From: Paolo Abeni <pabeni@redhat.com> mainline inclusion from mainline-v7.0-rc7 commit fd63f185979b047fb22a0dfc6bd94d0cab6a6a70 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14897 CVE: CVE-2026-43339 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The mentioned helper try to warn the user about an exceptional condition, but the message is delivered too late, accessing the ipv6 after its possible deletion. Reorder the statement to avoid the possible UaF; while at it, place the warning outside the idev->lock as it needs no protection. Reported-by: Jakub Kicinski <kuba@kernel.org> Closes: https://sashiko.dev/#/patchset/8c8bfe2e1a324e501f0e15fef404a77443fd8caf.1774... Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/ef973c3a8cb4f8f1787ed469f3e5391b9fe95aa0.1774601542... Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com> --- net/ipv6/addrconf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6c76c0c..98a24b5 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3421,12 +3421,12 @@ static void addrconf_permanent_addr(struct net *net, struct net_device *dev) if ((ifp->flags & IFA_F_PERMANENT) && fixup_permanent_addr(net, idev, ifp) < 0) { write_unlock_bh(&idev->lock); - in6_ifa_hold(ifp); - ipv6_del_addr(ifp); - write_lock_bh(&idev->lock); net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n", idev->dev->name, &ifp->addr); + in6_ifa_hold(ifp); + ipv6_del_addr(ifp); + write_lock_bh(&idev->lock); } } -- 2.9.5