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| author | Li Nan <linan122@huawei.com> | 2024-01-17 04:19:45 +0100 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2024-04-09 06:15:46 +0200 |
| commit | 3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e (patch) | |
| tree | 91b78d0052fa65b7b9d720b65d61dbf6ee654c70 /drivers/md/md.c | |
| parent | md: add check for sleepers in md_wakeup_thread() (diff) | |
| download | linux-3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e.tar.xz linux-3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e.zip | |
md: Fix overflow in is_mddev_idle
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>
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index fd574b015d78..f28e41f9ac4a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8577,14 +8577,15 @@ 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. |