KCSAN: data-race in add_input_randomness / add_input

KCSAN: data-race in add_input_randomness / add_input_randomness (3)
Status: moderation: reported on 2020/12/07 11:45
Reported-by: syzbot+2ccfc09f966037843ba8@syzkaller.appspotmail.com
First crash: 87d, last: 16d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in add_input_randomness / add_input_randomness				2	212d	218d	0/17	auto-closed as invalid on 2020/07/31 12:53
upstream	KCSAN: data-race in add_input_randomness / add_input_randomness (2)				3	148d	176d	0/17	auto-closed as invalid on 2020/10/04 07:48

Sample crash report:

==================================================================
BUG: KCSAN: data-race in add_input_randomness / add_input_randomness

write to 0xffffffff88bee994 of 1 bytes by interrupt on cpu 1:
 add_input_randomness+0x66/0x2a0 drivers/char/random.c:1210
 input_handle_event+0x9dd/0xd50 drivers/input/input.c:378
 input_event+0x7d/0xa0 drivers/input/input.c:446
 hidinput_hid_event+0xb9c/0xcd0 drivers/hid/hid-input.c:1403
 hid_process_event+0x2f3/0x3c0 drivers/hid/hid-core.c:1519
 hid_input_field drivers/hid/hid-core.c:1563 [inline]
 hid_report_raw_event+0xa30/0xd60 drivers/hid/hid-core.c:1783
 hid_input_report+0x2c9/0x330 drivers/hid/hid-core.c:1850
 hid_irq_in+0x2cb/0x3d0 drivers/hid/usbhid/hid-core.c:284
 __usb_hcd_giveback_urb+0x243/0x2e0 drivers/usb/core/hcd.c:1657
 usb_hcd_giveback_urb+0xae/0x210 drivers/usb/core/hcd.c:1728
 dummy_timer+0x4d3/0x2390 drivers/usb/gadget/udc/dummy_hcd.c:1971
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1417
 expire_timers+0x116/0x260 kernel/time/timer.c:1462
 __run_timers+0x338/0x3d0 kernel/time/timer.c:1731
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1744
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu+0xb4/0xc0 kernel/softirq.c:420
 sysvec_apic_timer_interrupt+0x74/0x90 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:516 [inline]
 acpi_idle_enter+0x25b/0x2e0 drivers/acpi/processor_idle.c:647
 cpuidle_enter_state+0x2bd/0x750 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x193/0x230 kernel/sched/idle.c:299
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:396
 secondary_startup_64_no_verify+0xb0/0xbb

read to 0xffffffff88bee994 of 1 bytes by interrupt on cpu 0:
 add_input_randomness+0x35/0x2a0 drivers/char/random.c:1207
 input_handle_event+0x6da/0xd50 drivers/input/input.c:378
 input_event+0x7d/0xa0 drivers/input/input.c:446
 hidinput_hid_event+0xb59/0xcd0 drivers/hid/hid-input.c:1401
 hid_process_event+0x2f3/0x3c0 drivers/hid/hid-core.c:1519
 hid_input_field drivers/hid/hid-core.c:1563 [inline]
 hid_report_raw_event+0xa30/0xd60 drivers/hid/hid-core.c:1783
 hid_input_report+0x2c9/0x330 drivers/hid/hid-core.c:1850
 hid_irq_in+0x2cb/0x3d0 drivers/hid/usbhid/hid-core.c:284
 __usb_hcd_giveback_urb+0x243/0x2e0 drivers/usb/core/hcd.c:1657
 usb_hcd_giveback_urb+0xae/0x210 drivers/usb/core/hcd.c:1728
 dummy_timer+0x4d3/0x2390 drivers/usb/gadget/udc/dummy_hcd.c:1971
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1417
 expire_timers+0x116/0x260 kernel/time/timer.c:1462
 __run_timers+0x338/0x3d0 kernel/time/timer.c:1731
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1744
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu+0xb4/0xc0 kernel/softirq.c:420
 sysvec_apic_timer_interrupt+0x74/0x90 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
 tomoyo_domain_quota_is_ok+0xc9/0x2d0 security/tomoyo/util.c:1061
 tomoyo_supervisor+0x1f4/0xb20 security/tomoyo/common.c:2089
 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
 tomoyo_path_permission security/tomoyo/file.c:587 [inline]
 tomoyo_path_perm+0x261/0x330 security/tomoyo/file.c:838
 tomoyo_inode_getattr+0x18/0x20 security/tomoyo/tomoyo.c:123
 security_inode_getattr+0x7f/0xd0 security/security.c:1280
 vfs_getattr fs/stat.c:121 [inline]
 vfs_fstat+0x45/0x390 fs/stat.c:146
 __do_sys_newfstat fs/stat.c:386 [inline]
 __se_sys_newfstat+0x35/0x240 fs/stat.c:383
 __x64_sys_newfstat+0x2d/0x40 fs/stat.c:383
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27572 Comm: systemd-udevd Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci2-upstream-kcsan-gce	2021/01/08 17:44	upstream	f5e6c330	c104d4a3	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2021/01/04 21:36	upstream	36bbbd0e	2a28ff1f	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2021/01/01 10:56	upstream	f6e1ea19	79264ae3	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2020/12/09 05:43	upstream	7d8761ba	40cc414d	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2020/11/25 23:53	upstream	fa02fcd9	3f581b43	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2020/11/08 21:24	upstream	9dbc1c03	cba33199	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2020/10/30 23:27	upstream	f5d80856	18e33098	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu
ci2-upstream-kcsan-gce	2020/10/29 18:51	upstream	23859ae4	a0c7169a	.config	log	report	info	linux-kernel@vger.kernel.org, tytso@mit.edu