From: Kuen-Han Tsai <khtsai@google.com> mainline inclusion from mainline-v7.0-rc4 commit ec35c1969650e7cb6c8a91020e568ed46e3551b0 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14979 CVE: CVE-2026-43421 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Commit ec35c1969650 ("usb: gadget: f_ncm: Fix net_device lifecycle with device_move") reparents the gadget device to /sys/devices/virtual during unbind, clearing the gadget pointer. If the userspace tool queries on the surviving interface during this detached window, this leads to a NULL pointer dereference. Unable to handle kernel NULL pointer dereference Call trace: eth_get_drvinfo+0x50/0x90 ethtool_get_drvinfo+0x5c/0x1f0 __dev_ethtool+0xaec/0x1fe0 dev_ethtool+0x134/0x2e0 dev_ioctl+0x338/0x560 Add a NULL check for dev->gadget in eth_get_drvinfo(). When detached, skip copying the fw_version and bus_info strings, which is natively handled by ethtool_get_drvinfo for empty strings. Suggested-by: Val Packett <val@packett.cool> Reported-by: Val Packett <val@packett.cool> Closes: https://lore.kernel.org/linux-usb/10890524-cf83-4a71-b879-93e2b2cc1fcc@packe... Fixes: ec35c1969650 ("usb: gadget: f_ncm: Fix net_device lifecycle with device_move") Cc: stable <stable@kernel.org> Signed-off-by: Kuen-Han Tsai <khtsai@google.com> Link: https://patch.msgid.link/20260316-eth-null-deref-v1-1-07005f33be85@google.co... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Xinyu Zheng <zhengxinyu6@huawei.com> --- drivers/usb/gadget/function/u_ether.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index fae3cd49e0f8..b952962a27ad 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -112,8 +112,10 @@ static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p) strscpy(p->driver, "g_ether", sizeof(p->driver)); strscpy(p->version, UETH__VERSION, sizeof(p->version)); - strscpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version)); - strscpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info)); + if (dev->gadget) { + strscpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version)); + strscpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info)); + } } /* REVISIT can also support: -- 2.34.1