syzbot


BUG: unable to handle kernel paging request in vga16fb_fillrect (2)

Status: upstream: reported C repro on 2021/09/05 18:24
Reported-by: syzbot+89b280d944b001a50ae4@syzkaller.appspotmail.com
First crash: 1012d, last: 653d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel paging request in vga16fb_fillrect (2) fbdev 4 934d 940d 0/27 auto-closed as invalid on 2022/02/20 19:10
upstream BUG: unable to handle kernel paging request in vga16fb_fillrect fbdev C inconclusive 14 950d 1066d 20/27 fixed on 2021/11/10 00:50
linux-4.19 BUG: unable to handle kernel paging request in vga16fb_fillrect C error 5 492d 1062d 0/1 upstream: reported C repro on 2021/07/17 15:13
linux-4.14 BUG: unable to handle kernel paging request in vga16fb_fillrect 1 1640d 1640d 0/1 auto-closed as invalid on 2020/04/15 20:20
Last patch testing requests (1)
Created Duration User Patch Repo Result
2023/03/06 23:32 0m retest repro linux-4.14.y error OK
Fix bisection attempts (8)
Created Duration User Patch Repo Result
2022/05/04 04:03 14m bisect fix linux-4.14.y error job log (0)
2022/04/04 03:35 27m bisect fix linux-4.14.y job log (0) log
2022/03/04 21:03 21m bisect fix linux-4.14.y job log (0) log
2022/02/02 20:38 25m bisect fix linux-4.14.y job log (0) log
2022/01/03 20:07 30m bisect fix linux-4.14.y job log (0) log
2021/12/04 19:42 25m bisect fix linux-4.14.y job log (0) log
2021/11/04 19:18 23m bisect fix linux-4.14.y job log (0) log
2021/10/05 18:48 30m bisect fix linux-4.14.y job log (0) log

Sample crash report:
BUG: unable to handle kernel paging request at ffff888001000050
IP: writeb arch/x86/include/asm/io.h:65 [inline]
IP: vga16fb_fillrect+0x910/0x1820 drivers/video/fbdev/vga16fb.c:923
PGD c9cf067 P4D c9cf067 PUD c9d0067 PMD 80000000010001e1 
Oops: 0003 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 7989 Comm: syz-executor270 Not tainted 4.14.246-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888097172500 task.stack: ffff8880a32b0000
RIP: 0010:writeb arch/x86/include/asm/io.h:65 [inline]
RIP: 0010:vga16fb_fillrect+0x910/0x1820 drivers/video/fbdev/vga16fb.c:923
RSP: 0018:ffff8880a32b73e0 EFLAGS: 00010297
RAX: ffff888097172500 RBX: ffff888001000050 RCX: 00000000000000c0
RDX: 0000000000000000 RSI: ffff8880a32b7470 RDI: ffff8880a32b7480
RBP: 000000000000001b R08: 0000000000000001 R09: ffffed1047111893
R10: ffff88823888c49f R11: 0000000000000000 R12: 000000000ffeb800
R13: 00000000000000a5 R14: ffff88800100006b R15: 0000000000000000
FS:  00000000009cd300(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888001000050 CR3: 00000000b3e3a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 bit_clear_margins+0x3af/0x480 drivers/video/fbdev/core/bitblit.c:224
 fbcon_clear_margins+0x1bb/0x300 drivers/video/fbdev/core/fbcon.c:1266
 fbcon_switch+0xde0/0x19e0 drivers/video/fbdev/core/fbcon.c:2133
 redraw_screen+0x32c/0x790 drivers/tty/vt/vt.c:689
 fbcon_modechanged+0x673/0x8d0 drivers/video/fbdev/core/fbcon.c:2665
 fbcon_event_notify+0x107/0x1760 drivers/video/fbdev/core/fbcon.c:3016
 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x79/0x90 kernel/notifier.c:325
 fb_set_var+0xb3b/0xd20 drivers/video/fbdev/core/fbmem.c:1058
 do_fb_ioctl+0x36d/0xa70 drivers/video/fbdev/core/fbmem.c:1131
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1246
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x43efd9
RSP: 002b:00007ffced794e88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043efd9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 0000000000402fc0 R08: 0000000000000000 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403050
R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488
Code: 85 e4 0f 84 ea fc ff ff e8 4e 3c 18 fe 4d 63 ed 45 31 ff e8 43 3c 18 fe 41 89 ee 49 01 de 85 ed 0f 84 7c 06 00 00 e8 30 3c 18 fe <44> 88 3b 48 83 c3 01 4c 39 f3 75 ef e8 1f 3c 18 fe 4b 8d 1c 2e 
RIP: writeb arch/x86/include/asm/io.h:65 [inline] RSP: ffff8880a32b73e0
RIP: vga16fb_fillrect+0x910/0x1820 drivers/video/fbdev/vga16fb.c:923 RSP: ffff8880a32b73e0
CR2: ffff888001000050
---[ end trace 8c89f355b31faba4 ]---
----------------
Code disassembly (best guess):
   0:	85 e4                	test   %esp,%esp
   2:	0f 84 ea fc ff ff    	je     0xfffffcf2
   8:	e8 4e 3c 18 fe       	callq  0xfe183c5b
   d:	4d 63 ed             	movslq %r13d,%r13
  10:	45 31 ff             	xor    %r15d,%r15d
  13:	e8 43 3c 18 fe       	callq  0xfe183c5b
  18:	41 89 ee             	mov    %ebp,%r14d
  1b:	49 01 de             	add    %rbx,%r14
  1e:	85 ed                	test   %ebp,%ebp
  20:	0f 84 7c 06 00 00    	je     0x6a2
  26:	e8 30 3c 18 fe       	callq  0xfe183c5b
* 2b:	44 88 3b             	mov    %r15b,(%rbx) <-- trapping instruction
  2e:	48 83 c3 01          	add    $0x1,%rbx
  32:	4c 39 f3             	cmp    %r14,%rbx
  35:	75 ef                	jne    0x26
  37:	e8 1f 3c 18 fe       	callq  0xfe183c5b
  3c:	4b 8d 1c 2e          	lea    (%r14,%r13,1),%rbx

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/09/05 18:23 linux-4.14.y f96eb53cbd76 d236a457 .config console log report syz C ci2-linux-4-14 BUG: unable to handle kernel paging request in vga16fb_fillrect
2022/08/31 12:09 linux-4.14.y e548869f356f 51e54e30 .config console log report info [disk image] [vmlinux] ci2-linux-4-14 BUG: unable to handle kernel paging request in vga16fb_fillrect
2022/08/11 09:55 linux-4.14.y b641242202ed 787ed7e0 .config console log report info ci2-linux-4-14 BUG: unable to handle kernel paging request in vga16fb_fillrect
* Struck through repros no longer work on HEAD.