iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

apparmor: add io_uring mediation

Browse Source 
For now, the io_uring mediation is limited to sqpoll and
override_creds.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
Georgia Garcia 2023-03-20 14:43:41 -03:00 committed by John Johansen
parent fa9b63adab
commit c4371d9063
6 changed files with 131 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
security/apparmor/apparmorfs.c
View File

@ -2390,6 +2390,12 @@ static struct aa_sfs_entry aa_sfs_entry_query[] = {
AA_SFS_DIR("label", aa_sfs_entry_query_label),
{ }
};
static struct aa_sfs_entry aa_sfs_entry_io_uring[] = {
AA_SFS_FILE_STRING("mask", "sqpoll override_creds"),
{ }
};
static struct aa_sfs_entry aa_sfs_entry_features[] = {
AA_SFS_DIR("policy", aa_sfs_entry_policy),
AA_SFS_DIR("domain", aa_sfs_entry_domain),
@ -2403,6 +2409,7 @@ static struct aa_sfs_entry aa_sfs_entry_features[] = {
AA_SFS_DIR("ptrace", aa_sfs_entry_ptrace),
AA_SFS_DIR("signal", aa_sfs_entry_signal),
AA_SFS_DIR("query", aa_sfs_entry_query),
AA_SFS_DIR("io_uring", aa_sfs_entry_io_uring),
{ }
};

2
security/apparmor/audit.c
View File

@ -59,7 +59,7 @@ static const char *const aa_class_names[] = {
"module",
"lsm",
"namespace",
"unknown",
"io_uring",
"unknown",
"unknown",
"unknown",

2
security/apparmor/include/apparmor.h
View File

@ -30,10 +30,10 @@
#define AA_CLASS_NET 14
#define AA_CLASS_LABEL 16
#define AA_CLASS_POSIX_MQUEUE 17
#define AA_CLASS_IO_URING 18
#define AA_CLASS_MODULE 19
#define AA_CLASS_DISPLAY_LSM 20
#define AA_CLASS_NS 21
#define AA_CLASS_IO_URING 22
#define AA_CLASS_X 31
#define AA_CLASS_DBUS 32

6
security/apparmor/include/audit.h
View File

@ -105,6 +105,9 @@ enum audit_type {
#define OP_USERNS_CREATE "userns_create"
#define OP_URING_OVERRIDE "uring_override"
#define OP_URING_SQPOLL "uring_sqpoll"
struct apparmor_audit_data {
int error;
int type;
@ -153,6 +156,9 @@ struct apparmor_audit_data {
const char *data;
unsigned long flags;
} mnt;
struct {
struct aa_label *target;
} uring;
};
struct common_audit_data common;

3
security/apparmor/include/perms.h
View File

@ -48,6 +48,9 @@
#define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */
#define AA_MAY_CREATE_SQPOLL AA_MAY_CREATE
#define AA_MAY_OVERRIDE_CRED AA_MAY_APPEND
#define AA_URING_PERM_MASK (AA_MAY_OVERRIDE_CRED | AA_MAY_CREATE_SQPOLL)
#define PERMS_CHRS_MASK (MAY_READ | MAY_WRITE | AA_MAY_CREATE | \
AA_MAY_DELETE | AA_MAY_LINK | AA_MAY_LOCK | \

113
security/apparmor/lsm.c
View File

@ -582,6 +582,114 @@ static int apparmor_file_mprotect(struct vm_area_struct *vma,
false);
}
#ifdef CONFIG_IO_URING
static const char *audit_uring_mask(u32 mask)
{
if (mask & AA_MAY_CREATE_SQPOLL)
return "sqpoll";
if (mask & AA_MAY_OVERRIDE_CRED)
return "override_creds";
return "";
}
static void audit_uring_cb(struct audit_buffer *ab, void *va)
{
struct apparmor_audit_data *ad = aad_of_va(va);
if (ad->request & AA_URING_PERM_MASK) {
audit_log_format(ab, " requested=\"%s\"",
audit_uring_mask(ad->request));
if (ad->denied & AA_URING_PERM_MASK) {
audit_log_format(ab, " denied=\"%s\"",
audit_uring_mask(ad->denied));
}
}
if (ad->uring.target) {
audit_log_format(ab, " tcontext=");
aa_label_xaudit(ab, labels_ns(ad->subj_label),
ad->uring.target,
FLAGS_NONE, GFP_ATOMIC);
}
}
static int profile_uring(struct aa_profile *profile, u32 request,
struct aa_label *new, int cap,
struct apparmor_audit_data *ad)
{
unsigned int state;
struct aa_ruleset *rules;
int error = 0;
AA_BUG(!profile);
rules = list_first_entry(&profile->rules, typeof(*rules), list);
state = RULE_MEDIATES(rules, AA_CLASS_IO_URING);
if (state) {
struct aa_perms perms = { };
if (new) {
aa_label_match(profile, rules, new, state,
false, request, &perms);
} else {
perms = *aa_lookup_perms(rules->policy, state);
}
aa_apply_modes_to_perms(profile, &perms);
error = aa_check_perms(profile, &perms, request, ad,
audit_uring_cb);
}
return error;
}
/**
* apparmor_uring_override_creds - check the requested cred override
* @new: the target creds
*
* Check to see if the current task is allowed to override it's credentials
* to service an io_uring operation.
*/
int apparmor_uring_override_creds(const struct cred *new)
{
struct aa_profile *profile;
struct aa_label *label;
int error;
DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
OP_URING_OVERRIDE);
ad.uring.target = cred_label(new);
label = __begin_current_label_crit_section();
error = fn_for_each(label, profile,
profile_uring(profile, AA_MAY_OVERRIDE_CRED,
cred_label(new), CAP_SYS_ADMIN, &ad));
__end_current_label_crit_section(label);
return error;
}
/**
* apparmor_uring_sqpoll - check if a io_uring polling thread can be created
*
* Check to see if the current task is allowed to create a new io_uring
* kernel polling thread.
*/
int apparmor_uring_sqpoll(void)
{
struct aa_profile *profile;
struct aa_label *label;
int error;
DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
OP_URING_SQPOLL);
label = __begin_current_label_crit_section();
error = fn_for_each(label, profile,
profile_uring(profile, AA_MAY_CREATE_SQPOLL,
NULL, CAP_SYS_ADMIN, &ad));
__end_current_label_crit_section(label);
return error;
}
#endif /* CONFIG_IO_URING */
static int apparmor_sb_mount(const char *dev_name, const struct path *path,
const char *type, unsigned long flags, void *data)
{
@ -1346,6 +1454,11 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
#ifdef CONFIG_IO_URING
LSM_HOOK_INIT(uring_override_creds, apparmor_uring_override_creds),
LSM_HOOK_INIT(uring_sqpoll, apparmor_uring_sqpoll),
#endif
};
/*