From: Christoph Hellwig Date: Wed, 31 May 2023 12:55:34 +0000 (+0200) Subject: mtd: block2mtd: don't call early_lookup_bdev after the system is running X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8d03187ee7328af8e18ef1782289e0b034e75485;p=linux.git mtd: block2mtd: don't call early_lookup_bdev after the system is running early_lookup_bdev is supposed to only be called from the early boot code, but mdtblock_early_get_bdev is called as a general fallback when lookup_bdev fails, which is problematic because early_lookup_bdev bypasses all normal path based permission checking, and might cause problems with certain container environments renaming devices. Switch to only call early_lookup_bdev when block2mtd is built-in and the system state in not running yet. Note that this strictly speaking changes the kernel ABI as the PARTUUID= and PARTLABEL= style syntax is now not available during a running systems. They never were intended for that, but this breaks things we'll have to figure out a way to make them available again. But if avoidable in any way I'd rather avoid that. Signed-off-by: Christoph Hellwig Reviewed-by: Miquel Raynal Link: https://lore.kernel.org/r/20230531125535.676098-24-hch@lst.de Signed-off-by: Jens Axboe --- diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index 457774eef4d0d..218eb2af564a8 100644 --- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -215,13 +215,23 @@ static void block2mtd_free_device(struct block2mtd_dev *dev) kfree(dev); } -static struct block_device *mdtblock_early_get_bdev(const char *devname, +/* + * This function is marked __ref because it calls the __init marked + * early_lookup_bdev when called from the early boot code. + */ +static struct block_device __ref *mdtblock_early_get_bdev(const char *devname, fmode_t mode, int timeout, struct block2mtd_dev *dev) { struct block_device *bdev = ERR_PTR(-ENODEV); #ifndef MODULE int i; + /* + * We can't use early_lookup_bdev from a running system. + */ + if (system_state >= SYSTEM_RUNNING) + return bdev; + /* * We might not have the root device mounted at this point. * Try to resolve the device name by other means.