[syzbot ci] Re: mm: Make per-VMA locks available in all builds

syzbot ci
2026-04-30T07:55:51Z

syzbot ci has tested the following series

[v1] mm: Make per-VMA locks available in all builds
https://lore.kernel.org/all/20260429181954.F50224AE@davehans-spike.ostc.intel.com
* [PATCH 1/6] mm: Make per-VMA locks available universally
* [PATCH 2/6] binder: Make shrinker rely solely on per-VMA lock
* [PATCH 3/6] mm: Add RCU-based VMA lookup that waits for writers
* [PATCH 4/6] binder: Remove mmap_lock fallback
* [PATCH 5/6] tcp: Remove mmap_lock fallback path
* [PATCH 6/6] x86/mm: Avoid mmap lock for shadow stack pop fast path

and found the following issue:
WARNING in mbind_range

Full report is available here:
https://ci.syzbot.org/series/374f338e-4b3b-4645-871c-78964f944bbd

***

WARNING in mbind_range

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: 57b8e2d666a31fa201432d58f5fe3469a0dd83ba
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/786ac31f-0f5e-4ceb-88c7-45f4bee79d60/config
syz repro: https://ci.syzbot.org/findings/4b270176-3e48-4ac7-8ddb-f326d6883d93/syz_repro

pgoff 200000000 file 0000000000000000 private_data 0000000000000000
flags: 0x8100077(read|write|exec|mayread|maywrite|mayexec|account|softdirty)
------------[ cut here ]------------
1
WARNING: ./include/linux/mmap_lock.h:332 at vma_assert_write_locked include/linux/mmap_lock.h:332 [inline], CPU#0: syz.2.19/5876
WARNING: ./include/linux/mmap_lock.h:332 at vma_replace_policy mm/mempolicy.c:1016 [inline], CPU#0: syz.2.19/5876
WARNING: ./include/linux/mmap_lock.h:332 at mbind_range+0x57a/0x810 mm/mempolicy.c:1063, CPU#0: syz.2.19/5876
Modules linked in:
CPU: 0 UID: 0 PID: 5876 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:vma_assert_write_locked include/linux/mmap_lock.h:332 [inline]
RIP: 0010:vma_replace_policy mm/mempolicy.c:1016 [inline]
RIP: 0010:mbind_range+0x57a/0x810 mm/mempolicy.c:1063
Code: 97 ff e9 b2 fb ff ff e8 a4 4a 97 ff 90 0f 0b 90 e9 14 fe ff ff e8 96 4a 97 ff 4c 89 ff e8 0e b5 f9 fe c6 05 9c 2e ec 0d 01 90 <0f> 0b 90 4d 85 e4 0f 85 48 fe ff ff e8 75 4a 97 ff 31 db 4d 8d 77
RSP: 0018:ffffc90003bc7c78 EFLAGS: 00010292
RAX: 000000000000011f RBX: 000000000000000b RCX: a410c902b7e34800
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000009 R08: ffffc90003bc7967 R09: 1ffff92000778f2c
R10: dffffc0000000000 R11: fffff52000778f2d R12: ffff8881012c9e00
R13: dffffc0000000000 R14: ffff888115b99bf8 R15: ffff8881162fa300
FS: 00007fa09187c6c0(0000) GS:ffff88818dc93000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33b63fff CR3: 0000000115bda000 CR4: 00000000000006f0
Call Trace:
<TASK>
do_mbind mm/mempolicy.c:1560 [inline]
kernel_mbind mm/mempolicy.c:1757 [inline]
__do_sys_mbind mm/mempolicy.c:1831 [inline]
__se_sys_mbind+0xad4/0x10f0 mm/mempolicy.c:1827
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa09099cdd9
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:00007fa09187c028 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007fa090c15fa0 RCX: 00007fa09099cdd9
RDX: 0000000000000001 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007fa090a32d69 R08: 0000000000000000 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa090c16038 R14: 00007fa090c15fa0 R15: 00007ffff596d0f8
</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

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

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.