| Message ID | 20220420140633.753772-9-stefanb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ima: Namespace IMA with audit support in IMA-ns | expand |
On Wed, Apr 20, 2022 at 10:06:15AM -0400, Stefan Berger wrote: > Earlier we simplified how dentry creation and deletion is manged in > securityfs. This allows us to move IMA securityfs files from global > variables directly into ima_fs_ns_init() itself. We can now rely on > those dentries to be cleaned up when the securityfs instance is cleaned > when the last reference to it is dropped. > > Things are slightly different for the initial IMA namespace. In contrast > to non-initial IMA namespaces it has pinning logic binding the lifetime > of the securityfs superblock to created dentries. We need to keep this > behavior to not regress userspace. Since IMA never removes most of the > securityfs files the initial securityfs instance stays pinned. This also > means even for the initial IMA namespace we don't need to keep > references to these dentries anywhere. > > The ima_policy file is the exception since IMA can end up removing it > on systems that don't allow reading or extending the IMA custom policy. > > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> > Acked-by: Christian Brauner <brauner@kernel.org> > Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Serge Hallyn <serge@hallyn.com> > > --- > > v9: > - Revert renaming of ima_policy to policy_dentry > --- > security/integrity/ima/ima.h | 2 ++ > security/integrity/ima/ima_fs.c | 37 ++++++++++++++++++--------------- > 2 files changed, 22 insertions(+), 17 deletions(-) > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > index a144edfdb9a1..b35c8504ef87 100644 > --- a/security/integrity/ima/ima.h > +++ b/security/integrity/ima/ima.h > @@ -142,6 +142,8 @@ struct ima_namespace { > struct mutex ima_write_mutex; > unsigned long ima_fs_flags; > int valid_policy; > + > + struct dentry *ima_policy; > } __randomize_layout; > extern struct ima_namespace init_ima_ns; > > diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c > index 4cf786f0bba8..89d3113ceda1 100644 > --- a/security/integrity/ima/ima_fs.c > +++ b/security/integrity/ima/ima_fs.c > @@ -359,14 +359,6 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf, > return result; > } > > -static struct dentry *ima_dir; > -static struct dentry *ima_symlink; > -static struct dentry *binary_runtime_measurements; > -static struct dentry *ascii_runtime_measurements; > -static struct dentry *runtime_measurements_count; > -static struct dentry *violations; > -static struct dentry *ima_policy; > - > enum ima_fs_flags { > IMA_FS_BUSY, > }; > @@ -436,8 +428,8 @@ static int ima_release_policy(struct inode *inode, struct file *file) > > ima_update_policy(ns); > #if !defined(CONFIG_IMA_WRITE_POLICY) && !defined(CONFIG_IMA_READ_POLICY) > - securityfs_remove(ima_policy); > - ima_policy = NULL; > + securityfs_remove(ns->ima_policy); > + ns->ima_policy = NULL; > #elif defined(CONFIG_IMA_WRITE_POLICY) > clear_bit(IMA_FS_BUSY, &ns->ima_fs_flags); > #elif defined(CONFIG_IMA_READ_POLICY) > @@ -454,8 +446,14 @@ static const struct file_operations ima_measure_policy_ops = { > .llseek = generic_file_llseek, > }; > > -int __init ima_fs_init(void) > +static int __init ima_fs_ns_init(struct ima_namespace *ns) > { > + struct dentry *ima_dir; > + struct dentry *ima_symlink = NULL; > + struct dentry *binary_runtime_measurements = NULL; > + struct dentry *ascii_runtime_measurements = NULL; > + struct dentry *runtime_measurements_count = NULL; > + struct dentry *violations = NULL; > int ret; > > ima_dir = securityfs_create_dir("ima", integrity_dir); > @@ -504,17 +502,17 @@ int __init ima_fs_init(void) > goto out; > } > > - ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, > - ima_dir, NULL, > - &ima_measure_policy_ops); > - if (IS_ERR(ima_policy)) { > - ret = PTR_ERR(ima_policy); > + ns->ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, > + ima_dir, NULL, > + &ima_measure_policy_ops); > + if (IS_ERR(ns->ima_policy)) { > + ret = PTR_ERR(ns->ima_policy); > goto out; > } > > return 0; > out: > - securityfs_remove(ima_policy); > + securityfs_remove(ns->ima_policy); > securityfs_remove(violations); > securityfs_remove(runtime_measurements_count); > securityfs_remove(ascii_runtime_measurements); > @@ -524,3 +522,8 @@ int __init ima_fs_init(void) > > return ret; > } > + > +int __init ima_fs_init(void) > +{ > + return ima_fs_ns_init(&init_ima_ns); > +} > -- > 2.34.1
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index a144edfdb9a1..b35c8504ef87 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -142,6 +142,8 @@ struct ima_namespace { struct mutex ima_write_mutex; unsigned long ima_fs_flags; int valid_policy; + + struct dentry *ima_policy; } __randomize_layout; extern struct ima_namespace init_ima_ns; diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 4cf786f0bba8..89d3113ceda1 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -359,14 +359,6 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf, return result; } -static struct dentry *ima_dir; -static struct dentry *ima_symlink; -static struct dentry *binary_runtime_measurements; -static struct dentry *ascii_runtime_measurements; -static struct dentry *runtime_measurements_count; -static struct dentry *violations; -static struct dentry *ima_policy; - enum ima_fs_flags { IMA_FS_BUSY, }; @@ -436,8 +428,8 @@ static int ima_release_policy(struct inode *inode, struct file *file) ima_update_policy(ns); #if !defined(CONFIG_IMA_WRITE_POLICY) && !defined(CONFIG_IMA_READ_POLICY) - securityfs_remove(ima_policy); - ima_policy = NULL; + securityfs_remove(ns->ima_policy); + ns->ima_policy = NULL; #elif defined(CONFIG_IMA_WRITE_POLICY) clear_bit(IMA_FS_BUSY, &ns->ima_fs_flags); #elif defined(CONFIG_IMA_READ_POLICY) @@ -454,8 +446,14 @@ static const struct file_operations ima_measure_policy_ops = { .llseek = generic_file_llseek, }; -int __init ima_fs_init(void) +static int __init ima_fs_ns_init(struct ima_namespace *ns) { + struct dentry *ima_dir; + struct dentry *ima_symlink = NULL; + struct dentry *binary_runtime_measurements = NULL; + struct dentry *ascii_runtime_measurements = NULL; + struct dentry *runtime_measurements_count = NULL; + struct dentry *violations = NULL; int ret; ima_dir = securityfs_create_dir("ima", integrity_dir); @@ -504,17 +502,17 @@ int __init ima_fs_init(void) goto out; } - ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, - ima_dir, NULL, - &ima_measure_policy_ops); - if (IS_ERR(ima_policy)) { - ret = PTR_ERR(ima_policy); + ns->ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, + ima_dir, NULL, + &ima_measure_policy_ops); + if (IS_ERR(ns->ima_policy)) { + ret = PTR_ERR(ns->ima_policy); goto out; } return 0; out: - securityfs_remove(ima_policy); + securityfs_remove(ns->ima_policy); securityfs_remove(violations); securityfs_remove(runtime_measurements_count); securityfs_remove(ascii_runtime_measurements); @@ -524,3 +522,8 @@ int __init ima_fs_init(void) return ret; } + +int __init ima_fs_init(void) +{ + return ima_fs_ns_init(&init_ima_ns); +}