bisecting fixing commit since eb575cd5d7f60241d016fdd13a9e86d962093c9b building syzkaller on c06f97ad4b8a38e6396ff90f6084063f2303ad43 testing commit eb575cd5d7f60241d016fdd13a9e86d962093c9b compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: ec8bdf8dbb081a38788ddfe902820835e2d89c44ae7f0066ac2d8e2ea4992f94 run #0: crashed: WARNING in drm_format_info run #1: crashed: WARNING in drm_format_info run #2: crashed: WARNING in drm_format_info run #3: crashed: WARNING in drm_format_info run #4: crashed: WARNING in drm_format_info run #5: crashed: WARNING in corrupted run #6: crashed: WARNING in drm_format_info run #7: crashed: WARNING in drm_format_info run #8: crashed: WARNING in drm_format_info run #9: crashed: WARNING in drm_format_info run #10: crashed: WARNING in drm_format_info run #11: crashed: WARNING in drm_format_info run #12: crashed: WARNING in drm_format_info run #13: crashed: WARNING in drm_format_info run #14: crashed: WARNING in drm_format_info run #15: crashed: WARNING in drm_format_info run #16: crashed: WARNING in drm_format_info run #17: crashed: WARNING in drm_format_info run #18: crashed: WARNING in drm_format_info run #19: crashed: WARNING in drm_format_info testing current HEAD e34184f53363f6bb873c2fe0ce1a08ed7d16e94a testing commit e34184f53363f6bb873c2fe0ce1a08ed7d16e94a compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 4ce0dc19e489023873fa01f9d58deaa3b55c5d7610e968f8ef878c4edb211288 run #0: crashed: WARNING in drm_format_info run #1: crashed: WARNING in drm_format_info run #2: crashed: WARNING in drm_format_info run #3: crashed: WARNING in drm_format_info run #4: crashed: WARNING in drm_format_info run #5: crashed: WARNING in drm_format_info run #6: crashed: WARNING in corrupted run #7: crashed: WARNING in drm_format_info run #8: crashed: WARNING in drm_format_info run #9: crashed: WARNING in corrupted revisions tested: 2, total time: 27m55.052555591s (build: 20m19.743894376s, test: 7m6.839301377s) the crash still happens on HEAD commit msg: Linux 4.19.210 crash: WARNING in corrupted wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 9863 at drivers/gpu/drm/drm_fourcc.c:204 drm_format_info.part.1+0x10/0x14 drivers/gpu/drm/drm_fourcc.c:204 ------------[ cut here ]------------ Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 9863 Comm: syz-executor.5 Not tainted 4.19.210-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 WARNING: CPU: 0 PID: 9868 at drivers/gpu/drm/drm_fourcc.c:204 drm_format_info.part.1+0x10/0x14 drivers/gpu/drm/drm_fourcc.c:204 panic+0x1cd/0x375 kernel/panic.c:186 Modules linked in: CPU: 0 PID: 9868 Comm: syz-executor.2 Not tainted 4.19.210-syzkaller #0 __warn.cold.7+0x1b/0x36 kernel/panic.c:541 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:drm_format_info.part.1+0x10/0x14 drivers/gpu/drm/drm_fourcc.c:204 report_bug+0x1a1/0x200 lib/bug.c:183 Code: eb cc 4c 89 ff 48 89 75 d0 e8 1e fb fe f9 48 8b 75 d0 49 8b 1f e9 fd 7a 14 fc 55 48 c7 c7 00 85 5f 88 48 89 e5 e8 42 4f f6 ff <0f> 0b 5d c3 48 c7 c7 60 8a 5f 88 e8 32 4f f6 ff 0f 0b e9 4e c5 14 fixup_bug arch/x86/kernel/traps.c:178 [inline] fixup_bug arch/x86/kernel/traps.c:173 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 RSP: 0018:ffff88809931f8f8 EFLAGS: 00010282 RAX: 0000000000000024 RBX: ffffffff885f89e0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff885024a0 RDI: ffffffff8bada720 RBP: ffff88809931f8f8 R08: ffffed1017444ea9 R09: ffffed1017444ea8 R10: ffffed1017444ea8 R11: ffff8880ba227547 R12: 0000000000000044 R13: 00000000b0334142 R14: dffffc0000000000 R15: ffff88809b48db40 FS: 00007f835c17a700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 CR2: 00007fff7b772fd0 CR3: 000000009b4d9000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 RIP: 0010:drm_format_info.part.1+0x10/0x14 drivers/gpu/drm/drm_fourcc.c:204 Call Trace: Code: eb cc 4c 89 ff 48 89 75 d0 e8 1e fb fe f9 48 8b 75 d0 49 8b 1f e9 fd 7a 14 fc 55 48 c7 c7 00 85 5f 88 48 89 e5 e8 42 4f f6 ff <0f> 0b 5d c3 48 c7 c7 60 8a 5f 88 e8 32 4f f6 ff 0f 0b e9 4e c5 14 drm_format_info drivers/gpu/drm/drm_fourcc.c:204 [inline] drm_get_format_info drivers/gpu/drm/drm_fourcc.c:228 [inline] drm_get_format_info+0x12d/0x140 drivers/gpu/drm/drm_fourcc.c:219 RSP: 0018:ffff8880902b78f8 EFLAGS: 00010282 framebuffer_check drivers/gpu/drm/drm_framebuffer.c:178 [inline] drm_internal_framebuffer_create+0x2b0/0x1080 drivers/gpu/drm/drm_framebuffer.c:303 RAX: 0000000000000024 RBX: ffffffff885f89e0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff885024a0 RDI: ffffffff8bada720 RBP: ffff8880902b78f8 R08: ffffed1017464ea9 R09: ffffed1017464ea8 R10: ffffed1017464ea8 R11: ffff8880ba327547 R12: 0000000000000044 R13: 00000000b0334142 R14: dffffc0000000000 R15: ffff8880990d0dc0 drm_format_info drivers/gpu/drm/drm_fourcc.c:204 [inline] drm_get_format_info drivers/gpu/drm/drm_fourcc.c:228 [inline] drm_get_format_info+0x12d/0x140 drivers/gpu/drm/drm_fourcc.c:219 framebuffer_check drivers/gpu/drm/drm_framebuffer.c:178 [inline] drm_internal_framebuffer_create+0x2b0/0x1080 drivers/gpu/drm/drm_framebuffer.c:303 drm_mode_addfb2+0x81/0x2b0 drivers/gpu/drm/drm_framebuffer.c:340 drm_ioctl_kernel+0x1b7/0x240 drivers/gpu/drm/drm_ioctl.c:758 drm_ioctl+0x6be/0xaf0 drivers/gpu/drm/drm_ioctl.c:861 drm_mode_addfb2+0x81/0x2b0 drivers/gpu/drm/drm_framebuffer.c:340 drm_ioctl_kernel+0x1b7/0x240 drivers/gpu/drm/drm_ioctl.c:758 drm_ioctl+0x6be/0xaf0 drivers/gpu/drm/drm_ioctl.c:861 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665d9 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f835c17a188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 RDX: 0000000020000040 RSI: 00000000c06864b8 RDI: 0000000000000003 entry_SYSCALL_64_after_hwframe+0x49/0xbe RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffe71b6e6ff R14: 00007f835c17a300 R15: 0000000000022000 RSP: 002b:00007fe907c64188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 irq event stamp: 68 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 hardirqs last enabled at (67): [] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (67): [] _raw_spin_unlock_irq+0x27/0x90 kernel/locking/spinlock.c:192 hardirqs last disabled at (68): [] trace_hardirqs_off_thunk+0x1a/0x1c RDX: 0000000020000040 RSI: 00000000c06864b8 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 softirqs last enabled at (0): [] copy_process.part.2+0x176b/0x7960 kernel/fork.c:1856 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fffa6f5f17f R14: 00007fe907c64300 R15: 0000000000022000 softirqs last disabled at (0): [<0000000000000000>] (null) ---[ end trace 916daee37cbe9fcb ]--- Kernel Offset: disabled Rebooting in 86400 seconds.. ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall * 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 bc ff ff ff mov $0xffffffffffffffbc,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W