Re: [moderation/CI] Re: mm/vmalloc: migrate vmap_area indexing from rb-tree to maple-tree

#syz upstream

On Sun, Jun 14, 2026 at 6:31 AM syzbot ci
<[email protected]> wrote:
>
> syzbot ci has tested the following series
>
> [v1] mm/vmalloc: migrate vmap_area indexing from rb-tree to maple-tree
> https://lore.kernel.org/all/[email protected]
> * [PATCH RFC 01/12] mm/vmalloc: introduce maple_tree-based indexing for vmap_area
> * [PATCH RFC 02/12] mm/vmalloc: convert allocation-side gap finding and insertion to maple_tree
> * [PATCH RFC 03/12] mm/vmalloc: convert free, purge, and pcpu paths to maple_tree
> * [PATCH RFC 04/12] mm/vmalloc: finalize maple-only indexing and shrink struct vmap_area
> * [PATCH RFC 05/12] mm/vmalloc: tighten failure handling under memory pressure
> * [PATCH RFC 06/12] mm/vmalloc: tighten alloc/free hot paths
> * [PATCH RFC 07/12] mm/vmalloc: consolidate occupied tree as authoritative index on hot path
> * [PATCH RFC 08/12] mm/vmalloc: track lazy-purge queue as a list_head
> * [PATCH RFC 09/12] mm/vmalloc: collapse busy-tree find-then-unlink into a single mas_erase
> * [PATCH RFC 10/12] mm/vmalloc: per-CPU caching of free ranges from the maple_tree allocator
> * [PATCH RFC 11/12] mm/vmalloc: O(1) lookup of cached vmap_areas with bounded fast-reject
> * [PATCH RFC 12/12] mm/vmalloc: harden bump-allocator alloc/free against UBSAN array bounds
>
> and found the following issue:
> WARNING in alloc_vmap_area
>
> Full report is available here:
> https://ci.syzbot.org/series/45e14120-bbb8-4a0c-b5c6-0aaf3b421101
>
> ***
>
> WARNING in alloc_vmap_area
>
> tree:      linux-next
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next
> base:      c425609d6ac4012c8bbf01ec2e10e801b1923a7b
> arch:      amd64
> compiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
> config:    https://ci.syzbot.org/builds/481f4f4b-8d55-4e3c-b96c-1de7b763686d/config
> syz repro: https://ci.syzbot.org/findings/ae02a227-b4c3-476a-826b-3bbf18bdbfe4/syz_repro
>
> ------------[ cut here ]------------
> (*left)->va_end > start
> WARNING: mm/vmalloc.c:1371 at find_vmap_area_insert_neighbors_mt_locked mm/vmalloc.c:1371 [inline], CPU#0: syz.0.17/5834
> WARNING: mm/vmalloc.c:1371 at validate_vmap_area_range_insert_mt_locked mm/vmalloc.c:1388 [inline], CPU#0: syz.0.17/5834
> WARNING: mm/vmalloc.c:1371 at insert_vmap_area_busy_locked mm/vmalloc.c:1480 [inline], CPU#0: syz.0.17/5834
> WARNING: mm/vmalloc.c:1371 at alloc_vmap_area+0x5458/0x87f0 mm/vmalloc.c:2917, CPU#0: syz.0.17/5834
> Modules linked in:
> CPU: 0 UID: 0 PID: 5834 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> RIP: 0010:find_vmap_area_insert_neighbors_mt_locked mm/vmalloc.c:1371 [inline]
> RIP: 0010:validate_vmap_area_range_insert_mt_locked mm/vmalloc.c:1388 [inline]
> RIP: 0010:insert_vmap_area_busy_locked mm/vmalloc.c:1480 [inline]
> RIP: 0010:alloc_vmap_area+0x5458/0x87f0 mm/vmalloc.c:2917
> Code: a5 ff e9 fc 0f 00 00 e8 e6 80 a5 ff 4c 8b 74 24 18 e9 ed 17 00 00 e8 d7 80 a5 ff 90 0f 0b 90 e9 34 e5 ff ff e8 c9 80 a5 ff 90 <0f> 0b 90 4c 8b 74 24 18 eb 09 e8 b9 80 a5 ff 90 0f 0b 90 49 bf 00
> RSP: 0018:ffffc90031ade360 EFLAGS: 00010293
> RAX: ffffffff82200aa7 RBX: ffffffffa0000000 RCX: ffff888109e2bb80
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffffc90031adf4f8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000100 R11: 0000000000000003 R12: ffff88810007d888
> R13: ffffffffa0002000 R14: ffffffffa0401000 R15: ffffc90031adeb80
> FS:  00007f97268b66c0(0000) GS:ffff88818e8af000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f9727132780 CR3: 000000010cd9e000 CR4: 00000000000006f0
> Call Trace:
>  <TASK>
>  __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:4214
>  __vmalloc_node_range_noprof+0x36a/0x1750 mm/vmalloc.c:5030
>  execmem_vmalloc+0xa7/0x1d0 mm/execmem.c:41
>  bpf_dispatcher_change_prog+0x25d/0xd70 kernel/bpf/dispatcher.c:151
>  bpf_prog_test_run_xdp+0x794/0x1160 net/bpf/test_run.c:1464
>  bpf_prog_test_run+0x2cd/0x340 kernel/bpf/syscall.c:4859
>  __sys_bpf+0xa20/0xd90 kernel/bpf/syscall.c:6436
>  __do_sys_bpf kernel/bpf/syscall.c:6537 [inline]
>  __se_sys_bpf kernel/bpf/syscall.c:6534 [inline]
>  __x64_sys_bpf+0xba/0xd0 kernel/bpf/syscall.c:6534
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f972725ce59
> Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f97268b6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
> RAX: ffffffffffffffda RBX: 00007f97274d5fa0 RCX: 00007f972725ce59
> RDX: 0000000000000050 RSI: 0000200000000b80 RDI: 000000000000000a
> RBP: 00007f97272f2d6f R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f97274d6038 R14: 00007f97274d5fa0 R15: 00007ffd7848c2a8
>  </TASK>
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
>   Tested-by: [email protected]
>
> ---
> This report is generated by a bot. It may contain errors.
> syzbot ci engineers can be reached at [email protected].
>
> To test a patch for this bug, please reply with `#syz test`
> (should be on a separate line).
>
> The patch should be attached to the email.
> Note: arguments like custom git repos and branches are not supported.
>
> The email will later be sent to:
> [[email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected]]
>
> If the report looks fine to you, reply with:
> #syz upstream
>
> If the report is a false positive, reply with
> #syz invalid
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6a2e2eb0.428ffe26.258b27.0168.GAE%40google.com.