This is a note to let you know that I've just added the patch titled
libbpf: Add explicit padding to bpf_xdp_set_link_opts
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
libbpf-add-explicit-padding-to-bpf_xdp_set_link_opts.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cc17aa997154381450a8e32d385fa2c74fc2209e
Author: Andrii Nakryiko <andrii@xxxxxxxxxx>
Date: Sat Mar 13 13:09:17 2021 -0800
libbpf: Add explicit padding to bpf_xdp_set_link_opts
[ Upstream commit dde7b3f5f2f458297aeccfd4783e53ab8ca046db ]
Adding such anonymous padding fixes the issue with uninitialized portions of
bpf_xdp_set_link_opts when using LIBBPF_DECLARE_OPTS macro with inline field
initialization:
DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1);
When such code is compiled in debug mode, compiler is generating code that
leaves padding bytes uninitialized, which triggers error inside libbpf APIs
that do strict zero initialization checks for OPTS structs.
Adding anonymous padding field fixes the issue.
Fixes: bd5ca3ef93cd ("libbpf: Add function to set link XDP fd while specifying old program")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6909ee81113a..57d10b779dea 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -507,6 +507,7 @@ struct xdp_link_info {
struct bpf_xdp_set_link_opts {
size_t sz;
int old_fd;
+ size_t :0;
};
#define bpf_xdp_set_link_opts__last_field old_fd
