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

[syzbot <syzbot+a504cb5bae4fe117ba94@syzkaller.appspotmail.com>]

>> 
>> Hello,
>> 
>> syzbot found the following issue on:
>> 
>> HEAD commit:    63676eefb7a0 Merge tag 'sched_ext-for-6.13-rc5-fixes' of g..
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=15fb66f8580000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=1c541fa8af5c9cc7
>> dashboard link:
>> https://syzkaller.appspot.com/bug?extid=a504cb5bae4fe117ba94
>> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian)
>> 2.40
>> 
>> Unfortunately, I don't have any reproducer for this issue yet.
>> 
>> Downloadable assets:
>> disk image (non-bootable): https://storage.googleapis.com/syzbot-
>> assets/7feb34a89c2a/non_bootable_disk-63676eef.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-
>> assets/599e1a07ba5c/vmlinux-63676eef.xz
>> kernel image: https://storage.googleapis.com/syzbot-
>> assets/b52f3534bdbe/bzImage-63676eef.xz
>> 
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+a504cb5bae4fe117ba94@syzkaller.appspotmail.com
>> 
>> ------------[ cut here ]------------
>> kernel BUG at mm/hugetlb.c:2403!
>> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
>> CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-
>> 00161-g63676eefb7a0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9,
>> 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
>> RIP: 0010:alloc_hugetlb_folio_reserve+0xbc/0xc0 mm/hugetlb.c:2403
>> Code: 1f eb 05 e8 56 18 a0 ff 48 c7 c7 40 56 61 8e e8 ba 21 cc 09 4c 89 f0 5b 41
>> 5c 41 5e 41 5f 5d c3 cc cc cc cc e8 35 18 a0 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:ffffc9000d3d77f8 EFLAGS: 00010087
>> RAX: ffffffff81ff6beb RBX: 0000000000000000 RCX: 0000000000100000
>> RDX: ffffc9000e51a000 RSI: 00000000000003ec RDI: 00000000000003ed
>> RBP: 1ffffffff34810d9 R08: ffffffff81ff6ba3 R09: 1ffffd4000093005
>> R10: dffffc0000000000 R11: fffff94000093006 R12: dffffc0000000000
>> R13: dffffc0000000000 R14: ffffea0000498000 R15: ffffffff9a4086c8
>> FS:  00007f77ac12e6c0(0000) GS:ffff88801fc00000(0000)
>> knlGS:0000000000000000
>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007f77ab54b170 CR3: 0000000040b70000 CR4: 0000000000352ef0
>> 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:3750  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: 0033:0x7f77ab385d29
>> 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:00007f77ac12e038 EFLAGS: 00000246 ORIG_RAX:
>> 0000000000000010
>> RAX: ffffffffffffffda RBX: 00007f77ab575fa0 RCX: 00007f77ab385d29
>> RDX: 0000000020000040 RSI: 0000000040187542 RDI: 0000000000000006
>> RBP: 00007f77ab401b08 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
>> R13: 0000000000000000 R14: 00007f77ab575fa0 R15: 00007fff748b7238
>> </TASK> Modules linked in:
>> ---[ end trace 0000000000000000 ]---
>> RIP: 0010:alloc_hugetlb_folio_reserve+0xbc/0xc0 mm/hugetlb.c:2403
>> Code: 1f eb 05 e8 56 18 a0 ff 48 c7 c7 40 56 61 8e e8 ba 21 cc 09 4c 89 f0 5b 41
>> 5c 41 5e 41 5f 5d c3 cc cc cc cc e8 35 18 a0 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:ffffc9000d3d77f8 EFLAGS: 00010087
>> RAX: ffffffff81ff6beb RBX: 0000000000000000 RCX: 0000000000100000
>> RDX: ffffc9000e51a000 RSI: 00000000000003ec RDI: 00000000000003ed
>> RBP: 1ffffffff34810d9 R08: ffffffff81ff6ba3 R09: 1ffffd4000093005
>> R10: dffffc0000000000 R11: fffff94000093006 R12: dffffc0000000000
>> R13: dffffc0000000000 R14: ffffea0000498000 R15: ffffffff9a4086c8
>> FS:  00007f77ac12e6c0(0000) GS:ffff88801fc00000(0000)
>> knlGS:0000000000000000
>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007f77ab54b170 CR3: 0000000040b70000 CR4: 0000000000352ef0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> 
>> 
>> ---
>> This report is generated by a bot. It may contain errors.
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>> 
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>> 
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>> 
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>> 
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>
> #syz test: https://gitlab.freedesktop.org/Vivek/drm-tip.git syzbot_fix_htlb_reserve

This crash does not have a reproducer. I cannot test it.

>