From: Alysa Liu <Alysa.Liu@amd.com>
Date: Tue, 21 Apr 2026 14:18:28 +0000 (-0400)
Subject: drm/amdkfd: validate SVM ioctl nattr against buffer size
X-Git-Tag: v7.2-rc1~141^2~24^2~98
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=5eca8bfdfa456c3304ca77523718fe24254c172f;p=thirdparty%2Flinux.git

drm/amdkfd: validate SVM ioctl nattr against buffer size

Validate nattr field against the buffer size, preventing
out-of-bounds buffer access via user-controlled attribute count.

Reviewed-by: Amir Shetaia <Amir.Shetaia@amd.com>
Signed-off-by: Alysa Liu <Alysa.Liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 55ea5145a28ac..f829d65a79b43 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -25,6 +25,7 @@
 #include <linux/err.h>
 #include <linux/fs.h>
 #include <linux/file.h>
+#include <linux/overflow.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
@@ -1695,6 +1696,16 @@ static int kfd_ioctl_smi_events(struct file *filep,
 	return kfd_smi_event_open(pdd->dev, &args->anon_fd);
 }
 
+static int kfd_ioctl_svm_validate(void *kdata, unsigned int usize)
+{
+	struct kfd_ioctl_svm_args *args = kdata;
+	size_t expected = struct_size(args, attrs, args->nattr);
+
+	if (expected == SIZE_MAX || usize < expected)
+		return -EINVAL;
+	return 0;
+}
+
 #if IS_ENABLED(CONFIG_HSA_AMD_SVM)
 
 static int kfd_ioctl_set_xnack_mode(struct file *filep,
@@ -3209,7 +3220,11 @@ static int kfd_ioctl_create_process(struct file *filep, struct kfd_process *p, v
 
 #define AMDKFD_IOCTL_DEF(ioctl, _func, _flags) \
 	[_IOC_NR(ioctl)] = {.cmd = ioctl, .func = _func, .flags = _flags, \
-			    .cmd_drv = 0, .name = #ioctl}
+			    .validate = NULL, .cmd_drv = 0, .name = #ioctl}
+
+#define AMDKFD_IOCTL_DEF_V(ioctl, _func, _validate, _flags) \
+	[_IOC_NR(ioctl)] = {.cmd = ioctl, .func = _func, .flags = _flags, \
+			    .validate = _validate, .cmd_drv = 0, .name = #ioctl}
 
 /** Ioctl table */
 static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = {
@@ -3306,7 +3321,8 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = {
 	AMDKFD_IOCTL_DEF(AMDKFD_IOC_SMI_EVENTS,
 			kfd_ioctl_smi_events, 0),
 
-	AMDKFD_IOCTL_DEF(AMDKFD_IOC_SVM, kfd_ioctl_svm, 0),
+	AMDKFD_IOCTL_DEF_V(AMDKFD_IOC_SVM, kfd_ioctl_svm,
+			   kfd_ioctl_svm_validate, 0),
 
 	AMDKFD_IOCTL_DEF(AMDKFD_IOC_SET_XNACK_MODE,
 			kfd_ioctl_set_xnack_mode, 0),
@@ -3431,6 +3447,12 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 		memset(kdata, 0, usize);
 	}
 
+	if (ioctl->validate) {
+		retcode = ioctl->validate(kdata, usize);
+		if (retcode)
+			goto err_i1;
+	}
+
 	retcode = func(filep, process, kdata);
 
 	if (cmd & IOC_OUT)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index 39b06544460c5..b7cf59b2699e8 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -1046,10 +1046,13 @@ extern struct srcu_struct kfd_processes_srcu;
 typedef int amdkfd_ioctl_t(struct file *filep, struct kfd_process *p,
 				void *data);
 
+typedef int amdkfd_ioctl_validate_t(void *kdata, unsigned int usize);
+
 struct amdkfd_ioctl_desc {
 	unsigned int cmd;
 	int flags;
 	amdkfd_ioctl_t *func;
+	amdkfd_ioctl_validate_t *validate;
 	unsigned int cmd_drv;
 	const char *name;
 };