Commit 1161da52d2 for qemu.org

commit 1161da52d2666140c06eb4f6cff72472afcfdb5b
Author: Peter Maydell <peter.maydell@linaro.org>
Date:   Tue May 5 21:13:24 2026 +0100

    net: mark struct ip6_header as QEMU_PACKED

    The ip6_header is often used by network devices to examine structures in
    packet data, and it's not guaranteed to be aligned. This manifests as
    errors from the clang sanitizer like this one:

    SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../../hw/net/rocker/rocker_of_dpa.c:321:37
    ../../hw/net/rocker/rocker_of_dpa.c:730:33: runtime error: member access within misaligned address 0x742970fe7ecd for type 'struct ip6_header', which requires 4 byte alignment
    0x742970fe7ecd: note: pointer points here
     00 00 02 81 00 60 00  00 00 00 38 3a ff fe 80  00 00 00 00 00 00 00 00  00 00 00 00 00 02 ff 02  00
                 ^

    Fix this by marking the ip6_header struct as QEMU_PACKED, the way we
    have done to handle similar problems involving tcp_header, ip_header,
    etc.

    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Reviewed-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
    Message-ID: <20260505201324.932323-1-peter.maydell@linaro.org>
    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/include/net/eth.h b/include/net/eth.h
index efe270dbfe..46dc9ed5ac 100644
--- a/include/net/eth.h
+++ b/include/net/eth.h
@@ -119,7 +119,7 @@ struct ip6_header {
     } ip6_ctlun;
     struct in6_address ip6_src;    /* source address */
     struct in6_address ip6_dst;    /* destination address */
-};
+} QEMU_PACKED;

 typedef struct ip6_pseudo_header {
     struct in6_address ip6_src;