* [jimc:dd-rust-parse] [dyndbg] ccfcff60ec: BUG:kernel_NULL_pointer_dereference,address
@ 2026-06-17 14:56 kernel test robot
0 siblings, 0 replies; only message in thread
From: kernel test robot @ 2026-06-17 14:56 UTC (permalink / raw)
To: Jim Cromie, Łukasz Bartosik; +Cc: oe-lkp, lkp, oliver.sang
hi, Jim Cromie,
for this change, we reported
"[jimc:dd-shrink] [dyndbg] 1663ffb9c1: BUG:kernel_NULL_pointer_dereference,address"
in
https://lore.kernel.org/all/202601211325.7e1f336-lkp@intel.com/
at that time, we understood that you've already fixed it by a separate patch.
now we found the similar issue in another branch, we are not sure if this branch
is still active. so report out what we observe in our tests just FYI.
Hello,
kernel test robot noticed "BUG:kernel_NULL_pointer_dereference,address" on:
commit: ccfcff60ec48f9294257908cb027b3e29c8f7462 ("dyndbg: resolve "protection" of class'd pr_debug")
https://github.com/jimc/linux.git dd-rust-parse
in testcase: boot
config: i386-randconfig-015-20260616
compiler: gcc-14
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G
(please refer to attached dmesg/kmsg for entire log/backtrace)
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@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202606172227.34266a1f-lkp@intel.com
[ 2.060784][ T1] BUG: kernel NULL pointer dereference, address: 00000000
[ 2.064447][ T1] #PF: supervisor read access in kernel mode
[ 2.064447][ T1] #PF: error_code(0x0000) - not-present page
[ 2.064447][ T1] *pde = 00000000
[ 2.064447][ T1] Oops: Oops: 0000 [#1] SMP
[ 2.064447][ T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.1.0-rc7-00035-gccfcff60ec48 #1 PREEMPT(lazy) 4e5eb1741e72fd9e4b9a514cfdc887aab03908af
[ 2.064447][ T1] EIP: strcmp+0x9/0x40
[ 2.064447][ T1] Code: 84 c0 75 f7 31 c0 aa 89 d8 5b 5e 5f 5d c3 8d 76 00 2e 8d b4 26 00 00 00 00 2e 8d b4 26 00 00 00 00 55 89 e5 57 89 d7 56 89 c6 <ac> ae 75 08 84 c0 75 f8 31 c0 eb 04 19 c0 0c 01 5e 5f 5d c3 8d 76
All code
========
0: 84 c0 test %al,%al
2: 75 f7 jne 0xfffffffffffffffb
4: 31 c0 xor %eax,%eax
6: aa stos %al,%es:(%rdi)
7: 89 d8 mov %ebx,%eax
9: 5b pop %rbx
a: 5e pop %rsi
b: 5f pop %rdi
c: 5d pop %rbp
d: c3 ret
e: 8d 76 00 lea 0x0(%rsi),%esi
11: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi
18: 00
19: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi
20: 00
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 57 push %rdi
25: 89 d7 mov %edx,%edi
27: 56 push %rsi
28: 89 c6 mov %eax,%esi
2a:* ac lods %ds:(%rsi),%al <-- trapping instruction
2b: ae scas %es:(%rdi),%al
2c: 75 08 jne 0x36
2e: 84 c0 test %al,%al
30: 75 f8 jne 0x2a
32: 31 c0 xor %eax,%eax
34: eb 04 jmp 0x3a
36: 19 c0 sbb %eax,%eax
38: 0c 01 or $0x1,%al
3a: 5e pop %rsi
3b: 5f pop %rdi
3c: 5d pop %rbp
3d: c3 ret
3e: 8d .byte 0x8d
3f: 76 .byte 0x76
Code starting with the faulting instruction
===========================================
0: ac lods %ds:(%rsi),%al
1: ae scas %es:(%rdi),%al
2: 75 08 jne 0xc
4: 84 c0 test %al,%al
6: 75 f8 jne 0x0
8: 31 c0 xor %eax,%eax
a: eb 04 jmp 0x10
c: 19 c0 sbb %eax,%eax
e: 0c 01 or $0x1,%al
10: 5e pop %rsi
11: 5f pop %rdi
12: 5d pop %rbp
13: c3 ret
14: 8d .byte 0x8d
15: 76 .byte 0x76
[ 2.064447][ T1] EAX: 00000000 EBX: c5c15680 ECX: 00000000 EDX: c45bc35a
[ 2.064447][ T1] ESI: 00000000 EDI: c45bc35a EBP: c5d2fe88 ESP: c5d2fe80
[ 2.064447][ T1] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010203
[ 2.064447][ T1] CR0: 80050033 CR2: 00000000 CR3: 05289000 CR4: 00040690
[ 2.064447][ T1] Call Trace:
[ 2.064447][ T1] ddebug_add_module+0xbb/0x380
[ 2.064447][ T1] ? blocking_notifier_chain_register+0x2e/0x80
[ 2.064447][ T1] ? dynamic_debug_init_control+0x74/0x74
[ 2.064447][ T1] dynamic_debug_init+0xf2/0x208
[ 2.064447][ T1] ? dynamic_debug_init_control+0x74/0x74
[ 2.064447][ T1] do_one_initcall+0x59/0x3c0
[ 2.064447][ T1] ? __register_sysctl_table+0x101/0x140
[ 2.064447][ T1] ? rest_init+0x180/0x180
[ 2.064447][ T1] kernel_init_freeable+0x8f/0x114
[ 2.064447][ T1] kernel_init+0x12/0x100
[ 2.064447][ T1] ret_from_fork+0x228/0x2c0
[ 2.064447][ T1] ? rest_init+0x180/0x180
[ 2.064447][ T1] ret_from_fork_asm+0x12/0x18
[ 2.064447][ T1] entry_INT80_32+0x10d/0x10d
[ 2.064447][ T1] Modules linked in:
[ 2.064447][ T1] CR2: 0000000000000000
[ 2.064447][ T1] ---[ end trace 0000000000000000 ]---
[ 2.064447][ T1] EIP: strcmp+0x9/0x40
[ 2.064447][ T1] Code: 84 c0 75 f7 31 c0 aa 89 d8 5b 5e 5f 5d c3 8d 76 00 2e 8d b4 26 00 00 00 00 2e 8d b4 26 00 00 00 00 55 89 e5 57 89 d7 56 89 c6 <ac> ae 75 08 84 c0 75 f8 31 c0 eb 04 19 c0 0c 01 5e 5f 5d c3 8d 76
All code
========
0: 84 c0 test %al,%al
2: 75 f7 jne 0xfffffffffffffffb
4: 31 c0 xor %eax,%eax
6: aa stos %al,%es:(%rdi)
7: 89 d8 mov %ebx,%eax
9: 5b pop %rbx
a: 5e pop %rsi
b: 5f pop %rdi
c: 5d pop %rbp
d: c3 ret
e: 8d 76 00 lea 0x0(%rsi),%esi
11: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi
18: 00
19: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi
20: 00
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 57 push %rdi
25: 89 d7 mov %edx,%edi
27: 56 push %rsi
28: 89 c6 mov %eax,%esi
2a:* ac lods %ds:(%rsi),%al <-- trapping instruction
2b: ae scas %es:(%rdi),%al
2c: 75 08 jne 0x36
2e: 84 c0 test %al,%al
30: 75 f8 jne 0x2a
32: 31 c0 xor %eax,%eax
34: eb 04 jmp 0x3a
36: 19 c0 sbb %eax,%eax
38: 0c 01 or $0x1,%al
3a: 5e pop %rsi
3b: 5f pop %rdi
3c: 5d pop %rbp
3d: c3 ret
3e: 8d .byte 0x8d
3f: 76 .byte 0x76
Code starting with the faulting instruction
===========================================
0: ac lods %ds:(%rsi),%al
1: ae scas %es:(%rdi),%al
2: 75 08 jne 0xc
4: 84 c0 test %al,%al
6: 75 f8 jne 0x0
8: 31 c0 xor %eax,%eax
a: eb 04 jmp 0x10
c: 19 c0 sbb %eax,%eax
e: 0c 01 or $0x1,%al
10: 5e pop %rsi
11: 5f pop %rdi
12: 5d pop %rbp
13: c3 ret
14: 8d .byte 0x8d
15: 76 .byte 0x76
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260617/202606172227.34266a1f-lkp@intel.com
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2026-06-17 14:56 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-06-17 14:56 [jimc:dd-rust-parse] [dyndbg] ccfcff60ec: BUG:kernel_NULL_pointer_dereference,address kernel test robot
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.