Hi,
On Tue 04-12-18 20:53:47, Sudip Mukherjee wrote:
> This has been applied to 4.19-stable, but should be needed in
> 4.14-stable also. I have attached the backported patch and have
> also tested with one such DVD where the problem was seen.
Thanks for the backport. I actually didn't get a message that application
of this patch to 4.14-stable would fail so probably it is just waiting in
Greg's queue. Anyway the patch looks good to me.
Honza
>
>
> --
> Regards
> Sudip
> From 197a1e1728bb1aab5a2e747a04ecd90390b1d8b7 Mon Sep 17 00:00:00 2001
> From: Jan Kara <jack@xxxxxxx>
> Date: Fri, 16 Nov 2018 13:43:17 +0100
> Subject: [PATCH] udf: Allow mounting volumes with incorrect identification strings
>
> commit b54e41f5efcb4316b2f30b30c2535cc194270373 upstream.
>
> Commit c26f6c615788 ("udf: Fix conversion of 'dstring' fields to UTF8")
> started to be more strict when checking whether converted strings are
> properly formatted. Sudip reports that there are DVDs where the volume
> identification string is actually too long - UDF reports:
>
> [ 632.309320] UDF-fs: incorrect dstring lengths (32/32)
>
> during mount and fails the mount. This is mostly harmless failure as we
> don't need volume identification (and even less volume set
> identification) for anything. So just truncate the volume identification
> string if it is too long and replace it with 'Invalid' if we just cannot
> convert it for other reasons. This keeps slightly incorrect media still
> mountable.
>
> CC: stable@xxxxxxxxxxxxxxx
> Fixes: c26f6c615788 ("udf: Fix conversion of 'dstring' fields to UTF8")
> Reported-and-tested-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
> ---
> fs/udf/super.c | 16 ++++++++++------
> fs/udf/unicode.c | 14 +++++++++++---
> 2 files changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/fs/udf/super.c b/fs/udf/super.c
> index 9b0d6562d0a1..242d960df9a1 100644
> --- a/fs/udf/super.c
> +++ b/fs/udf/super.c
> @@ -922,16 +922,20 @@ static int udf_load_pvoldesc(struct super_block *sb, sector_t block)
> }
>
> ret = udf_dstrCS0toUTF8(outstr, 31, pvoldesc->volIdent, 32);
> - if (ret < 0)
> - goto out_bh;
> -
> - strncpy(UDF_SB(sb)->s_volume_ident, outstr, ret);
> + if (ret < 0) {
> + strcpy(UDF_SB(sb)->s_volume_ident, "InvalidName");
> + pr_warn("incorrect volume identification, setting to "
> + "'InvalidName'\n");
> + } else {
> + strncpy(UDF_SB(sb)->s_volume_ident, outstr, ret);
> + }
> udf_debug("volIdent[] = '%s'\n", UDF_SB(sb)->s_volume_ident);
>
> ret = udf_dstrCS0toUTF8(outstr, 127, pvoldesc->volSetIdent, 128);
> - if (ret < 0)
> + if (ret < 0) {
> + ret = 0;
> goto out_bh;
> -
> + }
> outstr[ret] = 0;
> udf_debug("volSetIdent[] = '%s'\n", outstr);
>
> diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
> index 3a3be23689b3..61a1738895b7 100644
> --- a/fs/udf/unicode.c
> +++ b/fs/udf/unicode.c
> @@ -341,6 +341,11 @@ static int udf_name_to_CS0(uint8_t *ocu, int ocu_max_len,
> return u_len;
> }
>
> +/*
> + * Convert CS0 dstring to output charset. Warning: This function may truncate
> + * input string if it is too long as it is used for informational strings only
> + * and it is better to truncate the string than to refuse mounting a media.
> + */
> int udf_dstrCS0toUTF8(uint8_t *utf_o, int o_len,
> const uint8_t *ocu_i, int i_len)
> {
> @@ -349,9 +354,12 @@ int udf_dstrCS0toUTF8(uint8_t *utf_o, int o_len,
> if (i_len > 0) {
> s_len = ocu_i[i_len - 1];
> if (s_len >= i_len) {
> - pr_err("incorrect dstring lengths (%d/%d)\n",
> - s_len, i_len);
> - return -EINVAL;
> + pr_warn("incorrect dstring lengths (%d/%d),"
> + " truncating\n", s_len, i_len);
> + s_len = i_len - 1;
> + /* 2-byte encoding? Need to round properly... */
> + if (ocu_i[0] == 16)
> + s_len -= (s_len - 1) & 2;
> }
> }
>
> --
> 2.11.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
