From: "Gustavo A. R. Silva" gustavoars@kernel.org
[ Upstream commit c1d9e34e11281a8ba1a1c54e4db554232a461488 ]
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 lkp@intel.com Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/ethtool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 1011625a0ca4..83028017c26d 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -618,7 +618,7 @@ 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);