Let FSCONFIG_SET_FD handle O_PATH file descriptors. This is particularly
useful in the context of overlayfs where layers can be specified via
file descriptors instead of paths. But userspace must currently use
non-O_PATH file desriptors which is often pointless especially if
the file descriptors have been created via open_tree(OPEN_TREE_CLONE).
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
fs/fs_parser.c | 12 +++++++-----
fs/fsopen.c | 7 +++++--
fs/overlayfs/params.c | 10 ++++++----
include/linux/fs_context.h | 1 +
include/linux/fs_parser.h | 6 +++---
5 files changed, 22 insertions(+), 14 deletions(-)
diff --git a/fs/fs_parser.c b/fs/fs_parser.c
index e635a81e17d9..35aaea224007 100644
--- a/fs/fs_parser.c
+++ b/fs/fs_parser.c
@@ -310,15 +310,17 @@ int fs_param_is_fd(struct p_log *log, const struct fs_parameter_spec *p,
}
EXPORT_SYMBOL(fs_param_is_fd);
-int fs_param_is_file_or_string(struct p_log *log,
- const struct fs_parameter_spec *p,
- struct fs_parameter *param,
- struct fs_parse_result *result)
+int fs_param_is_raw_file_or_string(struct p_log *log,
+ const struct fs_parameter_spec *p,
+ struct fs_parameter *param,
+ struct fs_parse_result *result)
{
switch (param->type) {
case fs_value_is_string:
return fs_param_is_string(log, p, param, result);
case fs_value_is_file:
+ fallthrough;
+ case fs_value_is_raw_file:
result->uint_32 = param->dirfd;
if (result->uint_32 <= INT_MAX)
return 0;
@@ -328,7 +330,7 @@ int fs_param_is_file_or_string(struct p_log *log,
}
return fs_param_bad_value(log, param);
}
-EXPORT_SYMBOL(fs_param_is_file_or_string);
+EXPORT_SYMBOL(fs_param_is_raw_file_or_string);
int fs_param_is_uid(struct p_log *log, const struct fs_parameter_spec *p,
struct fs_parameter *param, struct fs_parse_result *result)
diff --git a/fs/fsopen.c b/fs/fsopen.c
index 094a7f510edf..3b5fc9f1f774 100644
--- a/fs/fsopen.c
+++ b/fs/fsopen.c
@@ -451,11 +451,14 @@ SYSCALL_DEFINE5(fsconfig,
param.size = strlen(param.name->name);
break;
case FSCONFIG_SET_FD:
- param.type = fs_value_is_file;
ret = -EBADF;
- param.file = fget(aux);
+ param.file = fget_raw(aux);
if (!param.file)
goto out_key;
+ if (param.file->f_mode & FMODE_PATH)
+ param.type = fs_value_is_raw_file;
+ else
+ param.type = fs_value_is_file;
param.dirfd = aux;
break;
default:
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index 1115c22deca0..846afa6081a5 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -141,10 +141,10 @@ static int ovl_verity_mode_def(void)
const struct fs_parameter_spec ovl_parameter_spec[] = {
fsparam_string_empty("lowerdir", Opt_lowerdir),
- fsparam_file_or_string("lowerdir+", Opt_lowerdir_add),
- fsparam_file_or_string("datadir+", Opt_datadir_add),
- fsparam_file_or_string("upperdir", Opt_upperdir),
- fsparam_file_or_string("workdir", Opt_workdir),
+ fsparam_raw_file_or_string("lowerdir+", Opt_lowerdir_add),
+ fsparam_raw_file_or_string("datadir+", Opt_datadir_add),
+ fsparam_raw_file_or_string("upperdir", Opt_upperdir),
+ fsparam_raw_file_or_string("workdir", Opt_workdir),
fsparam_flag("default_permissions", Opt_default_permissions),
fsparam_enum("redirect_dir", Opt_redirect_dir, ovl_parameter_redirect_dir),
fsparam_enum("index", Opt_index, ovl_parameter_bool),
@@ -438,6 +438,8 @@ static int ovl_parse_layer(struct fs_context *fc, struct fs_parameter *param,
return err;
err = ovl_do_parse_layer(fc, param->string, &layer_path, layer);
break;
+ case fs_value_is_raw_file:
+ fallthrough;
case fs_value_is_file: {
char *buf __free(kfree);
char *layer_name;
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 4b4bfef6f053..4ba18211046e 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -55,6 +55,7 @@ enum fs_value_type {
fs_value_is_blob, /* Value is a binary blob */
fs_value_is_filename, /* Value is a filename* + dirfd */
fs_value_is_file, /* Value is a file* */
+ fs_value_is_raw_file, /* Value is an O_PATH/FMODE_PATH file* */
};
/*
diff --git a/include/linux/fs_parser.h b/include/linux/fs_parser.h
index 53e566efd5fd..77d5d3c78d39 100644
--- a/include/linux/fs_parser.h
+++ b/include/linux/fs_parser.h
@@ -29,7 +29,7 @@ typedef int fs_param_type(struct p_log *,
fs_param_type fs_param_is_bool, fs_param_is_u32, fs_param_is_s32, fs_param_is_u64,
fs_param_is_enum, fs_param_is_string, fs_param_is_blob, fs_param_is_blockdev,
fs_param_is_path, fs_param_is_fd, fs_param_is_uid, fs_param_is_gid,
- fs_param_is_file_or_string;
+ fs_param_is_raw_file_or_string;
/*
* Specification of the type of value a parameter wants.
@@ -136,8 +136,8 @@ static inline bool fs_validate_description(const char *name,
#define fsparam_bdev(NAME, OPT) __fsparam(fs_param_is_blockdev, NAME, OPT, 0, NULL)
#define fsparam_path(NAME, OPT) __fsparam(fs_param_is_path, NAME, OPT, 0, NULL)
#define fsparam_fd(NAME, OPT) __fsparam(fs_param_is_fd, NAME, OPT, 0, NULL)
-#define fsparam_file_or_string(NAME, OPT) \
- __fsparam(fs_param_is_file_or_string, NAME, OPT, 0, NULL)
+#define fsparam_raw_file_or_string(NAME, OPT) \
+ __fsparam(fs_param_is_raw_file_or_string, NAME, OPT, 0, NULL)
#define fsparam_uid(NAME, OPT) __fsparam(fs_param_is_uid, NAME, OPT, 0, NULL)
#define fsparam_gid(NAME, OPT) __fsparam(fs_param_is_gid, NAME, OPT, 0, NULL)
--
2.47.2
