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  1. 11 3月, 2011 2 次提交
    • J
      nfs: close NFSv4 COMMIT vs. CLOSE race · d2224e7a
      由 Jeff Layton 提交于 
      I've been adding in more artificial delays in the NFSv4 commit and close
codepaths to uncover races. The kernel I'm testing has the patch to
close the race in __rpc_wait_for_completion_task that's in Trond's
cthon2011 branch. The reproducer I've been using does this in a loop:

	mkdir("DIR");
	fd = open("DIR/FILE", O_WRONLY|O_CREAT|O_EXCL, 0644);
	write(fd, "abcdefg", 7);
	close(fd);
	unlink("DIR/FILE");
	rmdir("DIR");

The above reproducer shouldn't result in any silly-renaming. However,
when I add a "msleep(100)" just after the nfs_commit_clear_lock call in
nfs_commit_release, I can almost always force one to occur. If I can
force it to occur with that, then it can happen without that delay
given the right timing.

nfs_commit_inode waits for the NFS_INO_COMMIT bit to clear when called
with FLUSH_SYNC set. nfs_commit_rpcsetup on the other hand does not wait
for the task to complete before putting its reference to it, so the last
reference get put in rpc_release task and gets queued to a workqueue.

In this situation, the last open context reference may be put by the
COMMIT release instead of the close() syscall. The close() syscall
returns too quickly and the unlink runs while the d_count is still
high since the COMMIT release hasn't put its dentry reference yet.

Fix this by having rpc_commit_rpcsetup wait for the RPC call to complete
before putting the task reference when FLUSH_SYNC is set. With this, the
last reference is put by the process that's initiating the FLUSH_SYNC
commit and the race is closed.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
      d2224e7a
    • T
      SUNRPC: Close a race in __rpc_wait_for_completion_task() · bf294b41
      由 Trond Myklebust 提交于 
      Although they run as rpciod background tasks, under normal operation
(i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck()
and nfs4_do_close() want to be fully synchronous. This means that when we
exit, we want all references to the rpc_task to be gone, and we want
any dentry references etc. held by that task to be released.

For this reason these functions call __rpc_wait_for_completion_task(),
followed by rpc_put_task() in the expectation that the latter will be
releasing the last reference to the rpc_task, and thus ensuring that the
callback_ops->rpc_release() has been called synchronously.

This patch fixes a race which exists due to the fact that
rpciod calls rpc_complete_task() (in order to wake up the callers of
__rpc_wait_for_completion_task()) and then subsequently calls
rpc_put_task() without ensuring that these two steps are done atomically.

In order to avoid adding new spin locks, the patch uses the existing
waitqueue spin lock to order the rpc_task reference count releases between
the waiting process and rpciod.
The common case where nobody is waiting for completion is optimised for by
checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task
reference count is 1: in those cases we drop trying to grab the spin lock,
and immediately free up the rpc_task.

Those few processes that need to put the rpc_task from inside an
asynchronous context and that do not care about ordering are given a new
helper: rpc_put_task_async().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
      bf294b41
  3. 08 3月, 2011 2 次提交
  5. 07 3月, 2011 2 次提交
  7. 06 3月, 2011 2 次提交
  9. 05 3月, 2011 22 次提交
  11. 04 3月, 2011 10 次提交
    • M
      Blackfin: iflush: update anomaly 05000491 workaround · be1229b4
      由 Mike Frysinger 提交于 
      Recent feedback from design says we need three NOPs in the hardware loop.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
      be1229b4
    • M
      Blackfin: outs[lwb]: make sure count is greater than 0 · bb7b1129
      由 Mike Frysinger 提交于 
      Some devices will use the outs* funcs with a length of zero, so make sure
we do not write any data in that case.
Reported-by: NGilbert Inho <gneny@edevice.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
      bb7b1129
    • K
      ARM: mach-shmobile: mackerel: modify LCDC clock divider value · 2c34e939
      由 Kuninori Morimoto 提交于 
      mackerel WVGA LCDC panel expect 33.3MHz for dot-clock,
but current dot-clock was 50.0MHz.
This patch modify clock divider value.
Signed-off-by: NMakoto Ueda <makoto.ueda.ub@renesas.com>
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      2c34e939
    • K
      ARM: mach-shmobile: ap4evb: modify LCDC clock divider value · f60cb470
      由 Kuninori Morimoto 提交于 
      ap4evb WVGA LCDC panel expect 33.3MHz for dot-clock,
but current dot-clock was 50.0MHz.
This patch modify clock divider value.
Signed-off-by: NMakoto Ueda <makoto.ueda.ub@renesas.com>
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      f60cb470
    • B
      drm/nouveau: allocate kernel's notifier object at end of block · 73412c38
      由 Ben Skeggs 提交于 
      The nv30/nv40 3d driver is about to start using DMA_FENCE from the 3D
object which, it turns out, doesn't like its DMA object to not be
aligned to a 4KiB boundary.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
      73412c38
    • L
      Merge branch 'for-linus' of... · b65a0e0c
      由 Linus Torvalds 提交于 
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  DNS: Fix a NULL pointer deref when trying to read an error key [CVE-2011-1076]
      b65a0e0c
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 · 4438a02f
      由 Linus Torvalds 提交于 
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (42 commits)
  MAINTAINERS: Add Andy Gospodarek as co-maintainer.
  r8169: disable ASPM
  RxRPC: Fix v1 keys
  AF_RXRPC: Handle receiving ACKALL packets
  cnic: Fix lost interrupt on bnx2x
  cnic: Prevent status block race conditions with hardware
  net: dcbnl: check correct ops in dcbnl_ieee_set()
  e1000e: disable broken PHY wakeup for ICH10 LOMs, use MAC wakeup instead
  igb: fix sparse warning
  e1000: fix sparse warning
  netfilter: nf_log: avoid oops in (un)bind with invalid nfproto values
  dccp: fix oops on Reset after close
  ipvs: fix dst_lock locking on dest update
  davinci_emac: Add Carrier Link OK check in Davinci RX Handler
  bnx2x: update driver version to 1.62.00-6
  bnx2x: properly calculate lro_mss
  bnx2x: perform statistics "action" before state transition.
  bnx2x: properly configure coefficients for MinBW algorithm (NPAR mode).
  bnx2x: Fix ethtool -t link test for MF (non-pmf) devices.
  bnx2x: Fix nvram test for single port devices.
  ...
      4438a02f
    • L
      Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block · fb4b10ab
      由 Linus Torvalds 提交于 
      * 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: kill loop_mutex
  blktrace: Remove blk_fill_rwbs_rq.
  block: blk-flush shouldn't call directly into q->request_fn() __blk_run_queue()
  block: add @force_kblockd to __blk_run_queue()
  block: fix kernel-doc format for blkdev_issue_zeroout
  blk-throttle: Do not use kblockd workqueue for throtl work
      fb4b10ab
    • L
      Merge branch 'i_nlink' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 · 83360269
      由 Linus Torvalds 提交于 
      * 'i_nlink' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  hfs: fix rename() over non-empty directory
  udf: fix i_nlink limit
  fix reiserfs mkdir() breakage
  exofs: i_nlink races in rename()
  nilfs2: i_nlink races in rename()
  minix: i_nlink races in rename()
  ufs: i_nlink races in rename()
  sysv: i_nlink races in rename()
      83360269
    • D
      DNS: Fix a NULL pointer deref when trying to read an error key [CVE-2011-1076] · 1362fa07
      由 David Howells 提交于 
      When a DNS resolver key is instantiated with an error indication, attempts to
read that key will result in an oops because user_read() is expecting there to
be a payload - and there isn't one [CVE-2011-1076].

Give the DNS resolver key its own read handler that returns the error cached in
key->type_data.x[0] as an error rather than crashing.

Also make the kenter() at the beginning of dns_resolver_instantiate() limit the
amount of data it prints, since the data is not necessarily NUL-terminated.

The buggy code was added in:

	commit 4a2d7892
	Author: Wang Lei <wang840925@gmail.com>
	Date:   Wed Aug 11 09:37:58 2010 +0100
	Subject: DNS: If the DNS server returns an error, allow that to be cached [ver #2]

This can trivially be reproduced by any user with the following program
compiled with -lkeyutils:

	#include <stdlib.h>
	#include <keyutils.h>
	#include <err.h>
	static char payload[] = "#dnserror=6";
	int main()
	{
		key_serial_t key;
		key = add_key("dns_resolver", "a", payload, sizeof(payload),
			      KEY_SPEC_SESSION_KEYRING);
		if (key == -1)
			err(1, "add_key");
		if (keyctl_read(key, NULL, 0) == -1)
			err(1, "read_key");
		return 0;
	}

What should happen is that keyctl_read() reports error 6 (ENXIO) to the user:

	dns-break: read_key: No such device or address

but instead the kernel oopses.

This cannot be reproduced with the 'keyutils add' or 'keyutils padd' commands
as both of those cut the data down below the NUL termination that must be
included in the data.  Without this dns_resolver_instantiate() will return
-EINVAL and the key will not be instantiated such that it can be read.

The oops looks like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffff811b99f7>] user_read+0x4f/0x8f
PGD 3bdf8067 PUD 385b9067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:19.0/irq
CPU 0
Modules linked in:

Pid: 2150, comm: dns-break Not tainted 2.6.38-rc7-cachefs+ #468                  /DG965RY
RIP: 0010:[<ffffffff811b99f7>]  [<ffffffff811b99f7>] user_read+0x4f/0x8f
RSP: 0018:ffff88003bf47f08  EFLAGS: 00010246
RAX: 0000000000000001 RBX: ffff88003b5ea378 RCX: ffffffff81972368
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88003b5ea378
RBP: ffff88003bf47f28 R08: ffff88003be56620 R09: 0000000000000000
R10: 0000000000000395 R11: 0000000000000002 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffffffffa1
FS:  00007feab5751700(0000) GS:ffff88003e000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000003de40000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process dns-break (pid: 2150, threadinfo ffff88003bf46000, task ffff88003be56090)
Stack:
 ffff88003b5ea378 ffff88003b5ea3a0 0000000000000000 0000000000000000
 ffff88003bf47f68 ffffffff811b708e ffff88003c442bc8 0000000000000000
 00000000004005a0 00007fffba368060 0000000000000000 0000000000000000
Call Trace:
 [<ffffffff811b708e>] keyctl_read_key+0xac/0xcf
 [<ffffffff811b7c07>] sys_keyctl+0x75/0xb6
 [<ffffffff81001f7b>] system_call_fastpath+0x16/0x1b
Code: 75 1f 48 83 7b 28 00 75 18 c6 05 58 2b fb 00 01 be bb 00 00 00 48 c7 c7 76 1c 75 81 e8 13 c2 e9 ff 4c 8b b3 e0 00 00 00 4d 85 ed <41> 0f b7 5e 10 74 2d 4d 85 e4 74 28 e8 98 79 ee ff 49 39 dd 48
RIP  [<ffffffff811b99f7>] user_read+0x4f/0x8f
 RSP <ffff88003bf47f08>
CR2: 0000000000000010
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
cc: Wang Lei <wang840925@gmail.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      1362fa07