Bug 2455336 (CVE-2026-31405)

Summary: CVE-2026-31405 kernel: media: dvb-net: fix OOB access in ULE extension header tables
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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A flaw was found in the Linux kernel's dvb-net component. A remote attacker could exploit this vulnerability by sending specially crafted network data. This could lead to an out-of-bounds read in the `handle_one_ule_extension()` function, potentially allowing the attacker to execute arbitrary code. The issue arises because an index derived from network-controlled data can exceed the bounds of an internal function pointer table.
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Description OSIDB Bzimport 2026-04-06 09:01:36 UTC 
In the Linux kernel, the following vulnerability has been resolved:

media: dvb-net: fix OOB access in ULE extension header tables

The ule_mandatory_ext_handlers[] and ule_optional_ext_handlers[] tables
in handle_one_ule_extension() are declared with 255 elements (valid
indices 0-254), but the index htype is derived from network-controlled
data as (ule_sndu_type & 0x00FF), giving a range of 0-255. When
htype equals 255, an out-of-bounds read occurs on the function pointer
table, and the OOB value may be called as a function pointer.

Add a bounds check on htype against the array size before either table
is accessed. Out-of-range values now cause the SNDU to be discarded.
Comment 1 Keith Grant 2026-04-06 11:41:48 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026040603-CVE-2026-31405-8cfb@gregkh/T