linux-toradex.git/fs, branch v3.3.5

hfsplus: Fix potential buffer overflows

2012-05-07T15:53:38+00:00

commit 6f24f892871acc47b40dd594c63606a17c714f77 upstream.

Commit ec81aecb2966 ("hfs: fix a potential buffer overflow") fixed a few
potential buffer overflows in the hfs filesystem.  But as Timo Warns
pointed out, these changes also need to be made on the hfsplus
filesystem as well.

Reported-by: Timo Warns 
Acked-by: WANG Cong 
Cc: Alexey Khoroshilov 
Cc: Miklos Szeredi 
Cc: Sage Weil 
Cc: Eugene Teo 
Cc: Roman Zippel 
Cc: Al Viro 
Cc: Christoph Hellwig 
Cc: Alexey Dobriyan 
Cc: Dave Anderson 
Cc: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Linus Torvalds

exit_signal: simplify the "we have changed execution domain" logic

2012-05-07T15:53:35+00:00

commit e636825346b36a07ccfc8e30946d52855e21f681 upstream.

exit_notify() checks "tsk->self_exec_id != tsk->parent_exec_id"
to handle the "we have changed execution domain" case.

We can change do_thread() to always set ->exit_signal = SIGCHLD
and remove this check to simplify the code.

We could change setup_new_exec() instead, this looks more logical
because it increments ->self_exec_id. But note that de_thread()
already resets ->exit_signal if it changes the leader, let's keep
both changes close to each other.

Note that we change ->exit_signal lockless, this changes the rules.
Thereafter ->exit_signal is not stable under tasklist but this is
fine, the only possible change is OLDSIG -> SIGCHLD. This can race
with eligible_child() but the race is harmless. We can race with
reparent_leader() which changes our ->exit_signal in parallel, but
it does the same change to SIGCHLD.

The noticeable user-visible change is that the execing task is not
"visible" to do_wait()->eligible_child(__WCLONE) right after exec.
To me this looks more logical, and this is consistent with mt case.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

autofs: make the autofsv5 packet file descriptor use a packetized pipe

2012-05-07T15:53:23+00:00

commit 64f371bc3107e69efce563a3d0f0e6880de0d537 upstream.

The autofs packet size has had a very unfortunate size problem on x86:
because the alignment of 'u64' differs in 32-bit and 64-bit modes, and
because the packet data was not 8-byte aligned, the size of the autofsv5
packet structure differed between 32-bit and 64-bit modes despite
looking otherwise identical (300 vs 304 bytes respectively).

We first fixed that up by making the 64-bit compat mode know about this
problem in commit a32744d4abae ("autofs: work around unhappy compat
problem on x86-64"), and that made a 32-bit 'systemd' work happily on a
64-bit kernel because everything then worked the same way as on a 32-bit
kernel.

But it turned out that 'automount' had actually known and worked around
this problem in user space, so fixing the kernel to do the proper 32-bit
compatibility handling actually *broke* 32-bit automount on a 64-bit
kernel, because it knew that the packet sizes were wrong and expected
those incorrect sizes.

As a result, we ended up reverting that compatibility mode fix, and
thus breaking systemd again, in commit fcbf94b9dedd.

With both automount and systemd doing a single read() system call, and
verifying that they get *exactly* the size they expect but using
different sizes, it seemed that fixing one of them inevitably seemed to
break the other.  At one point, a patch I seriously considered applying
from Michael Tokarev did a "strcmp()" to see if it was automount that
was doing the operation.  Ugly, ugly.

However, a prettier solution exists now thanks to the packetized pipe
mode.  By marking the communication pipe as being packetized (by simply
setting the O_DIRECT flag), we can always just write the bigger packet
size, and if user-space does a smaller read, it will just get that
partial end result and the extra alignment padding will simply be thrown
away.

This makes both automount and systemd happy, since they now get the size
they asked for, and the kernel side of autofs simply no longer needs to
care - it could pad out the packet arbitrarily.

Of course, if there is some *other* user of autofs (please, please,
please tell me it ain't so - and we haven't heard of any) that tries to
read the packets with multiple writes, that other user will now be
broken - the whole point of the packetized mode is that one system call
gets exactly one packet, and you cannot read a packet in pieces.

Tested-by: Michael Tokarev 
Cc: Alan Cox 
Cc: David Miller 
Cc: Ian Kent 
Cc: Thomas Meyer 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

pipes: add a "packetized pipe" mode for writing

2012-05-07T15:53:23+00:00

commit 9883035ae7edef3ec62ad215611cb8e17d6a1a5d upstream.

The actual internal pipe implementation is already really about
individual packets (called "pipe buffers"), and this simply exposes that
as a special packetized mode.

When we are in the packetized mode (marked by O_DIRECT as suggested by
Alan Cox), a write() on a pipe will not merge the new data with previous
writes, so each write will get a pipe buffer of its own.  The pipe
buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn
will tell the reader side to break the read at that boundary (and throw
away any partial packet contents that do not fit in the read buffer).

End result: as long as you do writes less than PIPE_BUF in size (so that
the pipe doesn't have to split them up), you can now treat the pipe as a
packet interface, where each read() system call will read one packet at
a time.  You can just use a sufficiently big read buffer (PIPE_BUF is
sufficient, since bigger than that doesn't guarantee atomicity anyway),
and the return value of the read() will naturally give you the size of
the packet.

NOTE! We do not support zero-sized packets, and zero-sized reads and
writes to a pipe continue to be no-ops.  Also note that big packets will
currently be split at write time, but that the size at which that
happens is not really specified (except that it's bigger than PIPE_BUF).
Currently that limit is the system page size, but we might want to
explicitly support bigger packets some day.

The main user for this is going to be the autofs packet interface,
allowing us to stop having to care so deeply about exact packet sizes
(which have had bugs with 32/64-bit compatibility modes).  But user
space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will
fail with an EINVAL on kernels that do not support this interface.

Tested-by: Michael Tokarev 
Cc: Alan Cox 
Cc: David Miller 
Cc: Ian Kent 
Cc: Thomas Meyer 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Revert "autofs: work around unhappy compat problem on x86-64"

2012-05-07T15:53:19+00:00

commit fcbf94b9dedd2ce08e798a99aafc94fec8668161 upstream.

This reverts commit a32744d4abae24572eff7269bc17895c41bd0085.

While that commit was technically the right thing to do, and made the
x86-64 compat mode work identically to native 32-bit mode (and thus
fixing the problem with a 32-bit systemd install on a 64-bit kernel), it
turns out that the automount binaries had workarounds for this compat
problem.

Now, the workarounds are disgusting: doing an "uname()" to find out the
architecture of the kernel, and then comparing it for the 64-bit cases
and fixing up the size of the read() in automount for those.  And they
were confused: it's not actually a generic 64-bit issue at all, it's
very much tied to just x86-64, which has different alignment for an
'u64' in 64-bit mode than in 32-bit mode.

But the end result is that fixing the compat layer actually breaks the
case of a 32-bit automount on a x86-64 kernel.

There are various approaches to fix this (including just doing a
"strcmp()" on current->comm and comparing it to "automount"), but I
think that I will do the one that teaches pipes about a special "packet
mode", which will allow user space to not have to care too deeply about
the padding at the end of the autofs packet.

That change will make the compat workaround unnecessary, so let's revert
it first, and get automount working again in compat mode.  The
packetized pipes will then fix autofs for systemd.

Reported-and-requested-by: Michael Tokarev 
Cc: Ian Kent 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

NFS: put open context on error in nfs_flush_multi

2012-05-07T15:53:18+00:00

commit 8ccd271f7a3a846ce6f85ead0760d9d12994a611 upstream.

Signed-off-by: Fred Isaman 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFS: put open context on error in nfs_pagein_multi

2012-05-07T15:53:18+00:00

commit 73fb7bc7c57d971b11f2e00536ac2d3e316e0609 upstream.

Signed-off-by: Fred Isaman 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFSv4: Ensure that we check lock exclusive/shared type against open modes

2012-05-07T15:53:18+00:00

commit 55725513b5ef9d462aa3e18527658a0362aaae83 upstream.

Since we may be simulating flock() locks using NFS byte range locks,
we can't rely on the VFS having checked the file open mode for us.

Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFSv4: Ensure that the LOCK code sets exception->inode

2012-05-07T15:53:18+00:00

commit 05ffe24f5290dc095f98fbaf84afe51ef404ccc5 upstream.

All callers of nfs4_handle_exception() that need to handle
NFS4ERR_OPENMODE correctly should set exception->inode

Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

nfs: Enclose hostname in brackets when needed in nfs_do_root_mount

2012-05-07T15:53:18+00:00

commit 98a2139f4f4d7b5fcc3a54c7fddbe88612abed20 upstream.

When hostname contains colon (e.g. when it is an IPv6 address) it needs
to be enclosed in brackets to make parsing of NFS device string possible.
Fix nfs_do_root_mount() to enclose hostname properly when needed. NFS code
actually does not need this as it does not parse the string passed by
nfs_do_root_mount() but the device string is exposed to userspace in
/proc/mounts.

CC: Josh Boyer 
CC: Trond Myklebust 
Signed-off-by: Jan Kara 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman