{"id":"DEBIAN-CVE-2025-38622","details":"In the Linux kernel, the following vulnerability has been resolved:  net: drop UFO packets in udp_rcv_segment()  When sending a packet with virtio_net_hdr to tun device, if the gso_type in virtio_net_hdr is SKB_GSO_UDP and the gso_size is less than udphdr size, below crash may happen.    ------------[ cut here ]------------   kernel BUG at net/core/skbuff.c:4572!   Oops: invalid opcode: 0000 [#1] SMP NOPTI   CPU: 0 UID: 0 PID: 62 Comm: mytest Not tainted 6.16.0-rc7 #203 PREEMPT(voluntary)   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014   RIP: 0010:skb_pull_rcsum+0x8e/0xa0   Code: 00 00 5b c3 cc cc cc cc 8b 93 88 00 00 00 f7 da e8 37 44 38 00 f7 d8 89 83 88 00 00 00 48 8b 83 c8 00 00 00 5b c3 cc cc cc cc \u003c0f\u003e 0b 0f 0b 66 66 2e 0f 1f 84 00 000   RSP: 0018:ffffc900001fba38 EFLAGS: 00000297   RAX: 0000000000000004 RBX: ffff8880040c1000 RCX: ffffc900001fb948   RDX: ffff888003e6d700 RSI: 0000000000000008 RDI: ffff88800411a062   RBP: ffff8880040c1000 R08: 0000000000000000 R09: 0000000000000001   R10: ffff888003606c00 R11: 0000000000000001 R12: 0000000000000000   R13: ffff888004060900 R14: ffff888004050000 R15: ffff888004060900   FS:  000000002406d3c0(0000) GS:ffff888084a19000(0000) knlGS:0000000000000000   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033   CR2: 0000000020000040 CR3: 0000000004007000 CR4: 00000000000006f0   Call Trace:    \u003cTASK\u003e    udp_queue_rcv_one_skb+0x176/0x4b0 net/ipv4/udp.c:2445    udp_queue_rcv_skb+0x155/0x1f0 net/ipv4/udp.c:2475    udp_unicast_rcv_skb+0x71/0x90 net/ipv4/udp.c:2626    __udp4_lib_rcv+0x433/0xb00 net/ipv4/udp.c:2690    ip_protocol_deliver_rcu+0xa6/0x160 net/ipv4/ip_input.c:205    ip_local_deliver_finish+0x72/0x90 net/ipv4/ip_input.c:233    ip_sublist_rcv_finish+0x5f/0x70 net/ipv4/ip_input.c:579    ip_sublist_rcv+0x122/0x1b0 net/ipv4/ip_input.c:636    ip_list_rcv+0xf7/0x130 net/ipv4/ip_input.c:670    __netif_receive_skb_list_core+0x21d/0x240 net/core/dev.c:6067    netif_receive_skb_list_internal+0x186/0x2b0 net/core/dev.c:6210    napi_complete_done+0x78/0x180 net/core/dev.c:6580    tun_get_user+0xa63/0x1120 drivers/net/tun.c:1909    tun_chr_write_iter+0x65/0xb0 drivers/net/tun.c:1984    vfs_write+0x300/0x420 fs/read_write.c:593    ksys_write+0x60/0xd0 fs/read_write.c:686    do_syscall_64+0x50/0x1c0 arch/x86/entry/syscall_64.c:63    \u003c/TASK\u003e  To trigger gso segment in udp_queue_rcv_skb(), we should also set option UDP_ENCAP_ESPINUDP to enable udp_sk(sk)-\u003eencap_rcv. When the encap_rcv hook return 1 in udp_queue_rcv_one_skb(), udp_csum_pull_header() will try to pull udphdr, but the skb size has been segmented to gso size, which leads to this crash.  Previous commit cf329aa42b66 (\"udp: cope with UDP GRO packet misdirection\") introduces segmentation in UDP receive path only for GRO, which was never intended to be used for UFO, so drop UFO packets in udp_rcv_segment().","modified":"2026-09-01T16:06:15.091388093Z","published":"2025-08-22T16:15:35.603Z","upstream":["CVE-2025-38622"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-38622"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.148-1"}]}],"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","6.1.133-1","6.1.135-1","6.1.137-1","6.1.139-1","6.1.140-1","6.1.147-1","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/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38622.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.43-1"}]}],"versions":["6.12.38-1","6.12.41-1","6.12.43-1~bpo12+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38622.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.16.3-1"}]}],"versions":["6.12.100-1","6.12.101-1","6.12.105-1","6.12.107-1","6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1","6.12.69-1~bpo12+1","6.12.73-1","6.12.73-1~bpo12+1","6.12.74-1","6.12.74-2","6.12.74-2~bpo12+1","6.12.85-1","6.12.85-1~bpo12+1","6.12.86-1","6.12.86-1~bpo12+1","6.12.88-1","6.12.88-1~bpo12+1","6.12.90-1","6.12.90-1~bpo12+1","6.12.90-2","6.12.90-2~bpo12+1","6.12.94-1","6.12.94-1~bpo12+1","6.12.95-1","6.12.95-1~bpo12+1","6.12.96-1","6.13.10-1~exp1","6.13.11-1~exp1","6.13.2-1~exp1","6.13.3-1~exp1","6.13.4-1~exp1","6.13.5-1~exp1","6.13.6-1~exp1","6.13.7-1~exp1","6.13.8-1~exp1","6.13.9-1~exp1","6.13~rc6-1~exp1","6.13~rc7-1~exp1","6.14.3-1~exp1","6.14.5-1~exp1","6.14.6-1~exp1","6.15-1~exp1","6.15.1-1~exp1","6.15.2-1~exp1","6.15.3-1~exp1","6.15.4-1~exp1","6.15.5-1~exp1","6.15.6-1~exp1","6.15~rc7-1~exp1","6.16-1~exp1","6.16.1-1~exp1","6.16.3-1~bpo13+1","6.16~rc7-1~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38622.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"}]}