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authorRoland Dreier <rolandd@cisco.com>2007-10-20 05:01:43 +0200
committerRoland Dreier <rolandd@cisco.com>2007-10-20 05:01:43 +0200
commitcbfb50e6e2e9c580848c0f51d37c24cdfb1cb704 (patch)
treeec7f484e83f348957a6cffa40a2c45821722612a /drivers
parentIB/mlx4: Sanity check userspace send queue sizes (diff)
downloadlinux-cbfb50e6e2e9c580848c0f51d37c24cdfb1cb704.tar.xz
linux-cbfb50e6e2e9c580848c0f51d37c24cdfb1cb704.zip
IB/uverbs: Fix checking of userspace object ownership
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. Cc: stable <stable@kernel.org> Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/infiniband/core/uverbs_cmd.c8
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;