From a42180dd361584816bfe15c137b665699b994d90 Mon Sep 17 00:00:00 2001 From: Jiasheng Jiang Date: Thu, 16 Mar 2023 14:55:06 +0800 Subject: dm stats: check for and propagate alloc_percpu failure commit d3aa3e060c4a80827eb801fc448debc9daa7c46b upstream. Check alloc_precpu()'s return value and return an error from dm_stats_init() if it fails. Update alloc_dev() to fail if dm_stats_init() does. Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup() even if dm-stats isn't being actively used. Fixes: fd2ed4d25270 ("dm: add statistics support") Cc: stable@vger.kernel.org Signed-off-by: Jiasheng Jiang Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-stats.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/md/dm-stats.c') diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c index f105a71915ab..d12ba9bce145 100644 --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -188,7 +188,7 @@ static int dm_stat_in_flight(struct dm_stat_shared *shared) atomic_read(&shared->in_flight[WRITE]); } -void dm_stats_init(struct dm_stats *stats) +int dm_stats_init(struct dm_stats *stats) { int cpu; struct dm_stats_last_position *last; @@ -197,11 +197,16 @@ void dm_stats_init(struct dm_stats *stats) INIT_LIST_HEAD(&stats->list); stats->precise_timestamps = false; stats->last = alloc_percpu(struct dm_stats_last_position); + if (!stats->last) + return -ENOMEM; + for_each_possible_cpu(cpu) { last = per_cpu_ptr(stats->last, cpu); last->last_sector = (sector_t)ULLONG_MAX; last->last_rw = UINT_MAX; } + + return 0; } void dm_stats_cleanup(struct dm_stats *stats) -- cgit v1.2.3