WARNING in mas_nomem

Status: upstream: reported syz repro on 2026/07/31 07:30
Subsystems: mm
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+78a7af91b68fc6394771@syzkaller.appspotmail.com
First crash: 8d16h, last: 5d07h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
b0ab9fed patching 💥 WARNING in mas_nomem 2026/07/31 08:28 2026/07/31 08:28 2026/07/31 08:36 aaffb173
reproducer did not crash
a9b25c80 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in mas_nomem 2026/07/28 02:20 2026/07/28 02:20 2026/07/28 03:06 4cb2b096

			
		
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] WARNING in mas_nomem 2 (3) 2026/07/31 16:07

Sample crash report:
------------[ cut here ]------------
!mas->sheaf && !mas->alloc
WARNING: lib/maple_tree.c:5751 at mas_nomem+0x1cc/0x210 lib/maple_tree.c:5751, CPU#0: udevd/5627
Modules linked in:
CPU: 0 UID: 0 PID: 5627 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:mas_nomem+0x1cc/0x210 lib/maple_tree.c:5751
Code: 4c 89 ff e8 d6 85 ea f6 49 c7 07 00 00 00 00 b0 01 e9 95 fe ff ff e8 f3 2d 7e f6 90 0f 0b 90 e9 2b ff ff ff e8 e5 2d 7e f6 90 <0f> 0b 90 e9 77 fe ff ff 89 d1 80 e1 07 80 c1 03 38 c1 0f 8c ce fe
RSP: 0018:ffffc9000562f8f0 EFLAGS: 00010293
RAX: ffffffff8b4775cb RBX: 1ffff92000ac5fbf RCX: ffff8880366e3e80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000cc0 R08: 00000000ffffffff R09: 1ffffffff1ca1a86
R10: dffffc0000000000 R11: fffffbfff1ca1a87 R12: dffffc0000000000
R13: ffffc9000562fe18 R14: ffffc9000562fde0 R15: ffffc9000562fdf8
FS:  00007f9021203880(0000) GS:ffff8881259f2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056467bb0d750 CR3: 0000000046416000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 mas_store_gfp+0x37a/0x820 lib/maple_tree.c:4987
 vma_iter_clear_gfp include/linux/mm.h:1674 [inline]
 do_vmi_align_munmap+0x30c/0x4d0 mm/vma.c:1644
 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1697
 __vm_munmap+0x241/0x3e0 mm/vma.c:3347
 __do_sys_munmap mm/mmap.c:1079 [inline]
 __se_sys_munmap mm/mmap.c:1076 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1076
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9021368097
Code: 73 01 c3 48 8b 0d 61 2d 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffeaf32d0a8 EFLAGS: 00000206 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 000056467bad9bf0 RCX: 00007f9021368097
RDX: 0000000000000000 RSI: 00000000009480e8 RDI: 00007f90208ba000
RBP: 000056467bad9910 R08: 000056467baec140 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000206 R12: 00005646569e2588
R13: 00007ffeaf32d130 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/28 21:49 linux-next cc2b5f627e8c 19622d9d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/28 00:03 linux-next cc2b5f627e8c 4cb2b096 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 22:38 linux-next cc2b5f627e8c 4cb2b096 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 13:31 linux-next cc2b5f627e8c 492bab15 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 12:01 linux-next cc2b5f627e8c 492bab15 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 10:35 linux-next cc2b5f627e8c 492bab15 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 09:11 linux-next cc2b5f627e8c 492bab15 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/30 15:58 linux-next cc2b5f627e8c 2377cd3d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/28 19:27 linux-next cc2b5f627e8c 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 19:58 linux-next cc2b5f627e8c 4cb2b096 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 19:57 linux-next cc2b5f627e8c 4cb2b096 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 07:26 linux-next cc2b5f627e8c 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
2026/07/27 07:24 linux-next cc2b5f627e8c 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in mas_nomem
* Struck through repros no longer work on HEAD.