[syzbot] [mm?] general protection fault in hugetlb_vma_lock_write

syzbot
2023-10-29T09:27:24Z

Hello,

syzbot found the following issue on:

HEAD commit: 888cf78c29e2 Merge tag 'iommu-fix-v6.6-rc7' of git://git.k..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10cbee95680000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ee601744db6e780
dashboard link: https://syzkaller.appspot.com/bug?extid=6ada951e7c0f7bc8a71e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10fa2557680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14285b57680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ca8ad4106267/disk-888cf78c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/aac2e80e0744/vmlinux-888cf78c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b14533456815/bzImage-888cf78c.xz

The issue was bisected to:

commit bf4916922c60f43efaa329744b3eef539aa6a2b2
Author: Rik van Riel <riel@surriel.com>
Date: Fri Oct 6 03:59:07 2023 +0000

hugetlbfs: extend hugetlb_vma_lock to private VMAs

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17d7dab5680000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1437dab5680000
console output: https://syzkaller.appspot.com/x/log.txt?x=1037dab5680000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ada951e7c0f7bc8a71e@syzkaller.appspotmail.com
Fixes: bf4916922c60 ("hugetlbfs: extend hugetlb_vma_lock to private VMAs")

general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]
CPU: 0 PID: 5048 Comm: syz-executor139 Not tainted 6.6.0-rc7-syzkaller-00142-g888cf78c29e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:__lock_acquire+0x109/0x5de0 kernel/locking/lockdep.c:5004
Code: 45 85 c9 0f 84 cc 0e 00 00 44 8b 05 c1 1e 42 0b 45 85 c0 0f 84 be 0d 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 d1 48 c1 e9 03 <80> 3c 11 00 0f 85 e8 40 00 00 49 81 3a a0 d9 5f 90 0f 84 96 0d 00
RSP: 0018:ffffc90003aa7798 EFLAGS: 00010016

RAX: ffff88807a0b9dc0 RBX: 1ffff92000754f23 RCX: 000000000000001d
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 00000000000000e8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 00000000000000e8 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000280 CR3: 00000000758bf000 CR4: 0000000000350ef0
Call Trace:
<TASK>
lock_acquire kernel/locking/lockdep.c:5753 [inline]
lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718
down_write+0x93/0x200 kernel/locking/rwsem.c:1573
hugetlb_vma_lock_write mm/hugetlb.c:300 [inline]
hugetlb_vma_lock_write+0xae/0x100 mm/hugetlb.c:291
__hugetlb_zap_begin+0x1e9/0x2b0 mm/hugetlb.c:5447
hugetlb_zap_begin include/linux/hugetlb.h:258 [inline]
unmap_vmas+0x2f4/0x470 mm/memory.c:1733
exit_mmap+0x1ad/0xa60 mm/mmap.c:3230
__mmput+0x12a/0x4d0 kernel/fork.c:1349
mmput+0x62/0x70 kernel/fork.c:1371
exit_mm kernel/exit.c:567 [inline]
do_exit+0x9ad/0x2a20 kernel/exit.c:861
__do_sys_exit kernel/exit.c:991 [inline]
__se_sys_exit kernel/exit.c:989 [inline]
__x64_sys_exit+0x42/0x50 kernel/exit.c:989
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ff2b7a78ab9
Code: Unable to access opcode bytes at 0x7ff2b7a78a8f.
RSP: 002b:00007fff926ea6b8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff2b7a78ab9
RDX: 00007ff2b7ab23f3 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000000cfda R08: 0000000000000000 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff926ea6cc
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x109/0x5de0 kernel/locking/lockdep.c:5004
Code: 45 85 c9 0f 84 cc 0e 00 00 44 8b 05 c1 1e 42 0b 45 85 c0 0f 84 be 0d 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 d1 48 c1 e9 03 <80> 3c 11 00 0f 85 e8 40 00 00 49 81 3a a0 d9 5f 90 0f 84 96 0d 00
RSP: 0018:ffffc90003aa7798 EFLAGS: 00010016
RAX: ffff88807a0b9dc0 RBX: 1ffff92000754f23 RCX: 000000000000001d
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 00000000000000e8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 00000000000000e8 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000280 CR3: 00000000758bf000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
0: 45 85 c9 test %r9d,%r9d
3: 0f 84 cc 0e 00 00 je 0xed5
9: 44 8b 05 c1 1e 42 0b mov 0xb421ec1(%rip),%r8d # 0xb421ed1
10: 45 85 c0 test %r8d,%r8d
13: 0f 84 be 0d 00 00 je 0xdd7
19: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
20: fc ff df
23: 4c 89 d1 mov %r10,%rcx
26: 48 c1 e9 03 shr $0x3,%rcx
* 2a: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) <-- trapping instruction
2e: 0f 85 e8 40 00 00 jne 0x411c
34: 49 81 3a a0 d9 5f 90 cmpq $0xffffffff905fd9a0,(%r10)
3b: 0f .byte 0xf
3c: 84 .byte 0x84
3d: 96 xchg %eax,%esi
3e: 0d .byte 0xd

---
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