6.17-stable review patch. If anyone has any objections, please let me know.
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From: Jiaming Zhang r772577952@gmail.com
[ Upstream commit f796a8dec9beafcc0f6f0d3478ed685a15c5e062 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/dev_ioctl.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index ad54b12d4b4c8..8bb71a10dba09 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;