Re: [syzbot] [mm?] WARNING in vma_modify

[syzbot <syzbot+d16409ea9ecc16ed261a@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in vma_modify

    7fcac9c9e000-7ffd51cbbfff: 0000000000000000
    7ffd51cbc000-7ffd51cdcfff: ffff88807946b8c0
    7ffd51cdd000-ffffffffffffffff: 0000000000000000
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6557 at mm/vma.c:808 vma_merge_existing_range mm/vma.c:808 [inline]
WARNING: CPU: 0 PID: 6557 at mm/vma.c:808 vma_modify+0x15ff/0x1a30 mm/vma.c:1604
Modules linked in:
CPU: 0 UID: 0 PID: 6557 Comm: syz.0.16 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344-dirty #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:vma_merge_existing_range mm/vma.c:808 [inline]
RIP: 0010:vma_modify+0x15ff/0x1a30 mm/vma.c:1604
Code: 0b 90 e9 a5 ec ff ff e8 3f 60 ab ff 90 0f 0b 90 e9 e5 eb ff ff e8 31 60 ab ff 4c 89 f7 48 c7 c6 a0 91 96 8b e8 b2 06 f3 ff 90 <0f> 0b 90 e9 46 ec ff ff e8 14 60 ab ff e9 57 ed ff ff e8 0a 60 ab
RSP: 0018:ffffc90003befb28 EFLAGS: 00010286
RAX: ffffffff8b5e58cd RBX: ffff88807e5c0280 RCX: ffff88802e4e3c00
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: ffffffffffffffff
RBP: 0000200000000000 R08: ffffc90003bef6a7 R09: 1ffff9200077ded4
R10: dffffc0000000000 R11: fffff5200077ded5 R12: 1ffff9200077df8c
R13: 0000200000000000 R14: ffffc90003befc40 R15: ffffc90003befc60
FS:  00007fcac9c746c0(0000) GS:ffff888125c55000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558b9147a950 CR3: 000000005bd9d000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 vma_modify_flags+0x1e8/0x230 mm/vma.c:1645
 mlock_fixup+0x22a/0x360 mm/mlock.c:483
 apply_mlockall_flags+0x2f0/0x3c0 mm/mlock.c:736
 __ia32_sys_munlockall+0x10a/0x220 mm/mlock.c:782
 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: 0033:0x7fcac8d8e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcac9c74038 EFLAGS: 00000246 ORIG_RAX: 0000000000000098
RAX: ffffffffffffffda RBX: 00007fcac8fb6080 RCX: 00007fcac8d8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fcac9c74090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000001 R14: 00007fcac8fb6080 R15: 00007ffd51cdb4b8
 </TASK>


Tested on:

commit:         e271ed52 Merge tag 'pm-6.16-rc1-3' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13bcb282580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=73696606574e3967
dashboard link: https://syzkaller.appspot.com/bug?extid=d16409ea9ecc16ed261a
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
patch:          https://syzkaller.appspot.com/x/patch.diff?x=152371d4580000