Re: [PATCH-block v2 1/3] bdi, blk-cgroup: Fix potential UAF of blkcg

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 12/12/22 17:13, Tejun Heo wrote:
On Sun, Dec 11, 2022 at 05:20:56PM -0500, Waiman Long wrote:
  static void blkcg_destroy_blkgs(struct blkcg *blkcg)
  {
+	/*
+	 * blkcg_destroy_blkgs() shouldn't be called with all the blkcg
+	 * references gone.
+	 */
+	if (WARN_ON_ONCE(!css_tryget(&blkcg->css)))
+		return;
Wouldn't it make more sense to use percpu_ref_is_zero()? It's not like the
obtained extra reference does anything, right?

Yes, that makes sense. Will incorporate the change in the next version.

Thanks,
Longman




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]     [Monitors]

  Powered by Linux