d14bdb553f
MOV to DR6 or DR7 causes a #GP if an attempt is made to write a 1 to any of bits 63:32. However, this is not detected at KVM_SET_DEBUGREGS time, and the next KVM_RUN oopses: general protection fault: 0000 [#1] SMP CPU: 2 PID: 14987 Comm: a.out Not tainted 4.4.9-300.fc23.x86_64 #1 Hardware name: LENOVO 2325F51/2325F51, BIOS G2ET32WW (1.12 ) 05/30/2012 [...] Call Trace: [<ffffffffa072c93d>] kvm_arch_vcpu_ioctl_run+0x141d/0x14e0 [kvm] [<ffffffffa071405d>] kvm_vcpu_ioctl+0x33d/0x620 [kvm] [<ffffffff81241648>] do_vfs_ioctl+0x298/0x480 [<ffffffff812418a9>] SyS_ioctl+0x79/0x90 [<ffffffff817a0f2e>] entry_SYSCALL_64_fastpath+0x12/0x71 Code: 55 83 ff 07 48 89 e5 77 27 89 ff ff 24 fd 90 87 80 81 0f 23 fe 5d c3 0f 23 c6 5d c3 0f 23 ce 5d c3 0f 23 d6 5d c3 0f 23 de 5d c3 <0f> 23 f6 5d c3 0f 0b 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 RIP [<ffffffff810639eb>] native_set_debugreg+0x2b/0x40 RSP <ffff88005836bd50> Testcase (beautified/reduced from syzkaller output): #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[8]; int main() { struct kvm_debugregs dr = { 0 }; r[2] = open("/dev/kvm", O_RDONLY); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7); memcpy(&dr, "\x5d\x6a\x6b\xe8\x57\x3b\x4b\x7e\xcf\x0d\xa1\x72" "\xa3\x4a\x29\x0c\xfc\x6d\x44\x00\xa7\x52\xc7\xd8" "\x00\xdb\x89\x9d\x78\xb5\x54\x6b\x6b\x13\x1c\xe9" "\x5e\xd3\x0e\x40\x6f\xb4\x66\xf7\x5b\xe3\x36\xcb", 48); r[7] = ioctl(r[4], KVM_SET_DEBUGREGS, &dr); r[6] = ioctl(r[4], KVM_RUN, 0); } Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> |
||
---|---|---|
.. | ||
alpha | ||
arc | ||
arm | ||
arm64 | ||
avr32 | ||
blackfin | ||
c6x | ||
cris | ||
frv | ||
h8300 | ||
hexagon | ||
ia64 | ||
m32r | ||
m68k | ||
metag | ||
microblaze | ||
mips | ||
mn10300 | ||
nios2 | ||
openrisc | ||
parisc | ||
powerpc | ||
s390 | ||
score | ||
sh | ||
sparc | ||
tile | ||
um | ||
unicore32 | ||
x86 | ||
xtensa | ||
.gitignore | ||
Kconfig |