ci2 starts bisection 2025-10-14 00:13:09.609608203 +0000 UTC m=+47358.570625655
bisecting fixing commit since 4cf22d97834887b6800b278f9862d78373d7fc5c
building syzkaller on e565f08d1cb546967f255601a17a0c958d06ce6d
ensuring issue is reproducible on original commit 4cf22d97834887b6800b278f9862d78373d7fc5c
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: dc9566b3ed2b49a13a8f6e6b72841908701b40ed7579deefdce2b6a5d490ea3e
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
check whether we can drop unnecessary instrumentation
disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 9503a4e1a36e0b314479add050a25955fdf8afcedc898e7b4f1a258dbbd26914
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the bug reproduces without the instrumentation
disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed
kconfig minimization: base=5186 full=6555 leaves diff=264
split chunks (needed=false): <264>
split chunk #0 of len 264 into 5 parts
testing without sub-chunk 1/5
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 3f1c736d680fb44eeed5033dae04ba4ae5ba54e346bb44be12e72468db91bbad
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 2/5
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: b2268633e454b7fdf0ae525a0b72f9a7543fc18df59433791be927dc3789a644
all runs: OK
false negative chance: 0.000
testing without sub-chunk 3/5
disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 0a0af0ece95f8f48538f60f330b8c2e71115044018f41206d8a170b7f6913420
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 522fa638a3f426f72d66001a1acf423f5763ad010abca4cf988329f973297c5b
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 5/5
disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed
testing commit 4cf22d97834887b6800b278f9862d78373d7fc5c gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 4ee64b9253d90273221c9b95c8bc21e01a6b96c0513f71dfc32d81962b75498d
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
minimized to 53 configs; suspects: [CFG80211 COMMON_CLK CPU_MITIGATIONS FB HID_HOLTEK HID_NTI HID_NTRIG HID_ORTEK HID_PENMOUNT HID_PETALYNX HID_PICOLCD_FB HID_PICOLCD_LEDS HID_PID HID_PRIMAX HID_PRODIKEYS HID_RMI HID_SAITEK HID_SAMSUNG HID_SENSOR_CUSTOM_SENSOR HID_SENSOR_HUB HID_SPEEDLINK HID_STEELSERIES HID_SUNPLUS HID_THINGM HID_TIVO HID_TOPSEED HID_TWINHAN HID_WALTOP HID_XINMO HID_ZYDACRON HOLTEK_FF HOTPLUG_PCI HWMON HW_CONSOLE I2C_DESIGNWARE_CORE I2C_DESIGNWARE_PLATFORM I2C_MUX INPUT_JOYSTICK INPUT_LEDS INPUT_MOUSE INPUT_TOUCHSCREEN INTEGRITY INTEGRITY_AUDIT JOYSTICK_XPAD JOYSTICK_XPAD_FF JOYSTICK_XPAD_LEDS KCOV KCOV_ENABLE_COMPARISONS KCOV_INSTRUMENT_ALL LCD_CLASS_DEVICE LOCK_MM_AND_FIND_VMA LOGIG940_FF LOGIRUMBLEPAD2_FF LOGITECH_FF LOGIWHEELS_FF MAC80211 MEDIA_ANALOG_TV_SUPPORT MEDIA_ATTACH MEDIA_DIGITAL_TV_SUPPORT MEDIA_RADIO_SUPPORT MEDIA_TUNER MFD_CORE MITIGATION_RFDS MITIGATION_SPECTRE_BHI NETFILTER_FAMILY_BRIDGE NET_DEVLINK RFKILL SND SOUND VT WIRELESS]
disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed
testing current HEAD 11f4a3092db93def1074ee14c7066d8802b62943
testing commit 11f4a3092db93def1074ee14c7066d8802b62943 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 80b9864f1f1ac3cebde6fdffea9fa3cb5cc4b130d016b8497d04863649ce02bb
all runs: crashed: KASAN: null-ptr-deref Write in n_tty_flush_buffer
representative crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
crash still not fixed/happens on the oldest tested release
revisions tested: 8, total time: 2h8m46.49150513s (build: 36m56.919398503s, test: 55m15.77354362s)
crash still not fixed or there were kernel test errors
commit msg: UPSTREAM: soc: qcom: mdt_loader: Deal with zero e_shentsize
crash: KASAN: null-ptr-deref Write in n_tty_flush_buffer
==================================================================
BUG: KASAN: null-ptr-deref in reset_buffer_flags drivers/tty/n_tty.c:332 [inline]
BUG: KASAN: null-ptr-deref in n_tty_flush_buffer+0x72/0x390 drivers/tty/n_tty.c:371
Write of size 24 at addr 0000000000000000 by task kworker/0:2/339
CPU: 0 PID: 339 Comm: kworker/0:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events vc_SAK
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
print_report+0x3d/0x60 mm/kasan/report.c:423
kasan_report+0x122/0x150 mm/kasan/report.c:524
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
memset+0x23/0x40 mm/kasan/shadow.c:44
reset_buffer_flags drivers/tty/n_tty.c:332 [inline]
n_tty_flush_buffer+0x72/0x390 drivers/tty/n_tty.c:371
tty_buffer_flush+0x2f5/0x3c0 drivers/tty/tty_buffer.c:242
tty_ldisc_flush+0x6c/0xc0 drivers/tty/tty_ldisc.c:389
__do_SAK+0x132/0x640 drivers/tty/tty_io.c:3011
vc_SAK+0x78/0x220 drivers/tty/vt/vt_ioctl.c:995
process_one_work+0x6e9/0xdc0 kernel/workqueue.c:2302
worker_thread+0x9b3/0x10c0 kernel/workqueue.c:2449
kthread+0x243/0x2c0 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
==================================================================
BUG: unable to handle page fault for address: 0000000000002260
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 11d599067 P4D 11d599067 PUD 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 339 Comm: kworker/0:2 Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events vc_SAK
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc900013d7b58 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000010
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000002260
RBP: ffffc900013d7b78 R08: 0000000000000000 R09: 0000000000002260
R10: fffffbfff0d3e2fd R11: 1ffffffff0d3e2fc R12: 0000000000000000
R13: 000000000000005d R14: 0000000000000000 R15: 0000000000002260
FS: 0000000000000000(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000002260 CR3: 0000000112270000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
reset_buffer_flags drivers/tty/n_tty.c:334 [inline]
n_tty_flush_buffer+0x81/0x390 drivers/tty/n_tty.c:371
tty_buffer_flush+0x2f5/0x3c0 drivers/tty/tty_buffer.c:242
tty_ldisc_flush+0x6c/0xc0 drivers/tty/tty_ldisc.c:389
__do_SAK+0x132/0x640 drivers/tty/tty_io.c:3011
vc_SAK+0x78/0x220 drivers/tty/vt/vt_ioctl.c:995
process_one_work+0x6e9/0xdc0 kernel/workqueue.c:2302
worker_thread+0x9b3/0x10c0 kernel/workqueue.c:2449
kthread+0x243/0x2c0 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Modules linked in:
CR2: 0000000000002260
---[ end trace 0000000000000000 ]---
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc900013d7b58 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000010
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000002260
RBP: ffffc900013d7b78 R08: 0000000000000000 R09: 0000000000002260
R10: fffffbfff0d3e2fd R11: 1ffffffff0d3e2fc R12: 0000000000000000
R13: 000000000000005d R14: 0000000000000000 R15: 0000000000002260
FS: 0000000000000000(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000002260 CR3: 0000000112270000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: c1 e9 03 shr $0x3,%ecx
3: 40 0f b6 f6 movzbl %sil,%esi
7: 48 b8 01 01 01 01 01 movabs $0x101010101010101,%rax
e: 01 01 01
11: 48 0f af c6 imul %rsi,%rax
15: f3 48 ab rep stos %rax,%es:(%rdi)
18: 89 d1 mov %edx,%ecx
1a: f3 aa rep stos %al,%es:(%rdi)
1c: 4c 89 c8 mov %r9,%rax
1f: c3 ret
20: 90 nop
21: 49 89 f9 mov %rdi,%r9
24: 40 88 f0 mov %sil,%al
27: 48 89 d1 mov %rdx,%rcx
* 2a: f3 aa rep stos %al,%es:(%rdi) <-- trapping instruction
2c: 4c 89 c8 mov %r9,%rax
2f: c3 ret
30: 90 nop
31: 49 89 fa mov %rdi,%r10
34: 40 0f b6 ce movzbl %sil,%ecx
38: 48 rex.W
39: b8 01 01 01 01 mov $0x1010101,%eax
3e: 01 01 add %eax,(%rcx)