When GET ioctls encounter insufficient buffer (-E2BIG), preserve u.data.length metadata in iwreq structure for size detection Typical usage in userspace tools like 'iwlist wlan0 scanning': - Detect required buffer size via u.data.length - Implement retry logic with proper allocation Signed-off-by: Callan Huang <luvings@xxxxxx> --- net/wireless/wext-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index c32a7c690..b4f72a49f 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -1075,7 +1075,7 @@ int wext_handle_ioctl(struct net *net, unsigned int cmd, void __user *arg) ret = wext_ioctl_dispatch(net, &iwr, cmd, &info, ioctl_standard_call, ioctl_private_call); - if (ret >= 0 && + if ((ret >= 0 || ret == -E2BIG) && IW_IS_GET(cmd) && copy_to_user(arg, &iwr, sizeof(struct iwreq))) return -EFAULT; @@ -1138,7 +1138,7 @@ int compat_wext_handle_ioctl(struct net *net, unsigned int cmd, compat_standard_call, compat_private_call); - if (ret >= 0 && + if ((ret >= 0 || ret == -E2BIG) && IW_IS_GET(cmd) && copy_to_user(argp, &iwr, sizeof(struct iwreq))) return -EFAULT; -- 2.25.1
