Bug 2425008 (CVE-2023-54056)

Summary: CVE-2023-54056 kernel: kheaders: Use array declaration instead of char
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 false positive buffer overflow detection was found in the Linux kernel's kheaders module. When CONFIG_FORTIFY_SOURCE is enabled, memcpy() performs size checks on source and destination buffers. The kernel_headers_data symbol was declared as "char" rather than an array, causing FORTIFY_SOURCE to incorrectly detect a buffer overflow when reading /sys/kernel/kheaders.tar.xz. The fix changes the declaration to an array type to match actual usage.
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Description OSIDB Bzimport 2025-12-24 13:01:34 UTC 
In the Linux kernel, the following vulnerability has been resolved:

kheaders: Use array declaration instead of char

Under CONFIG_FORTIFY_SOURCE, memcpy() will check the size of destination
and source buffers. Defining kernel_headers_data as "char" would trip
this check. Since these addresses are treated as byte arrays, define
them as arrays (as done everywhere else).

This was seen with:

  $ cat /sys/kernel/kheaders.tar.xz >> /dev/null

  detected buffer overflow in memcpy
  kernel BUG at lib/string_helpers.c:1027!
  ...
  RIP: 0010:fortify_panic+0xf/0x20
  [...]
  Call Trace:
   <TASK>
   ikheaders_read+0x45/0x50 [kheaders]
   kernfs_fop_read_iter+0x1a4/0x2f0
  ...
Comment 1 Alexander B 2025-12-25 09:20:18 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122426-CVE-2023-54056-fd56@gregkh/T