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| author | Sean Hefty <sean.hefty@intel.com> | 2011-02-23 08:17:40 -0800 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2011-03-15 10:56:12 -0700 |
| commit | 29963437a48475036353b95ab142bf199adb909e (patch) | |
| tree | 23564281f4d60b7a9cdbaab5e1babe3f67cc8ca8 /drivers/infiniband/core | |
| parent | 25ae21a10112875763c18b385624df713a288a05 (diff) | |
| download | linux-29963437a48475036353b95ab142bf199adb909e.tar.gz linux-29963437a48475036353b95ab142bf199adb909e.tar.bz2 linux-29963437a48475036353b95ab142bf199adb909e.zip | |
IB/cm: Bump reference count on cm_id before invoking callback
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 <sean.hefty@intel.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband/core')
| -rw-r--r-- | drivers/infiniband/core/cm.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 64e0903091a8..1d9616be4192 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -2989,6 +2989,7 @@ static int cm_sidr_req_handler(struct cm_work *work) goto out; /* No match. */ } atomic_inc(&cur_cm_id_priv->refcount); + atomic_inc(&cm_id_priv->refcount); spin_unlock_irq(&cm.lock); cm_id_priv->id.cm_handler = cur_cm_id_priv->id.cm_handler; |