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GHSA-M5M5-6FC4-PH6R

Vulnerability from github – Published: 2024-10-21 18:30 – Updated: 2024-11-12 21:30
VLAI
Details

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

net: test for not too small csum_start in virtio_net_hdr_to_skb()

syzbot was able to trigger this warning [1], after injecting a malicious packet through af_packet, setting skb->csum_start and thus the transport header to an incorrect value.

We can at least make sure the transport header is after the end of the network header (with a estimated minimal size).

[1] [ 67.873027] skb len=4096 headroom=16 headlen=14 tailroom=0 mac=(-1,-1) mac_len=0 net=(16,-6) trans=10 shinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0)) csum(0xa start=10 offset=0 ip_summed=3 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x0800 pkttype=0 iif=0 priority=0x0 mark=0x0 alloc_cpu=10 vlan_all=0x0 encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0) [ 67.877172] dev name=veth0_vlan feat=0x000061164fdd09e9 [ 67.877764] sk family=17 type=3 proto=0 [ 67.878279] skb linear: 00000000: 00 00 10 00 00 00 00 00 0f 00 00 00 08 00 [ 67.879128] skb frag: 00000000: 0e 00 07 00 00 00 28 00 08 80 1c 00 04 00 00 02 [ 67.879877] skb frag: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.880647] skb frag: 00000020: 00 00 02 00 00 00 08 00 1b 00 00 00 00 00 00 00 [ 67.881156] skb frag: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.881753] skb frag: 00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.882173] skb frag: 00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.882790] skb frag: 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.883171] skb frag: 00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.883733] skb frag: 00000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.884206] skb frag: 00000090: 00 00 00 00 00 00 00 00 00 00 69 70 76 6c 61 6e [ 67.884704] skb frag: 000000a0: 31 00 00 00 00 00 00 00 00 00 2b 00 00 00 00 00 [ 67.885139] skb frag: 000000b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.885677] skb frag: 000000c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.886042] skb frag: 000000d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.886408] skb frag: 000000e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.887020] skb frag: 000000f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.887384] skb frag: 00000100: 00 00 [ 67.887878] ------------[ cut here ]------------ [ 67.887908] offset (-6) >= skb_headlen() (14) [ 67.888445] WARNING: CPU: 10 PID: 2088 at net/core/dev.c:3332 skb_checksum_help (net/core/dev.c:3332 (discriminator 2)) [ 67.889353] Modules linked in: macsec macvtap macvlan hsr wireguard curve25519_x86_64 libcurve25519_generic libchacha20poly1305 chacha_x86_64 libchacha poly1305_x86_64 dummy bridge sr_mod cdrom evdev pcspkr i2c_piix4 9pnet_virtio 9p 9pnet netfs [ 67.890111] CPU: 10 UID: 0 PID: 2088 Comm: b363492833 Not tainted 6.11.0-virtme #1011 [ 67.890183] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 67.890309] RIP: 0010:skb_checksum_help (net/core/dev.c:3332 (discriminator 2)) [ 67.891043] Call Trace: [ 67.891173] [ 67.891274] ? __warn (kernel/panic.c:741) [ 67.891320] ? skb_checksum_help (net/core/dev.c:3332 (discriminator 2)) [ 67.891333] ? report_bug (lib/bug.c:180 lib/bug.c:219) [ 67.891348] ? handle_bug (arch/x86/kernel/traps.c:239) [ 67.891363] ? exc_invalid_op (arch/x86/kernel/traps.c:260 (discriminator 1)) [ 67.891372] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) [ 67.891388] ? skb_checksum_help (net/core/dev.c:3332 (discriminator 2)) [ 67.891399] ? skb_checksum_help (net/core/dev.c:3332 (discriminator 2)) [ 67.891416] ip_do_fragment (net/ipv4/ip_output.c:777 (discriminator 1)) [ 67.891448] ? __ip_local_out (./include/linux/skbuff.h:1146 ./include/net/l3mdev.h:196 ./include/net/l3mdev.h:213 ne ---truncated---

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-49947"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-10-21T18:15:16Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: test for not too small csum_start in virtio_net_hdr_to_skb()\n\nsyzbot was able to trigger this warning [1], after injecting a\nmalicious packet through af_packet, setting skb-\u003ecsum_start and thus\nthe transport header to an incorrect value.\n\nWe can at least make sure the transport header is after\nthe end of the network header (with a estimated minimal size).\n\n[1]\n[   67.873027] skb len=4096 headroom=16 headlen=14 tailroom=0\nmac=(-1,-1) mac_len=0 net=(16,-6) trans=10\nshinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0))\ncsum(0xa start=10 offset=0 ip_summed=3 complete_sw=0 valid=0 level=0)\nhash(0x0 sw=0 l4=0) proto=0x0800 pkttype=0 iif=0\npriority=0x0 mark=0x0 alloc_cpu=10 vlan_all=0x0\nencapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0)\n[   67.877172] dev name=veth0_vlan feat=0x000061164fdd09e9\n[   67.877764] sk family=17 type=3 proto=0\n[   67.878279] skb linear:   00000000: 00 00 10 00 00 00 00 00 0f 00 00 00 08 00\n[   67.879128] skb frag:     00000000: 0e 00 07 00 00 00 28 00 08 80 1c 00 04 00 00 02\n[   67.879877] skb frag:     00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.880647] skb frag:     00000020: 00 00 02 00 00 00 08 00 1b 00 00 00 00 00 00 00\n[   67.881156] skb frag:     00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.881753] skb frag:     00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.882173] skb frag:     00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.882790] skb frag:     00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.883171] skb frag:     00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.883733] skb frag:     00000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.884206] skb frag:     00000090: 00 00 00 00 00 00 00 00 00 00 69 70 76 6c 61 6e\n[   67.884704] skb frag:     000000a0: 31 00 00 00 00 00 00 00 00 00 2b 00 00 00 00 00\n[   67.885139] skb frag:     000000b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.885677] skb frag:     000000c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.886042] skb frag:     000000d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.886408] skb frag:     000000e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.887020] skb frag:     000000f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n[   67.887384] skb frag:     00000100: 00 00\n[   67.887878] ------------[ cut here ]------------\n[   67.887908] offset (-6) \u003e= skb_headlen() (14)\n[   67.888445] WARNING: CPU: 10 PID: 2088 at net/core/dev.c:3332 skb_checksum_help (net/core/dev.c:3332 (discriminator 2))\n[   67.889353] Modules linked in: macsec macvtap macvlan hsr wireguard curve25519_x86_64 libcurve25519_generic libchacha20poly1305 chacha_x86_64 libchacha poly1305_x86_64 dummy bridge sr_mod cdrom evdev pcspkr i2c_piix4 9pnet_virtio 9p 9pnet netfs\n[   67.890111] CPU: 10 UID: 0 PID: 2088 Comm: b363492833 Not tainted 6.11.0-virtme #1011\n[   67.890183] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   67.890309] RIP: 0010:skb_checksum_help (net/core/dev.c:3332 (discriminator 2))\n[   67.891043] Call Trace:\n[   67.891173]  \u003cTASK\u003e\n[   67.891274] ? __warn (kernel/panic.c:741)\n[   67.891320] ? skb_checksum_help (net/core/dev.c:3332 (discriminator 2))\n[   67.891333] ? report_bug (lib/bug.c:180 lib/bug.c:219)\n[   67.891348] ? handle_bug (arch/x86/kernel/traps.c:239)\n[   67.891363] ? exc_invalid_op (arch/x86/kernel/traps.c:260 (discriminator 1))\n[   67.891372] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)\n[   67.891388] ? skb_checksum_help (net/core/dev.c:3332 (discriminator 2))\n[   67.891399] ? skb_checksum_help (net/core/dev.c:3332 (discriminator 2))\n[   67.891416] ip_do_fragment (net/ipv4/ip_output.c:777 (discriminator 1))\n[   67.891448] ? __ip_local_out (./include/linux/skbuff.h:1146 ./include/net/l3mdev.h:196 ./include/net/l3mdev.h:213 ne\n---truncated---",
  "id": "GHSA-m5m5-6fc4-ph6r",
  "modified": "2024-11-12T21:30:50Z",
  "published": "2024-10-21T18:30:58Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-49947"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/49d14b54a527289d09a9480f214b8c586322310a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4cc0648e9e3240496835dc698ace1d046d8d57ea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7711c419a915ee0dd91c125d2b967bbf2a72e9ac"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d9dfd41e32ccc5198033ddd1ff1516822dfefa5a"
    }
  ],
  "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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