{"api_version":"1","generated_at":"2026-09-12T00:06:56+00:00","cve":"CVE-2026-89561","urls":{"html":"https://cve.report/CVE-2026-89561","api":"https://cve.report/api/cve/CVE-2026-89561.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89561","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89561"},"summary":{"title":"ipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()\n\nipv6_rpl_srh_rcv() dereferences idev from __in6_dev_get() without a NULL\ncheck when reading idev->cnf.rpl_seg_enabled.\n\nWhen the device's MTU drops below IPV6_MIN_MTU, addrconf_ifdown() clears\ndev->ip6_ptr through RCU_INIT_POINTER(). A packet that passed the idev\ncheck in ip6_rcv_core() can then reach ipv6_rpl_srh_rcv() with\ndev->ip6_ptr already NULL.\n\nReproduced by flooding the receiving interface with ping6 traffic while\nflapping its MTU between 1500 and 1200:\n\n BUG: KASAN: null-ptr-deref in ipv6_rpl_srh_rcv+0xb3/0x1070\n Read of size 4 at addr 00000000000006b4 by task ping6/394\n\n CPU: 2 UID: 0 PID: 394 Comm: ping6 Not tainted 7.2.0-rc7-micro-vm-dev-00095-g24ef02f934ee #240 PREEMPT(full)\n Call Trace:\n  <IRQ>\n  kasan_report+0xc6/0x100\n  ipv6_rpl_srh_rcv+0xb3/0x1070\n  ip6_protocol_deliver_rcu+0x759/0x9a0\n  ip6_input_finish+0xa8/0x1b0\n  ip6_input+0xe1/0x490\n  ipv6_rcv+0x33d/0x460\n  __netif_receive_skb_one_core+0xd6/0x130\n  process_backlog+0x2cc/0xa00\n  __napi_poll.constprop.0+0x56/0x270\n  net_rx_action+0x327/0x730\n  handle_softirqs+0x11e/0x630\n  do_softirq+0xb3/0xf0\n  </IRQ>\n\nBoth ipv6_rpl_srh_rcv() and ipv6_srh_rcv() are called only from\nipv6_rthdr_rcv(), which already has an idev lookup.\n\nFix the NULL dereference on the RPL path by checking idev in\nipv6_rthdr_rcv(), before it calls either function. The callees take idev as\nan argument and no longer call __in6_dev_get(), so the packet is now\ndropped in one place, with SKB_DROP_REASON_IPV6DISABLED on both paths.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:39","updated_at":"2026-09-11 20:19:39"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/eab3a917cdcb182542a3aac6a0d2d30659ca9821","name":"https://git.kernel.org/stable/c/eab3a917cdcb182542a3aac6a0d2d30659ca9821","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c","name":"https://git.kernel.org/stable/c/63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f826df95332c07380206dbd54178b6eefb311aba","name":"https://git.kernel.org/stable/c/f826df95332c07380206dbd54178b6eefb311aba","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89561","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89561","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 eab3a917cdcb182542a3aac6a0d2d30659ca9821 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 f826df95332c07380206dbd54178b6eefb311aba git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.7","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv6/exthdrs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"eab3a917cdcb182542a3aac6a0d2d30659ca9821","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"f826df95332c07380206dbd54178b6eefb311aba","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv6/exthdrs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.7"},{"lessThan":"5.7","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.7","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()\n\nipv6_rpl_srh_rcv() dereferences idev from __in6_dev_get() without a NULL\ncheck when reading idev->cnf.rpl_seg_enabled.\n\nWhen the device's MTU drops below IPV6_MIN_MTU, addrconf_ifdown() clears\ndev->ip6_ptr through RCU_INIT_POINTER(). A packet that passed the idev\ncheck in ip6_rcv_core() can then reach ipv6_rpl_srh_rcv() with\ndev->ip6_ptr already NULL.\n\nReproduced by flooding the receiving interface with ping6 traffic while\nflapping its MTU between 1500 and 1200:\n\n BUG: KASAN: null-ptr-deref in ipv6_rpl_srh_rcv+0xb3/0x1070\n Read of size 4 at addr 00000000000006b4 by task ping6/394\n\n CPU: 2 UID: 0 PID: 394 Comm: ping6 Not tainted 7.2.0-rc7-micro-vm-dev-00095-g24ef02f934ee #240 PREEMPT(full)\n Call Trace:\n  <IRQ>\n  kasan_report+0xc6/0x100\n  ipv6_rpl_srh_rcv+0xb3/0x1070\n  ip6_protocol_deliver_rcu+0x759/0x9a0\n  ip6_input_finish+0xa8/0x1b0\n  ip6_input+0xe1/0x490\n  ipv6_rcv+0x33d/0x460\n  __netif_receive_skb_one_core+0xd6/0x130\n  process_backlog+0x2cc/0xa00\n  __napi_poll.constprop.0+0x56/0x270\n  net_rx_action+0x327/0x730\n  handle_softirqs+0x11e/0x630\n  do_softirq+0xb3/0xf0\n  </IRQ>\n\nBoth ipv6_rpl_srh_rcv() and ipv6_srh_rcv() are called only from\nipv6_rthdr_rcv(), which already has an idev lookup.\n\nFix the NULL dereference on the RPL path by checking idev in\nipv6_rthdr_rcv(), before it calls either function. The callees take idev as\nan argument and no longer call __in6_dev_get(), so the packet is now\ndropped in one place, with SKB_DROP_REASON_IPV6DISABLED on both paths."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:44:32.822Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c"},{"url":"https://git.kernel.org/stable/c/eab3a917cdcb182542a3aac6a0d2d30659ca9821"},{"url":"https://git.kernel.org/stable/c/f826df95332c07380206dbd54178b6eefb311aba"}],"title":"ipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89561","datePublished":"2026-09-11T19:44:32.822Z","dateReserved":"2026-09-11T19:38:34.725Z","dateUpdated":"2026-09-11T19:44:32.822Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:39","lastModifiedDate":"2026-09-11 20:19:39","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89561","Ordinal":"1","Title":"ipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()","CVE":"CVE-2026-89561","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89561","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()\n\nipv6_rpl_srh_rcv() dereferences idev from __in6_dev_get() without a NULL\ncheck when reading idev->cnf.rpl_seg_enabled.\n\nWhen the device's MTU drops below IPV6_MIN_MTU, addrconf_ifdown() clears\ndev->ip6_ptr through RCU_INIT_POINTER(). A packet that passed the idev\ncheck in ip6_rcv_core() can then reach ipv6_rpl_srh_rcv() with\ndev->ip6_ptr already NULL.\n\nReproduced by flooding the receiving interface with ping6 traffic while\nflapping its MTU between 1500 and 1200:\n\n BUG: KASAN: null-ptr-deref in ipv6_rpl_srh_rcv+0xb3/0x1070\n Read of size 4 at addr 00000000000006b4 by task ping6/394\n\n CPU: 2 UID: 0 PID: 394 Comm: ping6 Not tainted 7.2.0-rc7-micro-vm-dev-00095-g24ef02f934ee #240 PREEMPT(full)\n Call Trace:\n  <IRQ>\n  kasan_report+0xc6/0x100\n  ipv6_rpl_srh_rcv+0xb3/0x1070\n  ip6_protocol_deliver_rcu+0x759/0x9a0\n  ip6_input_finish+0xa8/0x1b0\n  ip6_input+0xe1/0x490\n  ipv6_rcv+0x33d/0x460\n  __netif_receive_skb_one_core+0xd6/0x130\n  process_backlog+0x2cc/0xa00\n  __napi_poll.constprop.0+0x56/0x270\n  net_rx_action+0x327/0x730\n  handle_softirqs+0x11e/0x630\n  do_softirq+0xb3/0xf0\n  </IRQ>\n\nBoth ipv6_rpl_srh_rcv() and ipv6_srh_rcv() are called only from\nipv6_rthdr_rcv(), which already has an idev lookup.\n\nFix the NULL dereference on the RPL path by checking idev in\nipv6_rthdr_rcv(), before it calls either function. The callees take idev as\nan argument and no longer call __in6_dev_get(), so the packet is now\ndropped in one place, with SKB_DROP_REASON_IPV6DISABLED on both paths.","Type":"Description","Title":"ipv6: rpl: fix NULL dereference of idev in ipv6_rpl_srh_rcv()"}]}}}