lkml.org 
[lkml]   [2013]   [Mar]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: kernel 3.8.4 : kernel BUG at fs/locks.c:2093! part #2
On Tue, Mar 26, 2013 at 06:46:31PM +0100, Toralf Förster wrote:
> On 03/26/2013 03:46 PM, J. Bruce Fields wrote:
> > Can you run with test patches?
> >
> > This just makes nfsd's fput calls synchronous so that we see in the
> > backtrace who called them.
>
> Well - the patched 3.8.4 host kernel now survives the stress test of the UML system.

Bah, too bad. That patch was definitely not a fix, so there may be some
race here.

> What I get at the host is now :
>
> 2013-03-26T18:32:17.487+01:00 n22 kernel: ------------[ cut here ]------------
> 2013-03-26T18:32:17.487+01:00 n22 kernel: WARNING: at mm/page_alloc.c:2376 __alloc_pages_nodemask+0x262/0x7c0()
...
> 2013-03-26T18:32:17.487+01:00 n22 kernel: [<c110f149>] __kmalloc+0x1b9/0x1e0
> 2013-03-26T18:32:17.487+01:00 n22 kernel: [<f85835bf>] ? cache_check+0x22f/0x340 [sunrpc]
> 2013-03-26T18:32:17.487+01:00 n22 kernel: [<f90a0b1c>] nfs4_acl_new+0x1c/0x30 [nfsd]
> 2013-03-26T18:32:17.488+01:00 n22 kernel: [<f9095482>] nfsd4_decode_fattr+0x302/0x6c0 [nfsd]
...

A different bug, but thanks for catching it, I suspect the following is
all we need.

--b.

commit 814d9d4f9164c3d778dadd093a54bb55d9a0c576
Author: J. Bruce Fields <bfields@redhat.com>
Date: Tue Mar 26 14:11:13 2013 -0400

nfsd4: reject "negative" acl lengths

Since we only enforce an upper bound, not a lower bound, a "negative"
length can get through here.

The symptom seen was a warning when we attempt to a kmalloc with an
excessive size.

Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0dc1158..d1dd710 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -264,7 +264,7 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
iattr->ia_valid |= ATTR_SIZE;
}
if (bmval[0] & FATTR4_WORD0_ACL) {
- int nace;
+ u32 nace;
struct nfs4_ace *ace;

READ_BUF(4); len += 4;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2013-03-26 20:01    [W:0.140 / U:0.464 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site