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

[syzbot ci <syzbot+ciff8167f913c663d5@syzkaller.appspotmail.com>]

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/20260613-vmalloc_maple-v1-0-0aa740bb944b@oss.qualcomm.com
* [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: syzbot@syzkaller.appspotmail.com

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