Bug 2454779 (CVE-2026-23423)

Summary: CVE-2026-23423 kernel: btrfs: free pages on error in btrfs_uring_read_extent()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel's btrfs file system. This vulnerability occurs in the `btrfs_uring_read_extent()` function, where memory allocated for 'pages' is not properly freed when errors occur during read operations. This oversight can lead to resource exhaustion, potentially causing a Denial of Service (DoS) for affected systems.
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Description OSIDB Bzimport 2026-04-03 14:02:09 UTC 
In the Linux kernel, the following vulnerability has been resolved:

btrfs: free pages on error in btrfs_uring_read_extent()

In this function the 'pages' object is never freed in the hopes that it is
picked up by btrfs_uring_read_finished() whenever that executes in the
future. But that's just the happy path. Along the way previous
allocations might have gone wrong, or we might not get -EIOCBQUEUED from
btrfs_encoded_read_regular_fill_pages(). In all these cases, we go to a
cleanup section that frees all memory allocated by this function without
assuming any deferred execution, and this also needs to happen for the
'pages' allocation.
Comment 1 Alexander B 2026-04-03 14:54:22 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026040304-CVE-2026-23423-96fa@gregkh/T