From c1d9e34e11281a8ba1a1c54e4db554232a461488 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Fri, 16 Apr 2021 15:15:40 -0500 Subject: ethtool: ioctl: Fix out-of-bounds warning in store_link_ksettings_for_user() Fix the following out-of-bounds warning: net/ethtool/ioctl.c:492:2: warning: 'memcpy' offset [49, 84] from the object at 'link_usettings' is out of the bounds of referenced subobject 'base' with type 'struct ethtool_link_settings' at offset 0 [-Warray-bounds] The problem is that the original code is trying to copy data into a some struct members adjacent to each other in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &link_usettings.base. Fix this by directly using &link_usettings and _from_ as destination and source addresses, instead. This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller --- net/ethtool/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ethtool') diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 27f1c5224acb..3fa7a394eabf 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -489,7 +489,7 @@ store_link_ksettings_for_user(void __user *to, { struct ethtool_link_usettings link_usettings; - memcpy(&link_usettings.base, &from->base, sizeof(link_usettings)); + memcpy(&link_usettings, from, sizeof(link_usettings)); bitmap_to_arr32(link_usettings.link_modes.supported, from->link_modes.supported, __ETHTOOL_LINK_MODE_MASK_NBITS); -- cgit v1.2.3