diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-11-04 18:22:38 +0000 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2021-11-15 12:37:08 +0000 |
| commit | daf972118c517b91f74ff1731417feb4270625a4 (patch) | |
| tree | 621cc7939acb20f966290467e901957fa67303a7 | |
| parent | 8a7eb2d476c6823cd44d8c25a6230a52417d7ef8 (diff) | |
| download | linux-daf972118c517b91f74ff1731417feb4270625a4.tar.gz | |
x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails
Check for a valid hv_vp_index array prior to derefencing hv_vp_index when
setting Hyper-V's TSC change callback. If Hyper-V setup failed in
hyperv_init(), the kernel will still report that it's running under
Hyper-V, but will have silently disabled nearly all functionality.
BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP
CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc2+ #75
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:set_hv_tscchange_cb+0x15/0xa0
Code: <8b> 04 82 8b 15 12 17 85 01 48 c1 e0 20 48 0d ee 00 01 00 f6 c6 08
...
Call Trace:
kvm_arch_init+0x17c/0x280
kvm_init+0x31/0x330
vmx_init+0xba/0x13a
do_one_initcall+0x41/0x1c0
kernel_init_freeable+0x1f2/0x23b
kernel_init+0x16/0x120
ret_from_fork+0x22/0x30
Fixes: 93286261de1b ("x86/hyperv: Reenlightenment notifications support")
Cc: stable@vger.kernel.org
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20211104182239.1302956-2-seanjc@google.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
| -rw-r--r-- | arch/x86/hyperv/hv_init.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 24f4a06ac46ac..7d252a58fbe48 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -177,6 +177,9 @@ void set_hv_tscchange_cb(void (*cb)(void)) return; } + if (!hv_vp_index) + return; + hv_reenlightenment_cb = cb; /* Make sure callback is registered before we write to MSRs */ |