From: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com>
Fei has reported that KASAN triggers during apply_alternatives() on
a 5-level paging machine:
BUG: KASAN: out-of-bounds in rcu_is_watching()
Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0
...
__asan_load4()
rcu_is_watching()
trace_hardirqs_on()
text_poke_early()
apply_alternatives()
...
On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57)
gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on
__VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled().
KASAN gets confused when apply_alternatives() patches the
KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START
static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue.
Fix it for real by disabling KASAN while the kernel is patching alternatives.
[ mingo: updated the changelog ]
Fixes: 6657fca06e3f ("x86/mm: Allow to boot without LA57 if CONFIG_X86_5LEVEL=y")
Reported-by: Fei Yang <fei.yang(a)intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com>
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20231012100424.1456-1-kirill.shutemov@linux.intel…
(cherry picked from commit d35652a5fc9944784f6f50a5c979518ff8dacf61)
---
arch/x86/kernel/alternative.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 517ee01503be..73be3931e4f0 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -403,6 +403,17 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
u8 insn_buff[MAX_PATCH_LEN];
DPRINTK(ALT, "alt table %px, -> %px", start, end);
+
+ /*
+ * In the case CONFIG_X86_5LEVEL=y, KASAN_SHADOW_START is defined using
+ * cpu_feature_enabled(X86_FEATURE_LA57) and is therefore patched here.
+ * During the process, KASAN becomes confused seeing partial LA57
+ * conversion and triggers a false-positive out-of-bound report.
+ *
+ * Disable KASAN until the patching is complete.
+ */
+ kasan_disable_current();
+
/*
* The scan order should be from start to end. A later scanned
* alternative code can overwrite previously scanned alternative code.
@@ -452,6 +463,8 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
text_poke_early(instr, insn_buff, insn_buff_sz);
}
+
+ kasan_enable_current();
}
static inline bool is_jcc32(struct insn *insn)
--
2.25.1
[ Upstream commit 3971442870713de527684398416970cf025b4f89 ]
The ravb_stop() should call cancel_work_sync(). Otherwise,
ravb_tx_timeout_work() is possible to use the freed priv after
ravb_remove() was called like below:
CPU0 CPU1
ravb_tx_timeout()
ravb_remove()
unregister_netdev()
free_netdev(ndev)
// free priv
ravb_tx_timeout_work()
// use priv
unregister_netdev() will call .ndo_stop() so that ravb_stop() is
called. And, after phy_stop() is called, netif_carrier_off()
is also called. So that .ndo_tx_timeout() will not be called
after phy_stop().
Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Reported-by: Zheng Wang <zyytlz.wz(a)163.com>
Closes: https://lore.kernel.org/netdev/20230725030026.1664873-1-zyytlz.wz@163.com/
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh(a)renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov(a)omp.ru>
Link: https://lore.kernel.org/r/20231005011201.14368-3-yoshihiro.shimoda.uh@renes…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
Cc: <stable(a)vger.kernel.org> # for 5.10.x and 5.4.x
---
drivers/net/ethernet/renesas/ravb_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index a59da6a11976..f218bacec001 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1706,6 +1706,8 @@ static int ravb_close(struct net_device *ndev)
of_phy_deregister_fixed_link(np);
}
+ cancel_work_sync(&priv->work);
+
if (priv->chip_id != RCAR_GEN2) {
free_irq(priv->tx_irqs[RAVB_NC], ndev);
free_irq(priv->rx_irqs[RAVB_NC], ndev);
--
2.25.1
From: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
If we can't find a free fence register to handle a fault in the GMADR
range just return VM_FAULT_NOPAGE without populating the PTE so that
userspace will retry the access and trigger another fault. Eventually
we should find a free fence and the fault will get properly handled.
A further improvement idea might be to reserve a fence (or one per CPU?)
for the express purpose of handling faults without having to retry. But
that would require some additional work.
Looks like this may have gotten broken originally by
commit 39965b376601 ("drm/i915: don't trash the gtt when running out of fences")
as that changed the errno to -EDEADLK which wasn't handle by the gtt
fault code either. But later in commit 2feeb52859fc ("drm/i915/gt: Fix
-EDEADLK handling regression") I changed it again to -ENOBUFS as -EDEADLK
was now getting used for the ww mutex dance. So this fix only makes
sense after that last commit.
Cc: stable(a)vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9479
Fixes: 2feeb52859fc ("drm/i915/gt: Fix -EDEADLK handling regression")
Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index aa4d842d4c5a..310654542b42 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -235,6 +235,7 @@ static vm_fault_t i915_error_to_vmf_fault(int err)
case 0:
case -EAGAIN:
case -ENOSPC: /* transient failure to evict? */
+ case -ENOBUFS: /* temporarily out of fences? */
case -ERESTARTSYS:
case -EINTR:
case -EBUSY:
--
2.41.0
From: Paolo Bonzini <pbonzini(a)redhat.com>
svm_recalc_instruction_intercepts() is always called at least once
before the vCPU is started, so the setting or clearing of the RDTSCP
intercept can be dropped from the TSC_AUX virtualization support.
Extracted from a patch by Tom Lendacky.
Cc: stable(a)vger.kernel.org
Fixes: 296d5a17e793 ("KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts")
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
(cherry picked from commit e8d93d5d93f85949e7299be289c6e7e1154b2f78)
Signed-off-by: Michael Roth <michael.roth(a)amd.com>
---
arch/x86/kvm/svm/sev.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index b9a0a939d59f..fa1fb81323b5 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3027,11 +3027,8 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
if (boot_cpu_has(X86_FEATURE_V_TSC_AUX) &&
(guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDTSCP) ||
- guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDPID))) {
+ guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDPID)))
set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, 1, 1);
- if (guest_cpuid_has(&svm->vcpu, X86_FEATURE_RDTSCP))
- svm_clr_intercept(svm, INTERCEPT_RDTSCP);
- }
}
void sev_init_vmcb(struct vcpu_svm *svm)
--
2.25.1