From 1e8c813b083c4122dfeaa5c3b11028331026e85d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 31 May 2023 14:55:32 +0200 Subject: PM: hibernate: don't use early_lookup_bdev in resume_store resume_store is a sysfs attribute written during normal kernel runtime, and it should not use the early_lookup_bdev API that bypasses all normal path based permission checking, and might cause problems with certain container environments renaming devices. Switch to lookup_bdev, which does a normal path lookup instead, and fall back to trying to parse a numeric dev_t just like early_lookup_bdev did. 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. Fixes: 421a5fa1a6cf ("PM / hibernate: use name_to_dev_t to parse resume") Signed-off-by: Christoph Hellwig Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20230531125535.676098-22-hch@lst.de Signed-off-by: Jens Axboe --- kernel/power/hibernate.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'kernel/power') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index c52dedb9f7c8..7ae95ec72f99 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -1178,7 +1178,23 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr, if (!name) return -ENOMEM; - error = early_lookup_bdev(name, &dev); + error = lookup_bdev(name, &dev); + if (error) { + unsigned maj, min, offset; + char *p, dummy; + + if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 || + sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, + &dummy) == 3) { + dev = MKDEV(maj, min); + if (maj != MAJOR(dev) || min != MINOR(dev)) + error = -EINVAL; + } else { + dev = new_decode_dev(simple_strtoul(name, &p, 16)); + if (*p) + error = -EINVAL; + } + } kfree(name); if (error) return error; -- cgit v1.2.3