Re: [syzbot] [mm?] WARNING in copy_huge_pmd

[David Hildenbrand <david@redhat.com>]

On 23.09.24 14:18, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    88264981f208 Merge tag 'sched_ext-for-6.12' of git://git.k..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=16c36c27980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e851828834875d6f
> dashboard link: https://syzkaller.appspot.com/bug?extid=bf2c35fa302ebe3c7471
> 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=12773080580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ed5e9f980000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/0e011ac37c93/disk-88264981.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f5c65577e19e/vmlinux-88264981.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/984d963c8ea1/bzImage-88264981.xz
> 
> The issue was bisected to:
> 
> commit 75182022a0439788415b2dd1db3086e07aa506f7
> Author: Peter Xu <peterx@redhat.com>
> Date:   Mon Aug 26 20:43:51 2024 +0000
> 
>      mm/x86: support large pfn mappings
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17df9c27980000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=143f9c27980000
> console output: https://syzkaller.appspot.com/x/log.txt?x=103f9c27980000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+bf2c35fa302ebe3c7471@syzkaller.appspotmail.com
> Fixes: 75182022a043 ("mm/x86: support large pfn mappings")
> 
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 5508 at mm/huge_memory.c:1602 copy_huge_pmd+0x102c/0x1c60 mm/huge_memory.c:1602
> Modules linked in:
> CPU: 1 UID: 0 PID: 5508 Comm: syz-executor274 Not tainted 6.11.0-syzkaller-08481-g88264981f208 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
> RIP: 0010:copy_huge_pmd+0x102c/0x1c60 mm/huge_memory.c:1602
> Code: ff 90 0f 0b 90 e9 2e f5 ff ff e8 8f fc 92 ff 48 ff cb e9 0f f7 ff ff e8 82 fc 92 ff 48 ff cb e9 8a f7 ff ff e8 75 fc 92 ff 90 <0f> 0b 90 e9 11 fd ff ff 4c 8d ac 24 00 01 00 00 48 b8 06 fe ff ff
> RSP: 0018:ffffc90003cdf0c0 EFLAGS: 00010293
> RAX: ffffffff8201bd3b RBX: ffff88803090c118 RCX: ffff8880317a9e00
> RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
> RBP: ffffc90003cdf248 R08: ffffffff8201bc06 R09: 1ffffffff2038ef5
> R10: dffffc0000000000 R11: fffffbfff2038ef6 R12: ffff88802fab89c0
> R13: d7ffe7fff1cbfe02 R14: 0000000000000020 R15: ffff888031e5b780
> FS:  00007f38182a06c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f381831d9f0 CR3: 000000007b18c000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>   <TASK>
>   copy_pmd_range+0x425/0x85f0 mm/memory.c:1245
>   copy_pud_range mm/memory.c:1292 [inline]
>   copy_p4d_range mm/memory.c:1316 [inline]
>   copy_page_range+0x99f/0xe90 mm/memory.c:1414
>   dup_mmap kernel/fork.c:750 [inline]
>   dup_mm kernel/fork.c:1674 [inline]
>   copy_mm+0x11fb/0x1f40 kernel/fork.c:1723
>   copy_process+0x1845/0x3d50 kernel/fork.c:2375
>   kernel_clone+0x226/0x8f0 kernel/fork.c:2787
>   __do_sys_clone3 kernel/fork.c:3091 [inline]
>   __se_sys_clone3+0x2cb/0x350 kernel/fork.c:3070
>   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: 0033:0x7f3818306429
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f38182a0118 EFLAGS: 00000202 ORIG_RAX: 00000000000001b3
> RAX: ffffffffffffffda RBX: 00007f3818390318 RCX: 00007f3818306429
> RDX: 00007f38182e2ab6 RSI: 0000000000000058 RDI: 00007f38182a0120
> RBP: 00007f3818390310 R08: 00007fffb191b837 R09: 0000000000000080
> R10: 0000000000000000 R11: 0000000000000202 R12: 00007f381835d074
> R13: 00007f381839031c R14: 00007f38182a0120 R15: 000000080000000e
>   </TASK>
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
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> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 
> If the report is already addressed, let syzbot know by replying with:
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> 
> If you want syzbot to run the reproducer, reply with:
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> 
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> 
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> 
> If you want to undo deduplication, reply with:
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> 

#syz test: https://github.com/davidhildenbrand/linux.git copy_huge_pmd_pfn

-- 
Cheers,

David / dhildenb