From 7a126d5bf975f082281fb9b45d110cd49b7c3ee4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 31 May 2023 14:55:31 +0200 Subject: dm: only call early_lookup_bdev from early boot context early_lookup_bdev is supposed to only be called from the early boot code, but dm_get_device calls it 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. This means it is still available when tables are constructed by dm-init.c from the kernel command line, but not otherwise. 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: Mike Snitzer Link: https://lore.kernel.org/r/20230531125535.676098-21-hch@lst.de Signed-off-by: Jens Axboe --- drivers/md/dm-table.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 1576b408768d..2fd5826bfce1 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -326,8 +326,11 @@ static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode, /* * Add a device to the list, or just increment the usage count if * it's already present. + * + * Note: the __ref annotation is because this function can call the __init + * marked early_lookup_bdev when called during early boot code from dm-init.c. */ -int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, +int __ref dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, struct dm_dev **result) { int r; @@ -346,8 +349,10 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, return -EOVERFLOW; } else { r = lookup_bdev(path, &dev); - if (r) +#ifndef MODULE + if (r && system_state < SYSTEM_RUNNING) r = early_lookup_bdev(path, &dev); +#endif if (r) return r; } -- cgit v1.2.3