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

From: syzbot
Date: Sun Oct 29 2023 - 13:09:23 EST

Hello,

syzbot found the following issue on:

HEAD commit: 3a568e3a961b Merge tag 'soc-fixes-6.7-3' of git://git.kern..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=159d9cdd680000
kernel config: https://syzkaller.appspot.com/x/.config?x=174a257c5ae6b4fd
dashboard link: https://syzkaller.appspot.com/bug?extid=ec9435c038e451be48ff
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=14e433eb680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16808d35680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/70fcba190275/disk-3a568e3a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/65a6a954dd61/vmlinux-3a568e3a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e4d7963284af/bzImage-3a568e3a.xz

The issue was bisected to:

commit bf4916922c60f43efaa329744b3eef539aa6a2b2
Author: Rik van Riel <riel@xxxxxxxxxxx>
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=17d92743680000
final oops: https://syzkaller.appspot.com/x/report.txt?x=14392743680000
console output: https://syzkaller.appspot.com/x/log.txt?x=10392743680000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ec9435c038e451be48ff@xxxxxxxxxxxxxxxxxxxxxxxxx
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: 1 PID: 5048 Comm: syz-executor261 Not tainted 6.6.0-rc7-syzkaller-00123-g3a568e3a961b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:__lock_acquire+0x10d/0x7f70 kernel/locking/lockdep.c:5004
Code: 85 75 18 00 00 83 3d fd 93 2c 0d 00 48 89 9c 24 10 01 00 00 0f 84 f8 0f 00 00 83 3d 5c 8c b2 0b 00 74 34 48 89 d0 48 c1 e8 03 <42> 80 3c 00 00 74 1a 48 89 d7 e8 24 c0 7b 00 48 8b 94 24 80 00 00
RSP: 0018:ffffc90003abf440 EFLAGS: 00010006
RAX: 000000000000001d RBX: 1ffff92000757eac RCX: 0000000000000000
RDX: 00000000000000e8 RSI: 0000000000000000 RDI: 00000000000000e8
RBP: ffffc90003abf708 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d32d6e R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88807b34bb80
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbcd77db0d0 CR3: 0000000029b05000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
down_write+0x3a/0x50 kernel/locking/rwsem.c:1573
__hugetlb_zap_begin+0x2e0/0x380 mm/hugetlb.c:5447
hugetlb_zap_begin include/linux/hugetlb.h:258 [inline]
unmap_vmas+0x364/0x5c0 mm/memory.c:1733
exit_mmap+0x297/0xc50 mm/mmap.c:3230
__mmput+0x115/0x3c0 kernel/fork.c:1349
exit_mm+0x21f/0x300 kernel/exit.c:567
do_exit+0x9af/0x2650 kernel/exit.c:861
__do_sys_exit kernel/exit.c:991 [inline]
__se_sys_exit kernel/exit.c:989 [inline]
__x64_sys_exit+0x40/0x40 kernel/exit.c:989
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbcd7764af9
Code: Unable to access opcode bytes at 0x7fbcd7764acf.
RSP: 002b:00007ffe3ee5cb58 EFLAGS: 00000246
ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbcd7764af9
RDX: 00007fbcd779e433 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000011f97 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe3ee5cc7c
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x10d/0x7f70 kernel/locking/lockdep.c:5004
Code: 85 75 18 00 00 83 3d fd 93 2c 0d 00 48 89 9c 24 10 01 00 00 0f 84 f8 0f 00 00 83 3d 5c 8c b2 0b 00 74 34 48 89 d0 48 c1 e8 03 <42> 80 3c 00 00 74 1a 48 89 d7 e8 24 c0 7b 00 48 8b 94 24 80 00 00
RSP: 0018:ffffc90003abf440 EFLAGS: 00010006

RAX: 000000000000001d RBX: 1ffff92000757eac RCX: 0000000000000000
RDX: 00000000000000e8 RSI: 0000000000000000 RDI: 00000000000000e8
RBP: ffffc90003abf708 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d32d6e R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88807b34bb80
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbcd77db0d0 CR3: 0000000029b05000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 85 75 18 test %esi,0x18(%rbp)
3: 00 00 add %al,(%rax)
5: 83 3d fd 93 2c 0d 00 cmpl $0x0,0xd2c93fd(%rip) # 0xd2c9409
c: 48 89 9c 24 10 01 00 mov %rbx,0x110(%rsp)
13: 00
14: 0f 84 f8 0f 00 00 je 0x1012
1a: 83 3d 5c 8c b2 0b 00 cmpl $0x0,0xbb28c5c(%rip) # 0xbb28c7d
21: 74 34 je 0x57
23: 48 89 d0 mov %rdx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 00 00 cmpb $0x0,(%rax,%r8,1) <-- trapping instruction
2f: 74 1a je 0x4b
31: 48 89 d7 mov %rdx,%rdi
34: e8 24 c0 7b 00 call 0x7bc05d
39: 48 rex.W
3a: 8b .byte 0x8b
3b: 94 xchg %eax,%esp
3c: 24 80 and $0x80,%al


---
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@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup