On Wed, 27 Apr 2022 06:15:20 -0700 syzbot <syzbot+7728e4ab5371cebc9c00@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > syzbot has found a reproducer for the following issue on: Thanks. userfaultfd_release() appears to have offended vma_merge(). I'm not seeing any changes in that area from Peter, but Liam's mapletree work changed things around a bit. Gents, could you please take a look? > HEAD commit: f02ac5c95dfd Add linux-next specific files for 20220427 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=105a33a2f00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e9256c70f586da8a > dashboard link: https://syzkaller.appspot.com/bug?extid=7728e4ab5371cebc9c00 > 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=15f76f82f00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b42c3cf00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+7728e4ab5371cebc9c00@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 3593 at mm/mmap.c:1072 vma_merge+0x428/0x950 mm/mmap.c:1072 I assume this is VM_WARN_ON(area && end > area->vm_end); But lines change around a lot. It would be great if the script which generates these reports could quote the code around the indicated file and line. Like: next = find_vma(mm, prev ? prev->vm_end : 0); area = next; if (area && area->vm_end == end) /* cases 6, 7, 8 */ next = find_vma(mm, next->vm_end); /* verify some invariant that must be enforced by the caller */ VM_WARN_ON(prev && addr <= prev->vm_start); --> VM_WARN_ON(area && end > area->vm_end); VM_WARN_ON(addr >= end); /* * Can it merge with the predecessor? */ if (prev && prev->vm_end == addr && > Modules linked in: > CPU: 1 PID: 3593 Comm: syz-executor549 Not tainted 5.18.0-rc4-next-20220427-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:vma_merge+0x428/0x950 mm/mmap.c:1072 > Code: 00 e8 5c 1f c4 ff e8 57 1f c4 ff 45 31 f6 e8 4f 1f c4 ff 4c 89 f0 48 83 c4 28 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 38 1f c4 ff <0f> 0b e9 6c fd ff ff e8 2c 1f c4 ff 48 8d bd 88 00 00 00 48 b8 00 > RSP: 0018:ffffc90002edfd10 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000008102073 RCX: 0000000000000000 > RDX: ffff88801d0a3a80 RSI: ffffffff81b62968 RDI: 0000000000000003 > RBP: ffff88807e550bd0 R08: 0000000021001000 R09: 0000000000000000 > R10: ffffffff81b626ce R11: 0000000000000000 R12: 0000555557211000 > R13: 00005555571ef000 R14: ffff88807e550d80 R15: ffff88807e550d80 > FS: 00005555571ef300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00005564400b0df0 CR3: 0000000073d7f000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > mlock_fixup+0x349/0x7f0 mm/mlock.c:420 > apply_mlockall_flags+0x2be/0x440 mm/mlock.c:691 > __do_sys_mlockall+0x222/0x4b0 mm/mlock.c:719 > 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+0x44/0xae > RIP: 0033:0x7f9cdd5a1f99 > 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:00007ffecfa63c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000097 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9cdd5a1f99 > RDX: 00007f9cdd5a1f99 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: 00007f9cdd565f80 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cdd566010 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > </TASK>
