Hi,
在 2023/05/26 15:45, linan666@xxxxxxxxxxxxxxx 写道:
From: Li Nan <linan122@xxxxxxxxxx>
need_replace will be set to 1 if no-Faulty mreplace exists, and mreplace
will be deref later. However, the latter check of mreplace might set
mreplace to NULL, null-ptr-deref occurs if need_replace is 1 at this time.
Fix it by merging two checks into one. And replace 'need_replace' with
'mreplace' because their values are always the same.
Fixes: ee37d7314a32 ("md/raid10: Fix raid10 replace hang when new added disk faulty")
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
Other than some nits below, this patch looks good to me, feel free too
add:
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/md/raid10.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 4fcfcb350d2b..e21502c03b45 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3438,7 +3438,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
int must_sync;
int any_working;
int need_recover = 0;
- int need_replace = 0;
struct raid10_info *mirror = &conf->mirrors[i];
struct md_rdev *mrdev, *mreplace;
@@ -3451,10 +3450,10 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
!test_bit(In_sync, &mrdev->flags))
need_recover = 1;
if (mreplace != NULL &&
- !test_bit(Faulty, &mreplace->flags))
- need_replace = 1;
+ test_bit(Faulty, &mreplace->flags))
This can be keeped in one line.
+ mreplace = NULL;
- if (!need_recover && !need_replace) {
+ if (!need_recover && !mreplace) {
rcu_read_unlock();
continue;
}
@@ -3470,8 +3469,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
rcu_read_unlock();
continue;
}
- if (mreplace && test_bit(Faulty, &mreplace->flags))
- mreplace = NULL;
/* Unless we are doing a full sync, or a replacement
* we only need to recover the block if it is set in
* the bitmap
@@ -3594,11 +3591,11 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
bio = r10_bio->devs[1].repl_bio;
if (bio)
bio->bi_end_io = NULL;
- /* Note: if need_replace, then bio
+ /* Note: if replace is not NULL, then bio
* cannot be NULL as r10buf_pool_alloc will
* have allocated it.
*/
- if (!need_replace)
+ if (!mreplace)
break;
bio->bi_next = biolist;
biolist = bio;
