{"id":"CVE-2026-23277","title":"net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit\n\nteql_master_xmit() calls netdev_start_xmit(skb, slave) to transmit\nthrough slave devi…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 383493b9940e3d1b5517424081b3e072e20ec43c","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 6b1f563d670162e188a0f2aec39c24b67b106e17","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 57c153249143333bbf4ecf927bdf8aa2696ee397","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 59b06d8b9bdb6b64b3c534c18da68bce5ccd31be","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 81a43e8005366f16e629d8c95dfe05beaa8d36a7","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 0bad9c86edd22dec4df83c2b29872d66fd8a2ff4","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 21ea283c2750c8307aa35ee832b0951cc993c27d","Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 0cc0c2e661af418bbf7074179ea5cfffc0a5c466","Linux 4.5"],"published":"2026-03-20","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:45:19.497Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23277","references":[{"url":"https://git.kernel.org/stable/c/383493b9940e3d1b5517424081b3e072e20ec43c"},{"url":"https://git.kernel.org/stable/c/6b1f563d670162e188a0f2aec39c24b67b106e17"},{"url":"https://git.kernel.org/stable/c/57c153249143333bbf4ecf927bdf8aa2696ee397"},{"url":"https://git.kernel.org/stable/c/59b06d8b9bdb6b64b3c534c18da68bce5ccd31be"},{"url":"https://git.kernel.org/stable/c/81a43e8005366f16e629d8c95dfe05beaa8d36a7"},{"url":"https://git.kernel.org/stable/c/0bad9c86edd22dec4df83c2b29872d66fd8a2ff4"},{"url":"https://git.kernel.org/stable/c/21ea283c2750c8307aa35ee832b0951cc993c27d"},{"url":"https://git.kernel.org/stable/c/0cc0c2e661af418bbf7074179ea5cfffc0a5c466"}],"tags":["cve.org"],"epss":0.00122,"epssPercentile":0.02319,"ingestedAt":"2026-09-08T15:33:26.993Z","slug":"CVE-2026-23277","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit\n\nteql_master_xmit() calls netdev_start_xmit(skb, slave) to transmit\nthrough slave devices, but does not update skb->dev to the slave device\nbeforehand.\n\nWhen a gretap tunnel is a TEQL slave, the transmit path reaches\niptunnel_xmit() which saves dev = skb->dev (still pointing to teql0\nmaster) and later calls iptunnel_xmit_stats(dev, pkt_len). This\nfunction does:\n\n    get_cpu_ptr(dev->tstats)\n\nSince teql_master_setup() does not set dev->pcpu_stat_type to\nNETDEV_PCPU_STAT_TSTATS, the core network stack never allocates tstats\nfor teql0, so dev->tstats is NULL. get_cpu_ptr(NULL) computes\nNULL + __per_cpu_offset[cpu], resulting in a page fault.\n\n BUG: unable to handle page fault for address: ffff8880e6659018\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n PGD 68bc067 P4D 68bc067 PUD 0\n Oops: Oops: 0002 [#1] SMP KASAN PTI\n RIP: 0010:iptunnel_xmit (./include/net/ip_tunnels.h:664 net/ipv4/ip_tunnel_core.c:89)\n Call Trace:\n  <TASK>\n  ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)\n  __gre_xmit (net/ipv4/ip_gre.c:478)\n  gre_tap_xmit (net/ipv4/ip_gre.c:779)\n  teql_master_xmit (net/sched/sch_teql.c:319)\n  dev_hard_start_xmit (net/core/dev.c:3887)\n  sch_direct_xmit (net/sched/sch_generic.c:347)\n  __dev_queue_xmit (net/core/dev.c:4802)\n  neigh_direct_output (net/core/neighbour.c:1660)\n  ip_finish_output2 (net/ipv4/ip_output.c:237)\n  __ip_finish_output.part.0 (net/ipv4/ip_output.c:315)\n  ip_mc_output (net/ipv4/ip_output.c:369)\n  ip_send_skb (net/ipv4/ip_output.c:1508)\n  udp_send_skb (net/ipv4/udp.c:1195)\n  udp_sendmsg (net/ipv4/udp.c:1485)\n  inet_sendmsg (net/ipv4/af_inet.c:859)\n  __sys_sendto (net/socket.c:2206)\n\nFix this by setting skb->dev = slave before calling\nnetdev_start_xmit(), so that tunnel xmit functions see the correct\nslave device with properly allocated tstats.\n\n## Affected\n\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 383493b9940e3d1b5517424081b3e072e20ec43c`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 6b1f563d670162e188a0f2aec39c24b67b106e17`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 57c153249143333bbf4ecf927bdf8aa2696ee397`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 59b06d8b9bdb6b64b3c534c18da68bce5ccd31be`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 81a43e8005366f16e629d8c95dfe05beaa8d36a7`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 0bad9c86edd22dec4df83c2b29872d66fd8a2ff4`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 21ea283c2750c8307aa35ee832b0951cc993c27d`\n- `Linux >= 039f50629b7f860f36644ed1f34b27da9aa62f43 < 0cc0c2e661af418bbf7074179ea5cfffc0a5c466`\n- `Linux 4.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}