diff options
| author | Kuen-Han Tsai <khtsai@google.com> | 2026-03-16 15:49:09 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-11 14:29:56 +0200 |
| commit | 7de4d46be40738c7e48e64b5cc0a34aa1e047b0a (patch) | |
| tree | 81b7bb2a9063282924391de7cf78cf301bb179d6 | |
| parent | 8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8 (diff) | |
usb: gadget: u_ether: Fix NULL pointer deref in eth_get_drvinfo
commit e002e92e88e12457373ed096b18716d97e7bbb20 upstream.
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@packett.cool/
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.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/gadget/function/u_ether.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index da07b9ff5d2c..2b824db4d31b 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: |