queue-5.0/vmw_balloon-release-lock-on-error-in-vmballoon_reset.patch

   1 From d04071a5d6413b65f17f7bd6e2bdb22e22e4ace7 Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Mon, 11 Feb 2019 21:45:45 +0300
   4 Subject: vmw_balloon: release lock on error in vmballoon_reset()
   5
   6 From: Dan Carpenter <dan.carpenter@oracle.com>
   7
   8 commit d04071a5d6413b65f17f7bd6e2bdb22e22e4ace7 upstream.
   9
  10 We added some locking to this function but forgot to drop the lock on
  11 these two error paths.  This bug would lead to an immediate deadlock.
  12
  13 Fixes: c7b3690fb152 ("vmw_balloon: stats rework")
  14 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  15 Cc: stable@vger.kernel.org
  16 Reviewed-by: Nadav Amit <namit@vmware.com>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19 ---
  20  drivers/misc/vmw_balloon.c |    5 +++--
  21  1 file changed, 3 insertions(+), 2 deletions(-)
  22
  23 --- a/drivers/misc/vmw_balloon.c
  24 +++ b/drivers/misc/vmw_balloon.c
  25 @@ -1287,7 +1287,7 @@ static void vmballoon_reset(struct vmbal
  26         vmballoon_pop(b);
  27
  28         if (vmballoon_send_start(b, VMW_BALLOON_CAPABILITIES))
  29 -               return;
  30 +               goto unlock;
  31
  32         if ((b->capabilities & VMW_BALLOON_BATCHED_CMDS) != 0) {
  33                 if (vmballoon_init_batching(b)) {
  34 @@ -1298,7 +1298,7 @@ static void vmballoon_reset(struct vmbal
  35                          * The guest will retry in one second.
  36                          */
  37                         vmballoon_send_start(b, 0);
  38 -                       return;
  39 +                       goto unlock;
  40                 }
  41         } else if ((b->capabilities & VMW_BALLOON_BASIC_CMDS) != 0) {
  42                 vmballoon_deinit_batching(b);
  43 @@ -1314,6 +1314,7 @@ static void vmballoon_reset(struct vmbal
  44         if (vmballoon_send_guest_id(b))
  45                 pr_err("failed to send guest ID to the host\n");
  46
  47 +unlock:
  48         up_write(&b->conf_sem);
  49  }
  50