Messages in this thread Patch in this message | | | From | Wentao_Liang <> | Subject | [PATCH] drivers:md:fix a potential use-after-free bug | Date | Thu, 28 Jul 2022 19:39:19 +0800 |
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In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and may cause sh to be released. However, sh is subsequently used in lines 2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an use-after-free bug.
It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of the function.
The bug has been confirmed by Song on 2021-08-14. Now, I resend this patch with my real name. I hope the patch can be updated in a near future.
Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com> --- drivers/md/raid5.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5d09256d7f81..93fcbeac5096 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2881,10 +2881,10 @@ static void raid5_end_write_request(struct bio *bi) if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags)) clear_bit(R5_LOCKED, &sh->dev[i].flags); set_bit(STRIPE_HANDLE, &sh->state); - raid5_release_stripe(sh); if (sh->batch_head && sh != sh->batch_head) raid5_release_stripe(sh->batch_head); + raid5_release_stripe(sh); } static void raid5_error(struct mddev *mddev, struct md_rdev *rdev) -- 2.25.1
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