tree ec7f484e83f348957a6cffa40a2c45821722612a
parent 839041329fd3410e07d614f81e75bb43367d8f89
author Roland Dreier <rolandd@cisco.com> 1192849303 -0700
committer Roland Dreier <rolandd@cisco.com> 1192849303 -0700

IB/uverbs: Fix checking of userspace object ownership
    
Commit 9ead190b ("IB/uverbs: Don't serialize with ib_uverbs_idr_mutex")
rewrote how userspace objects are looked up in the uverbs module's
idrs, and introduced a severe bug in the process: there is no checking
that an operation is being performed by the right process any more.
Fix this by adding the missing check of uobj->context in __idr_get_uobj().

Apparently everyone is being very careful to only touch their own
objects, because this bug was introduced in June 2006 in 2.6.18, and
has gone undetected until now.

Cc: stable <stable@kernel.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>