Bug 2492279 (CVE-2026-53047) - CVE-2026-53047 kernel: efi/capsule-loader: fix incorrect sizeof in phys array reallocation
Summary: CVE-2026-53047 kernel: efi/capsule-loader: fix incorrect sizeof in phys array...
Keywords:
Status: NEW
Alias: CVE-2026-53047
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-24 18:02 UTC by OSIDB Bzimport
Modified: 2026-06-25 14:51 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-06-24 18:02:46 UTC
In the Linux kernel, the following vulnerability has been resolved:

efi/capsule-loader: fix incorrect sizeof in phys array reallocation

The krealloc() call for cap_info->phys in __efi_capsule_setup_info() uses
sizeof(phys_addr_t *) instead of sizeof(phys_addr_t), which might be
causing an undersized allocation.

The allocation is also inconsistent with the initial array allocation in
efi_capsule_open() that allocates one entry with sizeof(phys_addr_t),
and the efi_capsule_write() function that stores phys_addr_t values (not
pointers) via page_to_phys().

On 64-bit systems where sizeof(phys_addr_t) == sizeof(phys_addr_t *), this
goes unnoticed. On 32-bit systems with PAE where phys_addr_t is 64-bit but
pointers are 32-bit, this allocates half the required space, which might
lead to a heap buffer overflow when storing physical addresses.

This is similar to the bug fixed in commit fccfa646ef36 ("efi/capsule-loader:
fix incorrect allocation size") which fixed the same issue at the initial
allocation site.

Comment 1 Mauro Matteo Cascella 2026-06-25 14:44:43 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062458-CVE-2026-53047-7dc7@gregkh/T


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