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由 zhangwensheng 提交于
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4QXS1?from=project-issue CVE: NA -------------------------------- UBSAN reports this problem: [ 5984.281385] UBSAN: Undefined behaviour in drivers/md/md.c:8175:15 [ 5984.281390] signed integer overflow: [ 5984.281393] -2147483291 - 2072033152 cannot be represented in type 'int' [ 5984.281400] CPU: 25 PID: 1854 Comm: md101_resync Kdump: loaded Not tainted 4.19.90 [ 5984.281404] Hardware name: Huawei TaiShan 200 (Model 5280)/BC82AMDDA [ 5984.281406] Call trace: [ 5984.281415] dump_backtrace+0x0/0x310 [ 5984.281418] show_stack+0x28/0x38 [ 5984.281425] dump_stack+0xec/0x15c [ 5984.281430] ubsan_epilogue+0x18/0x84 [ 5984.281434] handle_overflow+0x14c/0x19c [ 5984.281439] __ubsan_handle_sub_overflow+0x34/0x44 [ 5984.281445] is_mddev_idle+0x338/0x3d8 [ 5984.281449] md_do_sync+0x1bb8/0x1cf8 [ 5984.281452] md_thread+0x220/0x288 [ 5984.281457] kthread+0x1d8/0x1e0 [ 5984.281461] ret_from_fork+0x10/0x18 When the stat aacum of the disk is greater than INT_MAX, its value becomes negative after casting to 'int', which may lead to overflow after subtracting a positive number. In the same way, when the value of sync_io is greater than INT_MAX,overflow may also occur. These situations will lead to undefined behavior. Otherwise, if the stat accum of the disk is close to INT_MAX when creating raid arrays, the initial value of last_events would be set close to INT_MAX when mddev initializes IO event counters. 'curr_events - rdev->last_events > 64' will always false during synchronization. If all the disks of mddev are in this case, is_mddev_idle() will always return 1, which may cause non-sync IO is very slow. To address these problems, need to use 64bit signed integer type for sync_io,last_events, and curr_events. Signed-off-by: Nzhangwensheng <zhangwensheng5@huawei.com> Reviewed-by: NTao Hou <houtao1@huawei.com> Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
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