bisecting cause commit starting from 510c9788991c58827373bca719d8cffa4d65f846 building syzkaller on b80769fcddb9da6408be78bbec0ed600a6cf381c testing commit 510c9788991c58827373bca719d8cffa4d65f846 with gcc (GCC) 8.1.0 kernel signature: 2c0775c306f2318ebe84205e797a7263291b2bd8 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.1.0 kernel signature: adf18b7f73c0b03a3990dc18b252ef2759f8c6de all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.1.0 kernel signature: 463224657e91df1e408e6d2548ba5d5e6bbe1369 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 kernel signature: 718079a91b449bda254abf5825cd0162e5465a14 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.1.0 kernel signature: c314a5be067d3572d4ca07469d150d0de75fc0de all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.1.0 kernel signature: 6ed0e63122d630030b6835ef1c392f2fa0419fe8 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.1.0 kernel signature: acd4cf98e951cad09b5ac80a85f868a496f65d2b all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.1.0 kernel signature: 0499c17dfc0861030429ef7ecc1751b584cf5b3a all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.1.0 kernel signature: e357573d3243f15ad2c52f5b0f83a1be1b873c08 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.1.0 kernel signature: 59bac124a77c4f4cfd1011e9b9295976d959c4b0 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 0163d8da6b9a73f5cbbf29e7d38e68a5ffe01a32 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: b3bfe8278789e42e3914fb5bbb61fb0c07749300 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: d0e348edcb67873e6bbb41321b1cff1859458a24 all runs: crashed: BUG: unable to handle kernel paging request in insert_char testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: b8ed8a5422c136c00e09341b75909ee59829adc4 all runs: crashed: general protection fault in insert_char testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 8ed4846bc5e6fb703ee85b9d4b7f68a46e5481c9 all runs: crashed: general protection fault in insert_char testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.3.0 kernel signature: 15187a54829521b42b3253027b846d0475eedff5 all runs: crashed: general protection fault in insert_char testing release v4.10 testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0 kernel signature: 1024a5a0e37a8b1a13498cdc658ab978d5b9d408 all runs: crashed: general protection fault in insert_char testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 6dcc77f3fdd95db8be8418f520472773c675faf6 all runs: crashed: general protection fault in insert_char testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: caac1e48170816f913b608e4164795f770251048 all runs: crashed: general protection fault in insert_char testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: cf8d90c445acd53c7e038e0e37c994f8dce7b6f4 all runs: crashed: general protection fault in insert_char testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: 802cf9902b969a454ccf751fedbdf879beb98f4a all runs: crashed: general protection fault in insert_char revisions tested: 21, total time: 3h2m38.854067786s (build: 1h45m37.708342347s, test: 1h14m29.35708058s) the crash already happened on the oldest tested release commit msg: Linux 4.6 crash: general protection fault in insert_char IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 7374 Comm: syz-executor.0 Not tainted 4.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800afff0480 ti: ffff8800af008000 task.ti: ffff8800af008000 RIP: 0010:[] [] scr_memsetw include/linux/vt_buffer.h:31 [inline] RIP: 0010:[] [] insert_char+0x19a/0x420 drivers/tty/vt/vt.c:551 RSP: 0018:ffff8800af00f768 EFLAGS: 00010203 RAX: 0000000020000001 RBX: 0000000100000010 RCX: 0000000100000010 RDX: 1ffff10025191b0e RSI: 0000000000000001 RDI: ffff880128c8d870 RBP: ffff8800af00f7b8 R08: 0000000000000720 R09: dffffc0000000000 R10: 0000000000000011 R11: 0000000000000001 R12: 000000010000000e R13: dffffc0000000000 R14: ffff880128c8d4c0 R15: 000000010000000e FS: 00007f4884cf5700(0000) GS:ffff88012c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000758090 CR3: 00000000af0cd000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8800afff0c80 ffff8800afff0c88 ffff8800afff0d50 1ffff10015e01ef2 ffff880000000000 0000000000000000 ffff880128c8d4c0 0000000000000000 ffffed0025191b0f 1ffff10015e01f00 ffff8800af00f928 ffffffff82fdbdae Call Trace: [] csi_at drivers/tty/vt/vt.c:1616 [inline] [] do_con_trol+0x504e/0x5a40 drivers/tty/vt/vt.c:2063 [] do_con_write.part.22+0x487/0x1950 drivers/tty/vt/vt.c:2421 [] do_con_write drivers/tty/vt/vt.c:2779 [inline] [] con_write+0x76/0x90 drivers/tty/vt/vt.c:2775 [] process_output_block drivers/tty/n_tty.c:581 [inline] [] n_tty_write+0x4f0/0x10b0 drivers/tty/n_tty.c:2313 [] do_tty_write drivers/tty/tty_io.c:1175 [inline] [] tty_write+0x44d/0x7f0 drivers/tty/tty_io.c:1260 [] __vfs_write+0xdb/0x4f0 fs/read_write.c:529 [] vfs_write+0x13a/0x4a0 fs/read_write.c:578 [] SYSC_write fs/read_write.c:625 [inline] [] SyS_write+0xcb/0x1a0 fs/read_write.c:617 [] entry_SYSCALL_64_fastpath+0x23/0xc1 Code: 0f b7 86 b0 03 00 00 49 bd 00 00 00 00 00 fc ff df d1 ee 8d 46 ff 85 f6 49 8d 4c 47 02 74 33 49 8d 5c 24 02 4c 89 e0 48 c1 e8 03 <42> 0f b6 14 28 4c 89 e0 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f RIP [] scr_memsetw include/linux/vt_buffer.h:31 [inline] RIP [] insert_char+0x19a/0x420 drivers/tty/vt/vt.c:551 RSP ---[ end trace 9bc0bfbff76e9164 ]---