From: Li Nan linan122@huawei.com
hulk inclusion category: bugfix bugzilla: 188378, https://gitee.com/openeuler/kernel/issues/I6GGV7 CVE: NA
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init_resync() init mempool and set conf->have_replacemnt at the begaining of sync, close_sync() free the mempool when sync is completed.
After commit 7e83ccbecd60 ("md/raid10: Allow skipping recovery when clean arrays are assembled"), recovery might skipped and init_resync() is called but close_sync() is not. null-ptr-deref occurs as below: 1) creat a array, wait for resync to complete, mddev->recovery_cp is set to MaxSector. 2) recovery is woken and it is skipped. conf->have_replacement is set to 0 in init_resync(). close_sync() not called. 3) some io errors and rdev A is set to WantReplacement. 4) a new device is added and set to A's replacement. 5) recovery is woken, A have replacement, but conf->have_replacemnt is 0. r10bio->dev[i].repl_bio will not be alloced and null-ptr-deref occurs.
Fix it by not init_resync() if recovery skipped.
Fixes: 7e83ccbecd60 md/raid10: Allow skipping recovery when clean arrays are assembled") Signed-off-by: Li Nan linan122@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com --- drivers/md/raid10.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index ec5f0a1794e9..badf02d8e848 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -2941,10 +2941,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, sector_t chunk_mask = conf->geo.chunk_mask; int page_idx = 0;
- if (!mempool_initialized(&conf->r10buf_pool)) - if (init_resync(conf)) - return 0; - /* * Allow skipping a full rebuild for incremental assembly * of a clean array, like RAID1 does. @@ -2960,6 +2956,10 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, return mddev->dev_sectors - sector_nr; }
+ if (!mempool_initialized(&conf->r10buf_pool)) + if (init_resync(conf)) + return 0; + skipped: max_sector = mddev->dev_sectors; if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||