Re: WARNING in get_pat_info

[David Hildenbrand <david@redhat.com>]

On 16.08.24 11:44, lee bruce wrote:
> Hello, I found a bug titled "WARNING in get_pat_info" with modified
> syzkaller in the lasted upstream and lasted mm branches.
> 
> If you fix this issue, please add the following tag to the commit:
> Reported-by: xingwei lee <xrivendell7@gmail.com>
> Reported-by: yuxin wang <wang1315768607@163.com>
> 
> TITLE: WARNING in get_pat_info
> ------------[ cut here ]------------
> WARNING: CPU: 2 PID: 12458 at arch/x86/mm/pat/memtype.c:1002
> get_pat_info+0x4b6/0x5c0 arch/x86/mm/pat/memtype.c:1002
> arch/x86/mm/pat/memtype.c:1002
> Modules linked in:
> CPU: 2 PID: 12458 Comm: syz-executor.0 Not tainted 6.10.0 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.16.2-debian-1.16.2-1 04/01/2014
> RIP: 0010:get_pat_info+0x4b6/0x5c0 arch/x86/mm/pat/memtype.c:1002
> arch/x86/mm/pat/memtype.c:1002
> Code: 00 00 00 48 89 de e8 79 28 54 00 48 83 fb 20 75 11 48 83 7c 24
> 18 00 74 6e 31 ff e8 74 23 54 00 eb 0b 31 ff e8 6b 23 54 00 90 <0f> 0b
> 90 bb ea ff ff ff 48 c7 44 24 40 0e 36 e0 45 4b c7 44 25 00
> RSP: 0018:ffffc9000f3ff2a0 EFLAGS: 00010246
> RAX: ffffffff81453f35 RBX: 0000000000000000 RCX: ffffc90013051000
> RDX: ffffffff81453f35 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffffc9000f3ff3b0 R08: 000000000001fcbe R09: 000000000001fcbf
> R10: dffffc0000000000 R11: fffffbfff1fdc6f6 R12: 1ffff92001e7fe5c
> R13: dffffc0000000000 R14: 1ffff92001e7fe64 R15: 1ffff92001e7fe68
> FS: 00007fb3403356c0(0000) GS:ffff888063500000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f74b7104000 CR3: 000000001c1ce000 CR4: 0000000000752ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> PKRU: 55555554
> Call Trace:
> <TASK>
> untrack_pfn+0x338/0x660 arch/x86/mm/pat/memtype.c:1104
> arch/x86/mm/pat/memtype.c:1104
> unmap_single_vma+0x20c/0x2c0 mm/memory.c:1819 mm/memory.c:1819
> unmap_vmas+0x3d7/0x600 mm/memory.c:1885 mm/memory.c:1885
> exit_mmap+0x279/0xce0 mm/mmap.c:3341 mm/mmap.c:3341
> __mmput+0x120/0x3a0 kernel/fork.c:1343 kernel/fork.c:1343
> mmput kernel/fork.c:1365 [inline]
> dup_mm kernel/fork.c:1687 [inline]
> mmput kernel/fork.c:1365 [inline] kernel/fork.c:1720
> dup_mm kernel/fork.c:1687 [inline] kernel/fork.c:1720
> copy_mm+0x1a5b/0x1fe0 kernel/fork.c:1720 kernel/fork.c:1720
> copy_process+0x1cc7/0x3f70 kernel/fork.c:2373 kernel/fork.c:2373
> kernel_clone+0x236/0x910 kernel/fork.c:2780 kernel/fork.c:2780
> __do_sys_clone kernel/fork.c:2923 [inline]
> __se_sys_clone kernel/fork.c:2907 [inline]
> __do_sys_clone kernel/fork.c:2923 [inline] kernel/fork.c:2907
> __se_sys_clone kernel/fork.c:2907 [inline] kernel/fork.c:2907
> __x64_sys_clone+0x25d/0x2b0 kernel/fork.c:2907 kernel/fork.c:2907
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_x64 arch/x86/entry/common.c:52 [inline] arch/x86/entry/common.c:83
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fb33f67dde9
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007fb340335078 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
> RAX: ffffffffffffffda RBX: 00007fb33f7abf80 RCX: 00007fb33f67dde9
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 00007fb340335120 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
> R13: 000000000000000b R14: 00007fb33f7abf80 R15: 00007ffd35a9fb48
> </TASK>
> 
> 
> I use the same kernel as syzbot instance
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=122bfdb8980000
> kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=8e5f5ae13ab96e5e
> compiler: clang version 15.0.6
> 
> =* repro.c =*

Simply compiling repro.c and running it does not seem to reproduce this 
for me. Can you please share the detailed steps to get this reproduced?

-- 
Cheers,

David / dhildenb