Greeting, FYI, we noticed BUG:kernel_NULL_pointer_dereference,address due to commit (built with gcc-11): commit: da74b30c774a4a0c62fc3dc2b95a8a3a34a48c23 ("ipc/shm: call underlying open/close vm_ops") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: trinity version: trinity-static-i386-x86_64-1c734c75-1_2020-01-06 with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): If you fix the issue, kindly add following tag | Reported-by: kernel test robot | Link: https://lore.kernel.org/oe-lkp/202211151618.9fcf9eca-oliver.sang@intel.com [ 37.140634][ T502] BUG: kernel NULL pointer dereference, address: 00000004 [ 37.141739][ T502] #PF: supervisor read access in kernel mode [ 37.142563][ T502] #PF: error_code(0x0000) - not-present page [ 37.143353][ T502] *pdpt = 000000002dd1c001 *pde = 0000000000000000 [ 37.144220][ T502] Oops: 0000 [#1] SMP PTI [ 37.144892][ T502] CPU: 1 PID: 502 Comm: trinity Tainted: G E 6.1.0-rc4-00027-gda74b30c774a #1 [ 37.146300][ T502] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 37.147705][ T502] EIP: shm_close (shm.c:?) [ 37.148341][ T502] Code: e8 d8 19 7c 00 e9 fd fe ff ff 8d 76 00 3e 8d 74 26 00 55 89 e5 57 56 53 83 ec 08 8b 50 3c 8b 9a 04 01 00 00 8b 53 0c 8b 73 04 <8b> 52 04 85 d2 74 02 ff d2 8d be c0 02 00 00 89 f8 e8 ad cf 7b 00 All code ======== 0: e8 d8 19 7c 00 callq 0x7c19dd 5: e9 fd fe ff ff jmpq 0xffffffffffffff07 a: 8d 76 00 lea 0x0(%rsi),%esi d: 3e 8d 74 26 00 lea %ds:0x0(%rsi,%riz,1),%esi 12: 55 push %rbp 13: 89 e5 mov %esp,%ebp 15: 57 push %rdi 16: 56 push %rsi 17: 53 push %rbx 18: 83 ec 08 sub $0x8,%esp 1b: 8b 50 3c mov 0x3c(%rax),%edx 1e: 8b 9a 04 01 00 00 mov 0x104(%rdx),%ebx 24: 8b 53 0c mov 0xc(%rbx),%edx 27: 8b 73 04 mov 0x4(%rbx),%esi 2a:* 8b 52 04 mov 0x4(%rdx),%edx <-- trapping instruction 2d: 85 d2 test %edx,%edx 2f: 74 02 je 0x33 31: ff d2 callq *%rdx 33: 8d be c0 02 00 00 lea 0x2c0(%rsi),%edi 39: 89 f8 mov %edi,%eax 3b: e8 ad cf 7b 00 callq 0x7bcfed Code starting with the faulting instruction =========================================== 0: 8b 52 04 mov 0x4(%rdx),%edx 3: 85 d2 test %edx,%edx 5: 74 02 je 0x9 7: ff d2 callq *%rdx 9: 8d be c0 02 00 00 lea 0x2c0(%rsi),%edi f: 89 f8 mov %edi,%eax 11: e8 ad cf 7b 00 callq 0x7bcfc3 [ 37.150789][ T502] EAX: ee1a6280 EBX: ee17e630 ECX: 00000000 EDX: 00000000 [ 37.158886][ T502] ESI: c292ede0 EDI: ee1a6280 EBP: edc69d30 ESP: edc69d1c [ 37.159836][ T502] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010292 [ 37.160890][ T502] CR0: 80050033 CR2: 00000004 CR3: 2deb4000 CR4: 000406f0 [ 37.161851][ T502] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 37.162822][ T502] DR6: fffe0ff0 DR7: 00000400 [ 37.163502][ T502] Call Trace: [ 37.164018][ T502] shm_mmap (shm.c:?) [ 37.164618][ T502] mmap_region (??:?) [ 37.165311][ T502] ? generic_get_unmapped_area_topdown (??:?) [ 37.166209][ T502] ? shm_get_unmapped_area (shm.c:?) [ 37.166978][ T502] ? security_mmap_addr (??:?) [ 37.167737][ T502] do_mmap (??:?) [ 37.168327][ T502] do_shmat (??:?) [ 37.168925][ T502] ksys_ipc (??:?) [ 37.169538][ T502] __ia32_sys_ipc (??:?) [ 37.170188][ T502] __do_fast_syscall_32 (common.c:?) [ 37.170910][ T502] ? syscall_exit_to_user_mode (??:?) [ 37.171830][ T502] ? __do_fast_syscall_32 (common.c:?) [ 37.172578][ T502] ? __do_fast_syscall_32 (common.c:?) [ 37.173326][ T502] ? syscall_exit_to_user_mode (??:?) [ 37.174108][ T502] ? lockdep_hardirqs_on_prepare (lockdep.c:?) [ 37.174977][ T502] ? syscall_exit_to_user_mode (??:?) [ 37.175905][ T502] ? __do_fast_syscall_32 (common.c:?) [ 37.176656][ T502] ? __task_pid_nr_ns (??:?) [ 37.177392][ T502] ? __do_fast_syscall_32 (common.c:?) [ 37.178136][ T502] ? syscall_exit_to_user_mode (??:?) [ 37.178894][ T502] ? lockdep_hardirqs_on_prepare (lockdep.c:?) [ 37.179914][ T502] ? syscall_exit_to_user_mode (??:?) [ 37.180674][ T502] ? __do_fast_syscall_32 (common.c:?) [ 37.181426][ T502] ? __do_fast_syscall_32 (common.c:?) [ 37.182128][ T502] ? lockdep_hardirqs_on_prepare (lockdep.c:?) [ 37.188288][ T502] do_fast_syscall_32 (??:?) [ 37.192396][ T502] do_SYSENTER_32 (??:?) [ 37.193081][ T502] entry_SYSENTER_32 (??:?) [ 37.193680][ T502] EIP: 0xb7eff559 [ 37.194228][ T502] Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d 76 00 58 b8 77 00 00 00 cd 80 90 8d 76 All code ======== 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 2a:* 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d 76 00 lea 0x0(%rsi),%esi 35: 58 pop %rax 36: b8 77 00 00 00 mov $0x77,%eax 3b: cd 80 int $0x80 3d: 90 nop 3e: 8d .byte 0x8d 3f: 76 .byte 0x76 Code starting with the faulting instruction =========================================== 0: 5d pop %rbp 1: 5a pop %rdx 2: 59 pop %rcx 3: c3 retq 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 8d 76 00 lea 0x0(%rsi),%esi b: 58 pop %rax c: b8 77 00 00 00 mov $0x77,%eax 11: cd 80 int $0x80 13: 90 nop 14: 8d .byte 0x8d 15: 76 .byte 0x76 To reproduce: # build kernel cd linux cp config-6.1.0-rc4-00027-gda74b30c774a .config make HOSTCC=gcc-11 CC=gcc-11 ARCH=i386 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-11 CC=gcc-11 ARCH=i386 INSTALL_MOD_PATH= modules_install cd find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k -m modules.cgz job-script # job-script is attached in this email # if come across any failure that blocks the test, # please remove ~/.lkp and /lkp dir to run from a clean state. -- 0-DAY CI Kernel Test Service https://01.org/lkp