[syzbot] WARNING: kmalloc bug in memslot_rmap_alloc

From: syzbot
Date: Sun Sep 05 2021 - 16:22:31 EST


Hello,

syzbot found the following issue on:

HEAD commit: f1583cb1be35 Merge tag 'linux-kselftest-next-5.15-rc1' of ..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11dd6315300000
kernel config: https://syzkaller.appspot.com/x/.config?x=9c582b69de20dde2
dashboard link: https://syzkaller.appspot.com/bug?extid=e0de2333cbf95ea473e8
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15db7e5d300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=170e66cd300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e0de2333cbf95ea473e8@xxxxxxxxxxxxxxxxxxxxxxxxx

L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8419 at mm/util.c:597 kvmalloc_node+0x111/0x120 mm/util.c:597
Modules linked in:
CPU: 0 PID: 8419 Comm: syz-executor520 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kvmalloc_node+0x111/0x120 mm/util.c:597
Code: 01 00 00 00 4c 89 e7 e8 ed 17 0d 00 49 89 c5 e9 69 ff ff ff e8 90 0a d1 ff 41 89 ed 41 81 cd 00 20 01 00 eb 95 e8 7f 0a d1 ff <0f> 0b e9 4c ff ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 66
RSP: 0018:ffffc90001a7f828 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888027ee5580 RSI: ffffffff81a51341 RDI: 0000000000000003
RBP: 0000000000400dc0 R08: 000000007fffffff R09: 00000000ffffffff
R10: ffffffff81a512fe R11: 0000000000000000 R12: 0000000380000000
R13: 0000000000000000 R14: 00000000ffffffff R15: dffffc0000000000
FS: 0000000000707300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faeea03f6c0 CR3: 0000000074a57000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kvmalloc include/linux/mm.h:806 [inline]
kvmalloc_array include/linux/mm.h:824 [inline]
kvcalloc include/linux/mm.h:829 [inline]
memslot_rmap_alloc+0xf6/0x310 arch/x86/kvm/x86.c:11320
kvm_alloc_memslot_metadata arch/x86/kvm/x86.c:11388 [inline]
kvm_arch_prepare_memory_region+0x48d/0x610 arch/x86/kvm/x86.c:11462
kvm_set_memslot+0xfe/0x1700 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1505
__kvm_set_memory_region+0x761/0x10e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1668
kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1689 [inline]
kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1701 [inline]
kvm_vm_ioctl+0x4c6/0x2330 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4236
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
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+0x44/0xae
RIP: 0033:0x43ee99
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc276d5138 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ee99
RDX: 00000000200005c0 RSI: 000000004020ae46 RDI: 0000000000000004
RBP: 0000000000402e80 R08: 0000000000400488 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402f10
R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488


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