diff options
| author | Leon Romanovsky <leonro@mellanox.com> | 2020-04-23 09:01:22 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2020-04-24 15:40:41 -0300 |
| commit | f0abc761bbb9418876cc4d1ebc473e4ea6352e42 (patch) | |
| tree | 3130425b974171526973c3d4b84eeeef919df68c /drivers/infiniband | |
| parent | 47c370c1a5eea9b2f6f026d49e060c3748c89667 (diff) | |
| download | linux-f0abc761bbb9418876cc4d1ebc473e4ea6352e42.tar.bz2 | |
RDMA/core: Fix race between destroy and release FD object
The call to ->lookup_put() was too early and it caused an unlock of the
read/write protection of the uobject after the FD was put. This allows a
race:
CPU1 CPU2
rdma_lookup_put_uobject()
lookup_put_fd_uobject()
fput()
fput()
uverbs_uobject_fd_release()
WARN_ON(uverbs_try_lock_object(uobj,
UVERBS_LOOKUP_WRITE));
atomic_dec(usecnt)
Fix the code by changing the order, first unlock and call to
->lookup_put() after that.
Fixes: 3832125624b7 ("IB/core: Add support for idr types")
Link: https://lore.kernel.org/r/20200423060122.6182-1-leon@kernel.org
Suggested-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/core/rdma_core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index 2947f4f83561..177333d8bcda 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -678,7 +678,6 @@ void rdma_lookup_put_uobject(struct ib_uobject *uobj, enum rdma_lookup_mode mode) { assert_uverbs_usecnt(uobj, mode); - uobj->uapi_object->type_class->lookup_put(uobj, mode); /* * In order to unlock an object, either decrease its usecnt for * read access or zero it in case of exclusive access. See @@ -695,6 +694,7 @@ void rdma_lookup_put_uobject(struct ib_uobject *uobj, break; } + uobj->uapi_object->type_class->lookup_put(uobj, mode); /* Pairs with the kref obtained by type->lookup_get */ uverbs_uobject_put(uobj); } |