[PATCH-block v2 0/3] blk-cgroup: Fix potential UAF & miscellaneous cleanup

From: Waiman Long
Date: Sun Dec 11 2022 - 17:23:13 EST


v2:
- Remove unnecessary rcu_read_{lock|unlock} from
cgroup_rstat_css_cpu_flush() in patch 3.

It was found that blkcg_destroy_blkgs() may be called with all blkcg
references gone. This may potentially cause user-after-free and so
should be fixed. The last 2 patches are miscellaneous cleanups of
commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()").

Waiman Long (3):
bdi, blk-cgroup: Fix potential UAF of blkcg
blk-cgroup: Don't flush a blkg if destroyed
blk-cgroup: Flush stats at blkgs destruction path

block/blk-cgroup.c | 26 ++++++++++++++++++++++++++
include/linux/cgroup.h | 1 +
kernel/cgroup/rstat.c | 18 ++++++++++++++++++
mm/backing-dev.c | 8 ++++++--
4 files changed, 51 insertions(+), 2 deletions(-)

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2.31.1