linux/arch
Paolo Bonzini d14bdb553f KVM: x86: fix OOPS after invalid KVM_SET_DEBUGREGS
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>
2016-06-02 17:38:50 +02:00
..
alpha lib/GCD.c: use binary GCD algorithm instead of Euclidean 2016-05-20 17:58:30 -07:00
arc Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-25 17:05:40 -07:00
arm - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00
arm64 arm64: KVM: vgic-v3: Relax synchronization when SRE==1 2016-05-31 16:12:17 +02:00
avr32 printk/nmi: generic solution for safe printk in NMI 2016-05-20 17:58:30 -07:00
blackfin printk/nmi: generic solution for safe printk in NMI 2016-05-20 17:58:30 -07:00
c6x asm-generic patch for 4.7 2016-05-24 15:24:37 -07:00
cris MTD updates for v4.7: 2016-05-24 11:00:20 -07:00
frv exit_thread: remove empty bodies 2016-05-20 17:58:30 -07:00
h8300 Merge branch 'hash' of git://ftp.sciencehorizons.net/linux 2016-05-28 16:15:25 -07:00
hexagon asm-generic patch for 4.7 2016-05-24 15:24:37 -07:00
ia64 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
m32r Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
m68k Merge branch 'hash' of git://ftp.sciencehorizons.net/linux 2016-05-28 16:15:25 -07:00
metag Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-25 17:05:40 -07:00
microblaze Merge branch 'hash' of git://ftp.sciencehorizons.net/linux 2016-05-28 16:15:25 -07:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-05-28 16:41:39 -07:00
mn10300 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
nios2 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
openrisc asm-generic patch for 4.7 2016-05-24 15:24:37 -07:00
parisc parisc: Whitespace cleanups in unistd.h 2016-05-25 15:40:49 +02:00
powerpc DAX error handling for 4.7 2016-05-26 19:34:26 -07:00
s390 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
score asm-generic patch for 4.7 2016-05-24 15:24:37 -07:00
sh Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
sparc Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-25 17:05:40 -07:00
tile Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-25 17:05:40 -07:00
um Merge branch 'for-linus-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2016-05-27 18:54:59 -07:00
unicore32 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-05-26 22:01:22 -07:00
x86 KVM: x86: fix OOPS after invalid KVM_SET_DEBUGREGS 2016-06-02 17:38:50 +02:00
xtensa Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-25 17:05:40 -07:00
.gitignore
Kconfig Merge branch 'hash' of git://ftp.sciencehorizons.net/linux 2016-05-28 16:15:25 -07:00