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| author | Roland Dreier <rolandd@cisco.com> | 2007-10-28 10:14:32 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-11-16 09:30:20 -0800 |
| commit | a8ebc7bceb104fa5e1ef1ce116d3fd85f2081af2 (patch) | |
| tree | 28a9b657e0943872e4e22ef4d9a2198d38cd4713 | |
| parent | 813476de234d567b55404d45a568abb95d1e05c6 (diff) | |
| download | lwn-a8ebc7bceb104fa5e1ef1ce116d3fd85f2081af2.tar.gz lwn-a8ebc7bceb104fa5e1ef1ce116d3fd85f2081af2.zip | |
IB/uverbs: Fix checking of userspace object ownership
Upstream as cbfb50e6e2e9c580848c0f51d37c24cdfb1cb704
Commit 9ead190b ("IB/uverbs: Don't serialize with ib_uverbs_idr_mutex")
rewrote how userspace objects are looked up in the uverbs module's
idrs, and introduced a severe bug in the process: there is no checking
that an operation is being performed by the right process any more.
Fix this by adding the missing check of uobj->context in __idr_get_uobj().
Apparently everyone is being very careful to only touch their own
objects, because this bug was introduced in June 2006 in 2.6.18, and
has gone undetected until now.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/infiniband/core/uverbs_cmd.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 01d70084aebe..495c803fb11d 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -147,8 +147,12 @@ static struct ib_uobject *__idr_get_uobj(struct idr *idr, int id, spin_lock(&ib_uverbs_idr_lock); uobj = idr_find(idr, id); - if (uobj) - kref_get(&uobj->ref); + if (uobj) { + if (uobj->context == context) + kref_get(&uobj->ref); + else + uobj = NULL; + } spin_unlock(&ib_uverbs_idr_lock); return uobj; |