2019-02-11 16:11:10

by Steven J. Magnani

Subject: [PATCH] udf: disallow RW mount without valid integrity descriptor

Refuse to mount a volume read-write without a coherent Logical Volume
Integrity Descriptor, because we can't generate truly unique IDs without
one.

This fixes a bug where all inodes created on a UDF filesystem following
mount without a coherent LVID are assigned UID 0.

Signed-off-by: Steven J. Magnani <[email protected]>
---
--- a/fs/udf/super.c 2018-11-16 06:43:00.622344354 -0600
+++ b/fs/udf/super.c 2019-02-11 08:08:00.478331631 -0600
@@ -1474,6 +1474,17 @@ static int udf_load_logicalvol(struct su
if (lvd->integritySeqExt.extLength)
udf_load_logicalvolint(sb, leea_to_cpu(lvd->integritySeqExt));
ret = 0;
+
+ if (!sbi->s_lvid_bh) {
+ /* We can't generate UIDs without a valid LVID */
+ if (sb_rdonly(sb))
+ UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT);
+ else {
+ udf_warn(sb, "Damaged or missing LVID, forcing "
+ "readonly mount\n");
+ ret = -EACCES;
+ }
+ }
out_bh:
brelse(bh);
return ret;

2019-02-11 20:33:53

by Jan Kara

Subject: Re: [PATCH] udf: disallow RW mount without valid integrity descriptor

On Mon 11-02-19 08:24:38, Steve Magnani wrote:
> Refuse to mount a volume read-write without a coherent Logical Volume
> Integrity Descriptor, because we can't generate truly unique IDs without
> one.
>
> This fixes a bug where all inodes created on a UDF filesystem following
> mount without a coherent LVID are assigned UID 0.
>
> Signed-off-by: Steven J. Magnani <[email protected]>

Thanks. Added to my tree.

Honza

> ---
> --- a/fs/udf/super.c 2018-11-16 06:43:00.622344354 -0600
> +++ b/fs/udf/super.c 2019-02-11 08:08:00.478331631 -0600
> @@ -1474,6 +1474,17 @@ static int udf_load_logicalvol(struct su
> if (lvd->integritySeqExt.extLength)
> udf_load_logicalvolint(sb, leea_to_cpu(lvd->integritySeqExt));
> ret = 0;
> +
> + if (!sbi->s_lvid_bh) {
> + /* We can't generate UIDs without a valid LVID */
> + if (sb_rdonly(sb))
> + UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT);
> + else {
> + udf_warn(sb, "Damaged or missing LVID, forcing "
> + "readonly mount\n");
> + ret = -EACCES;
> + }
> + }
> out_bh:
> brelse(bh);
> return ret;
>
--
Jan Kara <[email protected]>
SUSE Labs, CR