[syzbot] WARNING in anon_vma_name

syzbot
2022-11-14T06:28:46Z

Hello,

syzbot found the following issue on:

HEAD commit: f8f60f322f06 Add linux-next specific files for 20221111
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12f0f3fe880000
kernel config: https://syzkaller.appspot.com/x/.config?x=85ba52c07cd97289
dashboard link: https://syzkaller.appspot.com/bug?extid=62ed954113bf02c79f74
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=171f6c49880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fdfd99880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6008df424195/disk-f8f60f32.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/394340525f66/vmlinux-f8f60f32.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b13604a3343a/bzImage-f8f60f32.xz

The issue was bisected to:

commit 2220e3a8953e86b87adfc753fc57c2a5e0b0a032
Author: Pasha Tatashin <pasha.tatashin@soleen.com>
Date: Mon Nov 7 18:47:15 2022 +0000

mm: anonymous shared memory naming

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16d32f66880000
final oops: https://syzkaller.appspot.com/x/report.txt?x=15d32f66880000
console output: https://syzkaller.appspot.com/x/log.txt?x=11d32f66880000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+62ed954113bf02c79f74@syzkaller.appspotmail.com
Fixes: 2220e3a8953e ("mm: anonymous shared memory naming")

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5239 at include/linux/mmap_lock.h:155 mmap_assert_locked include/linux/mmap_lock.h:155 [inline]
WARNING: CPU: 0 PID: 5239 at include/linux/mmap_lock.h:155 anon_vma_name+0x11c/0x170 mm/madvise.c:97
Modules linked in:
CPU: 1 PID: 5239 Comm: syz-executor276 Not tainted 6.1.0-rc4-next-20221111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:mmap_assert_locked include/linux/mmap_lock.h:155 [inline]
RIP: 0010:anon_vma_name+0x11c/0x170 mm/madvise.c:97
Code: 8d bd 58 01 00 00 be ff ff ff ff e8 1e fc e0 07 31 ff 41 89 c4 89 c6 e8 c2 27 bc ff 45 85 e4 0f 85 5c ff ff ff e8 e4 2a bc ff <0f> 0b e9 50 ff ff ff e8 d8 2a bc ff 48 89 ef e8 00 e7 f2 ff 0f 0b
RSP: 0018:ffffc90003c7f810 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffffff8b9ae000 RCX: 0000000000000000
RDX: ffff88801d5fba80 RSI: ffffffff81c0a28c RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8b9ae008 R14: ffffffff8b9ae010 R15: 0000000000000000
FS: 0000555556387300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000061ba0c CR3: 000000007d6c4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
show_map_vma+0x22d/0x620 fs/proc/task_mmu.c:297
show_smap+0xe4/0x490 fs/proc/task_mmu.c:866
traverse.part.0+0xcf/0x5f0 fs/seq_file.c:111
traverse fs/seq_file.c:101 [inline]
seq_read_iter+0x90f/0x1280 fs/seq_file.c:195
seq_read+0x16d/0x210 fs/seq_file.c:162
do_loop_readv_writev fs/read_write.c:756 [inline]
do_loop_readv_writev fs/read_write.c:743 [inline]
do_iter_read+0x4f8/0x750 fs/read_write.c:798
vfs_readv+0xe5/0x150 fs/read_write.c:916
do_preadv fs/read_write.c:1008 [inline]
__do_sys_preadv fs/read_write.c:1058 [inline]
__se_sys_preadv fs/read_write.c:1053 [inline]
__x64_sys_preadv+0x22b/0x310 fs/read_write.c:1053
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f545e62b239
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffed9c02fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f545e62b239
RDX: 0000000000000001 RSI: 00000000200006c0 RDI: 0000000000000003
RBP: 00007ffed9c02ff0 R08: 0000000000000000 R09: 65732f636f72702f
R10: 00000000fffffffe R11: 0000000000000246 R12: 00007f545e5ef120
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>

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