syzbot


WARNING in handle_userfault

Status: upstream: reported C repro on 2023/07/05 06:32
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+339b02f826caafd5f7a8@syzkaller.appspotmail.com
Fix commit: mm: fix a lockdep issue in vma_assert_write_locked
Patched on: [ci-upstream-linux-next-kasan-gce-root], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 1110d, last: 1103d
Cause bisection: failed (error log, bisect log)
  
✨ AI Jobs (6)
ID Workflow Result Correct Bug Created Started Finished Revision Error
8ac2fec3-093e-4177-a31b-b95676d4ca0f assessment-security 💥 WARNING in handle_userfault 2026/07/05 07:58 2026/07/05 07:58 2026/07/05 08:21 93f579545ae410f5bccfa141d2e7bf03178f036c
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/b470468989f632692b...
truncated to first 200 bytes; open job for full error
66696af0-b1bb-41d9-8cc9-22431f3107f4 assessment-security 💥 WARNING in handle_userfault 2026/06/18 07:43 2026/06/18 07:43 2026/06/18 08:02 b62b3ded1759f79b37600c5ffe2b0a81b919b0b0
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/b470468989f632692b...
truncated to first 200 bytes; open job for full error
510a5030-fba7-4be9-a133-8e32572c89a2 assessment-security 💥 WARNING in handle_userfault 2026/06/10 03:28 2026/06/10 03:28 2026/06/10 03:43 c36c07f6c1f2230a36374cbd22235f635e8f9284
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/b470468989f632692b...
truncated to first 200 bytes; open job for full error
9904d4d9-5a1a-43cd-994a-bc0ddd9848f5 assessment-security 💥 WARNING in handle_userfault 2026/06/04 06:22 2026/06/04 06:22 2026/06/04 06:35 62fe15281f5011cd203d8845b8767b10e7443aa5
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/b470468989f632692b...
truncated to first 200 bytes; open job for full error
f8af91ab-66e4-4873-a4d1-39720e22f135 assessment-security 💥 WARNING in handle_userfault 2026/06/02 03:07 2026/06/02 03:07 2026/06/02 03:28 386cc6dacdf7e3ebce9507beed6755d7e999554d
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/b470468989f632692b...
truncated to first 200 bytes; open job for full error
7f078a84-18d6-4378-9c3b-1a7826a205ce assessment-security 💥 WARNING in handle_userfault 2026/05/21 08:47 2026/05/21 08:47 2026/05/21 09:08 cf874a1cf36318c06202027159ddac14acf00db7
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/b470468989f632692b...
truncated to first 200 bytes; open job for full error
Discussions (2)
Title Replies (including bot) Last reply
[PATCH 1/1] mm: fix a lockdep issue in vma_assert_write_locked 2 (2) 2023/07/12 20:00
[syzbot] [fs?] WARNING in handle_userfault 3 (5) 2023/07/12 19:59

Sample crash report:
kvm_intel: L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5028 at include/linux/mmap_lock.h:71 mmap_assert_write_locked include/linux/mmap_lock.h:71 [inline]
WARNING: CPU: 0 PID: 5028 at include/linux/mmap_lock.h:71 __is_vma_write_locked include/linux/mm.h:712 [inline]
WARNING: CPU: 0 PID: 5028 at include/linux/mmap_lock.h:71 vma_assert_locked include/linux/mm.h:753 [inline]
WARNING: CPU: 0 PID: 5028 at include/linux/mmap_lock.h:71 assert_fault_locked include/linux/mm.h:786 [inline]
WARNING: CPU: 0 PID: 5028 at include/linux/mmap_lock.h:71 handle_userfault+0x149b/0x27a0 fs/userfaultfd.c:440
Modules linked in:
CPU: 0 PID: 5028 Comm: syz-executor359 Not tainted 6.4.0-next-20230705-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:mmap_assert_write_locked include/linux/mmap_lock.h:71 [inline]
RIP: 0010:__is_vma_write_locked include/linux/mm.h:712 [inline]
RIP: 0010:vma_assert_locked include/linux/mm.h:753 [inline]
RIP: 0010:assert_fault_locked include/linux/mm.h:786 [inline]
RIP: 0010:handle_userfault+0x149b/0x27a0 fs/userfaultfd.c:440
Code: ff 49 8d bc 24 a0 01 00 00 31 f6 e8 2f b9 23 08 31 ff 41 89 c5 89 c6 e8 c3 a2 87 ff 45 85 ed 0f 85 83 ed ff ff e8 95 a6 87 ff <0f> 0b e9 77 ed ff ff e8 89 a6 87 ff 49 8d bc 24 a0 01 00 00 be ff
RSP: 0000:ffffc90003a4fb68 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffc90003a4fd88 RCX: 0000000000000000
RDX: ffff8880133bbb80 RSI: ffffffff81fd6ddb RDI: 0000000000000005
RBP: 0000000000000200 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807d8e4280
R13: 0000000000000000 R14: ffff888021cb9110 R15: ffff888021cb9100
FS:  000055555738f300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020b7d800 CR3: 0000000029d0e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_anonymous_page mm/memory.c:4151 [inline]
 do_pte_missing mm/memory.c:3671 [inline]
 handle_pte_fault mm/memory.c:4949 [inline]
 __handle_mm_fault+0x35ff/0x3cc0 mm/memory.c:5089
 handle_mm_fault+0x3c2/0xa20 mm/memory.c:5254
 do_user_addr_fault+0x2ed/0x13a0 arch/x86/mm/fault.c:1365
 handle_page_fault arch/x86/mm/fault.c:1509 [inline]
 exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1565
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7faa694e34d5
Code: 52 89 c2 01 f6 29 f2 83 fa 05 0f 87 0a 02 00 00 48 63 14 97 48 01 fa ff e2 0f 1f 40 00 4c 89 d2 66 c1 e9 03 83 c0 01 0f b7 c9 <48> 89 14 cd 00 d8 b7 20 83 f8 20 75 b6 48 8b 84 24 f0 00 00 00 f3
RSP: 002b:00007ffefcb0d8e0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000860000109120 RSI: 0000000000000000 RDI: 00007faa69564020
RBP: 0000000000000006 R08: 0000830000789120 R09: 00000000aaaaaaab
R10: 0000870000109120 R11: 00008f0000309120 R12: 00008b0000889120
R13: 0000000000000000 R14: 00008e0000309120 R15: 00007ffefcb0de40
 </TASK>

Crashes (71):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/05 13:15 linux-next e1f6a8eaf1c2 80298b6f .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/12 16:05 linux-next 40b055fe7f27 979d5fe2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/12 09:09 linux-next 40b055fe7f27 2f19aa4f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/12 05:25 linux-next 40b055fe7f27 2f19aa4f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/12 01:52 linux-next 8e4b7f2f3d60 2f19aa4f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/12 00:44 linux-next 8e4b7f2f3d60 2f19aa4f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/11 15:24 linux-next 8e4b7f2f3d60 f8780940 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/11 15:05 linux-next 8e4b7f2f3d60 f8780940 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/11 13:51 linux-next 8e4b7f2f3d60 f8780940 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/11 11:54 linux-next 8e4b7f2f3d60 f8780940 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 17:33 linux-next fe57d0d86f03 52ae002a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 12:08 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 07:14 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 06:11 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 06:11 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 06:01 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 05:43 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 05:35 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 04:48 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 04:40 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 04:39 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 04:34 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 04:22 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 04:19 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 03:59 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 03:20 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/10 03:10 linux-next fe57d0d86f03 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/06 01:39 linux-next e1f6a8eaf1c2 ba5dba36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 11:08 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 11:01 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 10:47 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 10:40 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 10:35 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 10:15 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 10:12 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 09:49 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 09:47 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 09:39 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 09:37 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 09:12 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 08:48 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 08:36 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 08:30 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 08:17 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 07:37 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 07:36 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 07:35 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 07:26 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 06:50 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 06:48 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 05:59 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 05:50 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
2023/07/05 05:43 linux-next e1f6a8eaf1c2 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in handle_userfault
* Struck through repros no longer work on HEAD.