[syzbot] BUG: unable to handle kernel paging request in truncate_inode_partial_folio

From: syzbot
Date: Tue Jun 28 2022 - 18:59:33 EST


Hello,

syzbot found the following issue on:

HEAD commit: 941e3e791269 Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1670ded4080000
kernel config: https://syzkaller.appspot.com/x/.config?x=833001d0819ddbc9
dashboard link: https://syzkaller.appspot.com/bug?extid=9bd2b7adbd34b30b87e4
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=140f9ba8080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15495188080000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9bd2b7adbd34b30b87e4@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: unable to handle page fault for address: ffff888021f7e005
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 11401067 P4D 11401067 PUD 11402067 PMD 21f7d063 PTE 800fffffde081060
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3761 Comm: syz-executor281 Not tainted 5.19.0-rc4-syzkaller-00014-g941e3e791269 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc9000329fa90 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000ffb
RDX: 0000000000000ffb RSI: 0000000000000000 RDI: ffff888021f7e005
RBP: ffffea000087df80 R08: 0000000000000001 R09: ffff888021f7e005
R10: ffffed10043efdff R11: 0000000000000000 R12: 0000000000000005
R13: 0000000000000000 R14: 0000000000001000 R15: 0000000000000ffb
FS: 00007fb29d8b2700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888021f7e005 CR3: 0000000026e7b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
zero_user_segments include/linux/highmem.h:272 [inline]
folio_zero_range include/linux/highmem.h:428 [inline]
truncate_inode_partial_folio+0x76a/0xdf0 mm/truncate.c:237
truncate_inode_pages_range+0x83b/0x1530 mm/truncate.c:381
truncate_inode_pages mm/truncate.c:452 [inline]
truncate_pagecache+0x63/0x90 mm/truncate.c:753
simple_setattr+0xed/0x110 fs/libfs.c:535
secretmem_setattr+0xae/0xf0 mm/secretmem.c:170
notify_change+0xb8c/0x12b0 fs/attr.c:424
do_truncate+0x13c/0x200 fs/open.c:65
do_sys_ftruncate+0x536/0x730 fs/open.c:193
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+0x46/0xb0
RIP: 0033:0x7fb29d900899
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb29d8b2318 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007fb29d988408 RCX: 00007fb29d900899
RDX: 00007fb29d900899 RSI: 0000000000000005 RDI: 0000000000000003
RBP: 00007fb29d988400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb29d98840c
R13: 00007ffca01a23bf R14: 00007fb29d8b2400 R15: 0000000000022000
</TASK>
Modules linked in:
CR2: ffff888021f7e005
---[ end trace 0000000000000000 ]---
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc9000329fa90 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000ffb
RDX: 0000000000000ffb RSI: 0000000000000000 RDI: ffff888021f7e005
RBP: ffffea000087df80 R08: 0000000000000001 R09: ffff888021f7e005
R10: ffffed10043efdff R11: 0000000000000000 R12: 0000000000000005
R13: 0000000000000000 R14: 0000000000001000 R15: 0000000000000ffb
FS: 00007fb29d8b2700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888021f7e005 CR3: 0000000026e7b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: c1 e9 03 shr $0x3,%ecx
3: 40 0f b6 f6 movzbl %sil,%esi
7: 48 b8 01 01 01 01 01 movabs $0x101010101010101,%rax
e: 01 01 01
11: 48 0f af c6 imul %rsi,%rax
15: f3 48 ab rep stos %rax,%es:(%rdi)
18: 89 d1 mov %edx,%ecx
1a: f3 aa rep stos %al,%es:(%rdi)
1c: 4c 89 c8 mov %r9,%rax
1f: c3 retq
20: 90 nop
21: 49 89 f9 mov %rdi,%r9
24: 40 88 f0 mov %sil,%al
27: 48 89 d1 mov %rdx,%rcx
* 2a: f3 aa rep stos %al,%es:(%rdi) <-- trapping instruction
2c: 4c 89 c8 mov %r9,%rax
2f: c3 retq
30: 90 nop
31: 49 89 fa mov %rdi,%r10
34: 40 0f b6 ce movzbl %sil,%ecx
38: 48 rex.W
39: b8 01 01 01 01 mov $0x1010101,%eax
3e: 01 01 add %eax,(%rcx)


---
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