ci2 starts bisection 2025-09-04 09:52:14.466036332 +0000 UTC m=+28249.455010168 bisecting fixing commit since e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 building syzkaller on 98683f8f094a4a5418f62711143436a99522360e ensuring issue is reproducible on original commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9bc21e3a4010d2a81420c95d104e7e59b995dfa2d20b2b671846c7cb4d3a41dd all runs: crashed: general protection fault in n_tty_flush_buffer representative crash: general protection fault in n_tty_flush_buffer, types: [DoS] check whether we can drop unnecessary instrumentation disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning kasan], they are not needed testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 6b790da2389e809260c3a01db748b400d66bf7eff175f58e3355a72d652276f8 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer representative crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer, types: [NULL-POINTER-DEREFERENCE] the bug reproduces without the instrumentation disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep hang memleak], they are not needed kconfig minimization: base=4921 full=6218 leaves diff=253 split chunks (needed=false): <253> split chunk #0 of len 253 into 5 parts testing without sub-chunk 1/5 disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 3db6b92d757a861d858852b35f7e303960f3f82417a4c460121d9c5954fda33c all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer representative crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep hang], they are not needed testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 51e4b93c4dbad519299e6070e97d213fbafdc15ca3f507da6184d21d6a2d0255 all runs: OK false negative chance: 0.000 testing without sub-chunk 3/5 disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep hang memleak], they are not needed testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 95ed5ab6d079786625c6cf24846aba12e708a783a5583f6e82a61a2604e53840 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer representative crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep hang], they are not needed testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 2548c723f8a1d6a0fdc657964181d2863da6ab6f914e6ead5d1ebc0d3c220b84 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer representative crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [bug_or_warning kasan locking atomic_sleep hang memleak ubsan], they are not needed testing commit e678c93d43cc59dbad86bb0ad0ff6a7ed675a154 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 2df9d02ebd7c6eabf969121acf013ea0a0a3bb1c08c589df801a030630d036a4 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer representative crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer, types: [NULL-POINTER-DEREFERENCE] the chunk can be dropped minimized to 51 configs; suspects: [CFG80211 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_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 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 NF_FLOW_TABLE_PROCFS RFKILL SND SOUND VT WIRELESS] disabling configs for [hang memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed testing current HEAD da3dbfdd15be0f7780f9c4807c7bf5429d52f201 testing commit da3dbfdd15be0f7780f9c4807c7bf5429d52f201 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 41fa5244d7b1680e1c953c271e7745b642d70544692a8948c5ec84d9aa0636a5 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer representative crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer, types: [NULL-POINTER-DEREFERENCE] crash still not fixed/happens on the oldest tested release revisions tested: 8, total time: 1h44m45.168452768s (build: 20m27.864357781s, test: 1h20m8.012800414s) crash still not fixed or there were kernel test errors commit msg: Merge android13-5.15 into android13-5.15-lts crash: BUG: unable to handle kernel NULL pointer dereference in n_tty_flush_buffer BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 120345067 P4D 120345067 PUD 0 Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 38 Comm: kworker/0:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events vc_SAK RIP: 0010:reset_buffer_flags drivers/tty/n_tty.c:332 [inline] RIP: 0010:n_tty_flush_buffer+0x36/0xa0 drivers/tty/n_tty.c:370 Code: f0 ff 78 ff 4d 8d ac 24 f0 00 00 00 4c 89 ef e8 10 fc c0 00 49 8b 94 24 b8 02 00 00 31 c0 b9 40 00 00 00 48 8d b2 60 10 00 00 <48> c7 42 10 00 00 00 00 48 89 f7 48 c7 02 00 00 00 00 48 c7 82 60 RSP: 0018:ffffc90000143d38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff81b69e40 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000001060 RDI: 00000000ffffffff RBP: ffffc90000143d48 R08: 000000000000000c R09: 0000000000000004 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88811da5f800 R13: ffff88811da5f8f0 R14: ffff88811da5fa18 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 00000001207ec000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tty_buffer_flush+0x10f/0x140 drivers/tty/tty_buffer.c:241 tty_ldisc_flush+0x4c/0xa0 drivers/tty/tty_ldisc.c:400 __do_SAK.part.0+0x1e5/0x230 drivers/tty/tty_io.c:3051 __do_SAK+0x20/0x30 drivers/tty/tty_io.c:3044 vc_SAK+0x3e/0xb0 drivers/tty/vt/vt_ioctl.c:993 process_one_work+0x243/0x510 kernel/workqueue.c:2325 worker_thread+0x5c/0x530 kernel/workqueue.c:2472 kthread+0x17b/0x1b0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Modules linked in: CR2: 0000000000000010 ---[ end trace 87ba8840c863e47e ]--- RIP: 0010:reset_buffer_flags drivers/tty/n_tty.c:332 [inline] RIP: 0010:n_tty_flush_buffer+0x36/0xa0 drivers/tty/n_tty.c:370 Code: f0 ff 78 ff 4d 8d ac 24 f0 00 00 00 4c 89 ef e8 10 fc c0 00 49 8b 94 24 b8 02 00 00 31 c0 b9 40 00 00 00 48 8d b2 60 10 00 00 <48> c7 42 10 00 00 00 00 48 89 f7 48 c7 02 00 00 00 00 48 c7 82 60 RSP: 0018:ffffc90000143d38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff81b69e40 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000001060 RDI: 00000000ffffffff RBP: ffffc90000143d48 R08: 000000000000000c R09: 0000000000000004 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88811da5f800 R13: ffff88811da5f8f0 R14: ffff88811da5fa18 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 00000001207ec000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: f0 ff lock (bad) 2: 78 ff js 0x3 4: 4d 8d ac 24 f0 00 00 lea 0xf0(%r12),%r13 b: 00 c: 4c 89 ef mov %r13,%rdi f: e8 10 fc c0 00 call 0xc0fc24 14: 49 8b 94 24 b8 02 00 mov 0x2b8(%r12),%rdx 1b: 00 1c: 31 c0 xor %eax,%eax 1e: b9 40 00 00 00 mov $0x40,%ecx 23: 48 8d b2 60 10 00 00 lea 0x1060(%rdx),%rsi * 2a: 48 c7 42 10 00 00 00 movq $0x0,0x10(%rdx) <-- trapping instruction 31: 00 32: 48 89 f7 mov %rsi,%rdi 35: 48 c7 02 00 00 00 00 movq $0x0,(%rdx) 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: 82 (bad) 3f: 60 (bad)