shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-09 12:17:12 +09:00
Code Issues Packages Projects Releases Wiki Activity

net: fix rds_iovec page count overflow

Browse Source 
commit 1b1f693d7a upstream.

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>
[v2: nr is unsigned in the old code]
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Linus Torvalds
2010-10-28 15:40:55 +00:00
committed by Greg Kroah-Hartman
parent c4f6afb9ce
commit dcef84f17a
1 changed files with 11 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
net/rds/rdma.c
View File

@@ -473,6 +473,17 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
max_pages = max(nr, max_pages);
nr_pages += nr;
/*
* nr for one entry in limited to (UINT_MAX>>PAGE_SHIFT)+1
* so nr_pages cannot overflow without becoming bigger than
* INT_MAX first. If nr cannot overflow then max_pages should
* be ok.
*/
if (nr_pages > INT_MAX) {
ret = -EINVAL;
goto out;
}
}
pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL);