From: Sven Eckelmann <sven@narfation.org> stable inclusion from stable-v5.10.258 commit 6314089acf0ddf64376fdc0b1420695504c73f52 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16427 CVE: CVE-2026-64089 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit fc92cdfcb295cefa4344d71a527d61b638b7bfc4 upstream. batadv_piv_tt::last_changeset_len len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer. In batadv_send_my_tt_response(), last_changeset_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_local_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized. Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_my_tt_response(). Cc: stable@kernel.org Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ze Zuo <zuoze1@huawei.com> --- net/batman-adv/types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index cc3334afbdd0..bf9b1ee568b9 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1003,7 +1003,7 @@ struct batadv_priv_tt { * @last_changeset_len: length of last tt changeset this host has * generated */ - s16 last_changeset_len; + u16 last_changeset_len; /** * @last_changeset_lock: lock protecting last_changeset & -- 2.25.1