Merge tag 'perf-urgent-2026-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

cab9e339 · Linus Torvalds <[email protected]> · 2026-07-11 10:11:45 -07:00

Pull perf events fixes from Ingo Molnar:

 - Fix SVM #GP on AMD CPUs that LBR but not BRS (Sandipan Das)

 - Fix UAF bug in the perf AUX code (Lee Jia Jie)

 - Fix address leakage in the AMD LBR code (Sandipan Das)

 - Fix address leakage in the AMD BRS code (Sandipan Das)

* tag 'perf-urgent-2026-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/brs: Fix kernel address leakage
  perf/x86/amd/lbr: Fix kernel address leakage
  perf/aux: Fix page UAF in map_range()
  perf/x86/amd/core: Avoid enabling BRS from the SVM reload path

Commit: cab9e339cfbc1a4e075e53e281dfb00391e1a6bb
Parents: b37fa0d0 · 47915e85

Merge commit. Changes below are compared with the first parent: b37fa0d0.

Changes

4 files changed · +17 −10

File	Status	Add	Del	Content
arch/x86/events/amd/brs.c	modified	+5	−5	View file
arch/x86/events/amd/core.c	modified	+8	−4	View file
arch/x86/events/amd/lbr.c	modified	+2	−1	View file
kernel/events/core.c	modified	+2	−0	View file

arch/x86/events/amd/brs.c

View file

diff --git a/arch/x86/events/amd/brs.c b/arch/x86/events/amd/brs.c
index 06f35a6..dc56468 100644
--- a/arch/x86/events/amd/brs.c
+++ b/arch/x86/events/amd/brs.c
@@ -259,13 +259,13 @@ void amd_brs_disable_all(void)
 		amd_brs_disable();
 }
 
-static bool amd_brs_match_plm(struct perf_event *event, u64 to)
+static bool amd_brs_match_plm(struct perf_event *event, u64 from, u64 to)
 {
 	int type = event->attr.branch_sample_type;
 	int plm_k = PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_HV;
 	int plm_u = PERF_SAMPLE_BRANCH_USER;
 
-	if (!(type & plm_k) && kernel_ip(to))
+	if (!(type & plm_k) && (kernel_ip(to) || kernel_ip(from)))
 		return 0;
 
 	if (!(type & plm_u) && !kernel_ip(to))
@@ -338,11 +338,11 @@ void amd_brs_drain(void)
 		 */
 		to = (u64)(((s64)to << shift) >> shift);
 
-		if (!amd_brs_match_plm(event, to))
-			continue;
-
 		rdmsrq(brs_from(brs_idx), from);
 
+		if (!amd_brs_match_plm(event, from, to))
+			continue;
+
 		perf_clear_branch_entry_bitfields(br+nr);
 
 		br[nr].from = from;

arch/x86/events/amd/core.c

View file

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 6569048..a787409 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -754,13 +754,11 @@ static void amd_pmu_enable_event(struct perf_event *event)
 	x86_pmu_enable_event(event);
 }
 
-static void amd_pmu_enable_all(int added)
+static void __amd_pmu_enable_all(void)
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
-	amd_brs_enable_all();
-
 	for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
 		/* only activate events which are marked as active */
 		if (!test_bit(idx, cpuc->active_mask))
@@ -775,6 +773,12 @@ static void amd_pmu_enable_all(int added)
 	}
 }
 
+static void amd_pmu_enable_all(int added)
+{
+	amd_brs_enable_all();
+	__amd_pmu_enable_all();
+}
+
 static void amd_pmu_v2_enable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
@@ -1561,7 +1565,7 @@ static inline void amd_pmu_reload_virt(void)
 		 * set global enable bits once again
 		 */
 		amd_pmu_v2_disable_all();
-		amd_pmu_enable_all(0);
+		__amd_pmu_enable_all();
 		amd_pmu_v2_enable_all(0);
 		return;
 	}

arch/x86/events/amd/lbr.c

View file

diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c
index 5b437dc..9d9c961 100644
--- a/arch/x86/events/amd/lbr.c
+++ b/arch/x86/events/amd/lbr.c
@@ -127,7 +127,8 @@ static void amd_pmu_lbr_filter(void)
 		}
 
 		/* If type does not correspond, then discard */
-		if (type == X86_BR_NONE || (br_sel & type) != type) {
+		if (type == X86_BR_NONE || (br_sel & type) != type ||
+		    (!(br_sel & X86_BR_KERNEL) && kernel_ip(cpuc->lbr_entries[i].from))) {
 			cpuc->lbr_entries[i].from = 0;	/* mark invalid */
 			compress = true;
 		}

kernel/events/core.c

View file

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d7f3e2c..ba5bd6a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7150,6 +7150,8 @@ static int map_range(struct perf_buffer *rb, struct vm_area_struct *vma)
 	int err = 0;
 	unsigned long pagenum;
 
+	guard(mutex)(&rb->aux_mutex);
+
 	/*
 	 * We map this as a VM_PFNMAP VMA.
 	 *