kernel BUG in validate_mm_rb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e3d35712 Add linux-next specific files for 20210423
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1163f955d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=e370221d7500b26a
dashboard link: https://syzkaller.appspot.com/bug?extid=c2e3661170e549db3bf0
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c2e366...@syzkaller.appspotmail.com

prot 8000000000000025 anon_vma ffff888013165d00 vm_ops ffffffff897f8900
pgoff 6 file ffff88801a434000 private_data 0000000000000000
flags: 0x8100071(read|mayread|maywrite|mayexec|account|softdirty)
------------[ cut here ]------------
kernel BUG at mm/mmap.c:388!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8477 Comm: systemd-udevd Not tainted 5.12.0-rc8-next-20210423-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:validate_mm_rb+0x1d6/0x2d0 mm/mmap.c:388
Code: 4c 0f 42 e8 e8 fb da c9 ff 4c 89 ee 4c 89 ff e8 30 e1 c9 ff 4d 39 ef 0f 84 70 fe ff ff e8 e2 da c9 ff 4c 89 e7 e8 81 7d 29 07 <0f> 0b 49 89 c5 e8 d0 da c9 ff 48 8d 7d f8 48 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc900016dfdb0 EFLAGS: 00010287
RAX: 0000000000000146 RBX: ffff888014b3b840 RCX: 0000000000000000
RDX: ffff888021f80000 RSI: ffffffff815cebe5 RDI: fffff520002dbf91
RBP: ffff88802ffd0128 R08: 0000000000000146 R09: 0000000000000000
R10: ffffffff815c8a2e R11: 0000000000000000 R12: ffff88802ffd0108
R13: 000000001ef85fb2 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007f3e1fa2e8c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bd37934070 CR3: 0000000025181000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
vma_rb_erase_ignore mm/mmap.c:488 [inline]
vma_rb_erase mm/mmap.c:496 [inline]
detach_vmas_to_be_unmapped mm/mmap.c:2699 [inline]
__do_munmap+0x512/0x11a0 mm/mmap.c:2905
__vm_munmap+0x101/0x230 mm/mmap.c:2934
__do_sys_munmap mm/mmap.c:2960 [inline]
__se_sys_munmap mm/mmap.c:2956 [inline]
__x64_sys_munmap+0x62/0x80 mm/mmap.c:2956
do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3e1e8a96e7
Code: c7 c0 ff ff ff ff eb 8d 48 8b 15 ac 47 2b 00 f7 d8 64 89 02 e9 5b ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 47 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd3884d2a8 EFLAGS: 00000206 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 000055bd3791e100 RCX: 00007f3e1e8a96e7
RDX: 0000000000000080 RSI: 000000000080ccec RDI: 00007f3e1d737000
RBP: 000055bd35c31d18 R08: 000055bd3791f3e0 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 000055bd3791e0e0
R13: 0000000000000000 R14: 0000000000000003 R15: 000000000000000e
Modules linked in:
---[ end trace c184e00d43da52e7 ]---
RIP: 0010:validate_mm_rb+0x1d6/0x2d0 mm/mmap.c:388
Code: 4c 0f 42 e8 e8 fb da c9 ff 4c 89 ee 4c 89 ff e8 30 e1 c9 ff 4d 39 ef 0f 84 70 fe ff ff e8 e2 da c9 ff 4c 89 e7 e8 81 7d 29 07 <0f> 0b 49 89 c5 e8 d0 da c9 ff 48 8d 7d f8 48 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc900016dfdb0 EFLAGS: 00010287
RAX: 0000000000000146 RBX: ffff888014b3b840 RCX: 0000000000000000
RDX: ffff888021f80000 RSI: ffffffff815cebe5 RDI: fffff520002dbf91


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.