NFSD: memory corruption due to writing beyond the stat array
commita8ebfc0286ec46f4367d77a4f02938c611bbc3bd
authorKonstantin Khorenko <khorenko@parallels.com>
Tue, 1 Feb 2011 14:16:29 +0000 (1 17:16 +0300)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 24 Feb 2011 22:54:22 +0000 (24 14:54 -0800)
tree3a88a754e5af22de3b4fb3436d4b463effcfc942
parentaf9a4eb329e0f6cf580218205d2f0c2d76587c62
NFSD: memory corruption due to writing beyond the stat array

commit 3aa6e0aa8ab3e64bbfba092c64d42fd1d006b124 upstream.

If nfsd fails to find an exported via NFS file in the readahead cache, it
should increment corresponding nfsdstats counter (ra_depth[10]), but due to a
bug it may instead write to ra_depth[11], corrupting the following field.

In a kernel with NFSDv4 compiled in the corruption takes the form of an
increment of a counter of the number of NFSv4 operation 0's received; since
there is no operation 0, this is harmless.

In a kernel with NFSDv4 disabled it corrupts whatever happens to be in the
memory beyond nfsdstats.

Signed-off-by: Konstantin Khorenko <khorenko@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs/nfsd/vfs.c