Re: [PATCH v2 5/8] landlock: Always allow signals between threads of the same process

From: kernel test robot
Date: Wed Mar 26 2025 - 03:52:51 EST




Hello,

kernel test robot noticed "Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]SMP_KASAN" on:

commit: b9fb5bfdb361fd6d945c09c93d351740310a26c7 ("[PATCH v2 5/8] landlock: Always allow signals between threads of the same process")
url: https://github.com/intel-lab-lkp/linux/commits/Micka-l-Sala-n/landlock-Move-code-to-ease-future-backports/20250319-003737
patch link: https://lore.kernel.org/all/20250318161443.279194-6-mic@xxxxxxxxxxx/
patch subject: [PATCH v2 5/8] landlock: Always allow signals between threads of the same process

in testcase: trinity
version: trinity-x86_64-ba2360ed-1_20241228
with following parameters:

runtime: 300s
group: group-03
nr_groups: 5



config: x86_64-randconfig-005-20250325
compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)


we noticed the issue happens randomly (35 times out of 200 runs as below).
but parent keeps clean.


37897789c51dd898 b9fb5bfdb361fd6d945c09c93d3
---------------- ---------------------------
fail:runs %reproduction fail:runs
| | |
:200 18% 35:200 dmesg.KASAN:null-ptr-deref_in_range[#-#]
:200 18% 35:200 dmesg.Kernel_panic-not_syncing:Fatal_exception
:200 18% 35:200 dmesg.Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]SMP_KASAN
:200 18% 35:200 dmesg.RIP:hook_file_set_fowner



If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-lkp/202503261534.22d970e8-lkp@xxxxxxxxx


[ 354.738531][ T222]
[ 355.199494][ T222] [main] 2245715 iterations. [F:1644455 S:601688 HI:11581]
[ 355.199514][ T222]
[ 355.934630][ T222] [main] 2273938 iterations. [F:1665198 S:609188 HI:11581]
[ 355.934650][ T222]
[ 356.308897][ T3147] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000151: 0000 [#1] SMP KASAN
[ 356.309510][ T3147] KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f]
[ 356.309910][ T3147] CPU: 1 UID: 65534 PID: 3147 Comm: trinity-c2 Not tainted 6.14.0-rc5-00005-gb9fb5bfdb361 #1 145c38dc5407add8933da653ccf9cf31d58da93c
[ 356.310560][ T3147] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 356.311050][ T3147] RIP: 0010:hook_file_set_fowner (kbuild/src/consumer/include/linux/sched/signal.h:707 (discriminator 9) kbuild/src/consumer/security/landlock/fs.c:1651 (discriminator 9))
[ 356.311345][ T3147] Code: 49 8b 7c 24 50 65 4c 8b 25 e7 e4 0c 7e e8 52 63 33 ff 48 ba 00 00 00 00 00 fc ff df 48 8d b8 88 0a 00 00 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 7e 02 00 00 49 8d bc 24 88 0a 00 00 4c 8b a8 88
All code
========
0: 49 8b 7c 24 50 mov 0x50(%r12),%rdi
5: 65 4c 8b 25 e7 e4 0c mov %gs:0x7e0ce4e7(%rip),%r12 # 0x7e0ce4f4
c: 7e
d: e8 52 63 33 ff call 0xffffffffff336364
12: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
19: fc ff df
1c: 48 8d b8 88 0a 00 00 lea 0xa88(%rax),%rdi
23: 48 89 f9 mov %rdi,%rcx
26: 48 c1 e9 03 shr $0x3,%rcx
2a:* 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) <-- trapping instruction
2e: 0f 85 7e 02 00 00 jne 0x2b2
34: 49 8d bc 24 88 0a 00 lea 0xa88(%r12),%rdi
3b: 00
3c: 4c rex.WR
3d: 8b .byte 0x8b
3e: a8 88 test $0x88,%al

Code starting with the faulting instruction
===========================================
0: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1)
4: 0f 85 7e 02 00 00 jne 0x288
a: 49 8d bc 24 88 0a 00 lea 0xa88(%r12),%rdi
11: 00
12: 4c rex.WR
13: 8b .byte 0x8b
14: a8 88 test $0x88,%al
[ 356.312254][ T3147] RSP: 0018:ffffc9000883fd20 EFLAGS: 00010002
[ 356.312556][ T3147] RAX: 0000000000000000 RBX: ffff88816ee4c700 RCX: 0000000000000151
[ 356.312933][ T3147] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000a88
[ 356.313310][ T3147] RBP: ffffc9000883fd48 R08: 0000000000000000 R09: 0000000000000000
[ 356.313687][ T3147] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88814f0c8000
[ 356.314063][ T3147] R13: ffff88814f92b700 R14: ffff888161e71450 R15: ffff888161e71408
[ 356.314440][ T3147] FS: 00007f3c72136740(0000) GS:ffff8883af000000(0000) knlGS:0000000000000000
[ 356.314879][ T3147] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 356.315194][ T3147] CR2: 00007f3c708bd000 CR3: 0000000165606000 CR4: 00000000000406f0
[ 356.315573][ T3147] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 356.315950][ T3147] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 356.316334][ T3147] Call Trace:
[ 356.316498][ T3147] <TASK>
[ 356.316645][ T3147] ? show_regs (kbuild/src/consumer/arch/x86/kernel/dumpstack.c:479)
[ 356.316859][ T3147] ? die_addr (kbuild/src/consumer/arch/x86/kernel/dumpstack.c:421 kbuild/src/consumer/arch/x86/kernel/dumpstack.c:460)
[ 356.317066][ T3147] ? exc_general_protection (kbuild/src/consumer/arch/x86/kernel/traps.c:751 kbuild/src/consumer/arch/x86/kernel/traps.c:693)
[ 356.317349][ T3147] ? asm_exc_general_protection (kbuild/src/consumer/arch/x86/include/asm/idtentry.h:574)


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250326/202503261534.22d970e8-lkp@xxxxxxxxx



--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki