Bug 2507814 (CVE-2026-64546)

Summary: CVE-2026-64546 kernel: drm/edid: fix OOB read in drm_parse_tiled_block()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
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. A specially crafted Extended Display Identification Data (EDID), which describes display capabilities, can cause a heap out-of-bounds read in the `drm_parse_tiled_block()` function within the `drm/edid` component. This vulnerability could lead to system instability or the disclosure of sensitive information.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-07-27 21:06:11 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/edid: fix OOB read in drm_parse_tiled_block()

drm_parse_tiled_block() casts the DisplayID block to a
struct displayid_tiled_block and reads the full fixed layout up to
tile->topology_id[7] without checking block->num_bytes. The DisplayID
iterator only validates the declared payload length, so a crafted EDID
can advertise a tiled-display block (tag DATA_BLOCK_TILED_DISPLAY, or
DATA_BLOCK_2_TILED_DISPLAY_TOPOLOGY for v2.0) with a small num_bytes at
the end of a DisplayID extension. The read then runs past the end of the
exact-sized kmemdup()'d EDID allocation, a heap out-of-bounds read.

Reject blocks shorter than the spec's 22-byte tiled payload before
reading the fixed struct, as drm_parse_vesa_mso_data() already does.

  BUG: KASAN: slab-out-of-bounds in drm_edid_connector_update
  Read of size 2 at addr ffff888010077700 by task exploit/147
   dump_stack_lvl (lib/dump_stack.c:94 ...)
   print_report (mm/kasan/report.c:378 ...)
   kasan_report (mm/kasan/report.c:595)
   drm_edid_connector_update (drivers/gpu/drm/drm_edid.c:7581)
   bochs_connector_helper_get_modes (drivers/gpu/drm/tiny/bochs.c:574)
   drm_helper_probe_single_connector_modes (drivers/gpu/drm/drm_probe_helper.c:426)
   status_store (drivers/gpu/drm/drm_sysfs.c:219)
   ...
   vfs_write (fs/read_write.c:595 fs/read_write.c:688)
   ksys_write (fs/read_write.c:740)