1. 12 Dec, 2012 14 commits
  2. 11 Dec, 2012 16 commits
  3. 10 Dec, 2012 4 commits
    • Linus Torvalds's avatar
      Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage · caf49191
      Linus Torvalds authored
      This reverts commits a5091539 and
      d7c3b937.
      
      This is a revert of a revert of a revert.  In addition, it reverts the
      even older i915 change to stop using the __GFP_NO_KSWAPD flag due to the
      original commits in linux-next.
      
      It turns out that the original patch really was bogus, and that the
      original revert was the correct thing to do after all.  We thought we
      had fixed the problem, and then reverted the revert, but the problem
      really is fundamental: waking up kswapd simply isn't the right thing to
      do, and direct reclaim sometimes simply _is_ the right thing to do.
      
      When certain allocations fail, we simply should try some direct reclaim,
      and if that fails, fail the allocation.  That's the right thing to do
      for THP allocations, which can easily fail, and the GPU allocations want
      to do that too.
      
      So starting kswapd is sometimes simply wrong, and removing the flag that
      said "don't start kswapd" was a mistake.  Let's hope we never revisit
      this mistake again - and certainly not this many times ;)
      Acked-by: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      caf49191
    • Johannes Berg's avatar
      ipv4: ip_check_defrag must not modify skb before unsharing · 1bf3751e
      Johannes Berg authored
      ip_check_defrag() might be called from af_packet within the
      RX path where shared SKBs are used, so it must not modify
      the input SKB before it has unshared it for defragmentation.
      Use skb_copy_bits() to get the IP header and only pull in
      everything later.
      
      The same is true for the other caller in macvlan as it is
      called from dev->rx_handler which can also get a shared SKB.
      Reported-by: default avatarEric Leblond <eric@regit.org>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1bf3751e
    • Linus Torvalds's avatar
      Revert "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended" · 31f8d42d
      Linus Torvalds authored
      This reverts commit 782fd304.
      
      We are going to reinstate the __GFP_NO_KSWAPD flag that has been
      removed, the removal reverted, and then removed again.  Making this
      commit a pointless fixup for a problem that was caused by the removal of
      __GFP_NO_KSWAPD flag.
      
      The thing is, we really don't want to wake up kswapd for THP allocations
      (because they fail quite commonly under any kind of memory pressure,
      including when there is tons of memory free), and these patches were
      just trying to fix up the underlying bug: the original removal of
      __GFP_NO_KSWAPD in commit c6543459 ("mm: remove __GFP_NO_KSWAPD")
      was simply bogus.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      31f8d42d
    • Neal Cardwell's avatar
      inet_diag: validate port comparison byte code to prevent unsafe reads · 5e1f5420
      Neal Cardwell authored
      Add logic to verify that a port comparison byte code operation
      actually has the second inet_diag_bc_op from which we read the port
      for such operations.
      
      Previously the code blindly referenced op[1] without first checking
      whether a second inet_diag_bc_op struct could fit there. So a
      malicious user could make the kernel read 4 bytes beyond the end of
      the bytecode array by claiming to have a whole port comparison byte
      code (2 inet_diag_bc_op structs) when in fact the bytecode was not
      long enough to hold both.
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5e1f5420
  4. 09 Dec, 2012 3 commits
    • Neal Cardwell's avatar
      inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run() · f67caec9
      Neal Cardwell authored
      Add logic to check the address family of the user-supplied conditional
      and the address family of the connection entry. We now do not do
      prefix matching of addresses from different address families (AF_INET
      vs AF_INET6), except for the previously existing support for having an
      IPv4 prefix match an IPv4-mapped IPv6 address (which this commit
      maintains as-is).
      
      This change is needed for two reasons:
      
      (1) The addresses are different lengths, so comparing a 128-bit IPv6
      prefix match condition to a 32-bit IPv4 connection address can cause
      us to unwittingly walk off the end of the IPv4 address and read
      garbage or oops.
      
      (2) The IPv4 and IPv6 address spaces are semantically distinct, so a
      simple bit-wise comparison of the prefixes is not meaningful, and
      would lead to bogus results (except for the IPv4-mapped IPv6 case,
      which this commit maintains).
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f67caec9
    • Neal Cardwell's avatar
      inet_diag: validate byte code to prevent oops in inet_diag_bc_run() · 405c0059
      Neal Cardwell authored
      Add logic to validate INET_DIAG_BC_S_COND and INET_DIAG_BC_D_COND
      operations.
      
      Previously we did not validate the inet_diag_hostcond, address family,
      address length, and prefix length. So a malicious user could make the
      kernel read beyond the end of the bytecode array by claiming to have a
      whole inet_diag_hostcond when the bytecode was not long enough to
      contain a whole inet_diag_hostcond of the given address family. Or
      they could make the kernel read up to about 27 bytes beyond the end of
      a connection address by passing a prefix length that exceeded the
      length of addresses of the given family.
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      405c0059
    • Neal Cardwell's avatar
      inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state · 1c95df85
      Neal Cardwell authored
      Fix inet_diag to be aware of the fact that AF_INET6 TCP connections
      instantiated for IPv4 traffic and in the SYN-RECV state were actually
      created with inet_reqsk_alloc(), instead of inet6_reqsk_alloc(). This
      means that for such connections inet6_rsk(req) returns a pointer to a
      random spot in memory up to roughly 64KB beyond the end of the
      request_sock.
      
      With this bug, for a server using AF_INET6 TCP sockets and serving
      IPv4 traffic, an inet_diag user like `ss state SYN-RECV` would lead to
      inet_diag_fill_req() causing an oops or the export to user space of 16
      bytes of kernel memory as a garbage IPv6 address, depending on where
      the garbage inet6_rsk(req) pointed.
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1c95df85
  5. 08 Dec, 2012 3 commits
    • Johannes Weiner's avatar
      mm: vmscan: fix inappropriate zone congestion clearing · ed23ec4f
      Johannes Weiner authored
      commit c702418f ("mm: vmscan: do not keep kswapd looping forever due
      to individual uncompactable zones") removed zone watermark checks from
      the compaction code in kswapd but left in the zone congestion clearing,
      which now happens unconditionally on higher order reclaim.
      
      This messes up the reclaim throttling logic for zones with
      dirty/writeback pages, where zones should only lose their congestion
      status when their watermarks have been restored.
      
      Remove the clearing from the zone compaction section entirely.  The
      preliminary zone check and the reclaim loop in kswapd will clear it if
      the zone is considered balanced.
      Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Reviewed-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ed23ec4f
    • Linus Torvalds's avatar
      vfs: fix O_DIRECT read past end of block device · 684c9aae
      Linus Torvalds authored
      The direct-IO write path already had the i_size checks in mm/filemap.c,
      but it turns out the read path did not, and removing the block size
      checks in fs/block_dev.c (commit bbec0270: "blkdev_max_block: make
      private to fs/buffer.c") removed the magic "shrink IO to past the end of
      the device" code there.
      
      Fix it by truncating the IO to the size of the block device, like the
      write path already does.
      
      NOTE! I suspect the write path would be *much* better off doing it this
      way in fs/block_dev.c, rather than hidden deep in mm/filemap.c.  The
      mm/filemap.c code is extremely hard to follow, and has various
      conditionals on the target being a block device (ie the flag passed in
      to 'generic_write_checks()', along with a conditional update of the
      inode timestamp etc).
      
      It is also quite possible that we should treat this whole block device
      size as a "s_maxbytes" issue, and try to make the logic even more
      generic.  However, in the meantime this is the fairly minimal targeted
      fix.
      
      Noted by Milan Broz thanks to a regression test for the cryptsetup
      reencrypt tool.
      Reported-and-tested-by: default avatarMilan Broz <mbroz@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      684c9aae
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 1b3c393c
      Linus Torvalds authored
      Pull networking fixes from David Miller:
       "Two stragglers:
      
         1) The new code that adds new flushing semantics to GRO can cause SKB
            pointer list corruption, manage the lists differently to avoid the
            OOPS.  Fix from Eric Dumazet.
      
         2) When TCP fast open does a retransmit of data in a SYN-ACK or
            similar, we update retransmit state that we shouldn't triggering a
            WARN_ON later.  Fix from Yuchung Cheng."
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
        net: gro: fix possible panic in skb_gro_receive()
        tcp: bug fix Fast Open client retransmission
      1b3c393c