diff options
| author | Kuen-Han Tsai <khtsai@google.com> | 2026-02-21 22:48:15 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:15:06 +0100 |
| commit | b23e86a3a15803c3dcb24701285f73e65099fdf9 (patch) | |
| tree | 058aa71c19b90a27308d00f4ff0d6e38820d8f6f | |
| parent | e95120b4b95ef1c16d8e94e201ae89f5e59e2612 (diff) | |
usb: legacy: ncm: Fix NPE in gncm_bind
commit fde0634ad9856b3943a2d1a8cc8de174a63ac840 upstream.
Commit 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle
with bind/unbind") deferred the allocation of the net_device. This
change leads to a NULL pointer dereference in the legacy NCM driver as
it attempts to access the net_device before it's fully instantiated.
Store the provided qmult, host_addr, and dev_addr into the struct
ncm_opts->net_opts during gncm_bind(). These values will be properly
applied to the net_device when it is allocated and configured later in
the binding process by the NCM function driver.
Fixes: 56a512a9b410 ("usb: gadget: f_ncm: align net_device lifecycle with bind/unbind")
Cc: stable@kernel.org
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202602181727.fd76c561-lkp@intel.com
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://patch.msgid.link/20260221-legacy-ncm-v2-1-dfb891d76507@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/gadget/legacy/ncm.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/usb/gadget/legacy/ncm.c b/drivers/usb/gadget/legacy/ncm.c index 0f1b45e3abd1..e8d565534053 100644 --- a/drivers/usb/gadget/legacy/ncm.c +++ b/drivers/usb/gadget/legacy/ncm.c @@ -15,8 +15,10 @@ /* #define DEBUG */ /* #define VERBOSE_DEBUG */ +#include <linux/hex.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/string.h> #include <linux/usb/composite.h> #include "u_ether.h" @@ -129,6 +131,7 @@ static int gncm_bind(struct usb_composite_dev *cdev) struct usb_gadget *gadget = cdev->gadget; struct f_ncm_opts *ncm_opts; int status; + u8 mac[ETH_ALEN]; f_ncm_inst = usb_get_function_instance("ncm"); if (IS_ERR(f_ncm_inst)) @@ -136,11 +139,15 @@ static int gncm_bind(struct usb_composite_dev *cdev) ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst); - gether_set_qmult(ncm_opts->net, qmult); - if (!gether_set_host_addr(ncm_opts->net, host_addr)) + ncm_opts->net_opts.qmult = qmult; + if (host_addr && mac_pton(host_addr, mac)) { + memcpy(&ncm_opts->net_opts.host_mac, mac, ETH_ALEN); pr_info("using host ethernet address: %s", host_addr); - if (!gether_set_dev_addr(ncm_opts->net, dev_addr)) + } + if (dev_addr && mac_pton(dev_addr, mac)) { + memcpy(&ncm_opts->net_opts.dev_mac, mac, ETH_ALEN); pr_info("using self ethernet address: %s", dev_addr); + } /* Allocate string descriptor numbers ... note that string * contents can be overridden by the composite_dev glue. |