apparmor: move ptrace mediation to more logical task.{h,c}

AppArmor split out task oriented controls to their own logical file
a while ago. Ptrace mediation is better grouped with task than
ipc, so move it.

Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen 2021-11-22 23:28:32 -08:00
parent f567e7fada
commit eac931254d
5 changed files with 133 additions and 128 deletions

View File

@ -36,6 +36,7 @@
#include "include/policy_ns.h"
#include "include/resource.h"
#include "include/policy_unpack.h"
#include "include/task.h"
/*
* The apparmor filesystem interface used for policy load and introspection

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@ -13,24 +13,6 @@
#include <linux/sched.h>
struct aa_profile;
#define AA_PTRACE_TRACE MAY_WRITE
#define AA_PTRACE_READ MAY_READ
#define AA_MAY_BE_TRACED AA_MAY_APPEND
#define AA_MAY_BE_READ AA_MAY_CREATE
#define PTRACE_PERM_SHIFT 2
#define AA_PTRACE_PERM_MASK (AA_PTRACE_READ | AA_PTRACE_TRACE | \
AA_MAY_BE_READ | AA_MAY_BE_TRACED)
#define AA_SIGNAL_PERM_MASK (MAY_READ | MAY_WRITE)
#define AA_SFS_SIG_MASK "hup int quit ill trap abrt bus fpe kill usr1 " \
"segv usr2 pipe alrm term stkflt chld cont stop stp ttin ttou urg " \
"xcpu xfsz vtalrm prof winch io pwr sys emt lost"
int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
u32 request);
int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig);
#endif /* __AA_IPC_H */

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@ -77,4 +77,22 @@ static inline void aa_clear_task_ctx_trans(struct aa_task_ctx *ctx)
ctx->token = 0;
}
#define AA_PTRACE_TRACE MAY_WRITE
#define AA_PTRACE_READ MAY_READ
#define AA_MAY_BE_TRACED AA_MAY_APPEND
#define AA_MAY_BE_READ AA_MAY_CREATE
#define PTRACE_PERM_SHIFT 2
#define AA_PTRACE_PERM_MASK (AA_PTRACE_READ | AA_PTRACE_TRACE | \
AA_MAY_BE_READ | AA_MAY_BE_TRACED)
#define AA_SIGNAL_PERM_MASK (MAY_READ | MAY_WRITE)
#define AA_SFS_SIG_MASK "hup int quit ill trap abrt bus fpe kill usr1 " \
"segv usr2 pipe alrm term stkflt chld cont stop stp ttin ttou urg " \
"xcpu xfsz vtalrm prof winch io pwr sys emt lost"
int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
u32 request);
#endif /* __AA_TASK_H */

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@ -9,7 +9,6 @@
*/
#include <linux/gfp.h>
#include <linux/ptrace.h>
#include "include/audit.h"
#include "include/capability.h"
@ -18,115 +17,6 @@
#include "include/ipc.h"
#include "include/sig_names.h"
/**
* audit_ptrace_mask - convert mask to permission string
* @mask: permission mask to convert
*
* Returns: pointer to static string
*/
static const char *audit_ptrace_mask(u32 mask)
{
switch (mask) {
case MAY_READ:
return "read";
case MAY_WRITE:
return "trace";
case AA_MAY_BE_READ:
return "readby";
case AA_MAY_BE_TRACED:
return "tracedby";
}
return "";
}
/* call back to audit ptrace fields */
static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
audit_log_format(ab, " requested_mask=\"%s\"",
audit_ptrace_mask(aad(sa)->request));
if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
audit_log_format(ab, " denied_mask=\"%s\"",
audit_ptrace_mask(aad(sa)->denied));
}
}
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
FLAGS_NONE, GFP_ATOMIC);
}
/* assumes check for PROFILE_MEDIATES is already done */
/* TODO: conditionals */
static int profile_ptrace_perm(struct aa_profile *profile,
struct aa_label *peer, u32 request,
struct common_audit_data *sa)
{
struct aa_perms perms = { };
aad(sa)->peer = peer;
aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
&perms);
aa_apply_modes_to_perms(profile, &perms);
return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
}
static int profile_tracee_perm(struct aa_profile *tracee,
struct aa_label *tracer, u32 request,
struct common_audit_data *sa)
{
if (profile_unconfined(tracee) || unconfined(tracer) ||
!PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
return 0;
return profile_ptrace_perm(tracee, tracer, request, sa);
}
static int profile_tracer_perm(struct aa_profile *tracer,
struct aa_label *tracee, u32 request,
struct common_audit_data *sa)
{
if (profile_unconfined(tracer))
return 0;
if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
return profile_ptrace_perm(tracer, tracee, request, sa);
/* profile uses the old style capability check for ptrace */
if (&tracer->label == tracee)
return 0;
aad(sa)->label = &tracer->label;
aad(sa)->peer = tracee;
aad(sa)->request = 0;
aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE,
CAP_OPT_NONE);
return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
}
/**
* aa_may_ptrace - test if tracer task can trace the tracee
* @tracer: label of the task doing the tracing (NOT NULL)
* @tracee: task label to be traced
* @request: permission request
*
* Returns: %0 else error code if permission denied or error
*/
int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
u32 request)
{
struct aa_profile *profile;
u32 xrequest = request << PTRACE_PERM_SHIFT;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
return xcheck_labels(tracer, tracee, profile,
profile_tracer_perm(profile, tracee, request, &sa),
profile_tracee_perm(profile, tracer, xrequest, &sa));
}
static inline int map_signal_num(int sig)
{

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@ -12,7 +12,12 @@
* should return to the previous cred if it has not been modified.
*/
#include <linux/gfp.h>
#include <linux/ptrace.h>
#include "include/audit.h"
#include "include/cred.h"
#include "include/policy.h"
#include "include/task.h"
/**
@ -177,3 +182,112 @@ int aa_restore_previous_label(u64 token)
return 0;
}
/**
* audit_ptrace_mask - convert mask to permission string
* @mask: permission mask to convert
*
* Returns: pointer to static string
*/
static const char *audit_ptrace_mask(u32 mask)
{
switch (mask) {
case MAY_READ:
return "read";
case MAY_WRITE:
return "trace";
case AA_MAY_BE_READ:
return "readby";
case AA_MAY_BE_TRACED:
return "tracedby";
}
return "";
}
/* call back to audit ptrace fields */
static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
audit_log_format(ab, " requested_mask=\"%s\"",
audit_ptrace_mask(aad(sa)->request));
if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
audit_log_format(ab, " denied_mask=\"%s\"",
audit_ptrace_mask(aad(sa)->denied));
}
}
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
FLAGS_NONE, GFP_ATOMIC);
}
/* assumes check for PROFILE_MEDIATES is already done */
/* TODO: conditionals */
static int profile_ptrace_perm(struct aa_profile *profile,
struct aa_label *peer, u32 request,
struct common_audit_data *sa)
{
struct aa_perms perms = { };
aad(sa)->peer = peer;
aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
&perms);
aa_apply_modes_to_perms(profile, &perms);
return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
}
static int profile_tracee_perm(struct aa_profile *tracee,
struct aa_label *tracer, u32 request,
struct common_audit_data *sa)
{
if (profile_unconfined(tracee) || unconfined(tracer) ||
!PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
return 0;
return profile_ptrace_perm(tracee, tracer, request, sa);
}
static int profile_tracer_perm(struct aa_profile *tracer,
struct aa_label *tracee, u32 request,
struct common_audit_data *sa)
{
if (profile_unconfined(tracer))
return 0;
if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
return profile_ptrace_perm(tracer, tracee, request, sa);
/* profile uses the old style capability check for ptrace */
if (&tracer->label == tracee)
return 0;
aad(sa)->label = &tracer->label;
aad(sa)->peer = tracee;
aad(sa)->request = 0;
aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE,
CAP_OPT_NONE);
return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
}
/**
* aa_may_ptrace - test if tracer task can trace the tracee
* @tracer: label of the task doing the tracing (NOT NULL)
* @tracee: task label to be traced
* @request: permission request
*
* Returns: %0 else error code if permission denied or error
*/
int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
u32 request)
{
struct aa_profile *profile;
u32 xrequest = request << PTRACE_PERM_SHIFT;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
return xcheck_labels(tracer, tracee, profile,
profile_tracer_perm(profile, tracee, request, &sa),
profile_tracee_perm(profile, tracer, xrequest, &sa));
}