Re: [PATCH 1/3] md/raid10: fix null-ptr-deref of mreplace in raid10_sync_request

From: Li Nan
Date: Thu May 25 2023 - 09:56:05 EST

在 2023/5/22 21:01, Yu Kuai 写道:

在 2023/05/22 19:54, 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>
  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;

need_recover can be removed as well. Otherwise, this patch looks good to

I agree. Let me improve this in v2.