BUG: unable to handle kernel paging request in vsscanf

Status: upstream: reported C repro on 2026/08/18 15:35
Reported-by: syzbot+6fae63536adc589b37ec@syzkaller.appspotmail.com
First crash: 12d, last: 12h03m
▶ ▼ Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 BUG: unable to handle kernel paging request in vsscanf 8 1 2327d 2327d 0/1 auto-closed as invalid on 2020/08/14 14:44
linux-4.19 BUG: unable to handle kernel paging request in vsscanf 8 2 2189d 2224d 0/1 auto-closed as invalid on 2020/12/30 13:41
upstream BUG: unable to handle kernel paging request in vsscanf (2) net 8 1 2246d 2246d 0/29 auto-closed as invalid on 2020/10/04 11:58
linux-4.19 BUG: unable to handle kernel paging request in vsscanf (2) 8 2 1780d 1883d 0/1 auto-closed as invalid on 2022/02/11 22:53
upstream BUG: unable to handle kernel paging request in vsscanf bridge 8 1 2407d 2407d 0/29 auto-closed as invalid on 2020/04/26 09:37
linux-4.19 BUG: unable to handle kernel paging request in vsscanf (3) 8 1 1588d 1588d 0/1 auto-closed as invalid on 2022/08/22 19:56
android-6-1 general protection fault in vsscanf 2 syz, C 20 7d13h 12d 0/2 upstream: reported C repro on 2026/08/18 10:26
linux-5.15 general protection fault in vsscanf origin:lts-only 2 syz, C 10 11h52m 11d 0/3 upstream: reported C repro on 2026/08/18 22:35
linux-6.6 general protection fault in vsscanf 2 syz, C 13 12h12m 11d 0/2 upstream: reported C repro on 2026/08/19 08:56
android-5-15 general protection fault in vsscanf 2 syz, C 13 12h44m 11d 0/2 upstream: reported C repro on 2026/08/18 22:10
upstream general protection fault in vsscanf (2) mm 2 syz, C 11 616d 622d 28/29 fixed on 2025/05/06 15:33
upstream KMSAN: uninit-value in vsscanf bluetooth 7 syz 9 1641d 1708d 0/29 auto-closed as invalid on 2022/09/27 18:52
android-6-12 general protection fault in vsscanf origin:lts 2 syz, C 29 12h47m 12d 0/1 premoderation: reported C repro on 2026/08/18 03:15
upstream general protection fault in vsscanf v9fs 2 syz, C 7 2942d 2972d 8/29 fixed on 2018/09/03 14:47
android-49 general protection fault in vsscanf 2 syz, C 6 2923d 2695d 0/3 public: reported C repro on 2019/04/14 00:00

Sample crash report:
Unable to handle kernel paging request at virtual address dfff800000000000
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff800000000000] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4522 Comm: syz.0.17 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 : vsscanf+0x170/0x1fe8 lib/vsprintf.c:3446
lr : vsscanf+0x158/0x1fe8 lib/vsprintf.c:3445
sp : ffff800021557320
x29: ffff800021557400 x28: ffff7000042aae70 x27: ffff800017d37b30
x26: dfff800000000000 x25: ffff8000215575c0 x24: ffff800011d968c0
x23: 0000000020001840 x22: 0000000000000030 x21: 0000000000000000
x20: 0000000000000004 x19: ffff800013e49760 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800011b90080 x15: 0000000000000000
x14: 0000000000000025 x13: 0000000000ff0100 x12: ffff800017d37b50
x11: ffff0000d2f6b800 x10: ffff800011a8a6e4 x9 : ffff800011d968c1
x8 : 0000000000000000 x7 : ffff8000215574a0 x6 : ffff800021557580
x5 : ffff8000215574c0 x4 : ffff800021557500 x3 : ffff800011a8c74c
x2 : ffff8000215574a0 x1 : ffff800017d37b30 x0 : 0000000000000030
Call trace:
 vsscanf+0x170/0x1fe8 lib/vsprintf.c:3446
 sscanf+0xd8/0x128 lib/vsprintf.c:3704
 split_huge_pages_write+0x384/0x163c mm/huge_memory.c:3166
 full_proxy_write+0x110/0x1f4 fs/debugfs/file.c:244
 do_loop_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x3d0/0x93c fs/read_write.c:863
 vfs_writev fs/read_write.c:934 [inline]
 do_pwritev+0x1e8/0x338 fs/read_write.c:1031
 __do_sys_pwritev fs/read_write.c:1078 [inline]
 __se_sys_pwritev fs/read_write.c:1073 [inline]
 __arm64_sys_pwritev+0xa4/0xbc fs/read_write.c:1073
 __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: 3400ea36 d343fea8 91000709 f9002fe9 (38fa6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	3400ea36 	cbz	w22, 0x1d44
   4:	d343fea8 	lsr	x8, x21, #3
   8:	91000709 	add	x9, x24, #0x1
   c:	f9002fe9 	str	x9, [sp, #88]
* 10:	38fa6908 	ldrsb	w8, [x8, x26] <-- trapping instruction

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/18 16:22 linux-6.1.y e4f7d8be268e 1e72964b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/18 15:58 linux-6.1.y e4f7d8be268e 1e72964b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/30 05:53 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/30 05:52 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/30 00:19 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/30 00:19 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/29 23:56 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/28 00:00 linux-6.1.y 79a9660d699e 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/28 00:00 linux-6.1.y 79a9660d699e 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/19 01:12 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/19 01:10 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/19 01:10 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/18 23:46 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/18 22:40 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/18 22:38 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/18 15:35 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in vsscanf
2026/08/30 06:18 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in vsscanf
2026/08/30 06:17 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in vsscanf
2026/08/30 01:02 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in vsscanf
2026/08/30 01:01 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in vsscanf
2026/08/29 16:30 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in vsscanf
2026/08/29 16:29 linux-6.1.y d64a499eea6b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in vsscanf
* Struck through repros no longer work on HEAD.