syzbot


WARNING in __vmap_pages_range_noflush

Status: upstream: reported C repro on 2025/08/08 08:17
Subsystems: io-uring
[Documentation on labels]
Reported-by: syzbot+23727438116feb13df15@syzkaller.appspotmail.com
Fix commit: 33503c083fda io_uring/memmap: cast nr_pages to size_t before shifting
Patched on: [ci-qemu-gce-upstream-auto 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-linux-next-kasan-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], missing on: [ci-qemu-native-arm64-kvm]
First crash: 26d, last: 26d
Cause bisection: introduced by (bisect log) :
commit 087f997870a948820ec366701d178f402c6a23a3
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri Nov 29 13:34:32 2024 +0000

  io_uring/memmap: implement mmap for regions

Crash: WARNING in __vmap_pages_range_noflush (log)
Repro: C syz .config
  
Duplicate bugs (1)
duplicates (1):
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
WARNING in vmap_small_pages_range_noflush io-uring -1 C done 4 26d 22d 0/29 closed as dup on 2025/08/11 19:52
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [io-uring?] WARNING in __vmap_pages_range_noflush 3 (7) 2025/08/08 13:11
[PATCH] io_uring/memmap: cast nr_pages to size_t before shifting 1 (1) 2025/08/08 12:42
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/08/08 12:43 22m axboe@kernel.dk patch upstream OK log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5848 at mm/vmalloc.c:542 vmap_pages_pte_range mm/vmalloc.c:542 [inline]
WARNING: CPU: 1 PID: 5848 at mm/vmalloc.c:542 vmap_pages_pmd_range mm/vmalloc.c:569 [inline]
WARNING: CPU: 1 PID: 5848 at mm/vmalloc.c:542 vmap_pages_pud_range mm/vmalloc.c:587 [inline]
WARNING: CPU: 1 PID: 5848 at mm/vmalloc.c:542 vmap_pages_p4d_range mm/vmalloc.c:605 [inline]
WARNING: CPU: 1 PID: 5848 at mm/vmalloc.c:542 vmap_small_pages_range_noflush mm/vmalloc.c:627 [inline]
WARNING: CPU: 1 PID: 5848 at mm/vmalloc.c:542 __vmap_pages_range_noflush+0xd4e/0xe10 mm/vmalloc.c:656
Modules linked in:
CPU: 1 UID: 0 PID: 5848 Comm: syz-executor242 Tainted: G        W           6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:vmap_pages_pte_range mm/vmalloc.c:542 [inline]
RIP: 0010:vmap_pages_pmd_range mm/vmalloc.c:569 [inline]
RIP: 0010:vmap_pages_pud_range mm/vmalloc.c:587 [inline]
RIP: 0010:vmap_pages_p4d_range mm/vmalloc.c:605 [inline]
RIP: 0010:vmap_small_pages_range_noflush mm/vmalloc.c:627 [inline]
RIP: 0010:__vmap_pages_range_noflush+0xd4e/0xe10 mm/vmalloc.c:656
Code: b1 ff eb 2f e8 53 5f b1 ff 45 31 e4 eb 25 e8 49 5f b1 ff 90 0f 0b 90 eb 14 e8 3e 5f b1 ff 90 0f 0b 90 eb 09 e8 33 5f b1 ff 90 <0f> 0b 90 41 bc f4 ff ff ff 44 89 e0 48 81 c4 e0 00 00 00 5b 41 5c
RSP: 0018:ffffc900046178d8 EFLAGS: 00010293
RAX: ffffffff820cfc2d RBX: ffff888063a5ddc8 RCX: ffff888034e81dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffea0003000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1e3a007 R12: ffffc9008c1ba000
R13: 1ffff1100c74bbb9 R14: 0000000000000000 R15: dffffc0000000000
FS:  00005555626ac380(0000) GS:ffff8881269cb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000565012284e70 CR3: 0000000041000000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 vmap_pages_range_noflush mm/vmalloc.c:681 [inline]
 vmap_pages_range mm/vmalloc.c:701 [inline]
 vmap+0x1ca/0x310 mm/vmalloc.c:3515
 io_region_init_ptr+0x24d/0x350 io_uring/memmap.c:125
 io_create_region+0x3a4/0x480 io_uring/memmap.c:228
 io_create_region_mmap_safe+0xc0/0x180 io_uring/memmap.c:245
 io_register_mem_region+0x27a/0x3c0 io_uring/register.c:616
 __io_uring_register io_uring/register.c:836 [inline]
 __do_sys_io_uring_register io_uring/register.c:929 [inline]
 __se_sys_io_uring_register+0x3b4/0x1130 io_uring/register.c:906
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f22db281b39
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd35fed818 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 0000000000000045 RCX: 00007f22db281b39
RDX: 0000200000000200 RSI: 0000000000000022 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000010000000 R09: 0000000000000006
R10: 0000000000000001 R11: 0000000000000246 R12: 0000200000000300
R13: 0000200000000100 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/07 23:40 upstream 6e64f4580381 04cffc22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 22:05 upstream 6e64f4580381 04cffc22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 20:08 upstream 6e64f4580381 04cffc22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 19:17 upstream 6e64f4580381 04cffc22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 19:03 upstream 038d61fd6422 04cffc22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in __vmap_pages_range_noflush
2025/08/07 18:28 upstream 6e64f4580381 04cffc22 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 19:31 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in __vmap_pages_range_noflush
2025/08/07 19:31 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in __vmap_pages_range_noflush
2025/08/07 18:16 upstream 038d61fd6422 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in __vmap_pages_range_noflush
2025/08/07 18:16 upstream 038d61fd6422 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in __vmap_pages_range_noflush
2025/08/07 17:37 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 17:36 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in __vmap_pages_range_noflush
2025/08/07 18:59 linux-next 442d93313cae 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __vmap_pages_range_noflush
2025/08/07 18:58 linux-next 442d93313cae 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __vmap_pages_range_noflush
* Struck through repros no longer work on HEAD.