cbcvebase.
CVE-2025-40287
published 2025-12-06

CVE-2025-40287: In the Linux kernel, the following vulnerability has been resolved: exfat: fix improper check of dentry.stream.valid_size We found an infinite loop bug in the…

PriorityP425high7.8
EPSS
0.18%
7.7th percentile
In the Linux kernel, the following vulnerability has been resolved: exfat: fix improper check of dentry.stream.valid_size We found an infinite loop bug in the exFAT file system that can lead to a Denial-of-Service (DoS) condition. When a dentry in an exFAT filesystem is malformed, the following system calls — SYS_openat, SYS_ftruncate, and SYS_pwrite64 — can cause the kernel to hang. Root cause analysis shows that the size validation code in exfat_find() does not check whether dentry.stream.valid_size is negative. As a result, the system calls mentioned above can succeed and eventually trigger the DoS issue. This patch adds a check for negative dentry.stream.valid_size to prevent this vulnerability.

Affected

15 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.17.9-1 (forky)linux 6.17.9-1 (forky)
linuxlinux
linuxlinux>= 11a347fb6cef62ce47e84b97c45f2b2497c7593b < 6c627bcc1896ba62ec793d0c00da74f3c93ce3ad6c627bcc1896ba62ec793d0c00da74f3c93ce3ad
linuxlinux>= 11a347fb6cef62ce47e84b97c45f2b2497c7593b < 204b1b02ee018ba52ad2ece21fe3a8643d66a1b2204b1b02ee018ba52ad2ece21fe3a8643d66a1b2
linuxlinux>= 11a347fb6cef62ce47e84b97c45f2b2497c7593b < 82ebecdc74ff555daf70b811d854b1f32a296bea82ebecdc74ff555daf70b811d854b1f32a296bea
linuxlinux_kernel>= 0 < 6.12.63-16.12.63-1
linuxlinux_kernel>= 0 < 6.17.9-16.17.9-1
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 6.13.0 < 6.17.96.17.9
linuxlinux_kernel>= 6.8.0 < 6.12.596.12.59
msrcazl3_kernel_6.6.117.1-1_on_azure_linux_3.0
ubuntulinux-aws
ubuntulinux-oracle
ubuntulinux-xilinx

CVSS provenance

vendor_ubuntu7.8HIGH
osv3.2LOW
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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