CVE-2024-36901 ipv6: prevent NULL dereference in ip6_output()

2024-05-3015:29:03

Linux

www.cve.org

ipv6

vulnerability

linux

kernel

null dereference

syzbot

general protection fault

6.3 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

ipv6: prevent NULL dereference in ip6_output()

According to syzbot, there is a chance that ip6_dst_idev()
returns NULL in ip6_output(). Most places in IPv6 stack
deal with a NULL idev just fine, but not here.

syzbot reported:

general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
CPU: 0 PID: 9775 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-00157-g6a30653b604a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:ip6_output+0x231/0x3f0 net/ipv6/ip6_output.c:237
Code: 3c 1e 00 49 89 df 74 08 4c 89 ef e8 19 58 db f7 48 8b 44 24 20 49 89 45 00 49 89 c5 48 8d 9d e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 4c 8b 74 24 28 0f 85 61 01 00 00 8b 1b 31 ff
RSP: 0018:ffffc9000927f0d8 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000040000
RDX: ffffc900131f9000 RSI: 0000000000004f47 RDI: 0000000000004f48
RBP: 0000000000000000 R08: ffffffff8a1f0b9a R09: 1ffffffff1f51fad
R10: dffffc0000000000 R11: fffffbfff1f51fae R12: ffff8880293ec8c0
R13: ffff88805d7fc000 R14: 1ffff1100527d91a R15: dffffc0000000000
FS: 00007f135c6856c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 0000000064096000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
NF_HOOK include/linux/netfilter.h:314 [inline]
ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358
sctp_v6_xmit+0x9f2/0x13f0 net/sctp/ipv6.c:248
sctp_packet_transmit+0x26ad/0x2ca0 net/sctp/output.c:653
sctp_packet_singleton+0x22c/0x320 net/sctp/outqueue.c:783
sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]
sctp_outq_flush+0x6d5/0x3e20 net/sctp/outqueue.c:1212
sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
sctp_do_sm+0x59cc/0x60c0 net/sctp/sm_sideeffect.c:1169
sctp_primitive_ASSOCIATE+0x95/0xc0 net/sctp/primitive.c:73
__sctp_connect+0x9cd/0xe30 net/sctp/socket.c:1234
sctp_connect net/sctp/socket.c:4819 [inline]
sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834
__sys_connect_file net/socket.c:2048 [inline]
__sys_connect+0x2df/0x310 net/socket.c:2065
__do_sys_connect net/socket.c:2075 [inline]
__se_sys_connect net/socket.c:2072 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2072
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/ipv6/ip6_output.c"
    ],
    "versions": [
      {
        "version": "778d80be5269",
        "lessThan": "ea0cb87402f7",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "778d80be5269",
        "lessThan": "e31b25cc2066",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "778d80be5269",
        "lessThan": "55f7eb4001ef",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "778d80be5269",
        "lessThan": "4db783d68b9b",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/ipv6/ip6_output.c"
    ],
    "versions": [
      {
        "version": "2.6.27",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "2.6.27",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.91",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.31",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.10",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]