syzbot has found a reproducer for the following issue on: HEAD commit: 7ebfc85e2cd7 Merge tag 'net-6.0-rc1' of git://git.kernel.o.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=179c3aa5080000 kernel config: https://syzkaller.appspot.com/x/.config?x=20bc0b329895d963 dashboard link: https://syzkaller.appspot.com/bug?extid=a168dbeaaa7778273c1b compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16e0ef4b080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11a1183d080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a168dbeaaa7778273c1b@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: unable to handle page fault for address: ffffc900043a1000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 12000067 P4D 12000067 PUD 121c9067 PMD 14733a067 PTE 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 3633 Comm: syz-executor339 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 RIP: 0010:memset64 arch/x86/include/asm/string_64.h:49 [inline] RIP: 0010:memset_l include/linux/string.h:128 [inline] RIP: 0010:bitfill_aligned+0x1ad/0x270 drivers/video/fbdev/core/sysfillrect.c:53 Code: 08 49 31 ef eb 66 e8 52 38 03 fd 45 89 e6 4c 8b 64 24 10 44 89 f0 31 d2 f7 f3 89 c3 48 8b 6c 24 08 48 89 e8 4c 89 e7 48 89 d9 <f3> 48 ab 31 ff 44 89 ee e8 46 3c 03 fd 4d 85 ed 74 5f 4d 8d 24 dc RSP: 0018:ffffc90003a6f7e8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000ffc RCX: 00000000000001fc RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900043a1000 RBP: 0000000000000000 R08: ffffffff848659ae R09: 0000000000000040 R10: 0000000000000002 R11: ffff888021ffd880 R12: ffffc9000439a000 R13: 0000000000000000 R14: 000000000003ff00 R15: ffffffffffffffff FS: 0000555556df7300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc900043a1000 CR3: 0000000072ba0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> sys_fillrect+0x5ce/0x7f0 drivers/video/fbdev/core/sysfillrect.c:281 drm_fb_helper_sys_fillrect drivers/gpu/drm/drm_fb_helper.c:807 [inline] drm_fbdev_fb_fillrect+0x163/0x300 drivers/gpu/drm/drm_fb_helper.c:2322 bit_clear_margins+0x3f1/0x6e0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1306 [inline] fbcon_do_set_font+0xd7c/0x1330 drivers/video/fbdev/core/fbcon.c:2431 fbcon_set_font+0xc29/0xf70 drivers/video/fbdev/core/fbcon.c:2519 con_font_set drivers/tty/vt/vt.c:4666 [inline] con_font_op+0xbe8/0x1070 drivers/tty/vt/vt.c:4710 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x172e/0x1d00 drivers/tty/vt/vt_ioctl.c:752 tty_ioctl+0x874/0xc60 drivers/tty/tty_io.c:2778 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7efe5924e239 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fffba970648 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007efe5924e239 RDX: 0000000020000000 RSI: 0000000000004b72 RDI: 0000000000000004 RBP: 00007fffba970660 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 00007fffba97065c R14: 00007fffba970680 R15: 00007fffba970670 </TASK> Modules linked in: CR2: ffffc900043a1000 ---[ end trace 0000000000000000 ]--- RIP: 0010:memset64 arch/x86/include/asm/string_64.h:49 [inline] RIP: 0010:memset_l include/linux/string.h:128 [inline] RIP: 0010:bitfill_aligned+0x1ad/0x270 drivers/video/fbdev/core/sysfillrect.c:53 Code: 08 49 31 ef eb 66 e8 52 38 03 fd 45 89 e6 4c 8b 64 24 10 44 89 f0 31 d2 f7 f3 89 c3 48 8b 6c 24 08 48 89 e8 4c 89 e7 48 89 d9 <f3> 48 ab 31 ff 44 89 ee e8 46 3c 03 fd 4d 85 ed 74 5f 4d 8d 24 dc RSP: 0018:ffffc90003a6f7e8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000ffc RCX: 00000000000001fc RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900043a1000 RBP: 0000000000000000 R08: ffffffff848659ae R09: 0000000000000040 R10: 0000000000000002 R11: ffff888021ffd880 R12: ffffc9000439a000 R13: 0000000000000000 R14: 000000000003ff00 R15: ffffffffffffffff FS: 0000555556df7300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc900043a1000 CR3: 0000000072ba0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 08 49 31 or %cl,0x31(%rcx) 3: ef out %eax,(%dx) 4: eb 66 jmp 0x6c 6: e8 52 38 03 fd callq 0xfd03385d b: 45 89 e6 mov %r12d,%r14d e: 4c 8b 64 24 10 mov 0x10(%rsp),%r12 13: 44 89 f0 mov %r14d,%eax 16: 31 d2 xor %edx,%edx 18: f7 f3 div %ebx 1a: 89 c3 mov %eax,%ebx 1c: 48 8b 6c 24 08 mov 0x8(%rsp),%rbp 21: 48 89 e8 mov %rbp,%rax 24: 4c 89 e7 mov %r12,%rdi 27: 48 89 d9 mov %rbx,%rcx * 2a: f3 48 ab rep stos %rax,%es:(%rdi) <-- trapping instruction 2d: 31 ff xor %edi,%edi 2f: 44 89 ee mov %r13d,%esi 32: e8 46 3c 03 fd callq 0xfd033c7d 37: 4d 85 ed test %r13,%r13 3a: 74 5f je 0x9b 3c: 4d 8d 24 dc lea (%r12,%rbx,8),%r12
