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LinuxCVE-2024-39510

HistoryJul 12, 2024 - 1:15 p.m.

CVE-2024-39510

2024-07-1213:15:13

CWE-416

Linux

web.nvd.nist.gov

linux kernel

slab-use-after-free

vulnerability

cachefiles_ondemand_daemon_read

fix

security

cve-2024-39510

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

6.5

Confidence

High

EPSS

Percentile

5.1%

JSON

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

cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read()

We got the following issue in a fuzz test of randomly issuing the restore
command:

==================================================================
BUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0xb41/0xb60
Read of size 8 at addr ffff888122e84088 by task ondemand-04-dae/963

CPU: 13 PID: 963 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #564
Call Trace:
kasan_report+0x93/0xc0
cachefiles_ondemand_daemon_read+0xb41/0xb60
vfs_read+0x169/0xb50
ksys_read+0xf5/0x1e0

Allocated by task 116:
kmem_cache_alloc+0x140/0x3a0
cachefiles_lookup_cookie+0x140/0xcd0
fscache_cookie_state_machine+0x43c/0x1230
[…]

Freed by task 792:
kmem_cache_free+0xfe/0x390
cachefiles_put_object+0x241/0x480
fscache_cookie_state_machine+0x5c8/0x1230
[…]

Following is the process that triggers the issue:

 mount  |   daemon_thread1    |    daemon_thread2

cachefiles_withdraw_cookie
cachefiles_ondemand_clean_object(object)
cachefiles_ondemand_send_req
REQ_A = kzalloc(sizeof(*req) + data_len)
wait_for_completion(&REQ_A->done)

        cachefiles_daemon_read
         cachefiles_ondemand_daemon_read
          REQ_A = cachefiles_ondemand_select_req
          msg-&gt;object_id = req-&gt;object-&gt;ondemand-&gt;ondemand_id
                              ------ restore ------
                              cachefiles_ondemand_restore
                              xas_for_each(&xas, req, ULONG_MAX)
                               xas_set_mark(&xas, CACHEFILES_REQ_NEW)

                              cachefiles_daemon_read
                               cachefiles_ondemand_daemon_read
                                REQ_A = cachefiles_ondemand_select_req
          copy_to_user(_buffer, msg, n)
           xa_erase(&cache-&gt;reqs, id)
           complete(&REQ_A-&gt;done)
          ------ close(fd) ------
          cachefiles_ondemand_fd_release
           cachefiles_put_object

cachefiles_put_object
kmem_cache_free(cachefiles_object_jar, object)
REQ_A->object->ondemand->ondemand_id
// object UAF !!!

When we see the request within xa_lock, req->object must not have been
freed yet, so grab the reference count of object before xa_unlock to
avoid the above issue.

Affected configurations

Nvd

Vulners

Node

linuxlinux_kernelRange6.8–6.9.6

linuxlinux_kernelMatch6.10rc1

linuxlinux_kernelMatch6.10rc2

linuxlinux_kernelMatch6.10rc3

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel6.10cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:*
linuxlinux_kernel6.10cpe:2.3:o:linux:linux_kernel:6.10:rc2:*:*:*:*:*:*
linuxlinux_kernel6.10cpe:2.3:o:linux:linux_kernel:6.10:rc3:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.10	cpe:2.3:o:linux:linux_kernel:6.10:rc1::::::
linux	linux_kernel	6.10	cpe:2.3:o:linux:linux_kernel:6.10:rc2::::::
linux	linux_kernel	6.10	cpe:2.3:o:linux:linux_kernel:6.10:rc3::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/cachefiles/ondemand.c",
      "include/trace/events/cachefiles.h"
    ],
    "versions": [
      {
        "version": "f17443d52d80",
        "lessThan": "cb55625f8eb9",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "f740fd943bb1",
        "lessThan": "3958679c4915",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0a7e54c1959c",
        "lessThan": "93064676a282",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0a7e54c1959c",
        "lessThan": "da4a82741606",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/cachefiles/ondemand.c",
      "include/trace/events/cachefiles.h"
    ],
    "versions": [
      {
        "version": "6.8",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.8",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9.6",
        "lessThanOrEqual": "6.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]