diff options
| author | Eli Cohen <eli@dev.mellanox.co.il> | 2012-01-04 08:36:48 +0400 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2012-01-04 08:36:48 +0400 |
| commit | e214a0fe2b382fa302c036ecd6e6ffe99e3b9875 (patch) | |
| tree | 6cfd92715630e3406521f700a3df3cf3295e7770 /drivers/infiniband | |
| parent | 5f0a6e2d503896062f641639dacfe5055c2f593b (diff) | |
| download | linux-e214a0fe2b382fa302c036ecd6e6ffe99e3b9875.tar.xz | |
IB/uverbs: Protect QP multicast list
Userspace verbs multicast attach/detach operations on a QP are done
while holding the rwsem of the QP for reading. That's not sufficient
since a reader lock allows more than one reader to acquire the
lock. However, multicast attach/detach does list manipulation that
can corrupt the list if multiple threads run in parallel.
Fix this by acquiring the rwsem as a writer to serialize attach/detach
operations. Add idr_write_qp() and put_qp_write() to encapsulate
this.
This fixes oops seen when running applications that perform multicast
joins/leaves.
Reported by: Mike Dubman <miked@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/core/uverbs_cmd.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 254f1649c734..e3db8ef4fe4e 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -241,11 +241,24 @@ static struct ib_qp *idr_read_qp(int qp_handle, struct ib_ucontext *context) return idr_read_obj(&ib_uverbs_qp_idr, qp_handle, context, 0); } +static struct ib_qp *idr_write_qp(int qp_handle, struct ib_ucontext *context) +{ + struct ib_uobject *uobj; + + uobj = idr_write_uobj(&ib_uverbs_qp_idr, qp_handle, context); + return uobj ? uobj->object : NULL; +} + static void put_qp_read(struct ib_qp *qp) { put_uobj_read(qp->uobject); } +static void put_qp_write(struct ib_qp *qp) +{ + put_uobj_write(qp->uobject); +} + static struct ib_srq *idr_read_srq(int srq_handle, struct ib_ucontext *context) { return idr_read_obj(&ib_uverbs_srq_idr, srq_handle, context, 0); @@ -2375,7 +2388,7 @@ ssize_t ib_uverbs_attach_mcast(struct ib_uverbs_file *file, if (copy_from_user(&cmd, buf, sizeof cmd)) return -EFAULT; - qp = idr_read_qp(cmd.qp_handle, file->ucontext); + qp = idr_write_qp(cmd.qp_handle, file->ucontext); if (!qp) return -EINVAL; @@ -2404,7 +2417,7 @@ ssize_t ib_uverbs_attach_mcast(struct ib_uverbs_file *file, kfree(mcast); out_put: - put_qp_read(qp); + put_qp_write(qp); return ret ? ret : in_len; } @@ -2422,7 +2435,7 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file, if (copy_from_user(&cmd, buf, sizeof cmd)) return -EFAULT; - qp = idr_read_qp(cmd.qp_handle, file->ucontext); + qp = idr_write_qp(cmd.qp_handle, file->ucontext); if (!qp) return -EINVAL; @@ -2441,7 +2454,7 @@ ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file, } out_put: - put_qp_read(qp); + put_qp_write(qp); return ret ? ret : in_len; } |