{"id":"DEBIAN-CVE-2023-53354","details":"In the Linux kernel, the following vulnerability has been resolved:  skbuff: skb_segment, Call zero copy functions before using skbuff frags  Commit bf5c25d60861 (\"skbuff: in skb_segment, call zerocopy functions once per nskb\") added the call to zero copy functions in skb_segment(). The change introduced a bug in skb_segment() because skb_orphan_frags() may possibly change the number of fragments or allocate new fragments altogether leaving nrfrags and frag to point to the old values. This can cause a panic with stacktrace like the one below.  [  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc [  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26 [  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0 [  194.021892] Call Trace: [  194.027422]  \u003cTASK\u003e [  194.072861]  tcp_gso_segment+0x107/0x540 [  194.082031]  inet_gso_segment+0x15c/0x3d0 [  194.090783]  skb_mac_gso_segment+0x9f/0x110 [  194.095016]  __skb_gso_segment+0xc1/0x190 [  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem] [  194.107071]  dev_qdisc_enqueue+0x16/0x70 [  194.110884]  __dev_queue_xmit+0x63b/0xb30 [  194.121670]  bond_start_xmit+0x159/0x380 [bonding] [  194.128506]  dev_hard_start_xmit+0xc3/0x1e0 [  194.131787]  __dev_queue_xmit+0x8a0/0xb30 [  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan] [  194.141477]  dev_hard_start_xmit+0xc3/0x1e0 [  194.144622]  sch_direct_xmit+0xe3/0x280 [  194.147748]  __dev_queue_xmit+0x54a/0xb30 [  194.154131]  tap_get_user+0x2a8/0x9c0 [tap] [  194.157358]  tap_sendmsg+0x52/0x8e0 [tap] [  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net] [  194.173631]  handle_tx+0xcd/0xe0 [vhost_net] [  194.176959]  vhost_worker+0x76/0xb0 [vhost] [  194.183667]  kthread+0x118/0x140 [  194.190358]  ret_from_fork+0x1f/0x30 [  194.193670]  \u003c/TASK\u003e  In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags local variable in skb_segment() stale. This resulted in the code hitting i \u003e= nrfrags prematurely and trying to move to next frag_skb using list_skb pointer, which was NULL, and caused kernel panic. Move the call to zero copy functions before using frags and nr_frags.","modified":"2026-09-15T09:02:51.113395377Z","published":"2025-09-17T15:15:39.403Z","upstream":["CVE-2023-53354"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-53354"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.55-1"}]}],"versions":["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~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53354.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53354.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.5.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-53354.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"}]}