nfsd4: fix bad bounds checking
commit 4aed9c46afb80164401143aa0fdcfe3798baa9d5 upstream.
A number of spots in the xdr decoding follow a pattern like
n = be32_to_cpup(p++);
READ_BUF(n + 4);
where n is a u32. The only bounds checking is done in READ_BUF itself,
but since it's checking (n + 4), it won't catch cases where n is very
large, (u32)(-4) or higher. I'm not sure exactly what the consequences
are, but we've seen crashes soon after.
Instead, just break these up into two READ_BUF()s.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed