syzbot


WARNING: kmalloc bug in memslot_rmap_alloc
Status: upstream: reported C repro on 2021/09/05 20:22
Reported-by: syzbot+e0de2333cbf95ea473e8@syzkaller.appspotmail.com
Fix commit: KVM: replace large kvmalloc allocation with vmalloc
Patched on: [ci-upstream-linux-next-kasan-gce-root], missing on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 265d, last: 235d

Cause bisection: introduced by (bisect log) [merge commit]:
commit 512bce50a41c528fa15c4c014293e7bebf018658
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Nov 10 12:58:05 2020 +0000

  Merge v5.10-rc3 into drm-next

Crash: BUG: sleeping function called from invalid context in sta_info_move_state (log)
Repro: C syz .config
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
WARNING: kmalloc bug in kvm_page_track_create_memslot C unreliable 11 206d 222d 0/22 closed as dup on 2021/10/18 08:10
Patch testing requests:
Created Duration User Patch Repo Result
2021/10/14 11:24 16m snovitoll@gmail.com https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/83/14783/2 OK

Sample crash report:
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

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2021/10/05 04:01 upstream f6274b06e326 d236a457 .config log report syz C
Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2021/09/05 03:40 upstream f1583cb1be35 d236a457 .config log report syz C WARNING: kmalloc bug in memslot_rmap_alloc
ci-upstream-kasan-gce 2021/09/05 03:23 upstream f1583cb1be35 d236a457 .config log report info WARNING: kmalloc bug in memslot_rmap_alloc
ci-upstream-kasan-gce-386 2021/09/05 03:22 upstream f1583cb1be35 d236a457 .config log report info WARNING: kmalloc bug in memslot_rmap_alloc