CVE-2022-48751 net/smc: Transitional solution for clcsock race issue

2024-06-2011:13:32

Linux

www.cve.org

linux kernel

cve-2022-48751

net/smc

vulnerability

fix

clcsock race issue

0.0004 Low

EPSS

Percentile

15.7%

JSON

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

net/smc: Transitional solution for clcsock race issue

We encountered a crash in smc_setsockopt() and it is caused by
accessing smc->clcsock after clcsock was released.

BUG: kernel NULL pointer dereference, address: 0000000000000020
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 50309 Comm: nginx Kdump: loaded Tainted: G E 5.16.0-rc4+ #53
RIP: 0010:smc_setsockopt+0x59/0x280 [smc]
Call Trace:
<TASK>
__sys_setsockopt+0xfc/0x190
__x64_sys_setsockopt+0x20/0x30
do_syscall_64+0x34/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f16ba83918e
</TASK>

This patch tries to fix it by holding clcsock_release_lock and
checking whether clcsock has already been released before access.

In case that a crash of the same reason happens in smc_getsockopt()
or smc_switch_to_fallback(), this patch also checkes smc->clcsock
in them too. And the caller of smc_switch_to_fallback() will identify
whether fallback succeeds according to the return value.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/smc/af_smc.c"
    ],
    "versions": [
      {
        "version": "fd57770dd198",
        "lessThan": "38f0bdd548fd",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "fd57770dd198",
        "lessThan": "4284225cd800",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "fd57770dd198",
        "lessThan": "c0bf3d8a943b",
        "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/smc/af_smc.c"
    ],
    "versions": [
      {
        "version": "5.1",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.1",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.19",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16.5",
        "lessThanOrEqual": "5.16.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.17",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]