diff options
| author | Jan Beulich <JBeulich@suse.com> | 2016-07-07 01:23:57 -0600 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-07-20 11:35:52 -0400 |
| commit | 19f46e355fc211e071896916b7e4ec1f9b243d90 (patch) | |
| tree | cfff40c001ab0c1ba71357bb431c9d9c0d2689dd | |
| parent | 12d75ae734c265f419cf063e750d476a6a2d99ff (diff) | |
| download | lwn-19f46e355fc211e071896916b7e4ec1f9b243d90.tar.gz lwn-19f46e355fc211e071896916b7e4ec1f9b243d90.zip | |
xenbus: don't BUG() on user mode induced condition
[ Upstream commit 0beef634b86a1350c31da5fcc2992f0d7c8a622b ]
Inability to locate a user mode specified transaction ID should not
lead to a kernel crash. For other than XS_TRANSACTION_START also
don't issue anything to xenbus if the specified ID doesn't match that
of any active transaction.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
| -rw-r--r-- | drivers/xen/xenbus/xenbus_dev_frontend.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index 9433e46518c8..531e76474983 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -316,11 +316,18 @@ static int xenbus_write_transaction(unsigned msg_type, rc = -ENOMEM; goto out; } + } else { + list_for_each_entry(trans, &u->transactions, list) + if (trans->handle.id == u->u.msg.tx_id) + break; + if (&trans->list == &u->transactions) + return -ESRCH; } reply = xenbus_dev_request_and_reply(&u->u.msg); if (IS_ERR(reply)) { - kfree(trans); + if (msg_type == XS_TRANSACTION_START) + kfree(trans); rc = PTR_ERR(reply); goto out; } @@ -333,12 +340,7 @@ static int xenbus_write_transaction(unsigned msg_type, list_add(&trans->list, &u->transactions); } } else if (u->u.msg.type == XS_TRANSACTION_END) { - list_for_each_entry(trans, &u->transactions, list) - if (trans->handle.id == u->u.msg.tx_id) - break; - BUG_ON(&trans->list == &u->transactions); list_del(&trans->list); - kfree(trans); } |