From: Li Nan linan122@huawei.com
[ Upstream commit 3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e ]
UBSAN reports this problem:
UBSAN: Undefined behaviour in drivers/md/md.c:8175:15 signed integer overflow: -2147483291 - 2072033152 cannot be represented in type 'int' Call trace: dump_backtrace+0x0/0x310 show_stack+0x28/0x38 dump_stack+0xec/0x15c ubsan_epilogue+0x18/0x84 handle_overflow+0x14c/0x19c __ubsan_handle_sub_overflow+0x34/0x44 is_mddev_idle+0x338/0x3d8 md_do_sync+0x1bb8/0x1cf8 md_thread+0x220/0x288 kthread+0x1d8/0x1e0 ret_from_fork+0x10/0x18
'curr_events' will overflow when stat accum or 'sync_io' is greater than INT_MAX.
Fix it by changing sync_io, last_events and curr_events to 64bit.
Signed-off-by: Li Nan linan122@huawei.com Reviewed-by: Yu Kuai yukuai3@huawei.com Link: https://lore.kernel.org/r/20240117031946.2324519-2-linan666@huaweicloud.com Signed-off-by: Song Liu song@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/md.c | 7 ++++--- drivers/md/md.h | 4 ++-- include/linux/blkdev.h | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c index 624259f79337f..57b1cb5f0ccfa 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8557,14 +8557,15 @@ static int is_mddev_idle(struct mddev *mddev, int init) { struct md_rdev *rdev; int idle; - int curr_events; + long long curr_events;
idle = 1; rcu_read_lock(); rdev_for_each_rcu(rdev, mddev) { struct gendisk *disk = rdev->bdev->bd_disk; - curr_events = (int)part_stat_read_accum(disk->part0, sectors) - - atomic_read(&disk->sync_io); + curr_events = + (long long)part_stat_read_accum(disk->part0, sectors) - + atomic64_read(&disk->sync_io); /* sync IO will cause sync_io to increase before the disk_stats * as sync_io is counted when a request starts, and * disk_stats is counted when it completes. diff --git a/drivers/md/md.h b/drivers/md/md.h index 7c9c13abd7cac..57463470c96f4 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -50,7 +50,7 @@ struct md_rdev {
sector_t sectors; /* Device size (in 512bytes sectors) */ struct mddev *mddev; /* RAID array if running */ - int last_events; /* IO event timestamp */ + long long last_events; /* IO event timestamp */
/* * If meta_bdev is non-NULL, it means that a separate device is @@ -605,7 +605,7 @@ extern void mddev_unlock(struct mddev *mddev);
static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors) { - atomic_add(nr_sectors, &bdev->bd_disk->sync_io); + atomic64_add(nr_sectors, &bdev->bd_disk->sync_io); }
static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5b6e86b2c37a5..95619569bc5c0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -168,7 +168,7 @@ struct gendisk { struct list_head slave_bdevs; #endif struct timer_rand_state *random; - atomic_t sync_io; /* RAID */ + atomic64_t sync_io; /* RAID */ struct disk_events *ev;
#ifdef CONFIG_BLK_DEV_ZONED