Description

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

exfat: fix potential deadlock on __exfat_get_dentry_set

When accessing a file with more entries than ES_MAX_ENTRY_NUM, the bh-array
is allocated in __exfat_get_entry_set. The problem is that the bh-array is
allocated with GFP_KERNEL. It does not make sense. In the following cases,
a deadlock for sbi->s_lock between the two processes may occur.

CPU0 CPU1
---- ----
kswapd
balance_pgdat
lock(fs_reclaim)
exfat_iterate
lock(&sbi->s_lock)
exfat_readdir
exfat_get_uniname_from_ext_entry
exfat_get_dentry_set
__exfat_get_dentry_set
kmalloc_array
...
lock(fs_reclaim)
...
evict
exfat_evict_inode
lock(&sbi->s_lock)

To fix this, let's allocate bh-array with GFP_NOFS.

Classification

CVE ID: CVE-2024-42315

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.5

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

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 8.64% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2024-42315
https://git.kernel.org/stable/c/632fb232b6bbf8277edcbe9ecd4b4d98ecb122eb
https://git.kernel.org/stable/c/c052f775ee6ccacd3c97e4cf41a2a657e63d4259
https://git.kernel.org/stable/c/cd1c7858641384191ff7033fb1fc65dfcd559c6f
https://git.kernel.org/stable/c/a7ac198f8dba791e3144c4da48a5a9b95773ee4b
https://git.kernel.org/stable/c/1d1970493c289e3f44b9ec847ed26a5dbdf56a62
https://git.kernel.org/stable/c/89fc548767a2155231128cb98726d6d2ea1256c9

Timeline