BUG: unable to handle kernel paging request in bitfill_aligned

Status: upstream: reported on 2026/08/15 01:29
Reported-by: syzbot+6af5de424a53c7e0070e@syzkaller.appspotmail.com
First crash: 15h49m, last: 15h49m
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel paging request in bitfill_aligned (4) fbdev 8 8 534d 615d 0/29 auto-obsoleted due to no activity on 2025/06/07 17:05
linux-4.14 BUG: unable to handle kernel paging request in bitfill_aligned 8 1 1458d 1458d 0/1 auto-obsoleted due to no activity on 2022/12/16 16:52
linux-4.19 BUG: unable to handle kernel paging request in bitfill_aligned 8 syz, C error 11 1279d 1709d 0/1 upstream: reported C repro on 2021/12/10 10:17
upstream BUG: unable to handle kernel paging request in bitfill_aligned (3) fbdev 8 syz, C unreliable 11 1453d 1496d 22/29 fixed on 2023/02/24 13:50
upstream BUG: unable to handle kernel paging request in bitfill_aligned (2) fbdev 21 syz, C inconclusive done 26 1689d 2096d 20/29 fixed on 2022/05/13 11:13
upstream BUG: unable to handle kernel paging request in bitfill_aligned fbdev 8 1 2288d 2286d 0/29 closed as dup on 2020/08/16 15:35

Sample crash report:
Unable to handle kernel paging request at virtual address ffff7000048f9200
KASAN: maybe wild-memory-access in range [0xffff8000247c9000-0xffff8000247c9007]
Mem abort info:
  ESR = 0x0000000096000007
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x07: level 3 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000007
  CM = 0, WnR = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000020dd2e000
[ffff7000048f9200] pgd=000000023ea48003, p4d=000000023ea48003, pud=000000023ea47003, pmd=100000010daa8003, pte=0000000000000000
Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 6529 Comm: syz.5.764 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 22400005 (nzCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : memset64+0x7c/0x118 lib/string.c:694
lr : memset_l include/linux/string.h:169 [inline]
lr : bitfill_aligned+0x16c/0x20c drivers/video/fbdev/core/sysfillrect.c:53
sp : ffff800021726e60
x29: ffff800021726e60 x28: 0000000000000180 x27: ffff8000247c9008
x26: dfff800000000000 x25: 0000000000000180 x24: 0000000000000000
x23: ffff8000247c9000 x22: 0000000000000180 x21: ffff8000247c9c00
x20: 0000000000000000 x19: ffff8000247c9000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff8000082dbd3c x15: 0000000000000002
x14: 0000000000000001 x13: 0000000000ff0100 x12: 0000000000080000
x11: 000000000003d6de x10: ffff800034000000 x9 : ffff80000aef73dc
x8 : 1ffff000048f9200 x7 : 0000000000000000 x6 : 0000000000000007
x5 : 0000000000000040 x4 : 0000000000006000 x3 : 0000000000000000
x2 : 0000000000000180 x1 : 0000000000000000 x0 : ffff8000247c9000
Call trace:
 memset64+0x7c/0x118 lib/string.c:694
 memset_l include/linux/string.h:169 [inline]
 bitfill_aligned+0x16c/0x20c drivers/video/fbdev/core/sysfillrect.c:53
 sys_fillrect+0x538/0x708 drivers/video/fbdev/core/sysfillrect.c:281
 drm_fb_helper_sys_fillrect+0x40/0x464 drivers/gpu/drm/drm_fb_helper.c:834
 drm_fbdev_fb_fillrect+0x170/0x1dc drivers/gpu/drm/drm_fb_helper.c:2384
 bit_clear+0x134/0x1cc drivers/video/fbdev/core/bitblit.c:73
 __fbcon_clear+0x420/0x73c drivers/video/fbdev/core/fbcon.c:1283
 fbcon_scroll+0x33c/0x5ac drivers/video/fbdev/core/fbcon.c:-1
 con_scroll+0x408/0x630 drivers/tty/vt/vt.c:630
 csi_M+0xa8/0x144 drivers/tty/vt/vt.c:2055
 do_con_trol drivers/tty/vt/vt.c:2463 [inline]
 do_con_write+0x3964/0x6030 drivers/tty/vt/vt.c:2951
 con_put_char+0x8c/0xd0 drivers/tty/vt/vt.c:3303
 tty_put_char+0xcc/0x148 drivers/tty/tty_io.c:3140
 do_output_char+0x518/0x7bc drivers/tty/n_tty.c:481
 process_output drivers/tty/n_tty.c:506 [inline]
 n_tty_write+0xbec/0xf50 drivers/tty/n_tty.c:2389
 do_tty_write drivers/tty/tty_io.c:1018 [inline]
 file_tty_write+0x3c0/0x6d8 drivers/tty/tty_io.c:1089
 tty_write+0x44/0x54 drivers/tty/tty_io.c:1110
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3c8/0x7c8 fs/read_write.c:584
 ksys_write+0x12c/0x228 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 910042f7 f8010774 540001c0 d343fee8 (387a6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	910042f7 	add	x23, x23, #0x10
   4:	f8010774 	str	x20, [x27], #16
   8:	540001c0 	b.eq	0x40  // b.none
   c:	d343fee8 	lsr	x8, x23, #3
* 10:	387a6908 	ldrb	w8, [x8, x26] <-- trapping instruction

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/15 01:29 linux-6.1.y e4f7d8be268e 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in bitfill_aligned
* Struck through repros no longer work on HEAD.