From: Esben Haabendal <esben(a)geanix.com>
mainline inclusion
from mainline-v6.10-rc1
commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAD0R6
CVE: CVE-2024-40967
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
--------------------------------
By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential
deadlock.
In case of the timeout, there is not much we can do, so we simply ignore
the transmitter state and optimistically try to continue.
Signed-off-by: Esben Haabendal <esben(a)geanix.com>
Acked-by: Marc Kleine-Budde <mkl(a)pengutronix.de>
Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.17128376…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Conflicts:
drivers/tty/serial/imx.c
[Fix context conflicts]
Signed-off-by: Felix Fu <fuzhen5(a)huawei.com>
---
drivers/tty/serial/imx.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 989ca7d662f3..51b8624a11e5 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -29,6 +29,7 @@
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/dma-mapping.h>
#include <asm/irq.h>
@@ -1912,7 +1913,7 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count)
{
struct imx_port *sport = imx_uart_ports[co->index];
struct imx_port_ucrs old_ucr;
- unsigned int ucr1;
+ unsigned int ucr1, usr2;
unsigned long flags = 0;
int locked = 1;
int retval;
@@ -1954,8 +1955,8 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count)
* Finally, wait for transmitter to become empty
* and restore UCR1/2/3
*/
- while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
-
+ read_poll_timeout_atomic(imx_uart_readl, usr2, usr2 & USR2_TXDC,
+ 0, USEC_PER_SEC, false, sport, USR2);
imx_uart_ucrs_restore(sport, &old_ucr);
if (locked)
--
2.34.1
From: Breno Leitao <leitao(a)debian.org>
mainline inclusion
from mainline-v6.10-rc5
commit 49f683b41f28918df3e51ddc0d928cb2e934ccdb
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IACT6J
CVE: CVE-2024-40953
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
--------------------------------
Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the
loads and stores are atomic. In the extremely unlikely scenario the
compiler tears the stores, it's theoretically possible for KVM to attempt
to get a vCPU using an out-of-bounds index, e.g. if the write is split
into multiple 8-bit stores, and is paired with a 32-bit load on a VM with
257 vCPUs:
CPU0 CPU1
last_boosted_vcpu = 0xff;
(last_boosted_vcpu = 0x100)
last_boosted_vcpu[15:8] = 0x01;
i = (last_boosted_vcpu = 0x1ff)
last_boosted_vcpu[7:0] = 0x00;
vcpu = kvm->vcpu_array[0x1ff];
As detected by KCSAN:
BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm]
write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16:
kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm
handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel
vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:?
arch/x86/kvm/vmx/vmx.c:6606) kvm_intel
vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm
kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm
kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm
__se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890)
__x64_sys_ioctl (fs/ioctl.c:890)
x64_sys_call (arch/x86/entry/syscall_64.c:33)
do_syscall_64 (arch/x86/entry/common.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4:
kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm
handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel
vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:?
arch/x86/kvm/vmx/vmx.c:6606) kvm_intel
vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm
kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm
kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm
__se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890)
__x64_sys_ioctl (fs/ioctl.c:890)
x64_sys_call (arch/x86/entry/syscall_64.c:33)
do_syscall_64 (arch/x86/entry/common.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
value changed: 0x00000012 -> 0x00000000
Fixes: 217ece6129f2 ("KVM: use yield_to instead of sleep in kvm_vcpu_on_spin")
Cc: stable(a)vger.kernel.org
Signed-off-by: Breno Leitao <leitao(a)debian.org>
Link: https://lore.kernel.org/r/20240510092353.2261824-1-leitao@debian.org
Signed-off-by: Sean Christopherson <seanjc(a)google.com>
Conflicts:
virt/kvm/kvm_main.c
[Fix context because of 46808a4cb89708c2e5b264eb9d1035762581921b not
merged]
Signed-off-by: Felix Fu <fuzhen5(a)huawei.com>
---
virt/kvm/kvm_main.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 53c83483653f..2b28fcb35641 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2503,12 +2503,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
{
struct kvm *kvm = me->kvm;
struct kvm_vcpu *vcpu;
- int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
+ int last_boosted_vcpu;
int yielded = 0;
int try = 3;
int pass;
int i;
+ last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu);
kvm_vcpu_set_in_spin_loop(me, true);
/*
* We boost the priority of a VCPU that is runnable but not
@@ -2538,7 +2539,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
yielded = kvm_vcpu_yield_to(vcpu);
if (yielded > 0) {
- kvm->last_boosted_vcpu = i;
+ WRITE_ONCE(kvm->last_boosted_vcpu, i);
break;
} else if (yielded < 0) {
try--;
--
2.34.1