From: Sean Hefty Date: Wed, 23 Feb 2011 16:17:40 +0000 (-0800) Subject: IB/cm: Bump reference count on cm_id before invoking callback X-Git-Tag: v2.6.37.5~56 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35e6f483095855c0efcf9da7c82f138f3ea04e15;p=pandora-kernel.git IB/cm: Bump reference count on cm_id before invoking callback commit 29963437a48475036353b95ab142bf199adb909e upstream. When processing a SIDR REQ, the ib_cm allocates a new cm_id. The refcount of the cm_id is initialized to 1. However, cm_process_work will decrement the refcount after invoking all callbacks. The result is that the cm_id will end up with refcount set to 0 by the end of the sidr req handler. If a user tries to destroy the cm_id, the destruction will proceed, under the incorrect assumption that no other threads are referencing the cm_id. This can lead to a crash when the cm callback thread tries to access the cm_id. This problem was noticed as part of a larger investigation with kernel crashes in the rdma_cm when running on a real time OS. Signed-off-by: Sean Hefty Acked-by: Doug Ledford Signed-off-by: Roland Dreier Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed