From 34817a2441747b48e444cb0e05d84e14bc9443da Mon Sep 17 00:00:00 2001
From: Li Nan <linan122@huawei.com>
Date: Sat, 27 May 2023 15:22:15 +0800
Subject: [PATCH] md/raid10: fix null-ptr-deref of mreplace in
raid10_sync_request
Git-commit: 34817a2441747b48e444cb0e05d84e14bc9443da
Patch-mainline: v6.5-rc1
References: git-fixes
There are two check of 'mreplace' in raid10_sync_request(). In the first
check, 'need_replace' will be set and 'mreplace' will be used later if
no-Faulty 'mreplace' exists, In the second check, 'mreplace' will be
set to NULL if it is Faulty, but 'need_replace' will not be changed
accordingly. null-ptr-deref occurs if Faulty is set between two check.
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@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230527072218.2365857-2-linan666@huaweicloud.com
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/raid10.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 0ae7e52983fa..51552280b325 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3441,7 +3441,6 @@ 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;
@@ -3453,11 +3452,10 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
!test_bit(Faulty, &mrdev->flags) &&
!test_bit(In_sync, &mrdev->flags))
need_recover = 1;
- if (mreplace != NULL &&
- !test_bit(Faulty, &mreplace->flags))
- need_replace = 1;
+ if (mreplace && test_bit(Faulty, &mreplace->flags))
+ mreplace = NULL;
- if (!need_recover && !need_replace) {
+ if (!need_recover && !mreplace) {
rcu_read_unlock();
continue;
}
@@ -3473,8 +3471,6 @@ 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
@@ -3597,11 +3593,11 @@ 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;
--
2.35.3