From: "Paul E. McKenney" <paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org,
hal.rosenstock-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: qib_lookup_qpn() appears to leak pointer out of rcu_read_unlock()
Date: Tue, 11 Feb 2014 16:35:11 -0800 [thread overview]
Message-ID: <20140212003511.GA27242@linux.vnet.ibm.com> (raw)
Hello!
The qib_lookup_qpn() function does RCU pointer traversals within RCU
read-side critical sections as required, but the qp pointer is returned
from this function after it does rcu_read_unlock(). One of the callers,
qib_rcv_hdrerr(), dereferences this pointer upon return.
This appears to me to be a bug. From what I can see, the structure
pointed to by qp could be freed immediately after the rcu_read_unlock(),
which would result in a SEGV when qib_rcv_hdrerr() does its later
spin_lock(&qp->r_lock).
So what am I missing here?
Thanx, Paul
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next reply other threads:[~2014-02-12 0:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-12 0:35 Paul E. McKenney [this message]
[not found] ` <20140212003511.GA27242-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2014-02-12 13:59 ` qib_lookup_qpn() appears to leak pointer out of rcu_read_unlock() Marciniszyn, Mike
[not found] ` <32E1700B9017364D9B60AED9960492BC211F3D24-AtyAts71sc9zLByeVOV5+bfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-02-12 14:55 ` Paul E. McKenney
[not found] ` <20140212145543.GY4250-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2014-02-12 14:57 ` Marciniszyn, Mike
[not found] ` <32E1700B9017364D9B60AED9960492BC211F3D75-AtyAts71sc9zLByeVOV5+bfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-02-12 21:50 ` Paul E. McKenney
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