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| author | Christoph Hellwig <hch@lst.de> | 2021-08-16 15:26:14 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-08-16 19:49:11 +0300 |
| commit | 889c05cc5834a1eef2dbe1e639cfd7a81c4f4c6d (patch) | |
| tree | 61d680894772d993d79976efa1c593cfdb1c0dff /block/genhd.c | |
| parent | 9451aa0aacaf7ea13d1acfd5de8b63a6e0b24fac (diff) | |
| download | linux-889c05cc5834a1eef2dbe1e639cfd7a81c4f4c6d.tar.xz | |
block: ensure the bdi is freed after inode_detach_wb
inode_detach_wb references the "main" bdi of the inode. With the
recent change to move the bdi from the request_queue to the gendisk
this causes a guaranteed use after free when using certain cgroup
configurations. The big itself is older through as any non-default
inode reference (e.g. an open file descriptor) could have injected
this use after free even before that.
Fixes: 52ebea749aae ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Reported-by: syzbot <syzbot+1fb38bb7d3ce0fa3e1c4@syzkaller.appspotmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816122614.601358-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/genhd.c')
| -rw-r--r-- | block/genhd.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/block/genhd.c b/block/genhd.c index ed58ddf6258b..731a46063132 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1084,7 +1084,6 @@ static void disk_release(struct device *dev) might_sleep(); - bdi_put(disk->bdi); disk_release_events(disk); kfree(disk->random); xa_destroy(&disk->part_tbl); |