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  1. 15 2月, 2013 2 次提交
  3. 14 2月, 2013 2 次提交
    • C
      xen: remove redundant NULL check before unregister_and_remove_pcpu(). · 4f8c8527
      由 Cyril Roelandt 提交于 
      unregister_and_remove_pcpu on a NULL pointer is a no-op, so the NULL check in
sync_pcpu can be removed.
Signed-off-by: NCyril Roelandt <tipecaml@gmail.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      4f8c8527
    • J
      x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS. · 13d2b4d1
      由 Jan Beulich 提交于 
      This fixes CVE-2013-0228 / XSA-42

Drew Jones while working on CVE-2013-0190 found that that unprivileged guest user
in 32bit PV guest can use to crash the > guest with the panic like this:

-------------
general protection fault: 0000 [#1] SMP
last sysfs file: /sys/devices/vbd-51712/block/xvda/dev
Modules linked in: sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4
iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6
xt_state nf_conntrack ip6table_filter ip6_tables ipv6 xen_netfront ext4
mbcache jbd2 xen_blkfront dm_mirror dm_region_hash dm_log dm_mod [last
unloaded: scsi_wait_scan]

Pid: 1250, comm: r Not tainted 2.6.32-356.el6.i686 #1
EIP: 0061:[<c0407462>] EFLAGS: 00010086 CPU: 0
EIP is at xen_iret+0x12/0x2b
EAX: eb8d0000 EBX: 00000001 ECX: 08049860 EDX: 00000010
ESI: 00000000 EDI: 003d0f00 EBP: b77f8388 ESP: eb8d1fe0
 DS: 0000 ES: 007b FS: 0000 GS: 00e0 SS: 0069
Process r (pid: 1250, ti=eb8d0000 task=c2953550 task.ti=eb8d0000)
Stack:
 00000000 0027f416 00000073 00000206 b77f8364 0000007b 00000000 00000000
Call Trace:
Code: c3 8b 44 24 18 81 4c 24 38 00 02 00 00 8d 64 24 30 e9 03 00 00 00
8d 76 00 f7 44 24 08 00 00 02 80 75 33 50 b8 00 e0 ff ff 21 e0 <8b> 40
10 8b 04 85 a0 f6 ab c0 8b 80 0c b0 b3 c0 f6 44 24 0d 02
EIP: [<c0407462>] xen_iret+0x12/0x2b SS:ESP 0069:eb8d1fe0
general protection fault: 0000 [#2]
---[ end trace ab0d29a492dcd330 ]---
Kernel panic - not syncing: Fatal exception
Pid: 1250, comm: r Tainted: G      D    ---------------
2.6.32-356.el6.i686 #1
Call Trace:
 [<c08476df>] ? panic+0x6e/0x122
 [<c084b63c>] ? oops_end+0xbc/0xd0
 [<c084b260>] ? do_general_protection+0x0/0x210
 [<c084a9b7>] ? error_code+0x73/
-------------

Petr says: "
 I've analysed the bug and I think that xen_iret() cannot cope with
 mangled DS, in this case zeroed out (null selector/descriptor) by either
 xen_failsafe_callback() or RESTORE_REGS because the corresponding LDT
 entry was invalidated by the reproducer. "

Jan took a look at the preliminary patch and came up a fix that solves
this problem:

"This code gets called after all registers other than those handled by
IRET got already restored, hence a null selector in %ds or a non-null
one that got loaded from a code or read-only data descriptor would
cause a kernel mode fault (with the potential of crashing the kernel
as a whole, if panic_on_oops is set)."

The way to fix this is to realize that the we can only relay on the
registers that IRET restores. The two that are guaranteed are the
%cs and %ss as they are always fixed GDT selectors. Also they are
inaccessible from user mode - so they cannot be altered. This is
the approach taken in this patch.

Another alternative option suggested by Jan would be to relay on
the subtle realization that using the %ebp or %esp relative references uses
the %ss segment.  In which case we could switch from using %eax to %ebp and
would not need the %ss over-rides. That would also require one extra
instruction to compensate for the one place where the register is used
as scaled index. However Andrew pointed out that is too subtle and if
further work was to be done in this code-path it could escape folks attention
and lead to accidents.
Reviewed-by: NPetr Matousek <pmatouse@redhat.com>
Reported-by: NPetr Matousek <pmatouse@redhat.com>
Reviewed-by: NAndrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      13d2b4d1
  5. 06 2月, 2013 2 次提交
  7. 17 1月, 2013 1 次提交
    • A
      xen: Fix stack corruption in xen_failsafe_callback for 32bit PVOPS guests. · 9174adbe
      由 Andrew Cooper 提交于 
      This fixes CVE-2013-0190 / XSA-40

There has been an error on the xen_failsafe_callback path for failed
iret, which causes the stack pointer to be wrong when entering the
iret_exc error path.  This can result in the kernel crashing.

In the classic kernel case, the relevant code looked a little like:

        popl %eax      # Error code from hypervisor
        jz 5f
        addl $16,%esp
        jmp iret_exc   # Hypervisor said iret fault
5:      addl $16,%esp
                       # Hypervisor said segment selector fault

Here, there are two identical addls on either option of a branch which
appears to have been optimised by hoisting it above the jz, and
converting it to an lea, which leaves the flags register unaffected.

In the PVOPS case, the code looks like:

        popl_cfi %eax         # Error from the hypervisor
        lea 16(%esp),%esp     # Add $16 before choosing fault path
        CFI_ADJUST_CFA_OFFSET -16
        jz 5f
        addl $16,%esp         # Incorrectly adjust %esp again
        jmp iret_exc

It is possible unprivileged userspace applications to cause this
behaviour, for example by loading an LDT code selector, then changing
the code selector to be not-present.  At this point, there is a race
condition where it is possible for the hypervisor to return back to
userspace from an interrupt, fault on its own iret, and inject a
failsafe_callback into the kernel.

This bug has been present since the introduction of Xen PVOPS support
in commit 5ead97c8 (xen: Core Xen implementation), in 2.6.23.
Signed-off-by: NFrediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: NAndrew Cooper <andrew.cooper3@citrix.com>
Cc: stable@vger.kernel.org
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      9174adbe
  9. 16 1月, 2013 9 次提交
  11. 12 1月, 2013 1 次提交
  13. 18 12月, 2012 3 次提交
  15. 11 12月, 2012 6 次提交
    • L
      Linux 3.7 · 29594404
      由 Linus Torvalds 提交于
      29594404
    • F
      Input: matrix-keymap - provide proper module license · 55220bb3
      由 Florian Fainelli 提交于 
      The matrix-keymap module is currently lacking a proper module license,
add one so we don't have this module tainting the entire kernel.  This
issue has been present since commit 1932811f ("Input: matrix-keymap
- uninline and prepare for device tree support")
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
CC: stable@vger.kernel.org # v3.5+
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      55220bb3
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 2c68bc72
      由 Linus Torvalds 提交于 
      Pull networking fixes from David Miller:

 1) Netlink socket dumping had several missing verifications and checks.

    In particular, address comparisons in the request byte code
    interpreter could access past the end of the address in the
    inet_request_sock.

    Also, address family and address prefix lengths were not validated
    properly at all.

    This means arbitrary applications can read past the end of certain
    kernel data structures.

    Fixes from Neal Cardwell.

 2) ip_check_defrag() operates in contexts where we're in the process
    of, or about to, input the packet into the real protocols
    (specifically macvlan and AF_PACKET snooping).

    Unfortunately, it does a pskb_may_pull() which can modify the
    backing packet data which is not legal if the SKB is shared.  It
    very much can be shared in this context.

    Deal with the possibility that the SKB is segmented by using
    skb_copy_bits().

    Fix from Johannes Berg based upon a report by Eric Leblond.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  ipv4: ip_check_defrag must not modify skb before unsharing
  inet_diag: validate port comparison byte code to prevent unsafe reads
  inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run()
  inet_diag: validate byte code to prevent oops in inet_diag_bc_run()
  inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state
      2c68bc72
    • L
      Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage · caf49191
      由 Linus Torvalds 提交于 
      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: NMel Gorman <mgorman@suse.de>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      caf49191
    • J
      ipv4: ip_check_defrag must not modify skb before unsharing · 1bf3751e
      由 Johannes Berg 提交于 
      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: NEric Leblond <eric@regit.org>
Cc: stable@vger.kernel.org
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1bf3751e
    • L
      Revert "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended" · 31f8d42d
      由 Linus Torvalds 提交于 
      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: NLinus Torvalds <torvalds@linux-foundation.org>
      31f8d42d
  17. 10 12月, 2012 4 次提交
    • N
      inet_diag: validate port comparison byte code to prevent unsafe reads · 5e1f5420
      由 Neal Cardwell 提交于 
      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: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5e1f5420
    • N
      inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run() · f67caec9
      由 Neal Cardwell 提交于 
      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: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f67caec9
    • N
      inet_diag: validate byte code to prevent oops in inet_diag_bc_run() · 405c0059
      由 Neal Cardwell 提交于 
      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: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      405c0059
    • N
      inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state · 1c95df85
      由 Neal Cardwell 提交于 
      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: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1c95df85
  19. 09 12月, 2012 2 次提交
    • J
      mm: vmscan: fix inappropriate zone congestion clearing · ed23ec4f
      由 Johannes Weiner 提交于 
      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: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ed23ec4f
    • L
      vfs: fix O_DIRECT read past end of block device · 684c9aae
      由 Linus Torvalds 提交于 
      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: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      684c9aae
  21. 08 12月, 2012 4 次提交
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 1b3c393c
      由 Linus Torvalds 提交于 
      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
    • E
      net: gro: fix possible panic in skb_gro_receive() · c3c7c254
      由 Eric Dumazet 提交于 
      commit 2e71a6f8 (net: gro: selective flush of packets) added
a bug for skbs using frag_list. This part of the GRO stack is rarely
used, as it needs skb not using a page fragment for their skb->head.

Most drivers do use a page fragment, but some of them use GFP_KERNEL
allocations for the initial fill of their RX ring buffer.

napi_gro_flush() overwrite skb->prev that was used for these skb to
point to the last skb in frag_list.

Fix this using a separate field in struct napi_gro_cb to point to the
last fragment.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c3c7c254
    • Y
      tcp: bug fix Fast Open client retransmission · 93b174ad
      由 Yuchung Cheng 提交于 
      If SYN-ACK partially acks SYN-data, the client retransmits the
remaining data by tcp_retransmit_skb(). This increments lost recovery
state variables like tp->retrans_out in Open state. If loss recovery
happens before the retransmission is acked, it triggers the WARN_ON
check in tcp_fastretrans_alert(). For example: the client sends
SYN-data, gets SYN-ACK acking only ISN, retransmits data, sends
another 4 data packets and get 3 dupacks.

Since the retransmission is not caused by network drop it should not
update the recovery state variables. Further the server may return a
smaller MSS than the cached MSS used for SYN-data, so the retranmission
needs a loop. Otherwise some data will not be retransmitted until timeout
or other loss recovery events.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      93b174ad
    • L
      Merge tag 'mmc-fixes-for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc · 1afa4717
      由 Linus Torvalds 提交于 
      Pull MMC fixes from Chris Ball:
 "Two small regression fixes:

   - sdhci-s3c: Fix runtime PM regression against 3.7-rc1
   - sh-mmcif: Fix oops against 3.6"

* tag 'mmc-fixes-for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc:
  mmc: sh-mmcif: avoid oops on spurious interrupts (second try)
  Revert misapplied "mmc: sh-mmcif: avoid oops on spurious interrupts"
  mmc: sdhci-s3c: fix missing clock for gpio card-detect
      1afa4717
  23. 07 12月, 2012 4 次提交