2022-09-28 01:23:58

by Ian Kent

[permalink] [raw]
Subject: [PATCH] vfs: parse sloppy mount option in correct order

From: Roberto Bergantinos Corpas <[email protected]>

With addition of fs_context support, options string is parsed
sequentially, if 'sloppy' option is not leftmost one, we may
return ENOPARAM to userland if a non-valid option preceeds sloopy
and mount will fail :

host# mount -o quota,sloppy 172.23.1.225:/share /mnt
mount.nfs: an incorrect mount option was specified
host# mount -o sloppy,quota 172.23.1.225:/share /mnt
host#

This patch correct that behaviour so that sloppy takes precedence
if specified anywhere on the string

changes since v1:
- add a boolean to fs context and postpone error reporting until
parsing is done.

Signed-off-by: Roberto Bergantinos Corpas <[email protected]>
---
fs/cifs/fs_context.c | 4 ++--
fs/cifs/fs_context.h | 1 -
fs/fs_context.c | 14 ++++++++++++--
fs/nfs/fs_context.c | 5 +++--
fs/nfs/internal.h | 1 -
include/linux/fs_context.h | 2 ++
6 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 0e13dec86b25..32c3fdd7d27a 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -864,7 +864,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
if (!skip_parsing) {
opt = fs_parse(fc, smb3_fs_parameters, param, &result);
if (opt < 0)
- return ctx->sloppy ? 1 : opt;
+ return fc->sloppy ? 1 : opt;
}

switch (opt) {
@@ -1420,7 +1420,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
ctx->multiuser = true;
break;
case Opt_sloppy:
- ctx->sloppy = true;
+ fc->sloppy = true;
break;
case Opt_nosharesock:
ctx->nosharesock = true;
diff --git a/fs/cifs/fs_context.h b/fs/cifs/fs_context.h
index bbaee4c2281f..75e4c41466fa 100644
--- a/fs/cifs/fs_context.h
+++ b/fs/cifs/fs_context.h
@@ -157,7 +157,6 @@ struct smb3_fs_context {
bool uid_specified;
bool cruid_specified;
bool gid_specified;
- bool sloppy;
bool got_ip;
bool got_version;
bool got_rsize;
diff --git a/fs/fs_context.c b/fs/fs_context.c
index df04e5fc6d66..911a36bf2226 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -157,8 +157,15 @@ int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
if (ret != -ENOPARAM)
return ret;

- return invalf(fc, "%s: Unknown parameter '%s'",
- fc->fs_type->name, param->key);
+ /* We got an invalid parameter, but sloppy may have been specified
+ * later on param string.
+ * Let's wait to process whole params to return EINVAL.
+ */
+
+ fc->param_inval = true;
+ errorf(fc, "%s: Unknown parameter '%s'", fc->fs_type->name, param->key);
+
+ return 0;
}
EXPORT_SYMBOL(vfs_parse_fs_param);

@@ -234,6 +241,9 @@ int generic_parse_monolithic(struct fs_context *fc, void *data)
}
}

+ if (!fc->sloppy && fc->param_inval)
+ ret = -EINVAL;
+
return ret;
}
EXPORT_SYMBOL(generic_parse_monolithic);
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 4da701fd1424..09da63cc84f7 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -485,7 +485,7 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,

opt = fs_parse(fc, nfs_fs_parameters, param, &result);
if (opt < 0)
- return (opt == -ENOPARAM && ctx->sloppy) ? 1 : opt;
+ return (opt == -ENOPARAM && fc->sloppy) ? 1 : opt;

if (fc->security)
ctx->has_sec_mnt_opts = 1;
@@ -853,7 +853,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
* Special options
*/
case Opt_sloppy:
- ctx->sloppy = true;
+ fc->sloppy = true;
+ dfprintk(MOUNT, "NFS: relaxing parsing rules\n");
break;
}

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 898dd95bc7a7..83552def96f1 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -90,7 +90,6 @@ struct nfs_fs_context {
bool internal;
bool skip_reconfig_option_check;
bool need_mount;
- bool sloppy;
unsigned int flags; /* NFS{,4}_MOUNT_* flags */
unsigned int rsize, wsize;
unsigned int timeo, retrans;
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index ff1375a16c8c..d91d42bc06ce 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -111,6 +111,8 @@ struct fs_context {
bool need_free:1; /* Need to call ops->free() */
bool global:1; /* Goes into &init_user_ns */
bool oldapi:1; /* Coming from mount(2) */
+ bool sloppy:1; /* If fs support it and was specified */
+ bool param_inval:1; /* If set, check sloppy value */
};

struct fs_context_operations {



2023-01-27 11:14:25

by Jeff Layton

[permalink] [raw]
Subject: Re: [PATCH] vfs: parse sloppy mount option in correct order

On Wed, 2022-09-28 at 09:09 +0800, Ian Kent wrote:
> From: Roberto Bergantinos Corpas <[email protected]>
>
> With addition of fs_context support, options string is parsed
> sequentially, if 'sloppy' option is not leftmost one, we may
> return ENOPARAM to userland if a non-valid option preceeds sloopy
> and mount will fail :
>
> host# mount -o quota,sloppy 172.23.1.225:/share /mnt
> mount.nfs: an incorrect mount option was specified
> host# mount -o sloppy,quota 172.23.1.225:/share /mnt
> host#
>
> This patch correct that behaviour so that sloppy takes precedence
> if specified anywhere on the string
>
> changes since v1:
> - add a boolean to fs context and postpone error reporting until
> parsing is done.
>
> Signed-off-by: Roberto Bergantinos Corpas <[email protected]>
> ---
> fs/cifs/fs_context.c | 4 ++--
> fs/cifs/fs_context.h | 1 -
> fs/fs_context.c | 14 ++++++++++++--
> fs/nfs/fs_context.c | 5 +++--
> fs/nfs/internal.h | 1 -
> include/linux/fs_context.h | 2 ++
> 6 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
> index 0e13dec86b25..32c3fdd7d27a 100644
> --- a/fs/cifs/fs_context.c
> +++ b/fs/cifs/fs_context.c
> @@ -864,7 +864,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
> if (!skip_parsing) {
> opt = fs_parse(fc, smb3_fs_parameters, param, &result);
> if (opt < 0)
> - return ctx->sloppy ? 1 : opt;
> + return fc->sloppy ? 1 : opt;
> }
>
> switch (opt) {
> @@ -1420,7 +1420,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
> ctx->multiuser = true;
> break;
> case Opt_sloppy:
> - ctx->sloppy = true;
> + fc->sloppy = true;
> break;
> case Opt_nosharesock:
> ctx->nosharesock = true;
> diff --git a/fs/cifs/fs_context.h b/fs/cifs/fs_context.h
> index bbaee4c2281f..75e4c41466fa 100644
> --- a/fs/cifs/fs_context.h
> +++ b/fs/cifs/fs_context.h
> @@ -157,7 +157,6 @@ struct smb3_fs_context {
> bool uid_specified;
> bool cruid_specified;
> bool gid_specified;
> - bool sloppy;
> bool got_ip;
> bool got_version;
> bool got_rsize;
> diff --git a/fs/fs_context.c b/fs/fs_context.c
> index df04e5fc6d66..911a36bf2226 100644
> --- a/fs/fs_context.c
> +++ b/fs/fs_context.c
> @@ -157,8 +157,15 @@ int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
> if (ret != -ENOPARAM)
> return ret;
>
> - return invalf(fc, "%s: Unknown parameter '%s'",
> - fc->fs_type->name, param->key);
> + /* We got an invalid parameter, but sloppy may have been specified
> + * later on param string.
> + * Let's wait to process whole params to return EINVAL.
> + */
> +
> + fc->param_inval = true;
> + errorf(fc, "%s: Unknown parameter '%s'", fc->fs_type->name, param->key);

Is it correct to store an error message when we don't know whether
"sloppy" has been specified yet?

> +
> + return 0;
> }
> EXPORT_SYMBOL(vfs_parse_fs_param);
>
> @@ -234,6 +241,9 @@ int generic_parse_monolithic(struct fs_context *fc, void *data)
> }
> }
>
> + if (!fc->sloppy && fc->param_inval)
> + ret = -EINVAL;
> +
> return ret;
> }
> EXPORT_SYMBOL(generic_parse_monolithic);
> diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
> index 4da701fd1424..09da63cc84f7 100644
> --- a/fs/nfs/fs_context.c
> +++ b/fs/nfs/fs_context.c
> @@ -485,7 +485,7 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
>
> opt = fs_parse(fc, nfs_fs_parameters, param, &result);
> if (opt < 0)
> - return (opt == -ENOPARAM && ctx->sloppy) ? 1 : opt;
> + return (opt == -ENOPARAM && fc->sloppy) ? 1 : opt;
>
> if (fc->security)
> ctx->has_sec_mnt_opts = 1;
> @@ -853,7 +853,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
> * Special options
> */
> case Opt_sloppy:
> - ctx->sloppy = true;
> + fc->sloppy = true;
> + dfprintk(MOUNT, "NFS: relaxing parsing rules\n");
> break;
> }
>
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 898dd95bc7a7..83552def96f1 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -90,7 +90,6 @@ struct nfs_fs_context {
> bool internal;
> bool skip_reconfig_option_check;
> bool need_mount;
> - bool sloppy;
> unsigned int flags; /* NFS{,4}_MOUNT_* flags */
> unsigned int rsize, wsize;
> unsigned int timeo, retrans;
> diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
> index ff1375a16c8c..d91d42bc06ce 100644
> --- a/include/linux/fs_context.h
> +++ b/include/linux/fs_context.h
> @@ -111,6 +111,8 @@ struct fs_context {
> bool need_free:1; /* Need to call ops->free() */
> bool global:1; /* Goes into &init_user_ns */
> bool oldapi:1; /* Coming from mount(2) */
> + bool sloppy:1; /* If fs support it and was specified */
> + bool param_inval:1; /* If set, check sloppy value */
> };
>
> struct fs_context_operations {
>
>

Overall, the patch looks reasonable though.
--
Jeff Layton <[email protected]>