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RFE: Add SCM_SECURITY support to IPv6 #24

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stephensmalley opened this issue Nov 29, 2016 · 5 comments
Open

RFE: Add SCM_SECURITY support to IPv6 #24

stephensmalley opened this issue Nov 29, 2016 · 5 comments

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@stephensmalley
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As reported by Richard Haines, IPv6 stream sockets support SO_PEERCON, but IPv6 datagram sockets do not currently support SCM_SECURITY, unlike IPv4 datagram sockets. For IPv4, the support is implemented in net/ipv4/ip_sockglue.c:ip_cmsg_rcv_security(). We would need to implement similar support in the ipv6 code.

pcmoore pushed a commit that referenced this issue Dec 5, 2016
The data_mutex is initialized too late, as it is needed for
each device driver's power control, causing an OOPS:

    dvb-usb: found a 'TerraTec/qanu USB2.0 Highspeed DVB-T Receiver' in warm state.
    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: [<ffffffff846617af>] __mutex_lock_slowpath+0x6f/0x100 PGD 0
    Oops: 0002 [#1] SMP
    Modules linked in: dvb_usb_cinergyT2(+) dvb_usb
    CPU: 0 PID: 2029 Comm: modprobe Not tainted 4.9.0-rc4-dvbmod #24
    Hardware name: FUJITSU LIFEBOOK A544/FJNBB35 , BIOS Version 1.17 05/09/2014
    task: ffff88020e943840 task.stack: ffff8801f36ec000
    RIP: 0010:[<ffffffff846617af>]  [<ffffffff846617af>] __mutex_lock_slowpath+0x6f/0x100
    RSP: 0018:ffff8801f36efb10  EFLAGS: 00010282
    RAX: 0000000000000000 RBX: ffff88021509bdc8 RCX: 00000000c0000100
    RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88021509bdcc
    RBP: ffff8801f36efb58 R08: ffff88021f216320 R09: 0000000000100000
    R10: ffff88021f216320 R11: 00000023fee6c5a1 R12: ffff88020e943840
    R13: ffff88021509bdcc R14: 00000000ffffffff R15: ffff88021509bdd0
    FS:  00007f21adb86740(0000) GS:ffff88021f200000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 0000000215bce000 CR4: 00000000001406f0
    Call Trace:
       mutex_lock+0x16/0x25
       cinergyt2_power_ctrl+0x1f/0x60 [dvb_usb_cinergyT2]
       dvb_usb_device_init+0x21e/0x5d0 [dvb_usb]
       cinergyt2_usb_probe+0x21/0x50 [dvb_usb_cinergyT2]
       usb_probe_interface+0xf3/0x2a0
       driver_probe_device+0x208/0x2b0
       __driver_attach+0x87/0x90
       driver_probe_device+0x2b0/0x2b0
       bus_for_each_dev+0x52/0x80
       bus_add_driver+0x1a3/0x220
       driver_register+0x56/0xd0
       usb_register_driver+0x77/0x130
       do_one_initcall+0x46/0x180
       free_vmap_area_noflush+0x38/0x70
       kmem_cache_alloc+0x84/0xc0
       do_init_module+0x50/0x1be
       load_module+0x1d8b/0x2100
       find_symbol_in_section+0xa0/0xa0
       SyS_finit_module+0x89/0x90
       entry_SYSCALL_64_fastpath+0x13/0x94
    Code: e8 a7 1d 00 00 8b 03 83 f8 01 0f 84 97 00 00 00 48 8b 43 10 4c 8d 7b 08 48 89 63 10 4c 89 3c 24 41 be ff ff ff ff 48 89 44 24 08 <48> 89 20 4c 89 64 24 10 eb 1a 49 c7 44 24 08 02 00 00 00 c6 43 RIP  [<ffffffff846617af>] __mutex_lock_slowpath+0x6f/0x100 RSP <ffff8801f36efb10>
    CR2: 0000000000000000

So, move it to the struct dvb_usb_device and initialize it
before calling the driver's callbacks.

Reported-by: Jörg Otte <[email protected]>
Tested-by: Jörg Otte <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
@pcmoore
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pcmoore commented Dec 15, 2016

Some initial thoughts from a few minutes of looking at this:

  • We will need to modify do_ipv6_setsockopt() and do_ipv6_getsockopt() to understand IP_PASSSEC, or similar (IPV6_PASSSEC?), and set/get a bit in the ipv6_pinfo.rxopts.bits structure.

  • Add support for sending the SCM_SECURITY cmsg via ip6_datagram_recv_common_ctl() or ip6_datagram_recv_specific_ctl().

@pcmoore
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pcmoore commented Dec 16, 2016

Unfortunately it doesn't look like we will be able to use SCM_SECURITY with IPv6, in fact we probably shouldn't have used it with IPv4 either, but it looks like we got lucky; SOL_IP/SCM_SECURITY conflicts with SOL_IP/IP_HDRINCL but since IP_HDRINCL is never used in a cmsg it doesn't present a problem in practice.

Looking at the rest of the IPv6 code, it looks like convention is to reuse the socket option as the cmsg type, that's probably our best bet.

@pcmoore
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pcmoore commented Dec 16, 2016

Completely untested, but this should give some idea about what I'm thinking:

@stephensmalley
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That's odd; why would SCM_ and IP_ be in the same namespace?
Is it because SCM_* was originally only for UNIX sockets?
In any event, now that Richard has added IPv6 support to selinux-testsuite, it should be easy to update for this.

@pcmoore
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pcmoore commented Dec 16, 2016

sds> That's odd; why would SCM_ and IP_ be in the same namespace?

Exactly, SCM_SECURITY never should have been used here. The change dates back to 2006:

commit 2c7946a7bf45ae86736ab3b43d0085e43947945c
Author: Catherine Zhang <[email protected]>
Date:   Mon Mar 20 22:41:23 2006 -0800

[SECURITY]: TCP/UDP getpeersec

This patch implements an application of the LSM-IPSec networking
controls whereby an application can determine the label of the
security association its TCP or UDP sockets are currently connected to
via getsockopt and the auxiliary data mechanism of recvmsg ...

Evidently no one was checking IBM's work very closely during that time period as there was also that IKEv1 ECN conflict.

sds> Is it because SCM_* was originally only for UNIX sockets?

I would think so, but this predates my serious involvement in the labeled networking area.

sds> In any event, now that Richard has added IPv6 support to selinux-testsuite,
sds> it should be easy to update for this.

Agreed.

pcmoore pushed a commit that referenced this issue May 17, 2017
As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <[email protected]>
Cc: Hannes Sowa <[email protected]>
Signed-off-by: Jon Maxwell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
pcmoore pushed a commit that referenced this issue May 17, 2017
The following warning can be triggered by hot-unplugging the CPU
on which an active SCHED_DEADLINE task is running on:

 ------------[ cut here ]------------
 WARNING: CPU: 7 PID: 0 at kernel/sched/sched.h:833 replenish_dl_entity+0x71e/0xc40
 rq->clock_update_flags < RQCF_ACT_SKIP
 CPU: 7 PID: 0 Comm: swapper/7 Tainted: G    B           4.11.0-rc1+ #24
 Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016
 Call Trace:
  <IRQ>
  dump_stack+0x85/0xc4
  __warn+0x172/0x1b0
  warn_slowpath_fmt+0xb4/0xf0
  ? __warn+0x1b0/0x1b0
  ? debug_check_no_locks_freed+0x2c0/0x2c0
  ? cpudl_set+0x3d/0x2b0
  replenish_dl_entity+0x71e/0xc40
  enqueue_task_dl+0x2ea/0x12e0
  ? dl_task_timer+0x777/0x990
  ? __hrtimer_run_queues+0x270/0xa50
  dl_task_timer+0x316/0x990
  ? enqueue_task_dl+0x12e0/0x12e0
  ? enqueue_task_dl+0x12e0/0x12e0
  __hrtimer_run_queues+0x270/0xa50
  ? hrtimer_cancel+0x20/0x20
  ? hrtimer_interrupt+0x119/0x600
  hrtimer_interrupt+0x19c/0x600
  ? trace_hardirqs_off+0xd/0x10
  local_apic_timer_interrupt+0x74/0xe0
  smp_apic_timer_interrupt+0x76/0xa0
  apic_timer_interrupt+0x93/0xa0

The DL task will be migrated to a suitable later deadline rq once the DL
timer fires and currnet rq is offline. The rq clock of the new rq should
be updated. This patch fixes it by updating the rq clock after holding
the new rq's rq lock.

Signed-off-by: Wanpeng Li <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Matt Fleming <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
pcmoore pushed a commit that referenced this issue Sep 5, 2017
pfkey_broadcast() might be called from non process contexts,
we can not use GFP_KERNEL in these cases [1].

This patch partially reverts commit ba51b6b ("net: Fix RCU splat in
af_key"), only keeping the GFP_ATOMIC forcing under rcu_read_lock()
section.

[1] : syzkaller reported :

in_atomic(): 1, irqs_disabled(): 0, pid: 2932, name: syzkaller183439
3 locks held by syzkaller183439/2932:
 #0:  (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff83b43888>] pfkey_sendmsg+0x4c8/0x9f0 net/key/af_key.c:3649
 #1:  (&pfk->dump_lock){+.+.+.}, at: [<ffffffff83b467f6>] pfkey_do_dump+0x76/0x3f0 net/key/af_key.c:293
 #2:  (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] spin_lock_bh include/linux/spinlock.h:304 [inline]
 #2:  (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] xfrm_policy_walk+0x192/0xa30 net/xfrm/xfrm_policy.c:1028
CPU: 0 PID: 2932 Comm: syzkaller183439 Not tainted 4.13.0-rc4+ #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:5994
 __might_sleep+0x95/0x190 kernel/sched/core.c:5947
 slab_pre_alloc_hook mm/slab.h:416 [inline]
 slab_alloc mm/slab.c:3383 [inline]
 kmem_cache_alloc+0x24b/0x6e0 mm/slab.c:3559
 skb_clone+0x1a0/0x400 net/core/skbuff.c:1037
 pfkey_broadcast_one+0x4b2/0x6f0 net/key/af_key.c:207
 pfkey_broadcast+0x4ba/0x770 net/key/af_key.c:281
 dump_sp+0x3d6/0x500 net/key/af_key.c:2685
 xfrm_policy_walk+0x2f1/0xa30 net/xfrm/xfrm_policy.c:1042
 pfkey_dump_sp+0x42/0x50 net/key/af_key.c:2695
 pfkey_do_dump+0xaa/0x3f0 net/key/af_key.c:299
 pfkey_spddump+0x1a0/0x210 net/key/af_key.c:2722
 pfkey_process+0x606/0x710 net/key/af_key.c:2814
 pfkey_sendmsg+0x4d6/0x9f0 net/key/af_key.c:3650
sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 ___sys_sendmsg+0x755/0x890 net/socket.c:2035
 __sys_sendmsg+0xe5/0x210 net/socket.c:2069
 SYSC_sendmsg net/socket.c:2080 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2076
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x445d79
RSP: 002b:00007f32447c1dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445d79
RDX: 0000000000000000 RSI: 000000002023dfc8 RDI: 0000000000000008
RBP: 0000000000000086 R08: 00007f32447c2700 R09: 00007f32447c2700
R10: 00007f32447c2700 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffe33edec4f R14: 00007f32447c29c0 R15: 0000000000000000

Fixes: ba51b6b ("net: Fix RCU splat in af_key")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: Dmitry Vyukov <[email protected]>
Cc: David Ahern <[email protected]>
Acked-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
stephensmalley pushed a commit to stephensmalley/selinux-kernel that referenced this issue Apr 17, 2018
Fix error handling in perf_kprobe_init():

	==================================================================
	BUG: KASAN: slab-out-of-bounds in strlen+0x8e/0xa0 lib/string.c:482
	Read of size 1 at addr ffff88003f9cc5c0 by task syz-executor2/23095

	CPU: 0 PID: 23095 Comm: syz-executor2 Not tainted 4.16.0+ SELinuxProject#24
	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
	Call Trace:
	 __dump_stack lib/dump_stack.c:77 [inline]
	 dump_stack+0xca/0x13e lib/dump_stack.c:113
	 print_address_description+0x6e/0x2c0 mm/kasan/report.c:256
	 kasan_report_error mm/kasan/report.c:354 [inline]
	 kasan_report+0x256/0x380 mm/kasan/report.c:412
	 strlen+0x8e/0xa0 lib/string.c:482
	 kstrdup+0x21/0x70 mm/util.c:55
	 alloc_trace_kprobe+0xc8/0x930 kernel/trace/trace_kprobe.c:325
	 create_local_trace_kprobe+0x4f/0x3a0 kernel/trace/trace_kprobe.c:1438
	 perf_kprobe_init+0x149/0x1f0 kernel/trace/trace_event_perf.c:264
	 perf_kprobe_event_init+0xa8/0x120 kernel/events/core.c:8407
	 perf_try_init_event+0xcb/0x2a0 kernel/events/core.c:9719
	 perf_init_event kernel/events/core.c:9750 [inline]
	 perf_event_alloc+0x1367/0x1e20 kernel/events/core.c:10022
	 SYSC_perf_event_open+0x242/0x2330 kernel/events/core.c:10477
	 do_syscall_64+0x198/0x640 arch/x86/entry/common.c:287
	 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Reported-by: 范龙飞 <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: e12f03d ("perf/core: Implement the 'perf_kprobe' PMU")
Signed-off-by: Ingo Molnar <[email protected]>
pcmoore pushed a commit to SELinuxProject/selinux-testsuite that referenced this issue Jun 12, 2018
Enhance the tests as follows:
1) Determine number of tests to run with current config.
2) Add CALIPSO STREAM tests (DGRAM not supported in kernel. See [1]).
3) Add support for CIPSO TAGS 1 & 2. Closes [2].
4) Run scripts using /bin/sh.
5) Shorten sleep time as more tests.

[1] SELinuxProject/selinux-kernel#24
[2] #1

Signed-off-by: Richard Haines <[email protected]>
[PM: adjusted file permissions on tests/inet_socket/test ]
Signed-off-by: Paul Moore <[email protected]>
stephensmalley pushed a commit to stephensmalley/selinux-kernel that referenced this issue Aug 26, 2020
For early sections, its memmap is handled specially even sub-section is
enabled.  The memmap could only be populated as a whole.

Quoted from the comment of section_activate():

    * The early init code does not consider partially populated
    * initial sections, it simply assumes that memory will never be
    * referenced.  If we hot-add memory into such a section then we
    * do not need to populate the memmap and can simply reuse what
    * is already there.

While current section_deactivate() breaks this rule.  When hot-remove a
sub-section, section_deactivate() would depopulate its memmap.  The
consequence is if we hot-add this subsection again, its memmap never get
proper populated.

We can reproduce the case by following steps:

1. Hacking qemu to allow sub-section early section

:   diff --git a/hw/i386/pc.c b/hw/i386/pc.c
:   index 51b3050d01..c6a78d83c0 100644
:   --- a/hw/i386/pc.c
:   +++ b/hw/i386/pc.c
:   @@ -1010,7 +1010,7 @@ void pc_memory_init(PCMachineState *pcms,
:            }
:
:            machine->device_memory->base =
:   -            ROUND_UP(0x100000000ULL + x86ms->above_4g_mem_size, 1 * GiB);
:   +            0x100000000ULL + x86ms->above_4g_mem_size;
:
:            if (pcmc->enforce_aligned_dimm) {
:                /* size device region assuming 1G page max alignment per slot */

2. Bootup qemu with PSE disabled and a sub-section aligned memory size

   Part of the qemu command would look like this:

   sudo x86_64-softmmu/qemu-system-x86_64 \
       --enable-kvm -cpu host,pse=off \
       -m 4160M,maxmem=20G,slots=1 \
       -smp sockets=2,cores=16 \
       -numa node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 \
       -machine pc,nvdimm \
       -nographic \
       -object memory-backend-ram,id=mem0,size=8G \
       -device nvdimm,id=vm0,memdev=mem0,node=0,addr=0x144000000,label-size=128k

3. Re-config a pmem device with sub-section size in guest

   ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax --size=16M

Then you would see the following call trace:

   pmem0: detected capacity change from 0 to 16777216
   BUG: unable to handle page fault for address: ffffec73c51000b4
   #PF: supervisor write access in kernel mode
   #PF: error_code(0x0002) - not-present page
   PGD 81ff8067 P4D 81ff8067 PUD 81ff7067 PMD 1437cb067 PTE 0
   Oops: 0002 [SELinuxProject#1] SMP NOPTI
   CPU: 16 PID: 1348 Comm: ndctl Kdump: loaded Tainted: G        W         5.8.0-rc2+ SELinuxProject#24
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.4
   RIP: 0010:memmap_init_zone+0x154/0x1c2
   Code: 77 16 f6 40 10 02 74 10 48 03 48 08 48 89 cb 48 c1 eb 0c e9 3a ff ff ff 48 89 df 48 c1 e7 06 48f
   RSP: 0018:ffffbdc7011a39b0 EFLAGS: 00010282
   RAX: ffffec73c5100088 RBX: 0000000000144002 RCX: 0000000000144000
   RDX: 0000000000000004 RSI: 007ffe0000000000 RDI: ffffec73c5100080
   RBP: 027ffe0000000000 R08: 0000000000000001 R09: ffff9f8d38f6d708
   R10: ffffec73c0000000 R11: 0000000000000000 R12: 0000000000000004
   R13: 0000000000000001 R14: 0000000000144200 R15: 0000000000000000
   FS:  00007efe6b65d780(0000) GS:ffff9f8d3f780000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: ffffec73c51000b4 CR3: 000000007d718000 CR4: 0000000000340ee0
   Call Trace:
    move_pfn_range_to_zone+0x128/0x150
    memremap_pages+0x4e4/0x5a0
    devm_memremap_pages+0x1e/0x60
    dev_dax_probe+0x69/0x160 [device_dax]
    really_probe+0x298/0x3c0
    driver_probe_device+0xe1/0x150
    ? driver_allows_async_probing+0x50/0x50
    bus_for_each_drv+0x7e/0xc0
    __device_attach+0xdf/0x160
    bus_probe_device+0x8e/0xa0
    device_add+0x3b9/0x740
    __devm_create_dev_dax+0x127/0x1c0
    __dax_pmem_probe+0x1f2/0x219 [dax_pmem_core]
    dax_pmem_probe+0xc/0x1b [dax_pmem]
    nvdimm_bus_probe+0x69/0x1c0 [libnvdimm]
    really_probe+0x147/0x3c0
    driver_probe_device+0xe1/0x150
    device_driver_attach+0x53/0x60
    bind_store+0xd1/0x110
    kernfs_fop_write+0xce/0x1b0
    vfs_write+0xb6/0x1a0
    ksys_write+0x5f/0xe0
    do_syscall_64+0x4d/0x90
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: ba72b4c ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Dan Williams <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
stephensmalley pushed a commit to stephensmalley/selinux-kernel that referenced this issue May 15, 2024
The current implementation of the mov instruction with sign extension has the
following problems:

  1. It clobbers the source register if it is not stacked because it
     sign extends the source and then moves it to the destination.
  2. If the dst_reg is stacked, the current code doesn't write the value
     back in case of 64-bit mov.
  3. There is room for improvement by emitting fewer instructions.

The steps for fixing this and the instructions emitted by the JIT are explained
below with examples in all combinations:

Case A: offset == 32:
=====================

  Case A.1: src and dst are stacked registers:
  --------------------------------------------
    1. Load src_lo into tmp_lo
    2. Store tmp_lo into dst_lo
    3. Sign extend tmp_lo into tmp_hi
    4. Store tmp_hi to dst_hi

    Example: r3 = (s32)r3
	r3 is a stacked register

	ldr     r6, [r11, #-16]	// Load r3_lo into tmp_lo
	// str to dst_lo is not emitted because src_lo == dst_lo
	asr     r7, r6, SELinuxProject#31	// Sign extend tmp_lo into tmp_hi
	str     r7, [r11, #-12] // Store tmp_hi into r3_hi

  Case A.2: src is stacked but dst is not:
  ----------------------------------------
    1. Load src_lo into dst_lo
    2. Sign extend dst_lo into dst_hi

    Example: r6 = (s32)r3
	r6 maps to {ARM_R5, ARM_R4} and r3 is stacked

	ldr     r4, [r11, #-16] // Load r3_lo into r6_lo
	asr     r5, r4, SELinuxProject#31	// Sign extend r6_lo into r6_hi

  Case A.3: src is not stacked but dst is stacked:
  ------------------------------------------------
    1. Store src_lo into dst_lo
    2. Sign extend src_lo into tmp_hi
    3. Store tmp_hi to dst_hi

    Example: r3 = (s32)r6
	r3 is stacked and r6 maps to {ARM_R5, ARM_R4}

	str     r4, [r11, #-16] // Store r6_lo to r3_lo
	asr     r7, r4, SELinuxProject#31	// Sign extend r6_lo into tmp_hi
	str     r7, [r11, #-12]	// Store tmp_hi to dest_hi

  Case A.4: Both src and dst are not stacked:
  -------------------------------------------
    1. Mov src_lo into dst_lo
    2. Sign extend src_lo into dst_hi

    Example: (bf) r6 = (s32)r6
	r6 maps to {ARM_R5, ARM_R4}

	// Mov not emitted because dst == src
	asr     r5, r4, SELinuxProject#31 // Sign extend r6_lo into r6_hi

Case B: offset != 32:
=====================

  Case B.1: src and dst are stacked registers:
  --------------------------------------------
    1. Load src_lo into tmp_lo
    2. Sign extend tmp_lo according to offset.
    3. Store tmp_lo into dst_lo
    4. Sign extend tmp_lo into tmp_hi
    5. Store tmp_hi to dst_hi

    Example: r9 = (s8)r3
	r9 and r3 are both stacked registers

	ldr     r6, [r11, #-16] // Load r3_lo into tmp_lo
	lsl     r6, r6, SELinuxProject#24	// Sign extend tmp_lo
	asr     r6, r6, SELinuxProject#24	// ..
	str     r6, [r11, #-56] // Store tmp_lo to r9_lo
	asr     r7, r6, SELinuxProject#31	// Sign extend tmp_lo to tmp_hi
	str     r7, [r11, #-52] // Store tmp_hi to r9_hi

  Case B.2: src is stacked but dst is not:
  ----------------------------------------
    1. Load src_lo into dst_lo
    2. Sign extend dst_lo according to offset.
    3. Sign extend tmp_lo into dst_hi

    Example: r6 = (s8)r3
	r6 maps to {ARM_R5, ARM_R4} and r3 is stacked

	ldr     r4, [r11, #-16] // Load r3_lo to r6_lo
	lsl     r4, r4, SELinuxProject#24	// Sign extend r6_lo
	asr     r4, r4, SELinuxProject#24	// ..
	asr     r5, r4, SELinuxProject#31	// Sign extend r6_lo into r6_hi

  Case B.3: src is not stacked but dst is stacked:
  ------------------------------------------------
    1. Sign extend src_lo into tmp_lo according to offset.
    2. Store tmp_lo into dst_lo.
    3. Sign extend src_lo into tmp_hi.
    4. Store tmp_hi to dst_hi.

    Example: r3 = (s8)r1
	r3 is stacked and r1 maps to {ARM_R3, ARM_R2}

	lsl     r6, r2, SELinuxProject#24 	// Sign extend r1_lo to tmp_lo
	asr     r6, r6, SELinuxProject#24	// ..
	str     r6, [r11, #-16] // Store tmp_lo to r3_lo
	asr     r7, r6, SELinuxProject#31	// Sign extend tmp_lo to tmp_hi
	str     r7, [r11, #-12] // Store tmp_hi to r3_hi

  Case B.4: Both src and dst are not stacked:
  -------------------------------------------
    1. Sign extend src_lo into dst_lo according to offset.
    2. Sign extend dst_lo into dst_hi.

    Example: r6 = (s8)r1
	r6 maps to {ARM_R5, ARM_R4} and r1 maps to {ARM_R3, ARM_R2}

	lsl     r4, r2, SELinuxProject#24	// Sign extend r1_lo to r6_lo
	asr     r4, r4, SELinuxProject#24	// ..
	asr     r5, r4, SELinuxProject#31	// Sign extend r6_lo to r6_hi

Fixes: fc83265 ("arm32, bpf: add support for sign-extension mov instruction")
Reported-by: [email protected]
Signed-off-by: Puranjay Mohan <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Russell King (Oracle) <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]
Link: https://lore.kernel.org/bpf/[email protected]
pcmoore pushed a commit that referenced this issue Jul 29, 2024
profile->parent->dents[AAFS_PROF_DIR] could be NULL only if its parent is made
from __create_missing_ancestors(..) and 'ent->old' is NULL in
aa_replace_profiles(..).
In that case, it must return an error code and the code, -ENOENT represents
its state that the path of its parent is not existed yet.

BUG: kernel NULL pointer dereference, address: 0000000000000030
PGD 0 P4D 0
PREEMPT SMP PTI
CPU: 4 PID: 3362 Comm: apparmor_parser Not tainted 6.8.0-24-generic #24
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:aafs_create.constprop.0+0x7f/0x130
Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae
RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 ? show_regs+0x6d/0x80
 ? __die+0x24/0x80
 ? page_fault_oops+0x99/0x1b0
 ? kernelmode_fixup_or_oops+0xb2/0x140
 ? __bad_area_nosemaphore+0x1a5/0x2c0
 ? find_vma+0x34/0x60
 ? bad_area_nosemaphore+0x16/0x30
 ? do_user_addr_fault+0x2a2/0x6b0
 ? exc_page_fault+0x83/0x1b0
 ? asm_exc_page_fault+0x27/0x30
 ? aafs_create.constprop.0+0x7f/0x130
 ? aafs_create.constprop.0+0x51/0x130
 __aafs_profile_mkdir+0x3d6/0x480
 aa_replace_profiles+0x83f/0x1270
 policy_update+0xe3/0x180
 profile_load+0xbc/0x150
 ? rw_verify_area+0x47/0x140
 vfs_write+0x100/0x480
 ? __x64_sys_openat+0x55/0xa0
 ? syscall_exit_to_user_mode+0x86/0x260
 ksys_write+0x73/0x100
 __x64_sys_write+0x19/0x30
 x64_sys_call+0x7e/0x25c0
 do_syscall_64+0x7f/0x180
 entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7be9f211c574
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007ffd26f2b8c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005d504415e200 RCX: 00007be9f211c574
RDX: 0000000000001fc1 RSI: 00005d504418bc80 RDI: 0000000000000004
RBP: 0000000000001fc1 R08: 0000000000001fc1 R09: 0000000080000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005d504418bc80
R13: 0000000000000004 R14: 00007ffd26f2b9b0 R15: 00007ffd26f2ba30
 </TASK>
Modules linked in: snd_seq_dummy snd_hrtimer qrtr snd_hda_codec_generic snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device i2c_i801 snd_timer i2c_smbus qxl snd soundcore drm_ttm_helper lpc_ich ttm joydev input_leds serio_raw mac_hid binfmt_misc msr parport_pc ppdev lp parport efi_pstore nfnetlink dmi_sysfs qemu_fw_cfg ip_tables x_tables autofs4 hid_generic usbhid hid ahci libahci psmouse virtio_rng xhci_pci xhci_pci_renesas
CR2: 0000000000000030
---[ end trace 0000000000000000 ]---
RIP: 0010:aafs_create.constprop.0+0x7f/0x130
Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae
RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0

Signed-off-by: Leesoo Ahn <[email protected]>
Signed-off-by: John Johansen <[email protected]>
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