From e0b6ef0fdbff0a0cf9d3c38df231b76719bbcd82 Mon Sep 17 00:00:00 2001 From: Agalakov Daniil Date: Wed, 18 Mar 2026 15:05:05 +0300 Subject: [PATCH] e1000: check return value of e1000_read_eeprom [ Upstream commit d3baa34a470771399c1495bc04b1e26ac15d598e ] [Why] e1000_set_eeprom() performs a read-modify-write operation when the write range is not word-aligned. This requires reading the first and last words of the range from the EEPROM to preserve the unmodified bytes. However, the code does not check the return value of e1000_read_eeprom(). If the read fails, the operation continues using uninitialized data from eeprom_buff. This results in corrupted data being written back to the EEPROM for the boundary words. Add the missing error checks and abort the operation if reading fails. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Co-developed-by: Iskhakov Daniil Signed-off-by: Iskhakov Daniil Signed-off-by: Agalakov Daniil Reviewed-by: Aleksandr Loktionov Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/e1000/e1000_ethtool.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c index 0a57172dfcbc..631165b895b6 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c +++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c @@ -496,14 +496,19 @@ static int e1000_set_eeprom(struct net_device *netdev, */ ret_val = e1000_read_eeprom(hw, first_word, 1, &eeprom_buff[0]); + if (ret_val) + goto out; + ptr++; } - if (((eeprom->offset + eeprom->len) & 1) && (ret_val == 0)) { + if ((eeprom->offset + eeprom->len) & 1) { /* need read/modify/write of last changed EEPROM word * only the first byte of the word is being modified */ ret_val = e1000_read_eeprom(hw, last_word, 1, &eeprom_buff[last_word - first_word]); + if (ret_val) + goto out; } /* Device's eeprom is always little-endian, word addressable */ @@ -522,6 +527,7 @@ static int e1000_set_eeprom(struct net_device *netdev, if ((ret_val == 0) && (first_word <= EEPROM_CHECKSUM_REG)) e1000_update_eeprom_checksum(hw); +out: kfree(eeprom_buff); return ret_val; }