On Mon, May 27, 2024 at 09:08:27AM +0800, Yu Kuai wrote:
Hi,
在 2024/05/26 17:41, Sasha Levin 写道:
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
Hi, please notice that this patch doesn't fix real issue expect for the ubsan warning, and this patch is reverted:
I'll drop it, thanks!