memory leak in kvm_vcpu_ioctl_set

memory leak in kvm_vcpu_ioctl_set_cpuid2

Status: fixed on 2023/02/24 13:50
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+ead0473557070d5432cd@syzkaller.appspotmail.com
Fix commit: 811f95ff9527 KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2}
First crash: 821d, last: 821d

▶ ▼ Discussions (3)

Title	Replies (including bot)	Last reply
[PATCH 5.16 000/200] 5.16.5-rc1 review	218 (218)	2022/02/14 15:34
[syzbot] memory leak in kvm_vcpu_ioctl_set_cpuid2	1 (2)	2022/01/26 20:07
[PATCH] KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2}	3 (3)	2022/01/26 11:25

Sample crash report:

BUG: memory leak
unreferenced object 0xffff88810963a800 (size 2048):
  comm "syz-executor025", pid 3610, jiffies 4294944928 (age 8.080s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 0d 00 00 00  ................
    47 65 6e 75 6e 74 65 6c 69 6e 65 49 00 00 00 00  GenuntelineI....
  backtrace:
    [<ffffffff814948ee>] kmalloc_node include/linux/slab.h:604 [inline]
    [<ffffffff814948ee>] kvmalloc_node+0x3e/0x100 mm/util.c:580
    [<ffffffff814950f2>] kvmalloc include/linux/slab.h:732 [inline]
    [<ffffffff814950f2>] vmemdup_user+0x22/0x100 mm/util.c:199
    [<ffffffff8109f5ff>] kvm_vcpu_ioctl_set_cpuid2+0x8f/0xf0 arch/x86/kvm/cpuid.c:423
    [<ffffffff810711b9>] kvm_arch_vcpu_ioctl+0xb99/0x1e60 arch/x86/kvm/x86.c:5251
    [<ffffffff8103e92d>] kvm_vcpu_ioctl+0x4ad/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4066
    [<ffffffff815afacc>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff815afacc>] __do_sys_ioctl fs/ioctl.c:874 [inline]
    [<ffffffff815afacc>] __se_sys_ioctl fs/ioctl.c:860 [inline]
    [<ffffffff815afacc>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
    [<ffffffff844a3335>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff844a3335>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2022/01/22 19:52	upstream	0809edbae347	214351e1	.config	console log	report	syz	C			ci-upstream-gce-leak	memory leak in kvm_vcpu_ioctl_set_cpuid2

* ~~Struck through~~ repros no longer work on HEAD.