From 5d7c44ef5e4f0149c9fb99faeae41e930485a1ec Mon Sep 17 00:00:00 2001 From: John Johansen Date: Mon, 20 Nov 2017 22:26:12 -0800 Subject: [PATCH] apparmor: fix locking when creating a new complain profile. 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: [] 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: 4227c333f65c ("apparmor: Move path lookup to using preallocated buffers") BugLink: http://bugs.launchpad.net/bugs/173228 Reported-by: Alban Browaeys Signed-off-by: John Johansen --- security/apparmor/domain.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index ad456546df5b..04ba9d0718ea 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -561,9 +561,21 @@ static struct aa_label *profile_transition(struct aa_profile *profile, } } else if (COMPLAIN_MODE(profile)) { /* no exec permission - learning mode */ - struct aa_profile *new_profile = aa_new_null_profile(profile, - false, name, - GFP_ATOMIC); + 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"; -- GitLab