mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-16 17:23:55 +08:00
5d7c44ef5e
Break the per cpu buffer atomic section when creating a new null
complain profile. In learning mode this won't matter and we can
safely re-aquire the buffer.
This fixes the following lockdep BUG trace
nov. 14 14:09:09 cyclope audit[7152]: AVC apparmor="ALLOWED" operation="exec" profile="/usr/sbin/sssd" name="/usr/sbin/adcli" pid=7152 comm="sssd_be" requested_mask="x" denied_mask="x" fsuid=0 ouid=0 target="/usr/sbin/sssd//null-/usr/sbin/adcli"
nov. 14 14:09:09 cyclope kernel: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
nov. 14 14:09:09 cyclope kernel: in_atomic(): 1, irqs_disabled(): 0, pid: 7152, name: sssd_be
nov. 14 14:09:09 cyclope kernel: 1 lock held by sssd_be/7152:
nov. 14 14:09:09 cyclope kernel: #0: (&sig->cred_guard_mutex){....}, at: [<ffffffff8182d53e>] prepare_bprm_creds+0x4e/0x100
nov. 14 14:09:09 cyclope kernel: CPU: 3 PID: 7152 Comm: sssd_be Not tainted 4.14.0prahal+intel #150
nov. 14 14:09:09 cyclope kernel: Hardware name: LENOVO 20CDCTO1WW/20CDCTO1WW, BIOS GQET53WW (1.33 ) 09/15/2017
nov. 14 14:09:09 cyclope kernel: Call Trace:
nov. 14 14:09:09 cyclope kernel: dump_stack+0xb0/0x135
nov. 14 14:09:09 cyclope kernel: ? _atomic_dec_and_lock+0x15b/0x15b
nov. 14 14:09:09 cyclope kernel: ? lockdep_print_held_locks+0xc4/0x130
nov. 14 14:09:09 cyclope kernel: ___might_sleep+0x29c/0x320
nov. 14 14:09:09 cyclope kernel: ? rq_clock+0xf0/0xf0
nov. 14 14:09:09 cyclope kernel: ? __kernel_text_address+0xd/0x40
nov. 14 14:09:09 cyclope kernel: __might_sleep+0x95/0x190
nov. 14 14:09:09 cyclope kernel: ? aa_new_null_profile+0x50a/0x960
nov. 14 14:09:09 cyclope kernel: __mutex_lock+0x13e/0x1a20
nov. 14 14:09:09 cyclope kernel: ? aa_new_null_profile+0x50a/0x960
nov. 14 14:09:09 cyclope kernel: ? save_stack+0x43/0xd0
nov. 14 14:09:09 cyclope kernel: ? kmem_cache_alloc_trace+0x13f/0x290
nov. 14 14:09:09 cyclope kernel: ? mutex_lock_io_nested+0x1880/0x1880
nov. 14 14:09:09 cyclope kernel: ? profile_transition+0x932/0x2d40
nov. 14 14:09:09 cyclope kernel: ? apparmor_bprm_set_creds+0x1479/0x1f70
nov. 14 14:09:09 cyclope kernel: ? security_bprm_set_creds+0x5a/0x80
nov. 14 14:09:09 cyclope kernel: ? prepare_binprm+0x366/0x980
nov. 14 14:09:09 cyclope kernel: ? do_execveat_common.isra.30+0x12a9/0x2350
nov. 14 14:09:09 cyclope kernel: ? SyS_execve+0x2c/0x40
nov. 14 14:09:09 cyclope kernel: ? do_syscall_64+0x228/0x650
nov. 14 14:09:09 cyclope kernel: ? entry_SYSCALL64_slow_path+0x25/0x25
nov. 14 14:09:09 cyclope kernel: ? deactivate_slab.isra.62+0x49d/0x5e0
nov. 14 14:09:09 cyclope kernel: ? save_stack_trace+0x16/0x20
nov. 14 14:09:09 cyclope kernel: ? init_object+0x88/0x90
nov. 14 14:09:09 cyclope kernel: ? ___slab_alloc+0x520/0x590
nov. 14 14:09:09 cyclope kernel: ? ___slab_alloc+0x520/0x590
nov. 14 14:09:09 cyclope kernel: ? aa_alloc_proxy+0xab/0x200
nov. 14 14:09:09 cyclope kernel: ? lock_downgrade+0x7e0/0x7e0
nov. 14 14:09:09 cyclope kernel: ? memcg_kmem_get_cache+0x970/0x970
nov. 14 14:09:09 cyclope kernel: ? kasan_unpoison_shadow+0x35/0x50
nov. 14 14:09:09 cyclope kernel: ? kasan_unpoison_shadow+0x35/0x50
nov. 14 14:09:09 cyclope kernel: ? kasan_kmalloc+0xad/0xe0
nov. 14 14:09:09 cyclope kernel: ? aa_alloc_proxy+0xab/0x200
nov. 14 14:09:09 cyclope kernel: ? kmem_cache_alloc_trace+0x13f/0x290
nov. 14 14:09:09 cyclope kernel: ? aa_alloc_proxy+0xab/0x200
nov. 14 14:09:09 cyclope kernel: ? aa_alloc_proxy+0xab/0x200
nov. 14 14:09:09 cyclope kernel: ? _raw_spin_unlock+0x22/0x30
nov. 14 14:09:09 cyclope kernel: ? vec_find+0xa0/0xa0
nov. 14 14:09:09 cyclope kernel: ? aa_label_init+0x6f/0x230
nov. 14 14:09:09 cyclope kernel: ? __label_insert+0x3e0/0x3e0
nov. 14 14:09:09 cyclope kernel: ? kmem_cache_alloc_trace+0x13f/0x290
nov. 14 14:09:09 cyclope kernel: ? aa_alloc_profile+0x58/0x200
nov. 14 14:09:09 cyclope kernel: mutex_lock_nested+0x16/0x20
nov. 14 14:09:09 cyclope kernel: ? mutex_lock_nested+0x16/0x20
nov. 14 14:09:09 cyclope kernel: aa_new_null_profile+0x50a/0x960
nov. 14 14:09:09 cyclope kernel: ? aa_fqlookupn_profile+0xdc0/0xdc0
nov. 14 14:09:09 cyclope kernel: ? aa_compute_fperms+0x4b5/0x640
nov. 14 14:09:09 cyclope kernel: ? disconnect.isra.2+0x1b0/0x1b0
nov. 14 14:09:09 cyclope kernel: ? aa_str_perms+0x8d/0xe0
nov. 14 14:09:09 cyclope kernel: profile_transition+0x932/0x2d40
nov. 14 14:09:09 cyclope kernel: ? up_read+0x1a/0x40
nov. 14 14:09:09 cyclope kernel: ? ext4_xattr_get+0x15c/0xaf0 [ext4]
nov. 14 14:09:09 cyclope kernel: ? x_table_lookup+0x190/0x190
nov. 14 14:09:09 cyclope kernel: ? ext4_xattr_ibody_get+0x590/0x590 [ext4]
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? ext4_xattr_security_get+0x1a/0x20 [ext4]
nov. 14 14:09:09 cyclope kernel: ? __vfs_getxattr+0x6d/0xa0
nov. 14 14:09:09 cyclope kernel: ? get_vfs_caps_from_disk+0x114/0x720
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? tsc_resume+0x10/0x10
nov. 14 14:09:09 cyclope kernel: ? get_vfs_caps_from_disk+0x720/0x720
nov. 14 14:09:09 cyclope kernel: ? native_sched_clock_from_tsc+0x201/0x2b0
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? sched_clock_cpu+0x1b/0x170
nov. 14 14:09:09 cyclope kernel: ? find_held_lock+0x3c/0x1e0
nov. 14 14:09:09 cyclope kernel: ? rb_insert_color_cached+0x1660/0x1660
nov. 14 14:09:09 cyclope kernel: apparmor_bprm_set_creds+0x1479/0x1f70
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? handle_onexec+0x31d0/0x31d0
nov. 14 14:09:09 cyclope kernel: ? tsc_resume+0x10/0x10
nov. 14 14:09:09 cyclope kernel: ? graph_lock+0xd0/0xd0
nov. 14 14:09:09 cyclope kernel: ? tsc_resume+0x10/0x10
nov. 14 14:09:09 cyclope kernel: ? sched_clock_cpu+0x1b/0x170
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? sched_clock+0x9/0x10
nov. 14 14:09:09 cyclope kernel: ? sched_clock_cpu+0x1b/0x170
nov. 14 14:09:09 cyclope kernel: ? find_held_lock+0x3c/0x1e0
nov. 14 14:09:09 cyclope kernel: security_bprm_set_creds+0x5a/0x80
nov. 14 14:09:09 cyclope kernel: prepare_binprm+0x366/0x980
nov. 14 14:09:09 cyclope kernel: ? install_exec_creds+0x150/0x150
nov. 14 14:09:09 cyclope kernel: ? __might_fault+0x89/0xb0
nov. 14 14:09:09 cyclope kernel: ? up_read+0x40/0x40
nov. 14 14:09:09 cyclope kernel: ? get_user_arg_ptr.isra.18+0x2c/0x70
nov. 14 14:09:09 cyclope kernel: ? count.isra.20.constprop.32+0x7c/0xf0
nov. 14 14:09:09 cyclope kernel: do_execveat_common.isra.30+0x12a9/0x2350
nov. 14 14:09:09 cyclope kernel: ? prepare_bprm_creds+0x100/0x100
nov. 14 14:09:09 cyclope kernel: ? _raw_spin_unlock+0x22/0x30
nov. 14 14:09:09 cyclope kernel: ? deactivate_slab.isra.62+0x49d/0x5e0
nov. 14 14:09:09 cyclope kernel: ? save_stack_trace+0x16/0x20
nov. 14 14:09:09 cyclope kernel: ? init_object+0x88/0x90
nov. 14 14:09:09 cyclope kernel: ? ___slab_alloc+0x520/0x590
nov. 14 14:09:09 cyclope kernel: ? ___slab_alloc+0x520/0x590
nov. 14 14:09:09 cyclope kernel: ? kasan_check_write+0x14/0x20
nov. 14 14:09:09 cyclope kernel: ? memcg_kmem_get_cache+0x970/0x970
nov. 14 14:09:09 cyclope kernel: ? kasan_unpoison_shadow+0x35/0x50
nov. 14 14:09:09 cyclope kernel: ? glob_match+0x730/0x730
nov. 14 14:09:09 cyclope kernel: ? kmem_cache_alloc+0x225/0x280
nov. 14 14:09:09 cyclope kernel: ? getname_flags+0xb8/0x510
nov. 14 14:09:09 cyclope kernel: ? mm_fault_error+0x2e0/0x2e0
nov. 14 14:09:09 cyclope kernel: ? getname_flags+0xf6/0x510
nov. 14 14:09:09 cyclope kernel: ? ptregs_sys_vfork+0x10/0x10
nov. 14 14:09:09 cyclope kernel: SyS_execve+0x2c/0x40
nov. 14 14:09:09 cyclope kernel: do_syscall_64+0x228/0x650
nov. 14 14:09:09 cyclope kernel: ? syscall_return_slowpath+0x2f0/0x2f0
nov. 14 14:09:09 cyclope kernel: ? syscall_return_slowpath+0x167/0x2f0
nov. 14 14:09:09 cyclope kernel: ? prepare_exit_to_usermode+0x220/0x220
nov. 14 14:09:09 cyclope kernel: ? prepare_exit_to_usermode+0xda/0x220
nov. 14 14:09:09 cyclope kernel: ? perf_trace_sys_enter+0x1060/0x1060
nov. 14 14:09:09 cyclope kernel: ? __put_user_4+0x1c/0x30
nov. 14 14:09:09 cyclope kernel: entry_SYSCALL64_slow_path+0x25/0x25
nov. 14 14:09:09 cyclope kernel: RIP: 0033:0x7f9320f23637
nov. 14 14:09:09 cyclope kernel: RSP: 002b:00007fff783be338 EFLAGS: 00000202 ORIG_RAX: 000000000000003b
nov. 14 14:09:09 cyclope kernel: RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9320f23637
nov. 14 14:09:09 cyclope kernel: RDX: 0000558c35002a70 RSI: 0000558c3505bd10 RDI: 0000558c35018b90
nov. 14 14:09:09 cyclope kernel: RBP: 0000558c34b63ae8 R08: 0000558c3505bd10 R09: 0000000000000080
nov. 14 14:09:09 cyclope kernel: R10: 0000000000000095 R11: 0000000000000202 R12: 0000000000000001
nov. 14 14:09:09 cyclope kernel: R13: 0000558c35018b90 R14: 0000558c3505bd18 R15: 0000558c3505bd10
Fixes: 4227c333f6
("apparmor: Move path lookup to using preallocated buffers")
BugLink: http://bugs.launchpad.net/bugs/173228
Reported-by: Alban Browaeys <prahal@yahoo.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
1318 lines
35 KiB
C
1318 lines
35 KiB
C
/*
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* AppArmor security module
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*
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* This file contains AppArmor policy attachment and domain transitions
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*
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* Copyright (C) 2002-2008 Novell/SUSE
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* Copyright 2009-2010 Canonical Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#include <linux/errno.h>
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#include <linux/fdtable.h>
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#include <linux/file.h>
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#include <linux/mount.h>
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#include <linux/syscalls.h>
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#include <linux/tracehook.h>
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#include <linux/personality.h>
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#include "include/audit.h"
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#include "include/apparmorfs.h"
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#include "include/context.h"
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#include "include/domain.h"
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#include "include/file.h"
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#include "include/ipc.h"
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#include "include/match.h"
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#include "include/path.h"
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#include "include/policy.h"
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#include "include/policy_ns.h"
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/**
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* aa_free_domain_entries - free entries in a domain table
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* @domain: the domain table to free (MAYBE NULL)
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*/
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void aa_free_domain_entries(struct aa_domain *domain)
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{
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int i;
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if (domain) {
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if (!domain->table)
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return;
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for (i = 0; i < domain->size; i++)
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kzfree(domain->table[i]);
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kzfree(domain->table);
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domain->table = NULL;
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}
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}
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/**
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* may_change_ptraced_domain - check if can change profile on ptraced task
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* @to_label: profile to change to (NOT NULL)
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* @info: message if there is an error
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*
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* Check if current is ptraced and if so if the tracing task is allowed
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* to trace the new domain
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*
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* Returns: %0 or error if change not allowed
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*/
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static int may_change_ptraced_domain(struct aa_label *to_label,
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const char **info)
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{
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struct task_struct *tracer;
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struct aa_label *tracerl = NULL;
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int error = 0;
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rcu_read_lock();
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tracer = ptrace_parent(current);
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if (tracer)
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/* released below */
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tracerl = aa_get_task_label(tracer);
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/* not ptraced */
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if (!tracer || unconfined(tracerl))
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goto out;
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error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
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out:
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rcu_read_unlock();
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aa_put_label(tracerl);
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if (error)
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*info = "ptrace prevents transition";
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return error;
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}
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/**** TODO: dedup to aa_label_match - needs perm and dfa, merging
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* specifically this is an exact copy of aa_label_match except
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* aa_compute_perms is replaced with aa_compute_fperms
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* and policy.dfa with file.dfa
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****/
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/* match a profile and its associated ns component if needed
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* Assumes visibility test has already been done.
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* If a subns profile is not to be matched should be prescreened with
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* visibility test.
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*/
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static inline unsigned int match_component(struct aa_profile *profile,
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struct aa_profile *tp,
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bool stack, unsigned int state)
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{
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const char *ns_name;
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if (stack)
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state = aa_dfa_match(profile->file.dfa, state, "&");
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if (profile->ns == tp->ns)
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return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
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/* try matching with namespace name and then profile */
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ns_name = aa_ns_name(profile->ns, tp->ns, true);
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state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
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state = aa_dfa_match(profile->file.dfa, state, ns_name);
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state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
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return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
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}
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/**
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* label_compound_match - find perms for full compound label
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* @profile: profile to find perms for
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* @label: label to check access permissions for
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* @stack: whether this is a stacking request
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* @start: state to start match in
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* @subns: whether to do permission checks on components in a subns
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* @request: permissions to request
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* @perms: perms struct to set
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*
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* Returns: 0 on success else ERROR
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*
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* For the label A//&B//&C this does the perm match for A//&B//&C
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* @perms should be preinitialized with allperms OR a previous permission
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* check to be stacked.
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*/
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static int label_compound_match(struct aa_profile *profile,
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struct aa_label *label, bool stack,
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unsigned int state, bool subns, u32 request,
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struct aa_perms *perms)
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{
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struct aa_profile *tp;
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struct label_it i;
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struct path_cond cond = { };
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/* find first subcomponent that is visible */
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label_for_each(i, label, tp) {
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if (!aa_ns_visible(profile->ns, tp->ns, subns))
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continue;
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state = match_component(profile, tp, stack, state);
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if (!state)
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goto fail;
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goto next;
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}
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/* no component visible */
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*perms = allperms;
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return 0;
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next:
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label_for_each_cont(i, label, tp) {
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if (!aa_ns_visible(profile->ns, tp->ns, subns))
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continue;
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state = aa_dfa_match(profile->file.dfa, state, "//&");
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state = match_component(profile, tp, false, state);
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if (!state)
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goto fail;
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}
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*perms = aa_compute_fperms(profile->file.dfa, state, &cond);
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aa_apply_modes_to_perms(profile, perms);
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if ((perms->allow & request) != request)
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return -EACCES;
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return 0;
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fail:
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*perms = nullperms;
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return -EACCES;
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}
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/**
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* label_components_match - find perms for all subcomponents of a label
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* @profile: profile to find perms for
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* @label: label to check access permissions for
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* @stack: whether this is a stacking request
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* @start: state to start match in
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* @subns: whether to do permission checks on components in a subns
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* @request: permissions to request
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* @perms: an initialized perms struct to add accumulation to
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*
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* Returns: 0 on success else ERROR
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*
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* For the label A//&B//&C this does the perm match for each of A and B and C
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* @perms should be preinitialized with allperms OR a previous permission
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* check to be stacked.
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*/
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static int label_components_match(struct aa_profile *profile,
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struct aa_label *label, bool stack,
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unsigned int start, bool subns, u32 request,
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struct aa_perms *perms)
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{
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struct aa_profile *tp;
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struct label_it i;
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struct aa_perms tmp;
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struct path_cond cond = { };
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unsigned int state = 0;
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/* find first subcomponent to test */
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label_for_each(i, label, tp) {
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if (!aa_ns_visible(profile->ns, tp->ns, subns))
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continue;
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state = match_component(profile, tp, stack, start);
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if (!state)
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goto fail;
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goto next;
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}
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/* no subcomponents visible - no change in perms */
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return 0;
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next:
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tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
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aa_apply_modes_to_perms(profile, &tmp);
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aa_perms_accum(perms, &tmp);
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label_for_each_cont(i, label, tp) {
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if (!aa_ns_visible(profile->ns, tp->ns, subns))
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continue;
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state = match_component(profile, tp, stack, start);
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if (!state)
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goto fail;
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tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
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aa_apply_modes_to_perms(profile, &tmp);
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aa_perms_accum(perms, &tmp);
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}
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if ((perms->allow & request) != request)
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return -EACCES;
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return 0;
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fail:
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*perms = nullperms;
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return -EACCES;
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}
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/**
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* label_match - do a multi-component label match
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* @profile: profile to match against (NOT NULL)
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* @label: label to match (NOT NULL)
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* @stack: whether this is a stacking request
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* @state: state to start in
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* @subns: whether to match subns components
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* @request: permission request
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|
* @perms: Returns computed perms (NOT NULL)
|
|
*
|
|
* Returns: the state the match finished in, may be the none matching state
|
|
*/
|
|
static int label_match(struct aa_profile *profile, struct aa_label *label,
|
|
bool stack, unsigned int state, bool subns, u32 request,
|
|
struct aa_perms *perms)
|
|
{
|
|
int error;
|
|
|
|
*perms = nullperms;
|
|
error = label_compound_match(profile, label, stack, state, subns,
|
|
request, perms);
|
|
if (!error)
|
|
return error;
|
|
|
|
*perms = allperms;
|
|
return label_components_match(profile, label, stack, state, subns,
|
|
request, perms);
|
|
}
|
|
|
|
/******* end TODO: dedup *****/
|
|
|
|
/**
|
|
* change_profile_perms - find permissions for change_profile
|
|
* @profile: the current profile (NOT NULL)
|
|
* @target: label to transition to (NOT NULL)
|
|
* @stack: whether this is a stacking request
|
|
* @request: requested perms
|
|
* @start: state to start matching in
|
|
*
|
|
*
|
|
* Returns: permission set
|
|
*
|
|
* currently only matches full label A//&B//&C or individual components A, B, C
|
|
* not arbitrary combinations. Eg. A//&B, C
|
|
*/
|
|
static int change_profile_perms(struct aa_profile *profile,
|
|
struct aa_label *target, bool stack,
|
|
u32 request, unsigned int start,
|
|
struct aa_perms *perms)
|
|
{
|
|
if (profile_unconfined(profile)) {
|
|
perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
|
|
perms->audit = perms->quiet = perms->kill = 0;
|
|
return 0;
|
|
}
|
|
|
|
/* TODO: add profile in ns screening */
|
|
return label_match(profile, target, stack, start, true, request, perms);
|
|
}
|
|
|
|
/**
|
|
* __attach_match_ - find an attachment match
|
|
* @name - to match against (NOT NULL)
|
|
* @head - profile list to walk (NOT NULL)
|
|
* @info - info message if there was an error (NOT NULL)
|
|
*
|
|
* Do a linear search on the profiles in the list. There is a matching
|
|
* preference where an exact match is preferred over a name which uses
|
|
* expressions to match, and matching expressions with the greatest
|
|
* xmatch_len are preferred.
|
|
*
|
|
* Requires: @head not be shared or have appropriate locks held
|
|
*
|
|
* Returns: profile or NULL if no match found
|
|
*/
|
|
static struct aa_profile *__attach_match(const char *name,
|
|
struct list_head *head,
|
|
const char **info)
|
|
{
|
|
int len = 0;
|
|
bool conflict = false;
|
|
struct aa_profile *profile, *candidate = NULL;
|
|
|
|
list_for_each_entry_rcu(profile, head, base.list) {
|
|
if (profile->label.flags & FLAG_NULL &&
|
|
&profile->label == ns_unconfined(profile->ns))
|
|
continue;
|
|
|
|
if (profile->xmatch) {
|
|
if (profile->xmatch_len == len) {
|
|
conflict = true;
|
|
continue;
|
|
} else if (profile->xmatch_len > len) {
|
|
unsigned int state;
|
|
u32 perm;
|
|
|
|
state = aa_dfa_match(profile->xmatch,
|
|
DFA_START, name);
|
|
perm = dfa_user_allow(profile->xmatch, state);
|
|
/* any accepting state means a valid match. */
|
|
if (perm & MAY_EXEC) {
|
|
candidate = profile;
|
|
len = profile->xmatch_len;
|
|
conflict = false;
|
|
}
|
|
}
|
|
} else if (!strcmp(profile->base.name, name))
|
|
/* exact non-re match, no more searching required */
|
|
return profile;
|
|
}
|
|
|
|
if (conflict) {
|
|
*info = "conflicting profile attachments";
|
|
return NULL;
|
|
}
|
|
|
|
return candidate;
|
|
}
|
|
|
|
/**
|
|
* find_attach - do attachment search for unconfined processes
|
|
* @ns: the current namespace (NOT NULL)
|
|
* @list: list to search (NOT NULL)
|
|
* @name: the executable name to match against (NOT NULL)
|
|
* @info: info message if there was an error
|
|
*
|
|
* Returns: label or NULL if no match found
|
|
*/
|
|
static struct aa_label *find_attach(struct aa_ns *ns, struct list_head *list,
|
|
const char *name, const char **info)
|
|
{
|
|
struct aa_profile *profile;
|
|
|
|
rcu_read_lock();
|
|
profile = aa_get_profile(__attach_match(name, list, info));
|
|
rcu_read_unlock();
|
|
|
|
return profile ? &profile->label : NULL;
|
|
}
|
|
|
|
static const char *next_name(int xtype, const char *name)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* x_table_lookup - lookup an x transition name via transition table
|
|
* @profile: current profile (NOT NULL)
|
|
* @xindex: index into x transition table
|
|
* @name: returns: name tested to find label (NOT NULL)
|
|
*
|
|
* Returns: refcounted label, or NULL on failure (MAYBE NULL)
|
|
*/
|
|
struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
|
|
const char **name)
|
|
{
|
|
struct aa_label *label = NULL;
|
|
u32 xtype = xindex & AA_X_TYPE_MASK;
|
|
int index = xindex & AA_X_INDEX_MASK;
|
|
|
|
AA_BUG(!name);
|
|
|
|
/* index is guaranteed to be in range, validated at load time */
|
|
/* TODO: move lookup parsing to unpack time so this is a straight
|
|
* index into the resultant label
|
|
*/
|
|
for (*name = profile->file.trans.table[index]; !label && *name;
|
|
*name = next_name(xtype, *name)) {
|
|
if (xindex & AA_X_CHILD) {
|
|
struct aa_profile *new_profile;
|
|
/* release by caller */
|
|
new_profile = aa_find_child(profile, *name);
|
|
if (new_profile)
|
|
label = &new_profile->label;
|
|
continue;
|
|
}
|
|
label = aa_label_parse(&profile->label, *name, GFP_ATOMIC,
|
|
true, false);
|
|
if (IS_ERR(label))
|
|
label = NULL;
|
|
}
|
|
|
|
/* released by caller */
|
|
|
|
return label;
|
|
}
|
|
|
|
/**
|
|
* x_to_label - get target label for a given xindex
|
|
* @profile: current profile (NOT NULL)
|
|
* @name: name to lookup (NOT NULL)
|
|
* @xindex: index into x transition table
|
|
* @lookupname: returns: name used in lookup if one was specified (NOT NULL)
|
|
*
|
|
* find label for a transition index
|
|
*
|
|
* Returns: refcounted label or NULL if not found available
|
|
*/
|
|
static struct aa_label *x_to_label(struct aa_profile *profile,
|
|
const char *name, u32 xindex,
|
|
const char **lookupname,
|
|
const char **info)
|
|
{
|
|
struct aa_label *new = NULL;
|
|
struct aa_ns *ns = profile->ns;
|
|
u32 xtype = xindex & AA_X_TYPE_MASK;
|
|
const char *stack = NULL;
|
|
|
|
switch (xtype) {
|
|
case AA_X_NONE:
|
|
/* fail exec unless ix || ux fallback - handled by caller */
|
|
*lookupname = NULL;
|
|
break;
|
|
case AA_X_TABLE:
|
|
/* TODO: fix when perm mapping done at unload */
|
|
stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
|
|
if (*stack != '&') {
|
|
/* released by caller */
|
|
new = x_table_lookup(profile, xindex, lookupname);
|
|
stack = NULL;
|
|
break;
|
|
}
|
|
/* fall through to X_NAME */
|
|
case AA_X_NAME:
|
|
if (xindex & AA_X_CHILD)
|
|
/* released by caller */
|
|
new = find_attach(ns, &profile->base.profiles,
|
|
name, info);
|
|
else
|
|
/* released by caller */
|
|
new = find_attach(ns, &ns->base.profiles,
|
|
name, info);
|
|
*lookupname = name;
|
|
break;
|
|
}
|
|
|
|
if (!new) {
|
|
if (xindex & AA_X_INHERIT) {
|
|
/* (p|c|n)ix - don't change profile but do
|
|
* use the newest version
|
|
*/
|
|
*info = "ix fallback";
|
|
/* no profile && no error */
|
|
new = aa_get_newest_label(&profile->label);
|
|
} else if (xindex & AA_X_UNCONFINED) {
|
|
new = aa_get_newest_label(ns_unconfined(profile->ns));
|
|
*info = "ux fallback";
|
|
}
|
|
}
|
|
|
|
if (new && stack) {
|
|
/* base the stack on post domain transition */
|
|
struct aa_label *base = new;
|
|
|
|
new = aa_label_parse(base, stack, GFP_ATOMIC, true, false);
|
|
if (IS_ERR(new))
|
|
new = NULL;
|
|
aa_put_label(base);
|
|
}
|
|
|
|
/* released by caller */
|
|
return new;
|
|
}
|
|
|
|
static struct aa_label *profile_transition(struct aa_profile *profile,
|
|
const struct linux_binprm *bprm,
|
|
char *buffer, struct path_cond *cond,
|
|
bool *secure_exec)
|
|
{
|
|
struct aa_label *new = NULL;
|
|
const char *info = NULL, *name = NULL, *target = NULL;
|
|
unsigned int state = profile->file.start;
|
|
struct aa_perms perms = {};
|
|
bool nonewprivs = false;
|
|
int error = 0;
|
|
|
|
AA_BUG(!profile);
|
|
AA_BUG(!bprm);
|
|
AA_BUG(!buffer);
|
|
|
|
error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
|
|
&name, &info, profile->disconnected);
|
|
if (error) {
|
|
if (profile_unconfined(profile) ||
|
|
(profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
|
|
AA_DEBUG("name lookup ix on error");
|
|
error = 0;
|
|
new = aa_get_newest_label(&profile->label);
|
|
}
|
|
name = bprm->filename;
|
|
goto audit;
|
|
}
|
|
|
|
if (profile_unconfined(profile)) {
|
|
new = find_attach(profile->ns, &profile->ns->base.profiles,
|
|
name, &info);
|
|
if (new) {
|
|
AA_DEBUG("unconfined attached to new label");
|
|
return new;
|
|
}
|
|
AA_DEBUG("unconfined exec no attachment");
|
|
return aa_get_newest_label(&profile->label);
|
|
}
|
|
|
|
/* find exec permissions for name */
|
|
state = aa_str_perms(profile->file.dfa, state, name, cond, &perms);
|
|
if (perms.allow & MAY_EXEC) {
|
|
/* exec permission determine how to transition */
|
|
new = x_to_label(profile, name, perms.xindex, &target, &info);
|
|
if (new && new->proxy == profile->label.proxy && info) {
|
|
/* hack ix fallback - improve how this is detected */
|
|
goto audit;
|
|
} else if (!new) {
|
|
error = -EACCES;
|
|
info = "profile transition not found";
|
|
/* remove MAY_EXEC to audit as failure */
|
|
perms.allow &= ~MAY_EXEC;
|
|
}
|
|
} else if (COMPLAIN_MODE(profile)) {
|
|
/* no exec permission - learning mode */
|
|
struct aa_profile *new_profile = NULL;
|
|
char *n = kstrdup(name, GFP_ATOMIC);
|
|
|
|
if (n) {
|
|
/* name is ptr into buffer */
|
|
long pos = name - buffer;
|
|
/* break per cpu buffer hold */
|
|
put_buffers(buffer);
|
|
new_profile = aa_new_null_profile(profile, false, n,
|
|
GFP_KERNEL);
|
|
get_buffers(buffer);
|
|
name = buffer + pos;
|
|
strcpy((char *)name, n);
|
|
kfree(n);
|
|
}
|
|
if (!new_profile) {
|
|
error = -ENOMEM;
|
|
info = "could not create null profile";
|
|
} else {
|
|
error = -EACCES;
|
|
new = &new_profile->label;
|
|
}
|
|
perms.xindex |= AA_X_UNSAFE;
|
|
} else
|
|
/* fail exec */
|
|
error = -EACCES;
|
|
|
|
if (!new)
|
|
goto audit;
|
|
|
|
/* Policy has specified a domain transitions. if no_new_privs and
|
|
* confined and not transitioning to the current domain fail.
|
|
*
|
|
* NOTE: Domain transitions from unconfined and to stritly stacked
|
|
* subsets are allowed even when no_new_privs is set because this
|
|
* aways results in a further reduction of permissions.
|
|
*/
|
|
if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
|
|
!profile_unconfined(profile) &&
|
|
!aa_label_is_subset(new, &profile->label)) {
|
|
error = -EPERM;
|
|
info = "no new privs";
|
|
nonewprivs = true;
|
|
perms.allow &= ~MAY_EXEC;
|
|
goto audit;
|
|
}
|
|
|
|
if (!(perms.xindex & AA_X_UNSAFE)) {
|
|
if (DEBUG_ON) {
|
|
dbg_printk("apparmor: scrubbing environment variables"
|
|
" for %s profile=", name);
|
|
aa_label_printk(new, GFP_ATOMIC);
|
|
dbg_printk("\n");
|
|
}
|
|
*secure_exec = true;
|
|
}
|
|
|
|
audit:
|
|
aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
|
|
cond->uid, info, error);
|
|
if (!new || nonewprivs) {
|
|
aa_put_label(new);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
return new;
|
|
}
|
|
|
|
static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
|
|
bool stack, const struct linux_binprm *bprm,
|
|
char *buffer, struct path_cond *cond,
|
|
bool *secure_exec)
|
|
{
|
|
unsigned int state = profile->file.start;
|
|
struct aa_perms perms = {};
|
|
const char *xname = NULL, *info = "change_profile onexec";
|
|
int error = -EACCES;
|
|
|
|
AA_BUG(!profile);
|
|
AA_BUG(!onexec);
|
|
AA_BUG(!bprm);
|
|
AA_BUG(!buffer);
|
|
|
|
if (profile_unconfined(profile)) {
|
|
/* change_profile on exec already granted */
|
|
/*
|
|
* NOTE: Domain transitions from unconfined are allowed
|
|
* even when no_new_privs is set because this aways results
|
|
* in a further reduction of permissions.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
|
|
&xname, &info, profile->disconnected);
|
|
if (error) {
|
|
if (profile_unconfined(profile) ||
|
|
(profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
|
|
AA_DEBUG("name lookup ix on error");
|
|
error = 0;
|
|
}
|
|
xname = bprm->filename;
|
|
goto audit;
|
|
}
|
|
|
|
/* find exec permissions for name */
|
|
state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms);
|
|
if (!(perms.allow & AA_MAY_ONEXEC)) {
|
|
info = "no change_onexec valid for executable";
|
|
goto audit;
|
|
}
|
|
/* test if this exec can be paired with change_profile onexec.
|
|
* onexec permission is linked to exec with a standard pairing
|
|
* exec\0change_profile
|
|
*/
|
|
state = aa_dfa_null_transition(profile->file.dfa, state);
|
|
error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
|
|
state, &perms);
|
|
if (error) {
|
|
perms.allow &= ~AA_MAY_ONEXEC;
|
|
goto audit;
|
|
}
|
|
/* Policy has specified a domain transitions. if no_new_privs and
|
|
* confined and not transitioning to the current domain fail.
|
|
*
|
|
* NOTE: Domain transitions from unconfined and to stritly stacked
|
|
* subsets are allowed even when no_new_privs is set because this
|
|
* aways results in a further reduction of permissions.
|
|
*/
|
|
if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
|
|
!profile_unconfined(profile) &&
|
|
!aa_label_is_subset(onexec, &profile->label)) {
|
|
error = -EPERM;
|
|
info = "no new privs";
|
|
perms.allow &= ~AA_MAY_ONEXEC;
|
|
goto audit;
|
|
}
|
|
|
|
if (!(perms.xindex & AA_X_UNSAFE)) {
|
|
if (DEBUG_ON) {
|
|
dbg_printk("apparmor: scrubbing environment "
|
|
"variables for %s label=", xname);
|
|
aa_label_printk(onexec, GFP_ATOMIC);
|
|
dbg_printk("\n");
|
|
}
|
|
*secure_exec = true;
|
|
}
|
|
|
|
audit:
|
|
return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
|
|
NULL, onexec, cond->uid, info, error);
|
|
}
|
|
|
|
/* ensure none ns domain transitions are correctly applied with onexec */
|
|
|
|
static struct aa_label *handle_onexec(struct aa_label *label,
|
|
struct aa_label *onexec, bool stack,
|
|
const struct linux_binprm *bprm,
|
|
char *buffer, struct path_cond *cond,
|
|
bool *unsafe)
|
|
{
|
|
struct aa_profile *profile;
|
|
struct aa_label *new;
|
|
int error;
|
|
|
|
AA_BUG(!label);
|
|
AA_BUG(!onexec);
|
|
AA_BUG(!bprm);
|
|
AA_BUG(!buffer);
|
|
|
|
if (!stack) {
|
|
error = fn_for_each_in_ns(label, profile,
|
|
profile_onexec(profile, onexec, stack,
|
|
bprm, buffer, cond, unsafe));
|
|
if (error)
|
|
return ERR_PTR(error);
|
|
new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
|
|
aa_get_newest_label(onexec),
|
|
profile_transition(profile, bprm, buffer,
|
|
cond, unsafe));
|
|
|
|
} else {
|
|
/* TODO: determine how much we want to losen this */
|
|
error = fn_for_each_in_ns(label, profile,
|
|
profile_onexec(profile, onexec, stack, bprm,
|
|
buffer, cond, unsafe));
|
|
if (error)
|
|
return ERR_PTR(error);
|
|
new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
|
|
aa_label_merge(&profile->label, onexec,
|
|
GFP_ATOMIC),
|
|
profile_transition(profile, bprm, buffer,
|
|
cond, unsafe));
|
|
}
|
|
|
|
if (new)
|
|
return new;
|
|
|
|
/* TODO: get rid of GLOBAL_ROOT_UID */
|
|
error = fn_for_each_in_ns(label, profile,
|
|
aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
|
|
AA_MAY_ONEXEC, bprm->filename, NULL,
|
|
onexec, GLOBAL_ROOT_UID,
|
|
"failed to build target label", -ENOMEM));
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
/**
|
|
* apparmor_bprm_set_creds - set the new creds on the bprm struct
|
|
* @bprm: binprm for the exec (NOT NULL)
|
|
*
|
|
* Returns: %0 or error on failure
|
|
*
|
|
* TODO: once the other paths are done see if we can't refactor into a fn
|
|
*/
|
|
int apparmor_bprm_set_creds(struct linux_binprm *bprm)
|
|
{
|
|
struct aa_task_ctx *ctx;
|
|
struct aa_label *label, *new = NULL;
|
|
struct aa_profile *profile;
|
|
char *buffer = NULL;
|
|
const char *info = NULL;
|
|
int error = 0;
|
|
bool unsafe = false;
|
|
struct path_cond cond = {
|
|
file_inode(bprm->file)->i_uid,
|
|
file_inode(bprm->file)->i_mode
|
|
};
|
|
|
|
if (bprm->called_set_creds)
|
|
return 0;
|
|
|
|
ctx = cred_ctx(bprm->cred);
|
|
AA_BUG(!ctx);
|
|
|
|
label = aa_get_newest_label(ctx->label);
|
|
|
|
/* buffer freed below, name is pointer into buffer */
|
|
get_buffers(buffer);
|
|
/* Test for onexec first as onexec override other x transitions. */
|
|
if (ctx->onexec)
|
|
new = handle_onexec(label, ctx->onexec, ctx->token,
|
|
bprm, buffer, &cond, &unsafe);
|
|
else
|
|
new = fn_label_build(label, profile, GFP_ATOMIC,
|
|
profile_transition(profile, bprm, buffer,
|
|
&cond, &unsafe));
|
|
|
|
AA_BUG(!new);
|
|
if (IS_ERR(new)) {
|
|
error = PTR_ERR(new);
|
|
goto done;
|
|
} else if (!new) {
|
|
error = -ENOMEM;
|
|
goto done;
|
|
}
|
|
|
|
/* TODO: Add ns level no_new_privs subset test */
|
|
|
|
if (bprm->unsafe & LSM_UNSAFE_SHARE) {
|
|
/* FIXME: currently don't mediate shared state */
|
|
;
|
|
}
|
|
|
|
if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
|
|
/* TODO: test needs to be profile of label to new */
|
|
error = may_change_ptraced_domain(new, &info);
|
|
if (error)
|
|
goto audit;
|
|
}
|
|
|
|
if (unsafe) {
|
|
if (DEBUG_ON) {
|
|
dbg_printk("scrubbing environment variables for %s "
|
|
"label=", bprm->filename);
|
|
aa_label_printk(new, GFP_ATOMIC);
|
|
dbg_printk("\n");
|
|
}
|
|
bprm->secureexec = 1;
|
|
}
|
|
|
|
if (label->proxy != new->proxy) {
|
|
/* when transitioning clear unsafe personality bits */
|
|
if (DEBUG_ON) {
|
|
dbg_printk("apparmor: clearing unsafe personality "
|
|
"bits. %s label=", bprm->filename);
|
|
aa_label_printk(new, GFP_ATOMIC);
|
|
dbg_printk("\n");
|
|
}
|
|
bprm->per_clear |= PER_CLEAR_ON_SETID;
|
|
}
|
|
aa_put_label(ctx->label);
|
|
/* transfer reference, released when ctx is freed */
|
|
ctx->label = new;
|
|
|
|
done:
|
|
/* clear out temporary/transitional state from the context */
|
|
aa_clear_task_ctx_trans(ctx);
|
|
|
|
aa_put_label(label);
|
|
put_buffers(buffer);
|
|
|
|
return error;
|
|
|
|
audit:
|
|
error = fn_for_each(label, profile,
|
|
aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
|
|
bprm->filename, NULL, new,
|
|
file_inode(bprm->file)->i_uid, info,
|
|
error));
|
|
aa_put_label(new);
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* Functions for self directed profile change
|
|
*/
|
|
|
|
|
|
/* helper fn for change_hat
|
|
*
|
|
* Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
|
|
*/
|
|
static struct aa_label *build_change_hat(struct aa_profile *profile,
|
|
const char *name, bool sibling)
|
|
{
|
|
struct aa_profile *root, *hat = NULL;
|
|
const char *info = NULL;
|
|
int error = 0;
|
|
|
|
if (sibling && PROFILE_IS_HAT(profile)) {
|
|
root = aa_get_profile_rcu(&profile->parent);
|
|
} else if (!sibling && !PROFILE_IS_HAT(profile)) {
|
|
root = aa_get_profile(profile);
|
|
} else {
|
|
info = "conflicting target types";
|
|
error = -EPERM;
|
|
goto audit;
|
|
}
|
|
|
|
hat = aa_find_child(root, name);
|
|
if (!hat) {
|
|
error = -ENOENT;
|
|
if (COMPLAIN_MODE(profile)) {
|
|
hat = aa_new_null_profile(profile, true, name,
|
|
GFP_KERNEL);
|
|
if (!hat) {
|
|
info = "failed null profile create";
|
|
error = -ENOMEM;
|
|
}
|
|
}
|
|
}
|
|
aa_put_profile(root);
|
|
|
|
audit:
|
|
aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
|
|
name, hat ? hat->base.hname : NULL,
|
|
hat ? &hat->label : NULL, GLOBAL_ROOT_UID, NULL,
|
|
error);
|
|
if (!hat || (error && error != -ENOENT))
|
|
return ERR_PTR(error);
|
|
/* if hat && error - complain mode, already audited and we adjust for
|
|
* complain mode allow by returning hat->label
|
|
*/
|
|
return &hat->label;
|
|
}
|
|
|
|
/* helper fn for changing into a hat
|
|
*
|
|
* Returns: label for hat transition or ERR_PTR. Does not return NULL
|
|
*/
|
|
static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
|
|
int count, int flags)
|
|
{
|
|
struct aa_profile *profile, *root, *hat = NULL;
|
|
struct aa_label *new;
|
|
struct label_it it;
|
|
bool sibling = false;
|
|
const char *name, *info = NULL;
|
|
int i, error;
|
|
|
|
AA_BUG(!label);
|
|
AA_BUG(!hats);
|
|
AA_BUG(count < 1);
|
|
|
|
if (PROFILE_IS_HAT(labels_profile(label)))
|
|
sibling = true;
|
|
|
|
/*find first matching hat */
|
|
for (i = 0; i < count && !hat; i++) {
|
|
name = hats[i];
|
|
label_for_each_in_ns(it, labels_ns(label), label, profile) {
|
|
if (sibling && PROFILE_IS_HAT(profile)) {
|
|
root = aa_get_profile_rcu(&profile->parent);
|
|
} else if (!sibling && !PROFILE_IS_HAT(profile)) {
|
|
root = aa_get_profile(profile);
|
|
} else { /* conflicting change type */
|
|
info = "conflicting targets types";
|
|
error = -EPERM;
|
|
goto fail;
|
|
}
|
|
hat = aa_find_child(root, name);
|
|
aa_put_profile(root);
|
|
if (!hat) {
|
|
if (!COMPLAIN_MODE(profile))
|
|
goto outer_continue;
|
|
/* complain mode succeed as if hat */
|
|
} else if (!PROFILE_IS_HAT(hat)) {
|
|
info = "target not hat";
|
|
error = -EPERM;
|
|
aa_put_profile(hat);
|
|
goto fail;
|
|
}
|
|
aa_put_profile(hat);
|
|
}
|
|
/* found a hat for all profiles in ns */
|
|
goto build;
|
|
outer_continue:
|
|
;
|
|
}
|
|
/* no hats that match, find appropriate error
|
|
*
|
|
* In complain mode audit of the failure is based off of the first
|
|
* hat supplied. This is done due how userspace interacts with
|
|
* change_hat.
|
|
*/
|
|
name = NULL;
|
|
label_for_each_in_ns(it, labels_ns(label), label, profile) {
|
|
if (!list_empty(&profile->base.profiles)) {
|
|
info = "hat not found";
|
|
error = -ENOENT;
|
|
goto fail;
|
|
}
|
|
}
|
|
info = "no hats defined";
|
|
error = -ECHILD;
|
|
|
|
fail:
|
|
label_for_each_in_ns(it, labels_ns(label), label, profile) {
|
|
/*
|
|
* no target as it has failed to be found or built
|
|
*
|
|
* change_hat uses probing and should not log failures
|
|
* related to missing hats
|
|
*/
|
|
/* TODO: get rid of GLOBAL_ROOT_UID */
|
|
if (count > 1 || COMPLAIN_MODE(profile)) {
|
|
aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
|
|
AA_MAY_CHANGEHAT, name, NULL, NULL,
|
|
GLOBAL_ROOT_UID, info, error);
|
|
}
|
|
}
|
|
return ERR_PTR(error);
|
|
|
|
build:
|
|
new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
|
|
build_change_hat(profile, name, sibling),
|
|
aa_get_label(&profile->label));
|
|
if (!new) {
|
|
info = "label build failed";
|
|
error = -ENOMEM;
|
|
goto fail;
|
|
} /* else if (IS_ERR) build_change_hat has logged error so return new */
|
|
|
|
return new;
|
|
}
|
|
|
|
/**
|
|
* aa_change_hat - change hat to/from subprofile
|
|
* @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
|
|
* @count: number of hat names in @hats
|
|
* @token: magic value to validate the hat change
|
|
* @flags: flags affecting behavior of the change
|
|
*
|
|
* Returns %0 on success, error otherwise.
|
|
*
|
|
* Change to the first profile specified in @hats that exists, and store
|
|
* the @hat_magic in the current task context. If the count == 0 and the
|
|
* @token matches that stored in the current task context, return to the
|
|
* top level profile.
|
|
*
|
|
* change_hat only applies to profiles in the current ns, and each profile
|
|
* in the ns must make the same transition otherwise change_hat will fail.
|
|
*/
|
|
int aa_change_hat(const char *hats[], int count, u64 token, int flags)
|
|
{
|
|
const struct cred *cred;
|
|
struct aa_task_ctx *ctx;
|
|
struct aa_label *label, *previous, *new = NULL, *target = NULL;
|
|
struct aa_profile *profile;
|
|
struct aa_perms perms = {};
|
|
const char *info = NULL;
|
|
int error = 0;
|
|
|
|
/*
|
|
* Fail explicitly requested domain transitions if no_new_privs.
|
|
* There is no exception for unconfined as change_hat is not
|
|
* available.
|
|
*/
|
|
if (task_no_new_privs(current)) {
|
|
/* not an apparmor denial per se, so don't log it */
|
|
AA_DEBUG("no_new_privs - change_hat denied");
|
|
return -EPERM;
|
|
}
|
|
|
|
/* released below */
|
|
cred = get_current_cred();
|
|
ctx = cred_ctx(cred);
|
|
label = aa_get_newest_cred_label(cred);
|
|
previous = aa_get_newest_label(ctx->previous);
|
|
|
|
if (unconfined(label)) {
|
|
info = "unconfined can not change_hat";
|
|
error = -EPERM;
|
|
goto fail;
|
|
}
|
|
|
|
if (count) {
|
|
new = change_hat(label, hats, count, flags);
|
|
AA_BUG(!new);
|
|
if (IS_ERR(new)) {
|
|
error = PTR_ERR(new);
|
|
new = NULL;
|
|
/* already audited */
|
|
goto out;
|
|
}
|
|
|
|
error = may_change_ptraced_domain(new, &info);
|
|
if (error)
|
|
goto fail;
|
|
|
|
if (flags & AA_CHANGE_TEST)
|
|
goto out;
|
|
|
|
target = new;
|
|
error = aa_set_current_hat(new, token);
|
|
if (error == -EACCES)
|
|
/* kill task in case of brute force attacks */
|
|
goto kill;
|
|
} else if (previous && !(flags & AA_CHANGE_TEST)) {
|
|
/* Return to saved label. Kill task if restore fails
|
|
* to avoid brute force attacks
|
|
*/
|
|
target = previous;
|
|
error = aa_restore_previous_label(token);
|
|
if (error) {
|
|
if (error == -EACCES)
|
|
goto kill;
|
|
goto fail;
|
|
}
|
|
} /* else ignore @flags && restores when there is no saved profile */
|
|
|
|
out:
|
|
aa_put_label(new);
|
|
aa_put_label(previous);
|
|
aa_put_label(label);
|
|
put_cred(cred);
|
|
|
|
return error;
|
|
|
|
kill:
|
|
info = "failed token match";
|
|
perms.kill = AA_MAY_CHANGEHAT;
|
|
|
|
fail:
|
|
fn_for_each_in_ns(label, profile,
|
|
aa_audit_file(profile, &perms, OP_CHANGE_HAT,
|
|
AA_MAY_CHANGEHAT, NULL, NULL, target,
|
|
GLOBAL_ROOT_UID, info, error));
|
|
|
|
goto out;
|
|
}
|
|
|
|
|
|
static int change_profile_perms_wrapper(const char *op, const char *name,
|
|
struct aa_profile *profile,
|
|
struct aa_label *target, bool stack,
|
|
u32 request, struct aa_perms *perms)
|
|
{
|
|
const char *info = NULL;
|
|
int error = 0;
|
|
|
|
/*
|
|
* Fail explicitly requested domain transitions when no_new_privs
|
|
* and not unconfined OR the transition results in a stack on
|
|
* the current label.
|
|
* Stacking domain transitions and transitions from unconfined are
|
|
* allowed even when no_new_privs is set because this aways results
|
|
* in a reduction of permissions.
|
|
*/
|
|
if (task_no_new_privs(current) && !stack &&
|
|
!profile_unconfined(profile) &&
|
|
!aa_label_is_subset(target, &profile->label)) {
|
|
info = "no new privs";
|
|
error = -EPERM;
|
|
}
|
|
|
|
if (!error)
|
|
error = change_profile_perms(profile, target, stack, request,
|
|
profile->file.start, perms);
|
|
if (error)
|
|
error = aa_audit_file(profile, perms, op, request, name,
|
|
NULL, target, GLOBAL_ROOT_UID, info,
|
|
error);
|
|
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* aa_change_profile - perform a one-way profile transition
|
|
* @fqname: name of profile may include namespace (NOT NULL)
|
|
* @onexec: whether this transition is to take place immediately or at exec
|
|
* @flags: flags affecting change behavior
|
|
*
|
|
* Change to new profile @name. Unlike with hats, there is no way
|
|
* to change back. If @name isn't specified the current profile name is
|
|
* used.
|
|
* If @onexec then the transition is delayed until
|
|
* the next exec.
|
|
*
|
|
* Returns %0 on success, error otherwise.
|
|
*/
|
|
int aa_change_profile(const char *fqname, int flags)
|
|
{
|
|
struct aa_label *label, *new = NULL, *target = NULL;
|
|
struct aa_profile *profile;
|
|
struct aa_perms perms = {};
|
|
const char *info = NULL;
|
|
const char *auditname = fqname; /* retain leading & if stack */
|
|
bool stack = flags & AA_CHANGE_STACK;
|
|
int error = 0;
|
|
char *op;
|
|
u32 request;
|
|
|
|
if (!fqname || !*fqname) {
|
|
AA_DEBUG("no profile name");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (flags & AA_CHANGE_ONEXEC) {
|
|
request = AA_MAY_ONEXEC;
|
|
if (stack)
|
|
op = OP_STACK_ONEXEC;
|
|
else
|
|
op = OP_CHANGE_ONEXEC;
|
|
} else {
|
|
request = AA_MAY_CHANGE_PROFILE;
|
|
if (stack)
|
|
op = OP_STACK;
|
|
else
|
|
op = OP_CHANGE_PROFILE;
|
|
}
|
|
|
|
label = aa_get_current_label();
|
|
|
|
if (*fqname == '&') {
|
|
stack = true;
|
|
/* don't have label_parse() do stacking */
|
|
fqname++;
|
|
}
|
|
target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
|
|
if (IS_ERR(target)) {
|
|
struct aa_profile *tprofile;
|
|
|
|
info = "label not found";
|
|
error = PTR_ERR(target);
|
|
target = NULL;
|
|
/*
|
|
* TODO: fixme using labels_profile is not right - do profile
|
|
* per complain profile
|
|
*/
|
|
if ((flags & AA_CHANGE_TEST) ||
|
|
!COMPLAIN_MODE(labels_profile(label)))
|
|
goto audit;
|
|
/* released below */
|
|
tprofile = aa_new_null_profile(labels_profile(label), false,
|
|
fqname, GFP_KERNEL);
|
|
if (!tprofile) {
|
|
info = "failed null profile create";
|
|
error = -ENOMEM;
|
|
goto audit;
|
|
}
|
|
target = &tprofile->label;
|
|
goto check;
|
|
}
|
|
|
|
/*
|
|
* self directed transitions only apply to current policy ns
|
|
* TODO: currently requiring perms for stacking and straight change
|
|
* stacking doesn't strictly need this. Determine how much
|
|
* we want to loosen this restriction for stacking
|
|
*
|
|
* if (!stack) {
|
|
*/
|
|
error = fn_for_each_in_ns(label, profile,
|
|
change_profile_perms_wrapper(op, auditname,
|
|
profile, target, stack,
|
|
request, &perms));
|
|
if (error)
|
|
/* auditing done in change_profile_perms_wrapper */
|
|
goto out;
|
|
|
|
/* } */
|
|
|
|
check:
|
|
/* check if tracing task is allowed to trace target domain */
|
|
error = may_change_ptraced_domain(target, &info);
|
|
if (error && !fn_for_each_in_ns(label, profile,
|
|
COMPLAIN_MODE(profile)))
|
|
goto audit;
|
|
|
|
/* TODO: add permission check to allow this
|
|
* if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
|
|
* info = "not a single threaded task";
|
|
* error = -EACCES;
|
|
* goto audit;
|
|
* }
|
|
*/
|
|
if (flags & AA_CHANGE_TEST)
|
|
goto out;
|
|
|
|
if (!(flags & AA_CHANGE_ONEXEC)) {
|
|
/* only transition profiles in the current ns */
|
|
if (stack)
|
|
new = aa_label_merge(label, target, GFP_KERNEL);
|
|
else
|
|
new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
|
|
aa_get_label(target),
|
|
aa_get_label(&profile->label));
|
|
if (IS_ERR_OR_NULL(new)) {
|
|
info = "failed to build target label";
|
|
error = PTR_ERR(new);
|
|
new = NULL;
|
|
perms.allow = 0;
|
|
goto audit;
|
|
}
|
|
error = aa_replace_current_label(new);
|
|
} else
|
|
/* full transition will be built in exec path */
|
|
error = aa_set_current_onexec(target, stack);
|
|
|
|
audit:
|
|
error = fn_for_each_in_ns(label, profile,
|
|
aa_audit_file(profile, &perms, op, request, auditname,
|
|
NULL, new ? new : target,
|
|
GLOBAL_ROOT_UID, info, error));
|
|
|
|
out:
|
|
aa_put_label(new);
|
|
aa_put_label(target);
|
|
aa_put_label(label);
|
|
|
|
return error;
|
|
}
|