1. 27 May, 2015 9 commits
    • mancha security's avatar
      lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR · 99c5da5e
      mancha security authored
      commit 0b053c95 upstream.
      
      OPTIMIZER_HIDE_VAR(), as defined when using gcc, is insufficient to
      ensure protection from dead store optimization.
      
      For the random driver and crypto drivers, calls are emitted ...
      
        $ gdb vmlinux
        (gdb) disassemble memzero_explicit
        Dump of assembler code for function memzero_explicit:
          0xffffffff813a18b0 <+0>:	push   %rbp
          0xffffffff813a18b1 <+1>:	mov    %rsi,%rdx
          0xffffffff813a18b4 <+4>:	xor    %esi,%esi
          0xffffffff813a18b6 <+6>:	mov    %rsp,%rbp
          0xffffffff813a18b9 <+9>:	callq  0xffffffff813a7120 <memset>
          0xffffffff813a18be <+14>:	pop    %rbp
          0xffffffff813a18bf <+15>:	retq
        End of assembler dump.
      
        (gdb) disassemble extract_entropy
        [...]
          0xffffffff814a5009 <+313>:	mov    %r12,%rdi
          0xffffffff814a500c <+316>:	mov    $0xa,%esi
          0xffffffff814a5011 <+321>:	callq  0xffffffff813a18b0 <memzero_explicit>
          0xffffffff814a5016 <+326>:	mov    -0x48(%rbp),%rax
        [...]
      
      ... but in case in future we might use facilities such as LTO, then
      OPTIMIZER_HIDE_VAR() is not sufficient to protect gcc from a possible
      eviction of the memset(). We have to use a compiler barrier instead.
      
      Minimal test example when we assume memzero_explicit() would *not* be
      a call, but would have been *inlined* instead:
      
        static inline void memzero_explicit(void *s, size_t count)
        {
          memset(s, 0, count);
          <foo>
        }
      
        int main(void)
        {
          char buff[20];
      
          snprintf(buff, sizeof(buff) - 1, "test");
          printf("%s", buff);
      
          memzero_explicit(buff, sizeof(buff));
          return 0;
        }
      
      With <foo> := OPTIMIZER_HIDE_VAR():
      
        (gdb) disassemble main
        Dump of assembler code for function main:
        [...]
         0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
         0x0000000000400469 <+41>:	xor    %eax,%eax
         0x000000000040046b <+43>:	add    $0x28,%rsp
         0x000000000040046f <+47>:	retq
        End of assembler dump.
      
      With <foo> := barrier():
      
        (gdb) disassemble main
        Dump of assembler code for function main:
        [...]
         0x0000000000400464 <+36>:	callq  0x400410 <printf@plt>
         0x0000000000400469 <+41>:	movq   $0x0,(%rsp)
         0x0000000000400471 <+49>:	movq   $0x0,0x8(%rsp)
         0x000000000040047a <+58>:	movl   $0x0,0x10(%rsp)
         0x0000000000400482 <+66>:	xor    %eax,%eax
         0x0000000000400484 <+68>:	add    $0x28,%rsp
         0x0000000000400488 <+72>:	retq
        End of assembler dump.
      
      As can be seen, movq, movq, movl are being emitted inlined
      via memset().
      
      Reference: http://thread.gmane.org/gmane.linux.kernel.cryptoapi/13764/
      Fixes: d4c5efdb ("random: add and use memzero_explicit() for clearing data")
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarmancha security <mancha1@zoho.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Acked-by: default avatarStephan Mueller <smueller@chronox.de>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      99c5da5e
    • Nicolas Iooss's avatar
      wl18xx: show rx_frames_per_rates as an array as it really is · ca654131
      Nicolas Iooss authored
      commit a3fa71c4 upstream.
      
      In struct wl18xx_acx_rx_rate_stat, rx_frames_per_rates field is an
      array, not a number.  This means WL18XX_DEBUGFS_FWSTATS_FILE can't be
      used to display this field in debugfs (it would display a pointer, not
      the actual data).  Use WL18XX_DEBUGFS_FWSTATS_FILE_ARRAY instead.
      
      This bug has been found by adding a __printf attribute to
      wl1271_format_buffer.  gcc complained about "format '%u' expects
      argument of type 'unsigned int', but argument 5 has type 'u32 *'".
      
      Fixes: c5d94169 ("wl18xx: use new fw stats structures")
      Signed-off-by: default avatarNicolas Iooss <nicolas.iooss_linux@m4x.org>
      Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      ca654131
    • Sabrina Dubroca's avatar
      e1000: add dummy allocator to fix race condition between mtu change and netpoll · b29d9b81
      Sabrina Dubroca authored
      commit 08e83316 upstream.
      
      There is a race condition between e1000_change_mtu's cleanups and
      netpoll, when we change the MTU across jumbo size:
      
      Changing MTU frees all the rx buffers:
          e1000_change_mtu -> e1000_down -> e1000_clean_all_rx_rings ->
              e1000_clean_rx_ring
      
      Then, close to the end of e1000_change_mtu:
          pr_info -> ... -> netpoll_poll_dev -> e1000_clean ->
              e1000_clean_rx_irq -> e1000_alloc_rx_buffers -> e1000_alloc_frag
      
      And when we come back to do the rest of the MTU change:
          e1000_up -> e1000_configure -> e1000_configure_rx ->
              e1000_alloc_jumbo_rx_buffers
      
      alloc_jumbo finds the buffers already != NULL, since data (shared with
      page in e1000_rx_buffer->rxbuf) has been re-alloc'd, but it's garbage,
      or at least not what is expected when in jumbo state.
      
      This results in an unusable adapter (packets don't get through), and a
      NULL pointer dereference on the next call to e1000_clean_rx_ring
      (other mtu change, link down, shutdown):
      
      BUG: unable to handle kernel NULL pointer dereference at           (null)
      IP: [<ffffffff81194d6e>] put_compound_page+0x7e/0x330
      
          [...]
      
      Call Trace:
       [<ffffffff81195445>] put_page+0x55/0x60
       [<ffffffff815d9f44>] e1000_clean_rx_ring+0x134/0x200
       [<ffffffff815da055>] e1000_clean_all_rx_rings+0x45/0x60
       [<ffffffff815df5e0>] e1000_down+0x1c0/0x1d0
       [<ffffffff811e2260>] ? deactivate_slab+0x7f0/0x840
       [<ffffffff815e21bc>] e1000_change_mtu+0xdc/0x170
       [<ffffffff81647050>] dev_set_mtu+0xa0/0x140
       [<ffffffff81664218>] do_setlink+0x218/0xac0
       [<ffffffff814459e9>] ? nla_parse+0xb9/0x120
       [<ffffffff816652d0>] rtnl_newlink+0x6d0/0x890
       [<ffffffff8104f000>] ? kvm_clock_read+0x20/0x40
       [<ffffffff810a2068>] ? sched_clock_cpu+0xa8/0x100
       [<ffffffff81663802>] rtnetlink_rcv_msg+0x92/0x260
      
      By setting the allocator to a dummy version, netpoll can't mess up our
      rx buffers.  The allocator is set back to a sane value in
      e1000_configure_rx.
      
      Fixes: edbbb3ca ("e1000: implement jumbo receive with partial descriptors")
      Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
      Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
      Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      b29d9b81
    • Jeff Layton's avatar
      nfs: fix high load average due to callback thread sleeping · f09a1ad6
      Jeff Layton authored
      commit 5d05e54a upstream.
      
      Chuck pointed out a problem that crept in with commit 6ffa30d3 (nfs:
      don't call blocking operations while !TASK_RUNNING). Linux counts tasks
      in uninterruptible sleep against the load average, so this caused the
      system's load average to be pinned at at least 1 when there was a
      NFSv4.1+ mount active.
      
      Not a huge problem, but it's probably worth fixing before we get too
      many complaints about it. This patch converts the code back to use
      TASK_INTERRUPTIBLE sleep, simply has it flush any signals on each loop
      iteration. In practice no one should really be signalling this thread at
      all, so I think this is reasonably safe.
      
      With this change, there's also no need to game the hung task watchdog so
      we can also convert the schedule_timeout call back to a normal schedule.
      Reported-by: default avatarChuck Lever <chuck.lever@oracle.com>
      Signed-off-by: default avatarJeff Layton <jeff.layton@primarydata.com>
      Tested-by: default avatarChuck Lever <chuck.lever@oracle.com>
      Fixes: commit 6ffa30d3 (“nfs: don't call blocking . . .”)
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      f09a1ad6
    • Jeff Layton's avatar
      nfs: don't call blocking operations while !TASK_RUNNING · d6cfb99d
      Jeff Layton authored
      commit 6ffa30d3 upstream.
      
      Bruce reported seeing this warning pop when mounting using v4.1:
      
           ------------[ cut here ]------------
           WARNING: CPU: 1 PID: 1121 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()
          do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff810ff58f>] prepare_to_wait+0x2f/0x90
          Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer ppdev joydev snd virtio_console virtio_balloon pcspkr serio_raw parport_pc parport pvpanic floppy soundcore i2c_piix4 virtio_blk virtio_net qxl drm_kms_helper ttm drm virtio_pci virtio_ring ata_generic virtio pata_acpi
          CPU: 1 PID: 1121 Comm: nfsv4.1-svc Not tainted 3.19.0-rc4+ #25
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153950- 04/01/2014
           0000000000000000 000000004e5e3f73 ffff8800b998fb48 ffffffff8186ac78
           0000000000000000 ffff8800b998fba0 ffff8800b998fb88 ffffffff810ac9da
           ffff8800b998fb68 ffffffff81c923e7 00000000000004d9 0000000000000000
          Call Trace:
           [<ffffffff8186ac78>] dump_stack+0x4c/0x65
           [<ffffffff810ac9da>] warn_slowpath_common+0x8a/0xc0
           [<ffffffff810aca65>] warn_slowpath_fmt+0x55/0x70
           [<ffffffff810ff58f>] ? prepare_to_wait+0x2f/0x90
           [<ffffffff810ff58f>] ? prepare_to_wait+0x2f/0x90
           [<ffffffff810dd2ad>] __might_sleep+0xbd/0xd0
           [<ffffffff8124c973>] kmem_cache_alloc_trace+0x243/0x430
           [<ffffffff810d941e>] ? groups_alloc+0x3e/0x130
           [<ffffffff810d941e>] groups_alloc+0x3e/0x130
           [<ffffffffa0301b1e>] svcauth_unix_accept+0x16e/0x290 [sunrpc]
           [<ffffffffa0300571>] svc_authenticate+0xe1/0xf0 [sunrpc]
           [<ffffffffa02fc564>] svc_process_common+0x244/0x6a0 [sunrpc]
           [<ffffffffa02fd044>] bc_svc_process+0x1c4/0x260 [sunrpc]
           [<ffffffffa03d5478>] nfs41_callback_svc+0x128/0x1f0 [nfsv4]
           [<ffffffff810ff970>] ? wait_woken+0xc0/0xc0
           [<ffffffffa03d5350>] ? nfs4_callback_svc+0x60/0x60 [nfsv4]
           [<ffffffff810d45bf>] kthread+0x11f/0x140
           [<ffffffff810ea815>] ? local_clock+0x15/0x30
           [<ffffffff810d44a0>] ? kthread_create_on_node+0x250/0x250
           [<ffffffff81874bfc>] ret_from_fork+0x7c/0xb0
           [<ffffffff810d44a0>] ? kthread_create_on_node+0x250/0x250
          ---[ end trace 675220a11e30f4f2 ]---
      
      nfs41_callback_svc does most of its work while in TASK_INTERRUPTIBLE,
      which is just wrong. Fix that by finishing the wait immediately if we've
      found that the list has something on it.
      
      Also, we don't expect this kthread to accept signals, so we should be
      using a TASK_UNINTERRUPTIBLE sleep instead. That however, opens us up
      hung task warnings from the watchdog, so have the schedule_timeout
      wake up every 60s if there's no callback activity.
      Reported-by: default avatar"J. Bruce Fields" <bfields@fieldses.org>
      Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      d6cfb99d
    • Len Brown's avatar
      sched/idle/x86: Restore mwait_idle() to fix boot hangs, to improve power... · 1f766656
      Len Brown authored
      sched/idle/x86: Restore mwait_idle() to fix boot hangs, to improve power savings and to improve performance
      
      commit b253149b upstream.
      
      In Linux-3.9 we removed the mwait_idle() loop:
      
        69fb3676 ("x86 idle: remove mwait_idle() and "idle=mwait" cmdline param")
      
      The reasoning was that modern machines should be sufficiently
      happy during the boot process using the default_idle() HALT
      loop, until cpuidle loads and either acpi_idle or intel_idle
      invoke the newer MWAIT-with-hints idle loop.
      
      But two machines reported problems:
      
       1. Certain Core2-era machines support MWAIT-C1 and HALT only.
          MWAIT-C1 is preferred for optimal power and performance.
          But if they support just C1, cpuidle never loads and
          so they use the boot-time default idle loop forever.
      
       2. Some laptops will boot-hang if HALT is used,
          but will boot successfully if MWAIT is used.
          This appears to be a hidden assumption in BIOS SMI,
          that is presumably valid on the proprietary OS
          where the BIOS was validated.
      
             https://bugzilla.kernel.org/show_bug.cgi?id=60770
      
      So here we effectively revert the patch above, restoring
      the mwait_idle() loop.  However, we don't bother restoring
      the idle=mwait cmdline parameter, since it appears to add
      no value.
      
      Maintainer notes:
      
        For 3.9, simply revert 69fb3676
        for 3.10, patch -F3 applies, fuzz needed due to __cpuinit use in
        context For 3.11, 3.12, 3.13, this patch applies cleanly
      Tested-by: default avatarMike Galbraith <bitbucket@online.de>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      Acked-by: default avatarMike Galbraith <bitbucket@online.de>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ian Malone <ibmalone@gmail.com>
      Cc: Josh Boyer <jwboyer@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/345254a551eb5a6a866e048d7ab570fd2193aca4.1389763084.git.len.brown@intel.com
      [ Ported to recent kernels. ]
      [ Mike: 3.10 backport ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarMike Galbraith <efault@gmx.de>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      1f766656
    • Krzysztof Kozlowski's avatar
      compal-laptop: Check return value of power_supply_register · 6f35715c
      Krzysztof Kozlowski authored
      commit 1915a718 upstream.
      
      The return value of power_supply_register() call was not checked and
      even on error probe() function returned 0. If registering failed then
      during unbind the driver tried to unregister power supply which was not
      actually registered.
      
      This could lead to memory corruption because power_supply_unregister()
      unconditionally cleans up given power supply.
      
      Fix this by checking return status of power_supply_register() call. In
      case of failure, clean up sysfs entries and fail the probe.
      Signed-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
      Fixes: 9be0fcb5 ("compal-laptop: add JHL90, battery & hwmon interface")
      Signed-off-by: default avatarSebastian Reichel <sre@kernel.org>
      Signed-off-by: Jiri Slaby <jslaby@suse.cz> [backport to 3.12]
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      6f35715c
    • Al Viro's avatar
      RCU pathwalk breakage when running into a symlink overmounting something · b1aaebf1
      Al Viro authored
      commit 3cab989a upstream.
      
      Calling unlazy_walk() in walk_component() and do_last() when we find
      a symlink that needs to be followed doesn't acquire a reference to vfsmount.
      That's fine when the symlink is on the same vfsmount as the parent directory
      (which is almost always the case), but it's not always true - one _can_
      manage to bind a symlink on top of something.  And in such cases we end up
      with excessive mntput().
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      b1aaebf1
    • Dmitry Torokhov's avatar
      drm/i915: cope with large i2c transfers · 345c304f
      Dmitry Torokhov authored
      commit 9535c475 upstream.
      
      The hardware, according to the specs, is limited to 256 byte transfers,
      and current driver has no protections in case users attempt to do larger
      transfers. The code will just stomp over status register and mayhem
      ensues.
      
      Let's split larger transfers into digestable chunks. Doing this allows
      Atmel MXT driver on Pixel 1 function properly (it hasn't since commit
      9d8dc3e5 "Input: atmel_mxt_ts -
      implement T44 message handling" which tries to consume multiple
      touchscreen/touchpad reports in a single transaction).
      Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
      Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      345c304f
  2. 26 May, 2015 31 commits