Bug 2555199 (CVE-2026-98816) - CVE-2026-98816 kernel: bpf: Fix overflow of jump offset in constant blinding
Summary: CVE-2026-98816 kernel: bpf: Fix overflow of jump offset in constant blinding
Keywords:
Status: NEW
Alias: CVE-2026-98816
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-18 16:01 UTC by OSIDB Bzimport
Modified: 2026-10-23 18:47 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-10-18 16:01:29 UTC
In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix overflow of jump offset in constant blinding

bpf_jit_blind_insn() rewrites 'if rX op imm goto off' into:

  AX = imm ^ rnd
  AX ^= rnd
  if rX op AX goto off

and subtracts 2 from off when the jump is backward. off is s16, so
-32767 and -32768 wrap and the jump goes 32767 insns forward, past the
end of the prog. The jump is inside the patch, hence bpf_adj_branches()
doesn't check it. The kernel crashes when such prog runs with
bpf_jit_harden=2.

Return -ERANGE in such case. bpf_jit_blind_constants() fails the same
way when blinding of other insns moves a jump out of range.


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