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authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-20 11:53:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-20 11:53:11 -0800
commit05e6295f7b5e05f09e369a3eb2882ec5b40fff20 (patch)
tree60ea7c6806f58371bfafe6317089c7ae1a65fca4 /security/apparmor
parentde630176bdf885eed442902afe94eb60d8f5f826 (diff)
parent7a80e5b8c6fa7d0ae6624bd6aedc4a6a1cfc62fa (diff)
Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs idmapping updates from Christian Brauner: - Last cycle we introduced the dedicated struct mnt_idmap type for mount idmapping and the required infrastucture in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). As promised in last cycle's pull request message this converts everything to rely on struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevant on the mount level. Especially for non-vfs developers without detailed knowledge in this area this was a potential source for bugs. This finishes the conversion. Instead of passing the plain namespace around this updates all places that currently take a pointer to a mnt_userns with a pointer to struct mnt_idmap. Now that the conversion is done all helpers down to the really low-level helpers only accept a struct mnt_idmap argument instead of two namespace arguments. Conflating mount and other idmappings will now cause the compiler to complain loudly thus eliminating the possibility of any bugs. This makes it impossible for filesystem developers to mix up mount and filesystem idmappings as they are two distinct types and require distinct helpers that cannot be used interchangeably. Everything associated with struct mnt_idmap is moved into a single separate file. With that change no code can poke around in struct mnt_idmap. It can only be interacted with through dedicated helpers. That means all filesystems are and all of the vfs is completely oblivious to the actual implementation of idmappings. We are now also able to extend struct mnt_idmap as we see fit. For example, we can decouple it completely from namespaces for users that don't require or don't want to use them at all. We can also extend the concept of idmappings so we can cover filesystem specific requirements. In combination with the vfs{g,u}id_t work we finished in v6.2 this makes this feature substantially more robust and thus difficult to implement wrong by a given filesystem and also protects the vfs. - Enable idmapped mounts for tmpfs and fulfill a longstanding request. A long-standing request from users had been to make it possible to create idmapped mounts for tmpfs. For example, to share the host's tmpfs mount between multiple sandboxes. This is a prerequisite for some advanced Kubernetes cases. Systemd also has a range of use-cases to increase service isolation. And there are more users of this. However, with all of the other work going on this was way down on the priority list but luckily someone other than ourselves picked this up. As usual the patch is tiny as all the infrastructure work had been done multiple kernel releases ago. In addition to all the tests that we already have I requested that Rodrigo add a dedicated tmpfs testsuite for idmapped mounts to xfstests. It is to be included into xfstests during the v6.3 development cycle. This should add a slew of additional tests. * tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits) shmem: support idmapped mounts for tmpfs fs: move mnt_idmap fs: port vfs{g,u}id helpers to mnt_idmap fs: port fs{g,u}id helpers to mnt_idmap fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap fs: port i_{g,u}id_{needs_}update() to mnt_idmap quota: port to mnt_idmap fs: port privilege checking helpers to mnt_idmap fs: port inode_owner_or_capable() to mnt_idmap fs: port inode_init_owner() to mnt_idmap fs: port acl to mnt_idmap fs: port xattr to mnt_idmap fs: port ->permission() to pass mnt_idmap fs: port ->fileattr_set() to pass mnt_idmap fs: port ->set_acl() to pass mnt_idmap fs: port ->get_acl() to pass mnt_idmap fs: port ->tmpfile() to pass mnt_idmap fs: port ->rename() to pass mnt_idmap fs: port ->mknod() to pass mnt_idmap fs: port ->mkdir() to pass mnt_idmap ...
Diffstat (limited to 'security/apparmor')
-rw-r--r--security/apparmor/apparmorfs.c2
-rw-r--r--security/apparmor/domain.c4
-rw-r--r--security/apparmor/file.c2
-rw-r--r--security/apparmor/lsm.c16
4 files changed, 11 insertions, 13 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 424b2c1e586d..db7a51acf9db 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -1793,7 +1793,7 @@ fail2:
return error;
}
-static int ns_mkdir_op(struct user_namespace *mnt_userns, struct inode *dir,
+static int ns_mkdir_op(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct aa_ns *ns, *parent;
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 6dd3cc5309bf..f3715cda59c5 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -313,7 +313,7 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
d = bprm->file->f_path.dentry;
for (i = 0; i < attach->xattr_count; i++) {
- size = vfs_getxattr_alloc(&init_user_ns, d, attach->xattrs[i],
+ size = vfs_getxattr_alloc(&nop_mnt_idmap, d, attach->xattrs[i],
&value, value_size, GFP_KERNEL);
if (size >= 0) {
u32 index, perm;
@@ -862,7 +862,7 @@ int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm)
const char *info = NULL;
int error = 0;
bool unsafe = false;
- vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_user_ns(bprm->file),
+ vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(bprm->file),
file_inode(bprm->file));
struct path_cond cond = {
vfsuid_into_kuid(vfsuid),
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index cb3d3060d104..9119ddda6217 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -459,7 +459,7 @@ static int __file_path_perm(const char *op, struct aa_label *label,
{
struct aa_profile *profile;
struct aa_perms perms = {};
- vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_user_ns(file),
+ vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(file),
file_inode(file));
struct path_cond cond = {
.uid = vfsuid_into_kuid(vfsuid),
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index c6728a629437..d6cc4812ca53 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -227,8 +227,7 @@ static int common_perm(const char *op, const struct path *path, u32 mask,
*/
static int common_perm_cond(const char *op, const struct path *path, u32 mask)
{
- struct user_namespace *mnt_userns = mnt_user_ns(path->mnt);
- vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns,
+ vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_idmap(path->mnt),
d_backing_inode(path->dentry));
struct path_cond cond = {
vfsuid_into_kuid(vfsuid),
@@ -273,14 +272,13 @@ static int common_perm_rm(const char *op, const struct path *dir,
struct dentry *dentry, u32 mask)
{
struct inode *inode = d_backing_inode(dentry);
- struct user_namespace *mnt_userns = mnt_user_ns(dir->mnt);
struct path_cond cond = { };
vfsuid_t vfsuid;
if (!inode || !path_mediated_fs(dentry))
return 0;
- vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+ vfsuid = i_uid_into_vfsuid(mnt_idmap(dir->mnt), inode);
cond.uid = vfsuid_into_kuid(vfsuid);
cond.mode = inode->i_mode;
@@ -379,7 +377,7 @@ static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_d
label = begin_current_label_crit_section();
if (!unconfined(label)) {
- struct user_namespace *mnt_userns = mnt_user_ns(old_dir->mnt);
+ struct mnt_idmap *idmap = mnt_idmap(old_dir->mnt);
vfsuid_t vfsuid;
struct path old_path = { .mnt = old_dir->mnt,
.dentry = old_dentry };
@@ -388,14 +386,14 @@ static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_d
struct path_cond cond = {
.mode = d_backing_inode(old_dentry)->i_mode
};
- vfsuid = i_uid_into_vfsuid(mnt_userns, d_backing_inode(old_dentry));
+ vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
cond.uid = vfsuid_into_kuid(vfsuid);
if (flags & RENAME_EXCHANGE) {
struct path_cond cond_exchange = {
.mode = d_backing_inode(new_dentry)->i_mode,
};
- vfsuid = i_uid_into_vfsuid(mnt_userns, d_backing_inode(old_dentry));
+ vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
cond_exchange.uid = vfsuid_into_kuid(vfsuid);
error = aa_path_perm(OP_RENAME_SRC, label, &new_path, 0,
@@ -460,13 +458,13 @@ static int apparmor_file_open(struct file *file)
label = aa_get_newest_cred_label(file->f_cred);
if (!unconfined(label)) {
- struct user_namespace *mnt_userns = file_mnt_user_ns(file);
+ struct mnt_idmap *idmap = file_mnt_idmap(file);
struct inode *inode = file_inode(file);
vfsuid_t vfsuid;
struct path_cond cond = {
.mode = inode->i_mode,
};
- vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+ vfsuid = i_uid_into_vfsuid(idmap, inode);
cond.uid = vfsuid_into_kuid(vfsuid);
error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,