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| author | Zheng Liang <zhengliang6@huawei.com> | 2021-10-18 10:42:25 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-19 15:18:30 -0600 |
| commit | 2fc428f6b7ca80794cb9928c90d4de524366659f (patch) | |
| tree | be8a64de2fcd8220fb80f76058341f1de37da8dd /block/bfq-cgroup.c | |
| parent | a808a9d545cdffb964f27239d1fc0c6e2330b424 (diff) | |
| download | lwn-2fc428f6b7ca80794cb9928c90d4de524366659f.tar.gz lwn-2fc428f6b7ca80794cb9928c90d4de524366659f.zip | |
block, bfq: fix UAF problem in bfqg_stats_init()
In bfq_pd_alloc(), the function bfqg_stats_init() init bfqg. If
blkg_rwstat_init() init bfqg_stats->bytes successful and init
bfqg_stats->ios failed, bfqg_stats_init() return failed, bfqg will
be freed. But blkg_rwstat->cpu_cnt is not deleted from the list of
percpu_counters. If we traverse the list of percpu_counters, It will
have UAF problem.
we should use blkg_rwstat_exit() to cleanup bfqg_stats bytes in the
above scenario.
Fixes: commit fd41e60331b ("bfq-iosched: stop using blkg->stat_bytes and ->stat_ios")
Signed-off-by: Zheng Liang <zhengliang6@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20211018024225.1493938-1-zhengliang6@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-cgroup.c')
| -rw-r--r-- | block/bfq-cgroup.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 882ec4bc51ad..24a5c5329bcd 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -463,7 +463,7 @@ static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp) { if (blkg_rwstat_init(&stats->bytes, gfp) || blkg_rwstat_init(&stats->ios, gfp)) - return -ENOMEM; + goto error; #ifdef CONFIG_BFQ_CGROUP_DEBUG if (blkg_rwstat_init(&stats->merged, gfp) || @@ -476,13 +476,15 @@ static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp) bfq_stat_init(&stats->dequeue, gfp) || bfq_stat_init(&stats->group_wait_time, gfp) || bfq_stat_init(&stats->idle_time, gfp) || - bfq_stat_init(&stats->empty_time, gfp)) { - bfqg_stats_exit(stats); - return -ENOMEM; - } + bfq_stat_init(&stats->empty_time, gfp)) + goto error; #endif return 0; + +error: + bfqg_stats_exit(stats); + return -ENOMEM; } static struct bfq_group_data *cpd_to_bfqgd(struct blkcg_policy_data *cpd) |