{"cve":"CVE-2024-26641","nvd":{"published":"2024-03-18T11:15:11.193","modified":"2026-08-04T11:16:52.303","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()\n\nsyzbot found __ip6_tnl_rcv() could access unitiliazed data [1].\n\nCall pskb_inet_may_pull() to fix this, and initialize ipv6h\nvariable after this call as it can change skb->head.\n\n[1]\n BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]\n BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]\n BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321\n  __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]\n  INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]\n  IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321\n  ip6ip6_dscp_ecn_decapsulate+0x178/0x1b0 net/ipv6/ip6_tunnel.c:727\n  __ip6_tnl_rcv+0xd4e/0x1590 net/ipv6/ip6_tunnel.c:845\n  ip6_tnl_rcv+0xce/0x100 net/ipv6/ip6_tunnel.c:888\n gre_rcv+0x143f/0x1870\n  ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438\n  ip6_input_finish net/ipv6/ip6_input.c:483 [inline]\n  NF_HOOK include/linux/netfilter.h:314 [inline]\n  ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492\n  ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586\n  dst_input include/net/dst.h:461 [inline]\n  ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79\n  NF_HOOK include/linux/netfilter.h:314 [inline]\n  ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310\n  __netif_receive_skb_one_core net/core/dev.c:5532 [inline]\n  __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5646\n  netif_receive_skb_internal net/core/dev.c:5732 [inline]\n  netif_receive_skb+0x58/0x660 net/core/dev.c:5791\n  tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555\n  tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002\n  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048\n  call_write_iter include/linux/fs.h:2084 [inline]\n  new_sync_write fs/read_write.c:497 [inline]\n  vfs_write+0x786/0x1200 fs/read_write.c:590\n  ksys_write+0x20f/0x4c0 fs/read_write.c:643\n  __do_sys_write fs/read_write.c:655 [inline]\n  __se_sys_write fs/read_write.c:652 [inline]\n  __x64_sys_write+0x93/0xd0 fs/read_write.c:652\n  do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n  do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nUninit was created at:\n  slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768\n  slab_alloc_node mm/slub.c:3478 [inline]\n  kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523\n  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560\n  __alloc_skb+0x318/0x740 net/core/skbuff.c:651\n  alloc_skb include/linux/skbuff.h:1286 [inline]\n  alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334\n  sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787\n  tun_alloc_skb drivers/net/tun.c:1531 [inline]\n  tun_get_user+0x1e8a/0x66d0 drivers/net/tun.c:1846\n  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048\n  call_write_iter include/linux/fs.h:2084 [inline]\n  new_sync_write fs/read_write.c:497 [inline]\n  vfs_write+0x786/0x1200 fs/read_write.c:590\n  ksys_write+0x20f/0x4c0 fs/read_write.c:643\n  __do_sys_write fs/read_write.c:655 [inline]\n  __se_sys_write fs/read_write.c:652 [inline]\n  __x64_sys_write+0x93/0xd0 fs/read_write.c:652\n  do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n  do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x63/0x6b\n\nCPU: 0 PID: 5034 Comm: syz-executor331 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-908"],"references":["https://git.kernel.org/stable/c/350a6640fac4b53564ec20aa3f4a0922cb0ba5e6","https://git.kernel.org/stable/c/8d975c15c0cd744000ca386247432d57b21f9df0","https://git.kernel.org/stable/c/a9bc32879a08f23cdb80a48c738017e39aea1080","https://git.kernel.org/stable/c/af6b5c50d47ab43e5272ad61935d0ed2e264d3f0","https://git.kernel.org/stable/c/c835df3bcc14858ae9b27315dd7de76370b94f3a"],"products":["debian:debian_linux","linux:linux_kernel","netapp:a150_firmware","netapp:a220_firmware","netapp:a800_firmware","netapp:a900_firmware","netapp:active_iq_unified_manager","netapp:c190_firmware","netapp:c800_firmware","netapp:fas2720_firmware","netapp:fas2750_firmware","netapp:fas2820_firmware","netapp:fas9500_firmware","netapp:ontap_select_deploy_administration_utility"],"source":"nvd","synced_at":"2026-10-19T21:46:54.846886191+00:00"},"epss":{"cve":"CVE-2024-26641","score":0.00577,"percentile":0.47589,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}