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cvelistLinuxCVELIST:CVE-2023-52813
HistoryMay 21, 2024 - 3:31 p.m.

CVE-2023-52813 crypto: pcrypt - Fix hungtask for PADATA_RESET

2024-05-2115:31:21
Linux
www.cve.org
linux kernel
vulnerability
pcrypt
hungtask
padata_reset
hung_task_timeout_secs
hung_task
padata_do_parallel
aead_request_complete
padata_reset
padata_replace
rcu_read_lock_bh
rcu_read_unlock_bh
retry
return err
padata_reset
padata_try_do_parallel
pcrypt_aead_encrypt
pcrypt_aead_decrypt

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

13.1%

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

crypto: pcrypt - Fix hungtask for PADATA_RESET

We found a hungtask bug in test_aead_vec_cfg as follows:

INFO: task cryptomgr_test:391009 blocked for more than 120 seconds.
“echo 0 > /proc/sys/kernel/hung_task_timeout_secs” disables this message.
Call trace:
__switch_to+0x98/0xe0
__schedule+0x6c4/0xf40
schedule+0xd8/0x1b4
schedule_timeout+0x474/0x560
wait_for_common+0x368/0x4e0
wait_for_completion+0x20/0x30
wait_for_completion+0x20/0x30
test_aead_vec_cfg+0xab4/0xd50
test_aead+0x144/0x1f0
alg_test_aead+0xd8/0x1e0
alg_test+0x634/0x890
cryptomgr_test+0x40/0x70
kthread+0x1e0/0x220
ret_from_fork+0x10/0x18
Kernel panic - not syncing: hung_task: blocked tasks

For padata_do_parallel, when the return err is 0 or -EBUSY, it will call
wait_for_completion(&wait->completion) in test_aead_vec_cfg. In normal
case, aead_request_complete() will be called in pcrypt_aead_serial and the
return err is 0 for padata_do_parallel. But, when pinst->flags is
PADATA_RESET, the return err is -EBUSY for padata_do_parallel, and it
won’t call aead_request_complete(). Therefore, test_aead_vec_cfg will
hung at wait_for_completion(&wait->completion), which will cause
hungtask.

The problem comes as following:
(padata_do_parallel) |
rcu_read_lock_bh(); |
err = -EINVAL; | (padata_replace)
| pinst->flags |= PADATA_RESET;
err = -EBUSY |
if (pinst->flags & PADATA_RESET) |
rcu_read_unlock_bh() |
return err

In order to resolve the problem, we replace the return err -EBUSY with
-EAGAIN, which means parallel_data is changing, and the caller should call
it again.

v3:
remove retry and just change the return err.
v2:
introduce padata_try_do_parallel() in pcrypt_aead_encrypt and
pcrypt_aead_decrypt to solve the hungtask.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "crypto/pcrypt.c",
      "kernel/padata.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "fb2d3a50a8f2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "039fec48e062",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "c9c133469730",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "e97bf4ada7dd",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "546c1796ad1e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "c55fc098fd9d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "e134f3aba98e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "372636debe85",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "8f4f68e788c3",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "crypto/pcrypt.c",
      "kernel/padata.c"
    ],
    "versions": [
      {
        "version": "4.14.331",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.300",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.262",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.202",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.140",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.64",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.5.13",
        "lessThanOrEqual": "6.5.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.3",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

13.1%

Related for CVELIST:CVE-2023-52813