From: Li Nan <linan122@huawei.com> mainline inclusion from mainline-v6.11-rc1 commit 3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e category: bugfix bugzilla: 190197 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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> --- drivers/md/md.h | 4 ++-- include/linux/blkdev.h | 2 +- drivers/md/md.c | 7 ++++--- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/md/md.h b/drivers/md/md.h index 3a067c04b93a..20fc443b7969 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -51,7 +51,7 @@ 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 @@ -622,7 +622,7 @@ 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 32f9f1cc7d3c..10b6651ec194 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -177,7 +177,7 @@ 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 diff --git a/drivers/md/md.c b/drivers/md/md.c index 501ff290e013..cc008df968cd 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8588,14 +8588,15 @@ 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. -- 2.39.2