CVE-2024-40947

2024-07-1213:15:17

Linux

web.nvd.nist.gov

linux kernel

vulnerability

fix

ima_match_policy

panic

uaf

cve-2024-40947

AI Score

6.2

Confidence

Low

EPSS

Percentile

10.6%

JSON

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

ima: Avoid blocking in RCU read-side critical section

A panic happens in ima_match_policy:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS: 00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ima_get_action+0x22/0x30
process_measurement+0xb0/0x830
? page_add_file_rmap+0x15/0x170
? alloc_set_pte+0x269/0x4c0
? prep_new_page+0x81/0x140
? simple_xattr_get+0x75/0xa0
? selinux_file_open+0x9d/0xf0
ima_file_check+0x64/0x90
path_openat+0x571/0x1720
do_filp_open+0x9b/0x110
? page_counter_try_charge+0x57/0xc0
? files_cgroup_alloc_fd+0x38/0x60
? __alloc_fd+0xd4/0x250
? do_sys_open+0x1bd/0x250
do_sys_open+0x1bd/0x250
do_syscall_64+0x5d/0x1d0
entry_SYSCALL_64_after_hwframe+0x65/0xca

Commit c7423dbdbc9e (“ima: Handle -ESTALE returned by
ima_filter_rule_match()”) introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.

Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.

To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.

[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]

Affected configurations

Vulners

Node

linuxlinux_kernelRange6.2–5.10.222

linuxlinux_kernelRange5.11.0–5.15.163

linuxlinux_kernelRange5.16.0–6.1.98

linuxlinux_kernelRange6.2.0–6.6.39

linuxlinux_kernelRange6.7.0–6.9.7

linuxlinux_kernelRange6.10.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "include/linux/lsm_hook_defs.h",
      "include/linux/security.h",
      "kernel/auditfilter.c",
      "security/apparmor/audit.c",
      "security/apparmor/include/audit.h",
      "security/integrity/ima/ima.h",
      "security/integrity/ima/ima_policy.c",
      "security/security.c",
      "security/selinux/include/audit.h",
      "security/selinux/ss/services.c",
      "security/smack/smack_lsm.c"
    ],
    "versions": [
      {
        "version": "c4b035b1f036",
        "lessThan": "a6176a802c4b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "2d4bc60693c4",
        "lessThan": "a38e02265c68",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8008f1691c15",
        "lessThan": "9c3906c37385",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "c7423dbdbc9e",
        "lessThan": "28d0ecc52f6c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "c7423dbdbc9e",
        "lessThan": "582754558930",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "c7423dbdbc9e",
        "lessThan": "9a95c5bfbf02",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "include/linux/lsm_hook_defs.h",
      "include/linux/security.h",
      "kernel/auditfilter.c",
      "security/apparmor/audit.c",
      "security/apparmor/include/audit.h",
      "security/integrity/ima/ima.h",
      "security/integrity/ima/ima_policy.c",
      "security/security.c",
      "security/selinux/include/audit.h",
      "security/selinux/ss/services.c",
      "security/smack/smack_lsm.c"
    ],
    "versions": [
      {
        "version": "6.2",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.2",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.222",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.163",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.98",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.39",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9.7",
        "lessThanOrEqual": "6.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]