1. 15 Feb, 2014 31 commits
  2. 03 Jan, 2014 9 commits
    • Ben Hutchings's avatar
      Linux 3.2.54 · 260716c8
      Ben Hutchings authored
      260716c8
    • KOBAYASHI Yoshitake's avatar
      mmc: block: fix a bug of error handling in MMC driver · 295efae4
      KOBAYASHI Yoshitake authored
      commit c8760069 upstream.
      
      Current MMC driver doesn't handle generic error (bit19 of device
      status) in write sequence. As a result, write data gets lost when
      generic error occurs. For example, a generic error when updating a
      filesystem management information causes a loss of write data and
      corrupts the filesystem. In the worst case, the system will never
      boot.
      
      This patch includes the following functionality:
        1. To enable error checking for the response of CMD12 and CMD13
           in write command sequence
        2. To retry write sequence when a generic error occurs
      
      Messages are added for v2 to show what occurs.
      
      [Backported to 3.4-stable]
      Signed-off-by: default avatarKOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>
      Signed-off-by: default avatarChris Ball <cjb@laptop.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      295efae4
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Fix function graph with loading of modules · 969a08e9
      Steven Rostedt (Red Hat) authored
      commit 8a56d776 upstream.
      
      Commit 8c4f3c3f "ftrace: Check module functions being traced on reload"
      fixed module loading and unloading with respect to function tracing, but
      it missed the function graph tracer. If you perform the following
      
       # cd /sys/kernel/debug/tracing
       # echo function_graph > current_tracer
       # modprobe nfsd
       # echo nop > current_tracer
      
      You'll get the following oops message:
      
       ------------[ cut here ]------------
       WARNING: CPU: 2 PID: 2910 at /linux.git/kernel/trace/ftrace.c:1640 __ftrace_hash_rec_update.part.35+0x168/0x1b9()
       Modules linked in: nfsd exportfs nfs_acl lockd ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables uinput snd_hda_codec_idt
       CPU: 2 PID: 2910 Comm: bash Not tainted 3.13.0-rc1-test #7
       Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
        0000000000000668 ffff8800787efcf8 ffffffff814fe193 ffff88007d500000
        0000000000000000 ffff8800787efd38 ffffffff8103b80a 0000000000000668
        ffffffff810b2b9a ffffffff81a48370 0000000000000001 ffff880037aea000
       Call Trace:
        [<ffffffff814fe193>] dump_stack+0x4f/0x7c
        [<ffffffff8103b80a>] warn_slowpath_common+0x81/0x9b
        [<ffffffff810b2b9a>] ? __ftrace_hash_rec_update.part.35+0x168/0x1b9
        [<ffffffff8103b83e>] warn_slowpath_null+0x1a/0x1c
        [<ffffffff810b2b9a>] __ftrace_hash_rec_update.part.35+0x168/0x1b9
        [<ffffffff81502f89>] ? __mutex_lock_slowpath+0x364/0x364
        [<ffffffff810b2cc2>] ftrace_shutdown+0xd7/0x12b
        [<ffffffff810b47f0>] unregister_ftrace_graph+0x49/0x78
        [<ffffffff810c4b30>] graph_trace_reset+0xe/0x10
        [<ffffffff810bf393>] tracing_set_tracer+0xa7/0x26a
        [<ffffffff810bf5e1>] tracing_set_trace_write+0x8b/0xbd
        [<ffffffff810c501c>] ? ftrace_return_to_handler+0xb2/0xde
        [<ffffffff811240a8>] ? __sb_end_write+0x5e/0x5e
        [<ffffffff81122aed>] vfs_write+0xab/0xf6
        [<ffffffff8150a185>] ftrace_graph_caller+0x85/0x85
        [<ffffffff81122dbd>] SyS_write+0x59/0x82
        [<ffffffff8150a185>] ftrace_graph_caller+0x85/0x85
        [<ffffffff8150a2d2>] system_call_fastpath+0x16/0x1b
       ---[ end trace 940358030751eafb ]---
      
      The above mentioned commit didn't go far enough. Well, it covered the
      function tracer by adding checks in __register_ftrace_function(). The
      problem is that the function graph tracer circumvents that (for a slight
      efficiency gain when function graph trace is running with a function
      tracer. The gain was not worth this).
      
      The problem came with ftrace_startup() which should always be called after
      __register_ftrace_function(), if you want this bug to be completely fixed.
      
      Anyway, this solution moves __register_ftrace_function() inside of
      ftrace_startup() and removes the need to call them both.
      Reported-by: default avatarDave Wysochanski <dwysocha@redhat.com>
      Fixes: ed926f9b ("ftrace: Use counters to enable functions to trace")
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      969a08e9
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Check module functions being traced on reload · 874d3954
      Steven Rostedt (Red Hat) authored
      commit 8c4f3c3f upstream.
      
      There's been a nasty bug that would show up and not give much info.
      The bug displayed the following warning:
      
       WARNING: at kernel/trace/ftrace.c:1529 __ftrace_hash_rec_update+0x1e3/0x230()
       Pid: 20903, comm: bash Tainted: G           O 3.6.11+ #38405.trunk
       Call Trace:
        [<ffffffff8103e5ff>] warn_slowpath_common+0x7f/0xc0
        [<ffffffff8103e65a>] warn_slowpath_null+0x1a/0x20
        [<ffffffff810c2ee3>] __ftrace_hash_rec_update+0x1e3/0x230
        [<ffffffff810c4f28>] ftrace_hash_move+0x28/0x1d0
        [<ffffffff811401cc>] ? kfree+0x2c/0x110
        [<ffffffff810c68ee>] ftrace_regex_release+0x8e/0x150
        [<ffffffff81149f1e>] __fput+0xae/0x220
        [<ffffffff8114a09e>] ____fput+0xe/0x10
        [<ffffffff8105fa22>] task_work_run+0x72/0x90
        [<ffffffff810028ec>] do_notify_resume+0x6c/0xc0
        [<ffffffff8126596e>] ? trace_hardirqs_on_thunk+0x3a/0x3c
        [<ffffffff815c0f88>] int_signal+0x12/0x17
       ---[ end trace 793179526ee09b2c ]---
      
      It was finally narrowed down to unloading a module that was being traced.
      
      It was actually more than that. When functions are being traced, there's
      a table of all functions that have a ref count of the number of active
      tracers attached to that function. When a function trace callback is
      registered to a function, the function's record ref count is incremented.
      When it is unregistered, the function's record ref count is decremented.
      If an inconsistency is detected (ref count goes below zero) the above
      warning is shown and the function tracing is permanently disabled until
      reboot.
      
      The ftrace callback ops holds a hash of functions that it filters on
      (and/or filters off). If the hash is empty, the default means to filter
      all functions (for the filter_hash) or to disable no functions (for the
      notrace_hash).
      
      When a module is unloaded, it frees the function records that represent
      the module functions. These records exist on their own pages, that is
      function records for one module will not exist on the same page as
      function records for other modules or even the core kernel.
      
      Now when a module unloads, the records that represents its functions are
      freed. When the module is loaded again, the records are recreated with
      a default ref count of zero (unless there's a callback that traces all
      functions, then they will also be traced, and the ref count will be
      incremented).
      
      The problem is that if an ftrace callback hash includes functions of the
      module being unloaded, those hash entries will not be removed. If the
      module is reloaded in the same location, the hash entries still point
      to the functions of the module but the module's ref counts do not reflect
      that.
      
      With the help of Steve and Joern, we found a reproducer:
      
       Using uinput module and uinput_release function.
      
       cd /sys/kernel/debug/tracing
       modprobe uinput
       echo uinput_release > set_ftrace_filter
       echo function > current_tracer
       rmmod uinput
       modprobe uinput
       # check /proc/modules to see if loaded in same addr, otherwise try again
       echo nop > current_tracer
      
       [BOOM]
      
      The above loads the uinput module, which creates a table of functions that
      can be traced within the module.
      
      We add uinput_release to the filter_hash to trace just that function.
      
      Enable function tracincg, which increments the ref count of the record
      associated to uinput_release.
      
      Remove uinput, which frees the records including the one that represents
      uinput_release.
      
      Load the uinput module again (and make sure it's at the same address).
      This recreates the function records all with a ref count of zero,
      including uinput_release.
      
      Disable function tracing, which will decrement the ref count for uinput_release
      which is now zero because of the module removal and reload, and we have
      a mismatch (below zero ref count).
      
      The solution is to check all currently tracing ftrace callbacks to see if any
      are tracing any of the module's functions when a module is loaded (it already does
      that with callbacks that trace all functions). If a callback happens to have
      a module function being traced, it increments that records ref count and starts
      tracing that function.
      
      There may be a strange side effect with this, where tracing module functions
      on unload and then reloading a new module may have that new module's functions
      being traced. This may be something that confuses the user, but it's not
      a big deal. Another approach is to disable all callback hashes on module unload,
      but this leaves some ftrace callbacks that may not be registered, but can
      still have hashes tracing the module's function where ftrace doesn't know about
      it. That situation can cause the same bug. This solution solves that case too.
      Another benefit of this solution, is it is possible to trace a module's
      function on unload and load.
      
      Link: http://lkml.kernel.org/r/20130705142629.GA325@redhat.comReported-by: default avatarJörn Engel <joern@logfs.org>
      Reported-by: default avatarDave Jones <davej@redhat.com>
      Reported-by: default avatarSteve Hodgson <steve@purestorage.com>
      Tested-by: default avatarSteve Hodgson <steve@purestorage.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      [bwh: Backported to 3.2: adjust context, indentation]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      874d3954
    • Steven Rostedt's avatar
      ftrace: Create ftrace_hash_empty() helper routine · 195c821e
      Steven Rostedt authored
      commit 06a51d93 upstream.
      
      There are two types of hashes in the ftrace_ops; one type
      is the filter_hash and the other is the notrace_hash. Either
      one may be null, meaning it has no elements. But when elements
      are added, the hash is allocated.
      
      Throughout the code, a check needs to be made to see if a hash
      exists or the hash has elements, but the check if the hash exists
      is usually missing causing the possible "NULL pointer dereference bug".
      
      Add a helper routine called "ftrace_hash_empty()" that returns
      true if the hash doesn't exist or its count is zero. As they mean
      the same thing.
      Last-bug-reported-by: default avatarJiri Olsa <jolsa@redhat.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      195c821e
    • Steven Rostedt's avatar
      ftrace: Fix ftrace hash record update with notrace · 4f02a393
      Steven Rostedt authored
      commit c842e975 upstream.
      
      When disabling the "notrace" records, that means we want to trace them.
      If the notrace_hash is zero, it means that we want to trace all
      records. But to disable a zero notrace_hash means nothing.
      
      The check for the notrace_hash count was incorrect with:
      
      	if (hash && !hash->count)
      		return
      
      With the correct comment above it that states that we do nothing
      if the notrace_hash has zero count. But !hash also means that
      the notrace hash has zero count. I think this was done to
      protect against dereferencing NULL. But if !hash is true, then
      we go through the following loop without doing a single thing.
      
      Fix it to:
      
      	if (!hash || !hash->count)
      		return;
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      4f02a393
    • Jason Wang's avatar
      net: flow_dissector: fail on evil iph->ihl · f7d537dc
      Jason Wang authored
      commit 6f092343 upstream.
      
      We don't validate iph->ihl which may lead a dead loop if we meet a IPIP
      skb whose iph->ihl is zero. Fix this by failing immediately when iph->ihl
      is evil (less than 5).
      
      This issue were introduced by commit ec5efe79
      (rps: support IPIP encapsulation).
      
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Petr Matousek <pmatouse@redhat.com>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Daniel Borkmann <dborkman@redhat.com>
      Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      [bwh: Backported to 3.2: the affected code is in __skb_get_rxhash()]
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      f7d537dc
    • Dan Carpenter's avatar
      xfs: underflow bug in xfs_attrlist_by_handle() · cc5285f4
      Dan Carpenter authored
      commit 31978b5c upstream.
      
      If we allocate less than sizeof(struct attrlist) then we end up
      corrupting memory or doing a ZERO_PTR_SIZE dereference.
      
      This can only be triggered with CAP_SYS_ADMIN.
      Reported-by: default avatarNico Golde <nico@ngolde.de>
      Reported-by: default avatarFabian Yamaguchi <fabs@goesec.de>
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarBen Myers <bpm@sgi.com>
      
      (cherry picked from commit 071c529e)
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      cc5285f4
    • Mahesh Rajashekhara's avatar
      aacraid: prevent invalid pointer dereference · 1016f060
      Mahesh Rajashekhara authored
      commit b4789b8e upstream.
      
      It appears that driver runs into a problem here if fibsize is too small
      because we allocate user_srbcmd with fibsize size only but later we
      access it until user_srbcmd->sg.count to copy it over to srbcmd.
      
      It is not correct to test (fibsize < sizeof(*user_srbcmd)) because this
      structure already includes one sg element and this is not needed for
      commands without data.  So, we would recommend to add the following
      (instead of test for fibsize == 0).
      Signed-off-by: default avatarMahesh Rajashekhara <Mahesh.Rajashekhara@pmcs.com>
      Reported-by: default avatarNico Golde <nico@ngolde.de>
      Reported-by: default avatarFabian Yamaguchi <fabs@goesec.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      1016f060