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authorJiaming Zhang <r772577952@gmail.com>2025-11-12 01:36:52 +0800
committerJakub Kicinski <kuba@kernel.org>2025-11-13 17:23:21 -0800
commitf796a8dec9beafcc0f6f0d3478ed685a15c5e062 (patch)
tree5a1fc3ac92daf850b23698da19ed347be27fc1aa /net/core/dev_ioctl.c
parent7410c86fc05b1423466c1a579bcc994f87822566 (diff)
net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()
The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL. Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config") Closes: https://lore.kernel.org/cd6a7056-fa6d-43f8-b78a-f5e811247ba8@linux.dev Signed-off-by: Jiaming Zhang <r772577952@gmail.com> Reviewed-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://patch.msgid.link/20251111173652.749159-2-r772577952@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/dev_ioctl.c')
-rw-r--r--net/core/dev_ioctl.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index ad54b12d4b4c..8bb71a10dba0 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -443,6 +443,9 @@ static int generic_hwtstamp_ioctl_lower(struct net_device *dev, int cmd,
struct ifreq ifrr;
int err;
+ if (!kernel_cfg->ifr)
+ return -EINVAL;
+
strscpy_pad(ifrr.ifr_name, dev->name, IFNAMSIZ);
ifrr.ifr_ifru = kernel_cfg->ifr->ifr_ifru;