On 04/29/2012 01:59 AM, Xi Wang wrote:
> On 32-bit systems, a large `pglen' would overflow `pglen*sizeof(u32)'
> and bypass the check ceph_decode_need(p, end, pglen*sizeof(u32), bad).
> It would also overflow the subsequent kmalloc() size, leading to
> out-of-bounds write.
>
> Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
This looks good. I'll wait to hear back on my comments on
your earlier patches before committing these.
Reviewed-by: Alex Elder <elder@xxxxxxxxxxx>
> ---
> net/ceph/osdmap.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 774eac6..b1ea6d1 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -891,6 +891,10 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
>
> if (pglen) {
> /* insert */
> + if (pglen > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) {
> + err = -EINVAL;
> + goto bad;
> + }
> ceph_decode_need(p, end, pglen*sizeof(u32), bad);
> pg = kmalloc(sizeof(*pg) + sizeof(u32)*pglen, GFP_NOFS);
> if (!pg) {
--
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