CVE-2026-64569mpls: fix NULL deref in mpls_valid_fib_dump_req() on CONFIG_INET=n

Official description

In the Linux kernel, the following vulnerability has been resolved: mpls: fix NULL deref in mpls_valid_fib_dump_req() on CONFIG_INET=n On CONFIG_INET=n builds, mpls_valid_fib_dump_req() walks the parsed attribute table itself instead of calling ip_valid_fib_dump_req(). The RTA_OIF arm passes tb[RTA_OIF] to nla_get_u32() without checking it is present, so an RTM_GETROUTE dump for AF_MPLS with strict checking and no RTA_OIF hits a NULL dereference. RTM_GETROUTE is RTNL_KIND_GET, which rtnetlink_rcv_msg() permits without CAP_NET_ADMIN, so an unprivileged user can trigger it. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:mpls_valid_fib_dump_req (net/mpls/af_mpls.c:2189) Call Trace: mpls_dump_routes (net/mpls/af_mpls.c:2236) netlink_dump (net/netlink/af_netlink.c:2331) __netlink_dump_start (net/netlink/af_netlink.c:2446) rtnetlink_rcv_msg (net/core/rtnetlink.c:7033) netlink_rcv_skb (net/netlink/af_netlink.c:2556) netlink_unicast (net/netlink/af_netlink.c:1345) netlink_sendmsg (net/netlink/af_netlink.c:1900) __sock_sendmsg (net/socket.c:790) ____sys_sendmsg (net/socket.c:2684) ___sys_sendmsg (net/socket.c:2738) __sys_sendmsg (net/socket.c:2770) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Skip unset attributes, as ip_valid_fib_dump_req() does.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/bfc1cb5d6a8308e493e307f1c823d2107abc0a47
• https://git.kernel.org/stable/c/03b5a2c29afc8e634924c75d6ee94140e70de88d
• https://git.kernel.org/stable/c/e796ce9ef4356dc7cbbaa8373843f77852f2814d
• https://git.kernel.org/stable/c/d6eee7cd078aaf9dd75efc801f6c9b608a37cd71
• https://git.kernel.org/stable/c/ad6284ced6a15e4abd57ca4d0793b7bd15ca52ce
• https://git.kernel.org/stable/c/5f6e7b32bd1fbde10fd31a4143260735ea535b8a
• https://git.kernel.org/stable/c/06db79411a280707c7e4bf4b221ff4e664b51502
• https://git.kernel.org/stable/c/56d96fededd61192cd7cc8d2b0f36adfd59036c3