| Message ID | 20200715125018.mjj6sj5uibd5s67b@pesu-pes-edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: block_dev.c: fix WARNING in submit_bio_check | expand |
diff --git a/fs/block_dev.c b/fs/block_dev.c index 64c4fe8181f2..472e3b046406 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1796,6 +1796,11 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) if (err) return ERR_PTR(err); + if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { + blkdev_put(bdev, mode); + return ERR_PTR(-EACCES); + } + return bdev; } EXPORT_SYMBOL(blkdev_get_by_dev);
duplicating the logic in blkdev_get_by_path to blkdev_get_by_dev to avoid a user-triggerable WARN trying to write to a read-only block device. blkdev_get_by_path() looks at ((mode & FMODE_WRITE) && bdev_read_only(bdev)) to check for write permissions. A user-triggerable WARN can be avoided by doing the same with bdev_get_by_dev. Reported-by: syzbot+4c50ac32e5b10e4133e1@syzkaller.appspotmail.com Signed-off-by: B K Karthik <karthik.bk2000@live.com> --- fs/block_dev.c | 5 +++++ 1 file changed, 5 insertions(+)