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authorJiasheng Jiang <jiasheng@iscas.ac.cn>2023-03-16 14:55:06 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-05 11:16:41 +0200
commit4a32a9a818a895671bd43e0c40351e60e4e9140b (patch)
treeb7d5ba38360b6f459a4c224d728fdbf7c780db1d /drivers/md
parentf8cbad984b1601435d087125ac760d3cae90213a (diff)
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 <jiasheng@iscas.ac.cn> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-stats.c7
-rw-r--r--drivers/md/dm-stats.h2
-rw-r--r--drivers/md/dm.c4
3 files changed, 10 insertions, 3 deletions
diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c
index ce6d3bce1b7b..0f42f4a7f382 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;
@@ -196,11 +196,16 @@ void dm_stats_init(struct dm_stats *stats)
mutex_init(&stats->mutex);
INIT_LIST_HEAD(&stats->list);
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)
diff --git a/drivers/md/dm-stats.h b/drivers/md/dm-stats.h
index 2ddfae678f32..dcac11fce03b 100644
--- a/drivers/md/dm-stats.h
+++ b/drivers/md/dm-stats.h
@@ -22,7 +22,7 @@ struct dm_stats_aux {
unsigned long long duration_ns;
};
-void dm_stats_init(struct dm_stats *st);
+int dm_stats_init(struct dm_stats *st);
void dm_stats_cleanup(struct dm_stats *st);
struct mapped_device;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b58ff1a0fda7..771167ee552c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1994,7 +1994,9 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->bdev)
goto bad;
- dm_stats_init(&md->stats);
+ r = dm_stats_init(&md->stats);
+ if (r < 0)
+ goto bad;
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);