summaryrefslogtreecommitdiff
path: root/drivers/hv/channel_mgmt.c
diff options
context:
space:
mode:
authorDexuan Cui <decui@microsoft.com>2018-08-02 06:08:23 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-08-02 11:20:59 +0300
commitd3b26dd7cb0e3433bfd3c1d4dcf74c6039bb49fb (patch)
treed6793900dfa4d886d23c1c33c37e9148bd0e12d2 /drivers/hv/channel_mgmt.c
parent7026a5fd7f2cd36fee5ec40f3652f942700671b7 (diff)
downloadlinux-d3b26dd7cb0e3433bfd3c1d4dcf74c6039bb49fb.tar.xz
Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()
Before setting channel->rescind in vmbus_rescind_cleanup(), we should make sure the channel callback won't run any more, otherwise a high-level driver like pci_hyperv, which may be infinitely waiting for the host VSP's response and notices the channel has been rescinded, can't safely give up: e.g., in hv_pci_protocol_negotiation() -> wait_for_response(), it's unsafe to exit from wait_for_response() and proceed with the on-stack variable "comp_pkt" popped. The issue was originally spotted by Michael Kelley <mikelley@microsoft.com>. In vmbus_close_internal(), the patch also minimizes the range protected by disabling/enabling channel->callback_event: we don't really need that for the whole function. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Michael Kelley <mikelley@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/channel_mgmt.c')
-rw-r--r--drivers/hv/channel_mgmt.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f3b551a50653..0f0e091c117c 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -893,6 +893,12 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
}
/*
+ * Before setting channel->rescind in vmbus_rescind_cleanup(), we
+ * should make sure the channel callback is not running any more.
+ */
+ vmbus_reset_channel_cb(channel);
+
+ /*
* Now wait for offer handling to complete.
*/
vmbus_rescind_cleanup(channel);