ghsa-94mv-98xv-9mqq
Vulnerability from github
Published
2024-02-28 09:30
Modified
2024-02-28 09:30
Details

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

net/sched: act_ct: fix wild memory access when clearing fragments

while testing re-assembly/re-fragmentation using act_ct, it's possible to observe a crash like the following one:

KASAN: maybe wild-memory-access in range [0x0001000000000448-0x000100000000044f] CPU: 50 PID: 0 Comm: swapper/50 Tainted: G S 5.12.0-rc7+ #424 Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017 RIP: 0010:inet_frag_rbtree_purge+0x50/0xc0 Code: 00 fc ff df 48 89 c3 31 ed 48 89 df e8 a9 7a 38 ff 4c 89 fe 48 89 df 49 89 c6 e8 5b 3a 38 ff 48 8d 7b 40 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 75 59 48 8d bb d0 00 00 00 4c 8b 6b 40 48 89 f8 48 RSP: 0018:ffff888c31449db8 EFLAGS: 00010203 RAX: 0000200000000089 RBX: 000100000000040e RCX: ffffffff989eb960 RDX: 0000000000000140 RSI: ffffffff97cfb977 RDI: 000100000000044e RBP: 0000000000000900 R08: 0000000000000000 R09: ffffed1186289350 R10: 0000000000000003 R11: ffffed1186289350 R12: dffffc0000000000 R13: 000100000000040e R14: 0000000000000000 R15: ffff888155e02160 FS: 0000000000000000(0000) GS:ffff888c31440000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005600cb70a5b8 CR3: 0000000a2c014005 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: inet_frag_destroy+0xa9/0x150 call_timer_fn+0x2d/0x180 run_timer_softirq+0x4fe/0xe70 __do_softirq+0x197/0x5a0 irq_exit_rcu+0x1de/0x200 sysvec_apic_timer_interrupt+0x6b/0x80

when act_ct temporarily stores an IP fragment, restoring the skb qdisc cb results in putting random data in FRAG_CB(), and this causes those "wild" memory accesses later, when the rbtree is purged. Never overwrite the skb cb in case tcf_ct_handle_fragments() returns -EINPROGRESS.

Show details on source website


{
  "affected": [],
  "aliases": [
    "CVE-2021-47014"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-02-28T09:15:38Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: fix wild memory access when clearing fragments\n\nwhile testing re-assembly/re-fragmentation using act_ct, it\u0027s possible to\nobserve a crash like the following one:\n\n KASAN: maybe wild-memory-access in range [0x0001000000000448-0x000100000000044f]\n CPU: 50 PID: 0 Comm: swapper/50 Tainted: G S                5.12.0-rc7+ #424\n Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017\n RIP: 0010:inet_frag_rbtree_purge+0x50/0xc0\n Code: 00 fc ff df 48 89 c3 31 ed 48 89 df e8 a9 7a 38 ff 4c 89 fe 48 89 df 49 89 c6 e8 5b 3a 38 ff 48 8d 7b 40 48 89 f8 48 c1 e8 03 \u003c42\u003e 80 3c 20 00 75 59 48 8d bb d0 00 00 00 4c 8b 6b 40 48 89 f8 48\n RSP: 0018:ffff888c31449db8 EFLAGS: 00010203\n RAX: 0000200000000089 RBX: 000100000000040e RCX: ffffffff989eb960\n RDX: 0000000000000140 RSI: ffffffff97cfb977 RDI: 000100000000044e\n RBP: 0000000000000900 R08: 0000000000000000 R09: ffffed1186289350\n R10: 0000000000000003 R11: ffffed1186289350 R12: dffffc0000000000\n R13: 000100000000040e R14: 0000000000000000 R15: ffff888155e02160\n FS:  0000000000000000(0000) GS:ffff888c31440000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00005600cb70a5b8 CR3: 0000000a2c014005 CR4: 00000000003706e0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n  \u003cIRQ\u003e\n  inet_frag_destroy+0xa9/0x150\n  call_timer_fn+0x2d/0x180\n  run_timer_softirq+0x4fe/0xe70\n  __do_softirq+0x197/0x5a0\n  irq_exit_rcu+0x1de/0x200\n  sysvec_apic_timer_interrupt+0x6b/0x80\n  \u003c/IRQ\u003e\n\nwhen act_ct temporarily stores an IP fragment, restoring the skb qdisc cb\nresults in putting random data in FRAG_CB(), and this causes those \"wild\"\nmemory accesses later, when the rbtree is purged. Never overwrite the skb\ncb in case tcf_ct_handle_fragments() returns -EINPROGRESS.",
  "id": "GHSA-94mv-98xv-9mqq",
  "modified": "2024-02-28T09:30:37Z",
  "published": "2024-02-28T09:30:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-47014"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0648941f4c8bbf8b4b6c0b270889ae7aa769b921"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f77bd544a6bbe69aa50d9ed09f13494cf36ff806"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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