From 67cfdd9210b99f260b3e0afeb9525e0acc7be31e Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 26 May 2026 08:35:33 -0700 Subject: [PATCH] ethtool: eeprom: add more safeties to EEPROM Netlink fallback The Netlink fallback path for reading module EEPROM (fallback_set_params()) validates that offset < eeprom_len, but does not check that offset + length stays within eeprom_len. The ioctl equivalent (ethtool_get_any_eeprom() in ioctl.c) has always enforced both bounds: if (eeprom.offset + eeprom.len > total_len) return -EINVAL; This could lead to surprises in both drivers and device FW. Add the missing offset + length validation to fallback_set_params(), mirroring the ioctl. Similarly - ethtool core in general, and ethtool_get_any_eeprom() in particular tries to zero-init all buffers passed to the drivers to avoid any extra work of zeroing things out. eeprom_fallback() uses a plain kmalloc(), change it to zalloc. Fixes: 96d971e307cc ("ethtool: Add fallback to get_module_eeprom from netlink command") Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20260526153533.2779187-11-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/ethtool/eeprom.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ethtool/eeprom.c b/net/ethtool/eeprom.c index 836316df3092..0b8cfeddb014 100644 --- a/net/ethtool/eeprom.c +++ b/net/ethtool/eeprom.c @@ -44,6 +44,9 @@ static int fallback_set_params(struct eeprom_req_info *request, if (offset >= modinfo->eeprom_len) return -EINVAL; + if (length > modinfo->eeprom_len - offset) + return -EINVAL; + eeprom->cmd = ETHTOOL_GMODULEEEPROM; eeprom->len = length; eeprom->offset = offset; @@ -69,7 +72,7 @@ static int eeprom_fallback(struct eeprom_req_info *request, if (err < 0) return err; - data = kmalloc(eeprom.len, GFP_KERNEL); + data = kzalloc(eeprom.len, GFP_KERNEL); if (!data) return -ENOMEM; err = ethtool_get_module_eeprom_call(dev, &eeprom, data);