Bug 2339126 (CVE-2024-57940)

Summary: CVE-2024-57940 kernel: exfat: fix the infinite loop in exfat_readdir()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-01-21 13:01:53 UTC 
In the Linux kernel, the following vulnerability has been resolved:

exfat: fix the infinite loop in exfat_readdir()

If the file system is corrupted so that a cluster is linked to
itself in the cluster chain, and there is an unused directory
entry in the cluster, 'dentry' will not be incremented, causing
condition 'dentry < max_dentries' unable to prevent an infinite
loop.

This infinite loop causes s_lock not to be released, and other
tasks will hang, such as exfat_sync_fs().

This commit stops traversing the cluster chain when there is unused
directory entry in the cluster to avoid this infinite loop.
Comment 1 Robb Gatica 2025-01-21 17:18:51 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025012128-CVE-2024-57940-e289@gregkh/T
Comment 3 errata-xmlrpc 2025-05-13 08:38:59 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966