{"id":"DEBIAN-CVE-2025-21891","details":"In the Linux kernel, the following vulnerability has been resolved:  ipvlan: ensure network headers are in skb linear part  syzbot found that ipvlan_process_v6_outbound() was assuming the IPv6 network header isis present in skb-\u003ehead [1]  Add the needed pskb_network_may_pull() calls for both IPv4 and IPv6 handlers.  [1] BUG: KMSAN: uninit-value in __ipv6_addr_type+0xa2/0x490 net/ipv6/addrconf_core.c:47   __ipv6_addr_type+0xa2/0x490 net/ipv6/addrconf_core.c:47   ipv6_addr_type include/net/ipv6.h:555 [inline]   ip6_route_output_flags_noref net/ipv6/route.c:2616 [inline]   ip6_route_output_flags+0x51/0x720 net/ipv6/route.c:2651   ip6_route_output include/net/ip6_route.h:93 [inline]   ipvlan_route_v6_outbound+0x24e/0x520 drivers/net/ipvlan/ipvlan_core.c:476   ipvlan_process_v6_outbound drivers/net/ipvlan/ipvlan_core.c:491 [inline]   ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:541 [inline]   ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:605 [inline]   ipvlan_queue_xmit+0xd72/0x1780 drivers/net/ipvlan/ipvlan_core.c:671   ipvlan_start_xmit+0x5b/0x210 drivers/net/ipvlan/ipvlan_main.c:223   __netdev_start_xmit include/linux/netdevice.h:5150 [inline]   netdev_start_xmit include/linux/netdevice.h:5159 [inline]   xmit_one net/core/dev.c:3735 [inline]   dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3751   sch_direct_xmit+0x399/0xd40 net/sched/sch_generic.c:343   qdisc_restart net/sched/sch_generic.c:408 [inline]   __qdisc_run+0x14da/0x35d0 net/sched/sch_generic.c:416   qdisc_run+0x141/0x4d0 include/net/pkt_sched.h:127   net_tx_action+0x78b/0x940 net/core/dev.c:5484   handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:561   __do_softirq+0x14/0x1a kernel/softirq.c:595   do_softirq+0x9a/0x100 kernel/softirq.c:462   __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:389   local_bh_enable include/linux/bottom_half.h:33 [inline]   rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]   __dev_queue_xmit+0x2758/0x57d0 net/core/dev.c:4611   dev_queue_xmit include/linux/netdevice.h:3311 [inline]   packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276   packet_snd net/packet/af_packet.c:3132 [inline]   packet_sendmsg+0x93e0/0xa7e0 net/packet/af_packet.c:3164   sock_sendmsg_nosec net/socket.c:718 [inline]","modified":"2026-09-01T20:05:42.905135375Z","published":"2025-03-27T15:15:57.027Z","upstream":["CVE-2025-21891"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-21891"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.133-1"}]}],"versions":["6.1.106-1","6.1.106-2","6.1.106-3","6.1.112-1","6.1.115-1","6.1.119-1","6.1.123-1","6.1.124-1","6.1.128-1","6.1.129-1","6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21891.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.19-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21891.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.19-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21891.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}