FAILED: patch "[PATCH] wifi: mt76: mt7996: bound the device EEPROM address before" failed to apply to 6.18-stable tree

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 13b3c29a782033ce4a230be9e5618032813dbcd4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090414-routine-poster-2605@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 13b3c29a782033ce4a230be9e5618032813dbcd4 Mon Sep 17 00:00:00 2001
From: Bryam Vargas <[email protected]>
Date: Thu, 25 Jun 2026 07:10:27 -0500
Subject: [PATCH] wifi: mt76: mt7996: bound the device EEPROM address before
the EFUSE copy

mt7996_mcu_get_eeprom() derives the destination of the EFUSE/EXT block copy from the address reported by the MCU response (event->addr, a device-controlled __le32) and clamps only the copy length, never the destination offset into dev->mt76.eeprom.data. A malicious or malfunctioning device can report an arbitrary address and drive an out-of-bounds write of up to MT7996_EXT_EEPROM_BLOCK_SIZE bytes past eeprom.data.

Reject a response whose address would place the copy outside eeprom.data before deriving the destination pointer. Devices that echo the requested in-bounds offset are unaffected.

index 2e83f4b79c87..a1bae5db8500 100644
@@ -4352,11 +4352,18 @@ int mt7996_mcu_get_eeprom(struct mt7996_dev *dev, u32 offset, u8 *buf, u32 buf_l
 	event = (struct mt7996_mcu_eeprom_access_event *)skb->data;
 	if (event->valid) {
 		u32 ret_len = le32_to_cpu(event->eeprom.ext_eeprom.data_len);
+		u32 block = mode == EEPROM_MODE_EXT ? MT7996_EXT_EEPROM_BLOCK_SIZE :
+						      MT7996_EEPROM_BLOCK_SIZE;
 
 		addr = le32_to_cpu(event->addr);
 
-		if (!buf)
+		if (!buf) {
+			if (addr > dev->mt76.eeprom.size - block) {
+				dev_kfree_skb(skb);
+				return -EINVAL;
+			}
 			buf = (u8 *)dev->mt76.eeprom.data + addr;
+		}
 
 		switch (mode) {
 		case EEPROM_MODE_EFUSE:

From: Bryam Vargas <[email protected]>

[ Upstream commit 13b3c29a782033ce4a230be9e5618032813dbcd4 ]

mt7996_mcu_get_eeprom() derives the destination of the EFUSE/EXT block copy from the address reported by the MCU response (event->addr, a device-controlled __le32) and clamps only the copy length, never the destination offset into dev->mt76.eeprom.data. A malicious or malfunctioning device can report an arbitrary address and drive an out-of-bounds write of up to MT7996_EXT_EEPROM_BLOCK_SIZE bytes past eeprom.data.

Reject a response whose address would place the copy outside eeprom.data before deriving the destination pointer. Devices that echo the requested in-bounds offset are unaffected.

---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

index 72851399575f9..ee9716868c907 100644
@@ -3866,8 +3866,14 @@ int mt7996_mcu_get_eeprom(struct mt7996_dev *dev, u32 offset, u8 *buf, u32 buf_l
 	if (valid) {
 		u32 addr = le32_to_cpu(*(__le32 *)(skb->data + 12));
 
-		if (!buf)
+		if (!buf) {
+			if (addr > dev->mt76.eeprom.size -
+			    MT7996_EEPROM_BLOCK_SIZE) {
+				dev_kfree_skb(skb);
+				return -EINVAL;
+			}
 			buf = (u8 *)dev->mt76.eeprom.data + addr;
+		}
 		if (!buf_len || buf_len > MT7996_EEPROM_BLOCK_SIZE)
 			buf_len = MT7996_EEPROM_BLOCK_SIZE;
 

2.53.0