Re: [PATCH 1/2] Btrfs: add more valid checks for superblock
From: Qu Wenruo <hidden>
Date: 2016-05-03 01:03:03
Liu Bo wrote on 2016/05/02 11:15 -0700:
quoted hunk ↗ jump to hunk
This adds valid checks for super_total_bytes, super_bytes_used and super_stripesize. Reported-by: Vegard Nossum <redacted> Reported-by: Quentin Casasnovas <redacted> Signed-off-by: Liu Bo <redacted> --- fs/btrfs/disk-io.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4e47849..988d03f 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c@@ -4120,6 +4120,20 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, * Hint to catch really bogus numbers, bitflips or so, more exact checks are * done later */ + if (btrfs_super_total_bytes(sb) == 0) { + printk(KERN_ERR "BTRFS: total bytes is zero\n"); + ret = -EINVAL; + }
Would it be better if using "6 * nodesize"? I'd like to use a precious low limit on total bytes, but we don't have such value, so 6 nodesize would be good. Thanks, Qu
+ if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {
+ printk(KERN_ERR "BTRFS: bytes_used is too small %llu\n",
+ btrfs_super_bytes_used(sb));
+ ret = -EINVAL;
+ }
+ if (btrfs_super_stripesize(sb) != 4096) {
+ printk(KERN_ERR "BTRFS: invalid stripesize %u\n",
+ btrfs_super_stripesize(sb));
+ ret = -EINVAL;
+ }
if (btrfs_super_num_devices(sb) > (1UL << 31))
printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",
btrfs_super_num_devices(sb));