| Message ID | 20230523074535.249802-24-hch@lst.de (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | [01/24] driver core: return bool from driver_probe_done | expand |
Hi Christoph, hch@lst.de wrote on Tue, 23 May 2023 09:45:34 +0200: > 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 dm 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. Sounds reasonable to me. Richard? Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Thanks, Miquèl
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index 182eed68c75634..59e4c71cfc6f53 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.
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 dm 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 <hch@lst.de> --- drivers/mtd/devices/block2mtd.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)