ci2 starts bisection 2025-07-29 09:27:27.170787275 +0000 UTC m=+13878.851501191 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: 86c7b6b1d8dc3a5dbed8155c6a693514f268539699b87fc2ff61f47714ab7159 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 [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], 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: 74744ae77df62f46b633e46900456281420f5f96bef20af05754551f70ff2993 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 [bug_or_warning kasan locking atomic_sleep hang memleak ubsan], 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 [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], 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: 75f09fea9fb8c2e2e6fbf922384e3087ef681eff67f93110e41bdb02b6fcf357 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 [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: 2e8e9a636e3debeb13807a38f54a502d070f372615e8c9768fc81f61e398e23f 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 kasan locking], 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: 6a0cc97fcf6522265cae12aca5c600163cc2f3ac5fb7bc1178251c608c22d969 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: e4dd47f9467398826ad8a6748905b4fc9f124a531d1c8d0f4d200c042bf29f90 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 [atomic_sleep hang memleak ubsan bug_or_warning kasan locking], 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: c942fc066004d388bf50d071a70886173eb79d49c05b84eee7cf3549e8661457 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 [bug_or_warning kasan locking atomic_sleep hang memleak ubsan], they are not needed testing current HEAD f32b52534f1d4df1fc1a6afe6cf4639adebf8a63 testing commit f32b52534f1d4df1fc1a6afe6cf4639adebf8a63 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: d91b98339d92a80789ed69898d9632b7ce8f22b1918ec79bd57507b5166195ed 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: 1h45m13.732632017s (build: 15m35.51593029s, test: 1h24m23.663727787s) 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 11cce8067 P4D 11cce8067 PUD 0 Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 372 Comm: kworker/0:3 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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: 50 02 79 ff 4d 8d ac 24 f0 00 00 00 4c 89 ef e8 f0 1a 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:ffffc9000202bd38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff81b69980 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000001060 RDI: 00000000ffffffff RBP: ffffc9000202bd48 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: ffff88810a712000 R13: ffff88810a7120f0 R14: ffff88810a712218 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000112a37000 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 e65471b858a3b29c ]--- 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: 50 02 79 ff 4d 8d ac 24 f0 00 00 00 4c 89 ef e8 f0 1a 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:ffffc9000202bd38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff81b69980 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000001060 RDI: 00000000ffffffff RBP: ffffc9000202bd48 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: ffff88810a712000 R13: ffff88810a7120f0 R14: ffff88810a712218 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000112a37000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 50 push %rax 1: 02 79 ff add -0x1(%rcx),%bh 4: 4d 8d ac 24 f0 00 00 lea 0xf0(%r12),%r13 b: 00 c: 4c 89 ef mov %r13,%rdi f: e8 f0 1a c0 00 call 0xc01b04 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)