BUG: unable to handle kernel NULL pointer dereference in do_syscall_32_irqs

BUG: unable to handle kernel NULL pointer dereference in do_syscall_32_irqs_on
Status: upstream: reported syz repro on 2020/07/26 08:03
Reported-by: syzbot+0e3a50ab9ac2fdf9ffc6@syzkaller.appspotmail.com
First crash: 28d, last: 14d

Cause bisection: the bug happens on the oldest tested release
Crash: WARNING in sysfs_warn_dup (log)
Repro: syz .config

Sample crash report:

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 94d49067 P4D 94d49067 PUD a1c93067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 6854 Comm: syz-executor.3 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:do_syscall_32_irqs_on+0x3f/0x60 arch/x86/entry/common.c:428
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc900017b7f28 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffffc900017b7f58 RCX: 1ffff920002f6fd2
RDX: ffff888098bb4240 RSI: ffffffff81c214b2 RDI: 0000000000000005
RBP: ffffc900017b7f58 R08: 0000000000000001 R09: ffff888098bb4b08
R10: 00000000ffffff8c R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:000000000a292900
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a1b88000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __do_fast_syscall_32 arch/x86/entry/common.c:475 [inline]
 do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:503
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 94d49067 P4D 94d49067 PUD a1c93067 PMD 0 
Oops: 0002 [#2] PREEMPT SMP KASAN
CPU: 0 PID: 6854 Comm: syz-executor.3 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:in_gate_area_no_mm+0x0/0x6a arch/x86/entry/vsyscall/vsyscall_64.c:343
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc900017b7440 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffc900017b74e0 RCX: ffffffff816a62f0
RDX: ffff888098bb4240 RSI: ffffffff816a631b RDI: 00000000f7f83569
RBP: 00000000f7f83569 R08: ffffc900017b75f0 R09: ffffffff8c8d7109
R10: 00000000f7f83569 R11: 0000000000000000 R12: ffffc900017b75f0
R13: 0000000000000001 R14: 00000000f7f83569 R15: ffffc900017b7500
FS:  0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:000000000a292900
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a1b88000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 is_kernel include/linux/kallsyms.h:44 [inline]
 is_ksym_addr include/linux/kallsyms.h:50 [inline]
 kallsyms_lookup+0xc3/0x2e0 kernel/kallsyms.c:290
 __sprint_symbol+0x9c/0x1c0 kernel/kallsyms.c:363
 symbol_string+0x14c/0x370 lib/vsprintf.c:969
 pointer+0x185/0x970 lib/vsprintf.c:2226
 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2624
 vscnprintf+0x29/0x80 lib/vsprintf.c:2723
 vprintk_store+0x44/0x4a0 kernel/printk/printk.c:1942
 vprintk_emit+0x139/0x770 kernel/printk/printk.c:2003
 vprintk_func+0x8f/0x1a6 kernel/printk/printk_safe.c:393
 printk+0xba/0xed kernel/printk/printk.c:2070
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:124
 show_iret_regs+0x10/0x32 arch/x86/kernel/dumpstack.c:131
 __show_regs+0x18/0x50 arch/x86/kernel/process_64.c:72
 show_trace_log_lvl+0x255/0x2b4 arch/x86/kernel/dumpstack.c:274
 show_regs arch/x86/kernel/dumpstack.c:447 [inline]
 __die_body arch/x86/kernel/dumpstack.c:393 [inline]
 __die+0x51/0x90 arch/x86/kernel/dumpstack.c:407
 no_context+0x56b/0x9f0 arch/x86/mm/fault.c:695
 __bad_area_nosemaphore+0xa9/0x480 arch/x86/mm/fault.c:789
 do_user_addr_fault+0x8ce/0xd00 arch/x86/mm/fault.c:1258
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:542
RIP: 0010:do_syscall_32_irqs_on+0x3f/0x60 arch/x86/entry/common.c:428
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc900017b7f28 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffffc900017b7f58 RCX: 1ffff920002f6fd2
RDX: ffff888098bb4240 RSI: ffffffff81c214b2 RDI: 0000000000000005
RBP: ffffc900017b7f58 R08: 0000000000000001 R09: ffff888098bb4b08
R10: 00000000ffffff8c R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 __do_fast_syscall_32 arch/x86/entry/common.c:475 [inline]
 do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:503
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 94d49067 P4D 94d49067 PUD a1c93067 PMD 0 
Oops: 0002 [#3] PREEMPT SMP KASAN
CPU: 0 PID: 6854 Comm: syz-executor.3 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:in_gate_area_no_mm+0x0/0x6a arch/x86/entry/vsyscall/vsyscall_64.c:343
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc900017b6930 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffc900017b69d0 RCX: ffffffff816a62f0
RDX: ffff888098bb4240 RSI: ffffffff816a631b RDI: 00000000f7f83569
RBP: 00000000f7f83569 R08: ffffc900017b6ae0 R09: ffff8880ae623dcd
R10: 00000000f7f83569 R11: 0000000000000001 R12: ffffc900017b6ae0
R13: 0000000000000001 R14: 00000000f7f83569 R15: ffffc900017b69f0
FS:  0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:000000000a292900
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a1b88000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 is_kernel include/linux/kallsyms.h:44 [inline]
 is_ksym_addr include/linux/kallsyms.h:50 [inline]
 kallsyms_lookup+0xc3/0x2e0 kernel/kallsyms.c:290
 __sprint_symbol+0x9c/0x1c0 kernel/kallsyms.c:363
 symbol_string+0x14c/0x370 lib/vsprintf.c:969
 pointer+0x185/0x970 lib/vsprintf.c:2226
 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2624
 vscnprintf+0x29/0x80 lib/vsprintf.c:2723
 printk_safe_log_store+0xf5/0x250 kernel/printk/printk_safe.c:94
 vprintk_safe kernel/printk/printk_safe.c:347 [inline]
 vprintk_func+0xef/0x1a6 kernel/printk/printk_safe.c:390
 printk+0xba/0xed kernel/printk/printk.c:2070
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:124
 show_iret_regs+0x10/0x32 arch/x86/kernel/dumpstack.c:131
 __show_regs+0x18/0x50 arch/x86/kernel/process_64.c:72
 show_trace_log_lvl+0x255/0x2b4 arch/x86/kernel/dumpstack.c:274
 show_regs arch/x86/kernel/dumpstack.c:447 [inline]
 __die_body arch/x86/kernel/dumpstack.c:393 [inline]
 __die+0x51/0x90 arch/x86/kernel/dumpstack.c:407
 no_context+0x56b/0x9f0 arch/x86/mm/fault.c:695
 __bad_area_nosemaphore+0xa9/0x480 arch/x86/mm/fault.c:789
 do_user_addr_fault+0x783/0xd00 arch/x86/mm/fault.c:1171
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:542
RIP: 0010:in_gate_area_no_mm+0x0/0x6a arch/x86/entry/vsyscall/vsyscall_64.c:343
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc900017b7440 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffc900017b74e0 RCX: ffffffff816a62f0
RDX: ffff888098bb4240 RSI: ffffffff816a631b RDI: 00000000f7f83569
RBP: 00000000f7f83569 R08: ffffc900017b75f0 R09: ffffffff8c8d7109
R10: 00000000f7f83569 R11: 0000000000000000 R12: ffffc900017b75f0
R13: 0000000000000001 R14: 00000000f7f83569 R15: ffffc900017b7500
 is_kernel include/linux/kallsyms.h:44 [inline]
 is_ksym_addr include/linux/kallsyms.h:50 [inline]
 kallsyms_lookup+0xc3/0x2e0 kernel/kallsyms.c:290
 __sprint_symbol+0x9c/0x1c0 kernel/kallsyms.c:363
 symbol_string+0x14c/0x370 lib/vsprintf.c:969
 pointer+0x185/0x970 lib/vsprintf.c:2226
 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2624
 vscnprintf+0x29/0x80 lib/vsprintf.c:2723
 vprintk_store+0x44/0x4a0 kernel/printk/printk.c:1942
 vprintk_emit+0x139/0x770 kernel/printk/printk.c:2003
 vprintk_func+0x8f/0x1a6 kernel/printk/printk_safe.c:393
 printk+0xba/0xed kernel/printk/printk.c:2070
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:124
 show_iret_regs+0x10/0x32 arch/x86/kernel/dumpstack.c:131
 __show_regs+0x18/0x50 arch/x86/kernel/process_64.c:72
 show_trace_log_lvl+0x255/0x2b4 arch/x86/kernel/dumpstack.c:274
 show_regs arch/x86/kernel/dumpstack.c:447 [inline]
 __die_body arch/x86/kernel/dumpstack.c:393 [inline]
 __die+0x51/0x90 arch/x86/kernel/dumpstack.c:407
 no_context+0x56b/0x9f0 arch/x86/mm/fault.c:695
 __bad_area_nosemaphore+0xa9/0x480 arch/x86/mm/fault.c:789
 do_user_addr_fault+0x8ce/0xd00 arch/x86/mm/fault.c:1258
Lost 45 message(s)!

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	Maintainers
ci-upstream-kasan-gce-386	2020/07/26 08:02	upstream	23ee3e4e	1f7cc1ca	.config	log	report	syz	bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-386	2020/07/28 03:54	upstream	92ed3019	cb93dc6a	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-386	2020/07/14 06:12	upstream	0dc589da	ce4c95b3	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org