tree cf216d1bfb8a51f3df2c989dcffd5381a0e446f1
parent bdfa3d8fe123a940be121daf374581727b3b6547
author Linus Torvalds <torvalds@linux-foundation.org> 1288280455 +0000
committer David S. Miller <davem@davemloft.net> 1288481656 -0700

net: fix rds_iovec page count overflow

As reported by Thomas Pollet, the rdma page counting can overflow.  We
get the rdma sizes in 64-bit unsigned entities, but then limit it to
UINT_MAX bytes and shift them down to pages (so with a possible "+1" for
an unaligned address).

So each individual page count fits comfortably in an 'unsigned int' (not
even close to overflowing into signed), but as they are added up, they
might end up resulting in a signed return value. Which would be wrong.

Catch the case of tot_pages turning negative, and return the appropriate
error code.

Reported-by: Thomas Pollet <thomas.pollet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>