Bug 2464392 (CVE-2026-31713)

Summary: CVE-2026-31713 kernel: fuse: abort on fatal signal during sync init
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Filesystem in Userspace (FUSE) component. When using synchronous initialization (sync init), if the FUSE server exits unexpectedly while processing the FUSE_INIT request, the filesystem creation process can hang. This issue occurs because the mounting thread keeps the device file descriptor open, preventing the operation from aborting. A local user could exploit this to cause a Denial of Service (DoS) by making the filesystem creation unresponsive.
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Description OSIDB Bzimport 2026-05-01 15:04:09 UTC 
In the Linux kernel, the following vulnerability has been resolved:

fuse: abort on fatal signal during sync init

When sync init is used and the server exits for some reason (error, crash)
while processing FUSE_INIT, the filesystem creation will hang.  The reason
is that while all other threads will exit, the mounting thread (or process)
will keep the device fd open, which will prevent an abort from happening.

This is a regression from the async mount case, where the mount was done
first, and the FUSE_INIT processing afterwards, in which case there's no
such recursive syscall keeping the fd open.
Comment 1 Keith Grant 2026-05-01 20:22:32 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050123-CVE-2026-31713-2109@gregkh/T