001720.GA32173@beastSigned-off-by: default avatarKees Cook <keescook@chromium.org>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Qualys Security Advisory <qsa@qualys.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2dff2164
  2. 26 Jun, 2017 24 commits