[lkml]   [2007]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[patch 07/40] IB/uverbs: Fix checking of userspace object ownership

-stable review patch. If anyone has any objections, please let us know.

From: Roland Dreier <>

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 <>
Signed-off-by: Greg Kroah-Hartman <>

drivers/infiniband/core/uverbs_cmd.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- 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

uobj = idr_find(idr, id);
- if (uobj)
- kref_get(&uobj->ref);
+ if (uobj) {
+ if (uobj->context == context)
+ kref_get(&uobj->ref);
+ else
+ uobj = NULL;
+ }

return uobj;
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-11-15 07:57    [W:0.137 / U:8.988 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site