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authorStefan Behrens <sbehrens@giantdisaster.de>2012-11-05 13:10:49 +0000
committerJosef Bacik <jbacik@fusionio.com>2012-12-12 17:15:26 -0500
commitd03f918ab9036cc71740c0aa796c8e02e6f6f6d3 (patch)
treeff6c9ec2d42a9d5e54c640a1ff88f0a8dc4404cf /fs/btrfs/volumes.c
parent109f2365f1928af241b2ccbd0f6ba0b93d911288 (diff)
downloadop-kernel-dev-d03f918ab9036cc71740c0aa796c8e02e6f6f6d3.zip
op-kernel-dev-d03f918ab9036cc71740c0aa796c8e02e6f6f6d3.tar.gz
Btrfs: Don't trust the superblock label and simply printk("%s") it
Someone who is root or capable(CAP_SYS_ADMIN) could corrupt the superblock and make Btrfs printk("%s") crash while holding the uuid_mutex since nobody forces a limit on the string. Since the uuid_mutex is significant, the system would be unusable afterwards. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs/volumes.c')
-rw-r--r--fs/btrfs/volumes.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3f4bfee..db79fb7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -764,10 +764,13 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
devid = btrfs_stack_device_id(&disk_super->dev_item);
transid = btrfs_super_generation(disk_super);
total_devices = btrfs_super_num_devices(disk_super);
- if (disk_super->label[0])
+ if (disk_super->label[0]) {
+ if (disk_super->label[BTRFS_LABEL_SIZE - 1])
+ disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
printk(KERN_INFO "device label %s ", disk_super->label);
- else
+ } else {
printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
+ }
printk(KERN_CONT "devid %llu transid %llu %s\n",
(unsigned long long)devid, (unsigned long long)transid, path);
ret = device_list_add(path, disk_super, devid, fs_devices_ret);
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