From: "Gustavo A. R. Silva" gustavoars@kernel.org
[ Upstream commit 1e3d976dbb23b3fce544752b434bdc32ce64aabc ]
Fix the following out-of-bounds warning:
net/core/flow_dissector.c:835:3: warning: 'memcpy' offset [33, 48] from the object at 'flow_keys' is out of the bounds of referenced subobject 'ipv6_src' with type '__u32[4]' {aka 'unsigned int[4]'} at offset 16 [-Warray-bounds]
The problem is that the original code is trying to copy data into a couple of struct members adjacent to each other in a single call to memcpy(). So, the compiler legitimately complains about it. As these are just a couple of members, fix this by copying each one of them in separate calls to memcpy().
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/flow_dissector.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index da86c0e1b677..96957a7c732f 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -811,8 +811,10 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, key_addrs = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_IPV6_ADDRS, target_container); - memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src, - sizeof(key_addrs->v6addrs)); + memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src, + sizeof(key_addrs->v6addrs.src)); + memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst, + sizeof(key_addrs->v6addrs.dst)); key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; }