On Sat, 2019-10-26 at 15:54 +0800, zhanglin wrote: > memset() the structure ethtool_wolinfo that has padded bytes > but the padded bytes have not been zeroed out. [] > diff --git a/net/core/ethtool.c b/net/core/ethtool.c [] > @@ -1471,11 +1471,13 @@ static int ethtool_reset(struct net_device *dev, char __user *useraddr) > > static int ethtool_get_wol(struct net_device *dev, char __user *useraddr) > { > - struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL }; > + struct ethtool_wolinfo wol; > > if (!dev->ethtool_ops->get_wol) > return -EOPNOTSUPP; > > + memset(&wol, 0, sizeof(struct ethtool_wolinfo)); > + wol.cmd = ETHTOOL_GWOL; > dev->ethtool_ops->get_wol(dev, &wol); > > if (copy_to_user(useraddr, &wol, sizeof(wol))) It seems likely there are more of these. Is there any way for coccinelle to find them? There are ~4000 structs in include/uapi and there are ~3000 uses of copy_to_user in the tree. $ git grep -P '\bstruct\s+\w+\s*{' include/uapi/ | cut -f2 -d" "|sort|uniq|wc -l 3785 $ git grep -w copy_to_user|wc -l 2854 A trivial grep and manual search using: $ git grep -B20 -w copy_to_user | grep -A20 -P '\bstruct\s+\w+\s*=\s*{' shows at least 1 (I didn't look very hard and stopped after finding 1): include/uapi/linux/utsname.h:struct oldold_utsname { include/uapi/linux/utsname.h- char sysname[9]; include/uapi/linux/utsname.h- char nodename[9]; include/uapi/linux/utsname.h- char release[9]; include/uapi/linux/utsname.h- char version[9]; include/uapi/linux/utsname.h- char machine[9]; include/uapi/linux/utsname.h-}; and kernel/sys.c- struct oldold_utsname tmp = {}; kernel/sys.c- kernel/sys.c- if (!name) kernel/sys.c- return -EFAULT; kernel/sys.c- kernel/sys.c- down_read(&uts_sem); kernel/sys.c- memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); kernel/sys.c- memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); kernel/sys.c- up_read(&uts_sem); kernel/sys.c: if (copy_to_user(name, &tmp, sizeof(tmp))) where there is likely 3 bytes of padding after 45 bytes of data in the struct.