RE: [syzbot] [mm?] kernel BUG in alloc_hugetlb_folio_reserve

[Kasireddy, Vivek]

> Subject: Re: [syzbot] [mm?] kernel BUG in alloc_hugetlb_folio_reserve
> 
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    69e858e0b8b2 Merge tag 'uml-for-linus-6.14-rc1' of git://g..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=1431cb24580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d033b14aeef39158
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=a504cb5bae4fe117ba94
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian)
> 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1324fddf980000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=128b55f8580000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-
> assets/144a7468bf1b/disk-69e858e0.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-
> assets/86d7d452eecc/vmlinux-69e858e0.xz
> kernel image: https://storage.googleapis.com/syzbot-
> assets/f56e292b01f5/bzImage-69e858e0.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+a504cb5bae4fe117ba94@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> ------------[ cut here ]------------
> kernel BUG at mm/hugetlb.c:2333!
> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
> CPU: 0 UID: 0 PID: 5832 Comm: syz-executor274 Not tainted 6.13.0-syzkaller-
> 09760-g69e858e0b8b2 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine,
> BIOS Google 12/27/2024
> RIP: 0010:alloc_hugetlb_folio_reserve+0xbc/0xc0 mm/hugetlb.c:2333
> Code: 1f eb 05 e8 c6 e9 9f ff 48 c7 c7 40 56 61 8e e8 1a 9b d8 09 4c 89 f0 5b
> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc e8 a5 e9 9f ff 90 <0f> 0b 66 90 90 90 90 90
> 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
> RSP: 0018:ffffc90003e3f7f8 EFLAGS: 00010093
> RAX: ffffffff821f831b RBX: 0000000000000000 RCX: ffff888034813c00
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 1ffffffff348b4d1 R08: ffffffff821f82d3 R09: 1ffffd40005a2005
> R10: dffffc0000000000 R11: fffff940005a2006 R12: dffffc0000000000
> R13: dffffc0000000000 R14: ffffea0002d10000 R15: ffffffff9a45a688
> FS:  000055557d1c0380(0000) GS:ffff8880b8600000(0000)
> knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000563d6d164000 CR3: 000000007abaa000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  memfd_alloc_folio+0x1bd/0x370 mm/memfd.c:88
>  memfd_pin_folios+0xf10/0x1570 mm/gup.c:3746
>  udmabuf_pin_folios drivers/dma-buf/udmabuf.c:346 [inline]
>  udmabuf_create+0x70e/0x10c0 drivers/dma-buf/udmabuf.c:443
>  udmabuf_ioctl_create drivers/dma-buf/udmabuf.c:495 [inline]
>  udmabuf_ioctl+0x301/0x4e0 drivers/dma-buf/udmabuf.c:526
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:906 [inline]
>  __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fcd524733a9
> Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 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 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffddb5cce58 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000010
> RAX: ffffffffffffffda RBX: 00007ffddb5cd028 RCX: 00007fcd524733a9
> RDX: 0000000020000040 RSI: 0000000040187542 RDI: 0000000000000004
> RBP: 00007fcd524e6610 R08: 0000000020000000 R09: 00007ffddb5cd028
> R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000001
> R13: 00007ffddb5cd018 R14: 0000000000000001 R15: 0000000000000001
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:alloc_hugetlb_folio_reserve+0xbc/0xc0 mm/hugetlb.c:2333
> Code: 1f eb 05 e8 c6 e9 9f ff 48 c7 c7 40 56 61 8e e8 1a 9b d8 09 4c 89 f0 5b
> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc e8 a5 e9 9f ff 90 <0f> 0b 66 90 90 90 90 90
> 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
> RSP: 0018:ffffc90003e3f7f8 EFLAGS: 00010093
> RAX: ffffffff821f831b RBX: 0000000000000000 RCX: ffff888034813c00
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 1ffffffff348b4d1 R08: ffffffff821f82d3 R09: 1ffffd40005a2005
> R10: dffffc0000000000 R11: fffff940005a2006 R12: dffffc0000000000
> R13: dffffc0000000000 R14: ffffea0002d10000 R15: ffffffff9a45a688
> FS:  000055557d1c0380(0000) GS:ffff8880b8600000(0000)
> knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000563d6d164000 CR3: 000000007abaa000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> 
> 
> ---
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.

#syz test: https://gitlab.freedesktop.org/Vivek/drm-tip.git syzbot_fix_htlb_reserve