Linux Kernel BPF: ld_{abs,ind} Failure Path in Subprogs
CVE-2026-53090 Published on June 24, 2026
bpf: Fix ld_{abs,ind} failure path analysis in subprogs
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix ld_{abs,ind} failure path analysis in subprogs
Usage of ld_{abs,ind} instructions got extended into subprogs some time
ago via commit 09b28d76eac4 ("bpf: Add abnormal return checks."). These
are only allowed in subprograms when the latter are BTF annotated and
have scalar return types.
The code generator in bpf_gen_ld_abs() has an abnormal exit path (r0=0 +
exit) from legacy cBPF times. While the enforcement is on scalar return
types, the verifier must also simulate the path of abnormal exit if the
packet data load via ld_{abs,ind} failed.
This is currently not the case. Fix it by having the verifier simulate
both success and failure paths, and extend it in similar ways as we do
for tail calls. The success path (r0=unknown, continue to next insn) is
pushed onto stack for later validation and the r0=0 and return to the
caller is done on the fall-through side.
Products Associated with CVE-2026-53090
Want to know whenever a new CVE is published for Linux Kernel? stack.watch will email you.
Affected Versions
Linux:- Version 09b28d76eac48e922dc293da1aa2b2b85c32aeee and below d846d83bdacbd8f14fc45c63b8c1d22608452e1c is affected.
- Version 09b28d76eac48e922dc293da1aa2b2b85c32aeee and below ee861486e377edc55361c08dcbceab3f6b6577bd is affected.
- Version 5.10 is affected.
- Before 5.10 is unaffected.
- Version 7.0.10, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.