Commit 29cda393 authored Jan 24, 2020 by Coly Li Committed by Jens Axboe Jan 23, 2020

bcache: properly initialize 'path' and 'err' in register_bcache()



Patch "bcache: rework error unwinding in register_bcache" from
Christoph Hellwig changes the local variables 'path' and 'err'
in undefined initial state. If the code in register_bcache() jumps
to label 'out:' or 'out_module_put:' by goto, these two variables
might be reference with undefined value by the following line,

	out_module_put:
	        module_put(THIS_MODULE);
	out:
	        pr_info("error %s: %s", path, err);
	        return ret;

Therefore this patch initializes these two local variables properly
in register_bcache() to avoid such issue.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 50246693

drivers/md/bcache/super.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -2376,18 +2376,20 @@ static ssize_t register_bcache(struct kobject k, struct kobj_attribute attr,
		const char *buffer, size_t size)
		{
		const char *err;
		char *path;
		char *path = NULL;
		struct cache_sb *sb;
		struct block_device *bdev = NULL;
		struct page *sb_page;
		ssize_t ret;

		ret = -EBUSY;
		err = "failed to reference bcache module";
		if (!try_module_get(THIS_MODULE))
		goto out;

		/* For latest state of bcache_is_reboot */
		smp_mb();
		err = "bcache is in reboot";
		if (bcache_is_reboot)
		goto out_module_put;

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