Commit 92900e51 authored Jan 27, 2019 by Al Viro Committed by David Sterba Jan 30, 2019

btrfs: fix potential oops in device_list_add



alloc_fs_devices() can return ERR_PTR(-ENOMEM), so dereferencing its
result before the check for IS_ERR() is a bad idea.

Fixes: d1a63002 ("btrfs: add members to fs_devices to track fsid changes")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 302167c5

fs/btrfs/volumes.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -957,11 +957,11 @@ static noinline struct btrfs_device device_list_add(const char path,
		else
		fs_devices = alloc_fs_devices(disk_super->fsid, NULL);

		fs_devices->fsid_change = fsid_change_in_progress;

		if (IS_ERR(fs_devices))
		return ERR_CAST(fs_devices);

		fs_devices->fsid_change = fsid_change_in_progress;

		mutex_lock(&fs_devices->device_list_mutex);
		list_add(&fs_devices->fs_list, &fs_uuids);

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