[chardev] c194b1c9f0: BUG:kernel_NULL_pointer_dereference,address
by kernel test robot
Greeting,
FYI, we noticed the following commit (built with gcc-9):
commit: c194b1c9f07df8228702e6117703de4b4eac0777 ("[PATCH] chardev: call tty_init() in real chrdev_init()")
url: https://github.com/0day-ci/linux/commits/Xu-Yu/chardev-call-tty_init-in-r...
base: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git 2c271fe77d52a0555161926c232cd5bc07178b39
patch link: https://lore.kernel.org/lkml/4e753e51d0516413fbf557cf861d654ca73486cc.164...
in testcase: boot
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 <oliver.sang(a)intel.com>
[ 0.706940][ T0] BUG: kernel NULL pointer dereference, address: 000000000000008c
[ 0.708307][ T0] #PF: supervisor read access in kernel mode
[ 0.709271][ T0] #PF: error_code(0x0000) - not-present page
[ 0.709913][ T0] PGD 0 P4D 0
[ 0.709913][ T0] Oops: 0000 [#1] PTI
[ 0.709913][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 5.16.0-11414-gc194b1c9f07d #1 e2938b95216b0a390b46d405eced1ebac117cf4b
[ 0.709913][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[ 0.709913][ T0] RIP: 0010:kobject_get (lib/kobject.c:655)
[ 0.709913][ T0] Code: ff 48 89 ef e8 2b fd ff ff 5b 5d 41 5c e9 f2 62 54 ff 66 90 41 54 49 89 fc 55 53 e8 e4 62 54 ff 4d 85 e4 74 64 e8 da 62 54 ff <41> 0f b6 5c 24 3c 31 ff 83 e3 01 89 de e8 28 64 54 ff 84 db 74 56
All code
========
0: ff 48 89 decl -0x77(%rax)
3: ef out %eax,(%dx)
4: e8 2b fd ff ff callq 0xfffffffffffffd34
9: 5b pop %rbx
a: 5d pop %rbp
b: 41 5c pop %r12
d: e9 f2 62 54 ff jmpq 0xffffffffff546304
12: 66 90 xchg %ax,%ax
14: 41 54 push %r12
16: 49 89 fc mov %rdi,%r12
19: 55 push %rbp
1a: 53 push %rbx
1b: e8 e4 62 54 ff callq 0xffffffffff546304
20: 4d 85 e4 test %r12,%r12
23: 74 64 je 0x89
25: e8 da 62 54 ff callq 0xffffffffff546304
2a:* 41 0f b6 5c 24 3c movzbl 0x3c(%r12),%ebx <-- trapping instruction
30: 31 ff xor %edi,%edi
32: 83 e3 01 and $0x1,%ebx
35: 89 de mov %ebx,%esi
37: e8 28 64 54 ff callq 0xffffffffff546464
3c: 84 db test %bl,%bl
3e: 74 56 je 0x96
Code starting with the faulting instruction
===========================================
0: 41 0f b6 5c 24 3c movzbl 0x3c(%r12),%ebx
6: 31 ff xor %edi,%edi
8: 83 e3 01 and $0x1,%ebx
b: 89 de mov %ebx,%esi
d: e8 28 64 54 ff callq 0xffffffffff54643a
12: 84 db test %bl,%bl
14: 74 56 je 0x6c
[ 0.709913][ T0] RSP: 0000:ffffffffa1403c60 EFLAGS: 00010246
[ 0.709913][ T0] RAX: 0000000000000000 RBX: 0000000000000076 RCX: ffffffff9e8860b2
[ 0.709913][ T0] RDX: 0000000000000000 RSI: ffffffffa147e100 RDI: 0000000000000002
[ 0.709913][ T0] RBP: ffff88810029d440 R08: 0000000000000040 R09: 0000000000000000
[ 0.709913][ T0] R10: ffff88810029d440 R11: 0000000000000000 R12: 0000000000000050
[ 0.709913][ T0] R13: ffff88810029d440 R14: ffffffffa114e65a R15: 0000000000700000
[ 0.709913][ T0] FS: 0000000000000000(0000) GS:ffffffffa14b3000(0000) knlGS:0000000000000000
[ 0.709913][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.709913][ T0] CR2: 000000000000008c CR3: 0000000268476000 CR4: 00000000000406b0
[ 0.709913][ T0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 0.709913][ T0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 0.709913][ T0] Call Trace:
[ 0.709913][ T0] <TASK>
[ 0.709913][ T0] kobject_add_internal (lib/kobject.c:243)
[ 0.709913][ T0] ? __sanitizer_cov_trace_pc (kernel/kcov.c:200)
[ 0.709913][ T0] kobject_add (lib/kobject.c:390 lib/kobject.c:442)
[ 0.709913][ T0] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:50 (discriminator 22))
[ 0.709913][ T0] ? write_comp_data (kernel/kcov.c:221)
[ 0.709913][ T0] kobject_create_and_add (lib/kobject.c:815)
[ 0.709913][ T0] get_device_parent (drivers/base/core.c:2895 drivers/base/core.c:2975)
[ 0.709913][ T0] device_add (drivers/base/core.c:3327)
[ 0.709913][ T0] ? rcu_read_lock_sched_held (kernel/rcu/update.c:104 kernel/rcu/update.c:123)
[ 0.709913][ T0] ? kfree (include/trace/events/kmem.h:118 mm/slab.c:3780)
[ 0.709913][ T0] ? __sanitizer_cov_trace_pc (kernel/kcov.c:200)
[ 0.709913][ T0] device_create_groups_vargs (drivers/base/core.c:4063)
[ 0.709913][ T0] device_create (drivers/base/core.c:4107)
[ 0.709913][ T0] ? kobject_put (include/linux/refcount.h:282 include/linux/refcount.h:315 include/linux/refcount.h:333 include/linux/kref.h:64 lib/kobject.c:753)
[ 0.709913][ T0] ? __sanitizer_cov_trace_pc (kernel/kcov.c:200)
[ 0.709913][ T0] ? write_comp_data (kernel/kcov.c:221)
[ 0.709913][ T0] vcs_init (drivers/tty/vt/vc_screen.c:810)
[ 0.709913][ T0] vty_init (drivers/tty/vt/vt.c:3602)
[ 0.709913][ T0] tty_init (drivers/tty/tty_io.c:3611)
[ 0.709913][ T0] ? trace_init_perf_perm_irq_work_exit (arch/x86/kernel/time.c:86)
[ 0.709913][ T0] start_kernel (init/main.c:1117)
[ 0.709913][ T0] ? copy_bootdata (arch/x86/kernel/head64.c:440)
[ 0.709913][ T0] secondary_startup_64_no_verify (arch/x86/kernel/head_64.S:300)
[ 0.709913][ T0] </TASK>
[ 0.709913][ T0] Modules linked in:
[ 0.709913][ T0] CR2: 000000000000008c
[ 0.709913][ T0] ---[ end trace 0000000000000000 ]---
[ 0.709913][ T0] RIP: 0010:kobject_get (lib/kobject.c:655)
[ 0.709913][ T0] Code: ff 48 89 ef e8 2b fd ff ff 5b 5d 41 5c e9 f2 62 54 ff 66 90 41 54 49 89 fc 55 53 e8 e4 62 54 ff 4d 85 e4 74 64 e8 da 62 54 ff <41> 0f b6 5c 24 3c 31 ff 83 e3 01 89 de e8 28 64 54 ff 84 db 74 56
All code
========
0: ff 48 89 decl -0x77(%rax)
3: ef out %eax,(%dx)
4: e8 2b fd ff ff callq 0xfffffffffffffd34
9: 5b pop %rbx
a: 5d pop %rbp
b: 41 5c pop %r12
d: e9 f2 62 54 ff jmpq 0xffffffffff546304
12: 66 90 xchg %ax,%ax
14: 41 54 push %r12
16: 49 89 fc mov %rdi,%r12
19: 55 push %rbp
1a: 53 push %rbx
1b: e8 e4 62 54 ff callq 0xffffffffff546304
20: 4d 85 e4 test %r12,%r12
23: 74 64 je 0x89
25: e8 da 62 54 ff callq 0xffffffffff546304
2a:* 41 0f b6 5c 24 3c movzbl 0x3c(%r12),%ebx <-- trapping instruction
30: 31 ff xor %edi,%edi
32: 83 e3 01 and $0x1,%ebx
35: 89 de mov %ebx,%esi
37: e8 28 64 54 ff callq 0xffffffffff546464
3c: 84 db test %bl,%bl
3e: 74 56 je 0x96
Code starting with the faulting instruction
===========================================
0: 41 0f b6 5c 24 3c movzbl 0x3c(%r12),%ebx
6: 31 ff xor %edi,%edi
8: 83 e3 01 and $0x1,%ebx
b: 89 de mov %ebx,%esi
d: e8 28 64 54 ff callq 0xffffffffff54643a
12: 84 db test %bl,%bl
14: 74 56 je 0x6c
To reproduce:
# build kernel
cd linux
cp config-5.16.0-11414-gc194b1c9f07d .config
make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules
make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install
cd <mod-install-dir>
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 <bzImage> -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.
---
0DAY/LKP+ Test Infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/lkp@lists.01.org Intel Corporation
Thanks,
Oliver Sang
7 months, 1 week
