From e9941e7963b90654cd0ddfa7956ad4ca264d439c Mon Sep 17 00:00:00 2001 From: Mingzhe Zou Date: Fri, 3 Apr 2026 12:21:35 +0800 Subject: [PATCH] bcache: fix uninitialized closure object commit 20a8e451ec1c7e99060b1bbaaad03ce88c39ddb8 upstream. In the previous patch ("bcache: fix cached_dev.sb_bio use-after-free and crash"), we adopted a simple modification suggestion from AI to fix the use-after-free. But in actual testing, we found an extreme case where the device is stopped before calling bch_write_bdev_super(). At this point, struct closure sb_write has not been initialized yet. For this patch, we ensure that sb_bio has been completed via sb_write_mutex. Signed-off-by: Mingzhe Zou Signed-off-by: Coly Li Link: https://patch.msgid.link/20260403042135.2221247-1-colyli@fnnas.com Fixes: fec114a98b87 ("bcache: fix cached_dev.sb_bio use-after-free and crash") Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/md/bcache/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 4c01a7969981..4c5639e06d6b 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1382,7 +1382,8 @@ static void cached_dev_free(struct closure *cl) * The sb_bio is embedded in struct cached_dev, so we must * ensure no I/O is in progress. */ - closure_sync(&dc->sb_write); + down(&dc->sb_write_mutex); + up(&dc->sb_write_mutex); if (dc->sb_disk) put_page(virt_to_page(dc->sb_disk));