From: Zheng Liang <zhengliang6@huawei.com> To: <paolo.valente@linaro.org>, <axboe@kernel.dk> Cc: <linux-block@vger.kernel.org>, <cgroups@vger.kernel.org>, <yi.zhang@huawei.com>, <yanaijie@huawei.com> Subject: [PATCH] block, bfq: fix UAF problem in bfqg_stats_init() Date: Tue, 12 Oct 2021 09:58:41 +0800 [thread overview] Message-ID: <20211012015841.233753-1-zhengliang6@huawei.com> (raw) In bfq_pd_alloc(), the function bfqg_stats_init() init bfqg. If blkg_rwstat_init() init bytes successful and init ios failed, bfqg_stats_init() return failed, bfqg will be freed. If we traverse the list of percpu_counters, It will have use after free 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> --- block/bfq-cgroup.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index e2f14508f2d6..243ffbc1f106 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) -- 2.25.4
WARNING: multiple messages have this Message-ID (diff)
From: Zheng Liang <zhengliang6-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> To: paolo.valente-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org Cc: linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yi.zhang-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, yanaijie-hv44wF8Li93QT0dZR+AlfA@public.gmane.org Subject: [PATCH] block, bfq: fix UAF problem in bfqg_stats_init() Date: Tue, 12 Oct 2021 09:58:41 +0800 [thread overview] Message-ID: <20211012015841.233753-1-zhengliang6@huawei.com> (raw) In bfq_pd_alloc(), the function bfqg_stats_init() init bfqg. If blkg_rwstat_init() init bytes successful and init ios failed, bfqg_stats_init() return failed, bfqg will be freed. If we traverse the list of percpu_counters, It will have use after free 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-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> --- block/bfq-cgroup.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index e2f14508f2d6..243ffbc1f106 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) -- 2.25.4
next reply other threads:[~2021-10-12 1:50 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-10-12 1:58 Zheng Liang [this message] 2021-10-12 1:58 ` [PATCH] block, bfq: fix UAF problem in bfqg_stats_init() Zheng Liang
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