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GHSA-MCP4-W22Q-6Q4H

Vulnerability from github – Published: 2024-05-19 09:34 – Updated: 2026-05-12 12:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

erspan: make sure erspan_base_hdr is present in skb->head

syzbot reported a problem in ip6erspan_rcv() [1]

Issue is that ip6erspan_rcv() (and erspan_rcv()) no longer make sure erspan_base_hdr is present in skb linear part (skb->head) before getting @ver field from it.

Add the missing pskb_may_pull() calls.

v2: Reload iph pointer in erspan_rcv() after pskb_may_pull() because skb->head might have changed.

[1]

BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2742 [inline] BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2756 [inline] BUG: KMSAN: uninit-value in ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline] BUG: KMSAN: uninit-value in gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610 pskb_may_pull_reason include/linux/skbuff.h:2742 [inline] pskb_may_pull include/linux/skbuff.h:2756 [inline] ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline] gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610 ip6_protocol_deliver_rcu+0x1d4c/0x2ca0 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:460 [inline] ip6_rcv_finish+0x955/0x970 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [inline] ipv6_rcv+0xde/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5652 netif_receive_skb_internal net/core/dev.c:5738 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5798 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549 tun_get_user+0x5566/0x69e0 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb63/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was created at: slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577 __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [inline] alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795 tun_alloc_skb drivers/net/tun.c:1525 [inline] tun_get_user+0x209a/0x69e0 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb63/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75

CPU: 1 PID: 5045 Comm: syz-executor114 Not tainted 6.9.0-rc1-syzkaller-00021-g962490525cff #0

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2024-35888"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-908"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-05-19T09:15:09Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nerspan: make sure erspan_base_hdr is present in skb-\u003ehead\n\nsyzbot reported a problem in ip6erspan_rcv() [1]\n\nIssue is that ip6erspan_rcv() (and erspan_rcv()) no longer make\nsure erspan_base_hdr is present in skb linear part (skb-\u003ehead)\nbefore getting @ver field from it.\n\nAdd the missing pskb_may_pull() calls.\n\nv2: Reload iph pointer in erspan_rcv() after pskb_may_pull()\n    because skb-\u003ehead might have changed.\n\n[1]\n\n BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2742 [inline]\n BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2756 [inline]\n BUG: KMSAN: uninit-value in ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline]\n BUG: KMSAN: uninit-value in gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610\n  pskb_may_pull_reason include/linux/skbuff.h:2742 [inline]\n  pskb_may_pull include/linux/skbuff.h:2756 [inline]\n  ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline]\n  gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610\n  ip6_protocol_deliver_rcu+0x1d4c/0x2ca0 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:460 [inline]\n  ip6_rcv_finish+0x955/0x970 net/ipv6/ip6_input.c:79\n  NF_HOOK include/linux/netfilter.h:314 [inline]\n  ipv6_rcv+0xde/0x390 net/ipv6/ip6_input.c:310\n  __netif_receive_skb_one_core net/core/dev.c:5538 [inline]\n  __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5652\n  netif_receive_skb_internal net/core/dev.c:5738 [inline]\n  netif_receive_skb+0x58/0x660 net/core/dev.c:5798\n  tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549\n  tun_get_user+0x5566/0x69e0 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:2108 [inline]\n  new_sync_write fs/read_write.c:497 [inline]\n  vfs_write+0xb63/0x1520 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+0x93/0xe0 fs/read_write.c:652\n do_syscall_64+0xd5/0x1f0\n entry_SYSCALL_64_after_hwframe+0x6d/0x75\n\nUninit was created at:\n  slab_post_alloc_hook mm/slub.c:3804 [inline]\n  slab_alloc_node mm/slub.c:3845 [inline]\n  kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888\n  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577\n  __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668\n  alloc_skb include/linux/skbuff.h:1318 [inline]\n  alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504\n  sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795\n  tun_alloc_skb drivers/net/tun.c:1525 [inline]\n  tun_get_user+0x209a/0x69e0 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:2108 [inline]\n  new_sync_write fs/read_write.c:497 [inline]\n  vfs_write+0xb63/0x1520 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+0x93/0xe0 fs/read_write.c:652\n do_syscall_64+0xd5/0x1f0\n entry_SYSCALL_64_after_hwframe+0x6d/0x75\n\nCPU: 1 PID: 5045 Comm: syz-executor114 Not tainted 6.9.0-rc1-syzkaller-00021-g962490525cff #0",
  "id": "GHSA-mcp4-w22q-6q4h",
  "modified": "2026-05-12T12:31:47Z",
  "published": "2024-05-19T09:34:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35888"
    },
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html"
    },
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-398330.html"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/06a939f72a24a7d8251f84cf4c042df86c6666ac"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0ac328a5a4138a6c03dfc3f46017bd5c19167446"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/17af420545a750f763025149fa7b833a4fc8b8f0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1db7fcb2b290c47c202b79528824f119fa28937d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4e3fdeecec5707678b0d1f18c259dadb97262e9d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b14b9f9503ec823ca75be766dcaeff4f0bfeca85"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e54a0c79cdc2548729dd7e2e468b08c5af4d0df5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ee0088101beee10fa809716d6245d915b09c37c7"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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