apparmor NULL pointer dereference on resume
Malte Schröder
malte.schroeder at tnxip.de
Wed Mar 5 21:47:09 UTC 2025
On 05/03/2025 20:22, Ryan Lee wrote:
> On Wed, Mar 5, 2025 at 11:11 AM Malte Schröder <malte.schroeder at tnxip.de> wrote:
>> Hi,
>>
>> I hope this is the right place to report this. Since 6.14-rc1 ff. resume
>> from hibernate does not work anymore. Now I finally managed to get dmesg
>> from when this happens (Console is frozen, but managed to login via
>> network). If I read that trace correctly there seems to be some
>> interaction with apparmor. I retried with apparmor disabled and the
>> issue didn't trigger.
> Also CC'ing the AppArmor-specific mailing list in this reply.
>
>> I am happy to provide more data if required.
> Could you try to reproduce this NULL pointer dereference with a clean
> kernel with debug info (that I'd be able to access the source code of)
> and send a symbolized stacktrace processed with
> scripts/decode_stacktrace.sh?
Sure. Result using plain v6.14-rc5:
[ 142.014428] BUG: kernel NULL pointer dereference, address:
0000000000000018
[ 142.014429] #PF: supervisor read access in kernel mode
[ 142.014431] #PF: error_code(0x0000) - not-present page
[ 142.014432] PGD 0 P4D 0
[ 142.014433] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 142.014436] CPU: 4 UID: 0 PID: 6833 Comm: systemd-sleep Not tainted
6.14.0-rc5 #1
[ 142.014437] Hardware name: To Be Filled By O.E.M. X570 Extreme4/X570
Extreme4, BIOS P5.60 01/18/2024
[ 142.014439] RIP: 0010:apparmor_file_open (./include/linux/mount.h:78
(discriminator 2) ./include/linux/fs.h:2781 (discriminator 2)
security/apparmor/lsm.c:483 (discriminator 2))
[ 142.014442] Code: c5 00 08 00 00 0f 85 4b 01 00 00 4c 89 e9 31 c0 f6
c1 02 0f 85 fd 00 00 00 48 8b 87 88 00 00 00 4c 8d b7 88 00 00 00 48 89
fd <48> 8b 40 18 48 8b 4f 70 0f b7 11 48 89 c7 66 89 54 24 04 48 8b 51
All code
========
0: c5 00 08 (bad)
3: 00 00 add %al,(%rax)
5: 0f 85 4b 01 00 00 jne 0x156
b: 4c 89 e9 mov %r13,%rcx
e: 31 c0 xor %eax,%eax
10: f6 c1 02 test $0x2,%cl
13: 0f 85 fd 00 00 00 jne 0x116
19: 48 8b 87 88 00 00 00 mov 0x88(%rdi),%rax
20: 4c 8d b7 88 00 00 00 lea 0x88(%rdi),%r14
27: 48 89 fd mov %rdi,%rbp
2a:* 48 8b 40 18 mov 0x18(%rax),%rax <--
trapping instruction
2e: 48 8b 4f 70 mov 0x70(%rdi),%rcx
32: 0f b7 11 movzwl (%rcx),%edx
35: 48 89 c7 mov %rax,%rdi
38: 66 89 54 24 04 mov %dx,0x4(%rsp)
3d: 48 rex.W
3e: 8b .byte 0x8b
3f: 51 push %rcx
Code starting with the faulting instruction
===========================================
0: 48 8b 40 18 mov 0x18(%rax),%rax
4: 48 8b 4f 70 mov 0x70(%rdi),%rcx
8: 0f b7 11 movzwl (%rcx),%edx
b: 48 89 c7 mov %rax,%rdi
e: 66 89 54 24 04 mov %dx,0x4(%rsp)
13: 48 rex.W
14: 8b .byte 0x8b
15: 51 push %rcx
[ 142.014443] RSP: 0018:ffffb9ef7189bc50 EFLAGS: 00010246
[ 142.014445] RAX: 0000000000000000 RBX: ffff95eb5e555b00 RCX:
0000000000000300
[ 142.014446] RDX: ffff95f838227538 RSI: 00000000002ba677 RDI:
ffff95e992be2a00
[ 142.014447] RBP: ffff95e992be2a00 R08: ffff95f838227520 R09:
0000000000000002
[ 142.014447] R10: ffff95ea72241d00 R11: 0000000000000001 R12:
0000000000000010
[ 142.014448] R13: 0000000000000300 R14: ffff95e992be2a88 R15:
ffff95e95a6034e0
[ 142.014449] FS: 00007f74ab6cf880(0000) GS:ffff95f838200000(0000)
knlGS:0000000000000000
[ 142.014450] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 142.014451] CR2: 0000000000000018 CR3: 00000002473b6000 CR4:
0000000000f50ef0
[ 142.014452] PKRU: 55555554
[ 142.014453] Call Trace:
[ 142.014454] <TASK>
[ 142.014456] ? __die_body (arch/x86/kernel/dumpstack.c:421)
[ 142.014459] ? page_fault_oops (arch/x86/mm/fault.c:710)
[ 142.014460] ? __lock_acquire (kernel/locking/lockdep.c:?
kernel/locking/lockdep.c:5174)
[ 142.014462] ? local_lock_acquire
(./include/linux/local_lock_internal.h:29 (discriminator 1))
[ 142.014465] ? do_user_addr_fault (arch/x86/mm/fault.c:?)
[ 142.014467] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:37
./arch/x86/include/asm/irqflags.h:92 arch/x86/mm/fault.c:1488
arch/x86/mm/fault.c:1538)
[ 142.014468] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623)
[ 142.014471] ? apparmor_file_open (./include/linux/mount.h:78
(discriminator 2) ./include/linux/fs.h:2781 (discriminator 2)
security/apparmor/lsm.c:483 (discriminator 2))
[ 142.014472] security_file_open (security/security.c:?)
[ 142.014474] do_dentry_open (fs/open.c:934)
[ 142.014476] kernel_file_open (fs/open.c:1201)
[ 142.014477] efivarfs_pm_notify (fs/efivarfs/super.c:505)
[ 142.014479] ? __cfi_efivarfs_actor (fs/efivarfs/super.c:404)
[ 142.014480] ? fw_pm_notify (./include/linux/workqueue.h:?
drivers/base/firmware_loader/main.c:1585
drivers/base/firmware_loader/main.c:1615)
[ 142.014482] notifier_call_chain.llvm.227730641462406920
(kernel/notifier.c:?)
[ 142.014485] blocking_notifier_call_chain (kernel/notifier.c:381)
[ 142.014486] hibernate (kernel/power/hibernate.c:850)
[ 142.014488] state_store (kernel/power/main.c:?)
[ 142.014490] kernfs_fop_write_iter.llvm.8178385953439778559
(fs/kernfs/file.c:334)
[ 142.014492] vfs_write (fs/read_write.c:587 (discriminator 1))
[ 142.014494] ksys_write (fs/read_write.c:732)
[ 142.014496] do_syscall_64 (arch/x86/entry/common.c:?)
[ 142.014498] ? irqentry_exit_to_user_mode
(./arch/x86/include/asm/processor.h:722
./arch/x86/include/asm/entry-common.h:100
./include/linux/entry-common.h:365 kernel/entry/common.c:233)
[ 142.014499] entry_SYSCALL_64_after_hwframe
(arch/x86/entry/entry_64.S:130)
[ 142.014501] RIP: 0033:0x7f74ab09fe56
[ 142.014503] Code: 89 df e8 7d bd 00 00 8b 93 08 03 00 00 59 5e 48 83
f8 fc 75 15 83 e2 39 83 fa 08 75 0d e8 32 ff ff ff 66 90 48 8b 45 10 0f
05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08
All code
========
0: 89 df mov %ebx,%edi
2: e8 7d bd 00 00 call 0xbd84
7: 8b 93 08 03 00 00 mov 0x308(%rbx),%edx
d: 59 pop %rcx
e: 5e pop %rsi
f: 48 83 f8 fc cmp $0xfffffffffffffffc,%rax
13: 75 15 jne 0x2a
15: 83 e2 39 and $0x39,%edx
18: 83 fa 08 cmp $0x8,%edx
1b: 75 0d jne 0x2a
1d: e8 32 ff ff ff call 0xffffffffffffff54
22: 66 90 xchg %ax,%ax
24: 48 8b 45 10 mov 0x10(%rbp),%rax
28: 0f 05 syscall
2a:* 48 8b 5d f8 mov -0x8(%rbp),%rbx <--
trapping instruction
2e: c9 leave
2f: c3 ret
30: 0f 1f 40 00 nopl 0x0(%rax)
34: f3 0f 1e fa endbr64
38: 55 push %rbp
39: 48 89 e5 mov %rsp,%rbp
3c: 48 83 ec 08 sub $0x8,%rsp
Code starting with the faulting instruction
===========================================
0: 48 8b 5d f8 mov -0x8(%rbp),%rbx
4: c9 leave
5: c3 ret
6: 0f 1f 40 00 nopl 0x0(%rax)
a: f3 0f 1e fa endbr64
e: 55 push %rbp
f: 48 89 e5 mov %rsp,%rbp
12: 48 83 ec 08 sub $0x8,%rsp
[ 142.014504] RSP: 002b:00007ffcbaa60170 EFLAGS: 00000202 ORIG_RAX:
0000000000000001
[ 142.014505] RAX: ffffffffffffffda RBX: 00007f74ab6cf880 RCX:
00007f74ab09fe56
[ 142.014506] RDX: 0000000000000005 RSI: 000056105b899c30 RDI:
0000000000000007
[ 142.014507] RBP: 00007ffcbaa60180 R08: 0000000000000000 R09:
0000000000000000
[ 142.014507] R10: 0000000000000000 R11: 0000000000000202 R12:
0000000000000005
[ 142.014508] R13: 000056105b899c30 R14: 000056105b88e2a0 R15:
00007f74ab1f4ea0
[ 142.014510] </TASK>
[ 142.014510] Modules linked in: rfcomm bnep snd_seq_dummy snd_hrtimer
snd_seq nct6775 hwmon_vid nct6775_core btusb btrtl btmtk btbcm btintel
bluetooth snd_usb_audio snd_ump snd_usbmidi_lib snd_rawmidi
snd_seq_device snd_hda_codec_realtek snd_hda_scodec_component
snd_hda_codec_generic kvm_amd snd_hda_codec_hdmi snd_hda_intel
snd_intel_dspcfg snd_hda_codec snd_hwdep cfg80211 kvm wmi_bmof rfkill
snd_pcsp snd_hda_core snd_ctxfi nfnetlink ip_tables x_tables
hid_roccat_kone hid_roccat hid_logitech_hidpp hid_logitech_dj amdgpu
drm_panel_backlight_quirks cec mfd_core drm_buddy drm_suballoc_helper
video drm_exec drm_display_helper gpu_sched amdxcp drm_client_lib
drm_ttm_helper drm_kms_helper ttm wmi uhid snd_aloop snd_pcm snd_timer
snd soundcore videodev mc
[ 142.014533] CR2: 0000000000000018
[ 142.014534] ---[ end trace 0000000000000000 ]---
[ 142.023833] mlx4_en: 0000:04:00.0: Port 1: Using 32 TX rings
[ 142.023836] mlx4_en: 0000:04:00.0: Port 1: Using 16 RX rings
[ 142.031513] mlx4_en: 0000:04:00.0: Port 1: Initializing port
[ 142.031932] mlx4_en 0000:04:00.0: registered PHC clock
[ 142.078775] mlx4_en: eth0: Link Up
[ 142.157707] RIP: 0010:apparmor_file_open (./include/linux/mount.h:78
(discriminator 2) ./include/linux/fs.h:2781 (discriminator 2)
security/apparmor/lsm.c:483 (discriminator 2))
[ 142.157711] Code: c5 00 08 00 00 0f 85 4b 01 00 00 4c 89 e9 31 c0 f6
c1 02 0f 85 fd 00 00 00 48 8b 87 88 00 00 00 4c 8d b7 88 00 00 00 48 89
fd <48> 8b 40 18 48 8b 4f 70 0f b7 11 48 89 c7 66 89 54 24 04 48 8b 51
All code
========
0: c5 00 08 (bad)
3: 00 00 add %al,(%rax)
5: 0f 85 4b 01 00 00 jne 0x156
b: 4c 89 e9 mov %r13,%rcx
e: 31 c0 xor %eax,%eax
10: f6 c1 02 test $0x2,%cl
13: 0f 85 fd 00 00 00 jne 0x116
19: 48 8b 87 88 00 00 00 mov 0x88(%rdi),%rax
20: 4c 8d b7 88 00 00 00 lea 0x88(%rdi),%r14
27: 48 89 fd mov %rdi,%rbp
2a:* 48 8b 40 18 mov 0x18(%rax),%rax <--
trapping instruction
2e: 48 8b 4f 70 mov 0x70(%rdi),%rcx
32: 0f b7 11 movzwl (%rcx),%edx
35: 48 89 c7 mov %rax,%rdi
38: 66 89 54 24 04 mov %dx,0x4(%rsp)
3d: 48 rex.W
3e: 8b .byte 0x8b
3f: 51 push %rcx
Code starting with the faulting instruction
===========================================
0: 48 8b 40 18 mov 0x18(%rax),%rax
4: 48 8b 4f 70 mov 0x70(%rdi),%rcx
8: 0f b7 11 movzwl (%rcx),%edx
b: 48 89 c7 mov %rax,%rdi
e: 66 89 54 24 04 mov %dx,0x4(%rsp)
13: 48 rex.W
14: 8b .byte 0x8b
15: 51 push %rcx
[ 142.157713] RSP: 0018:ffffb9ef7189bc50 EFLAGS: 00010246
[ 142.157714] RAX: 0000000000000000 RBX: ffff95eb5e555b00 RCX:
0000000000000300
[ 142.157715] RDX: ffff95f838227538 RSI: 00000000002ba677 RDI:
ffff95e992be2a00
[ 142.157716] RBP: ffff95e992be2a00 R08: ffff95f838227520 R09:
0000000000000002
[ 142.157717] R10: ffff95ea72241d00 R11: 0000000000000001 R12:
0000000000000010
[ 142.157718] R13: 0000000000000300 R14: ffff95e992be2a88 R15:
ffff95e95a6034e0
[ 142.157719] FS: 00007f74ab6cf880(0000) GS:ffff95f838200000(0000)
knlGS:0000000000000000
[ 142.157720] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 142.157720] CR2: 0000000000000018 CR3: 00000002473b6000 CR4:
0000000000f50ef0
[ 142.157721] PKRU: 55555554
>
>> Regards
>>
>> /Malte
>>
>> ...
>> <snip old backtrace>
>> ...
>>
>>
> Ryan
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