Bug 2389497 (CVE-2025-38607)

Summary: CVE-2025-38607 kernel: bpf: handle jset (if a & b ...) as a jump in CFG computation
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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Description OSIDB Bzimport 2025-08-19 18:04:12 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: handle jset (if a & b ...) as a jump in CFG computation

BPF_JSET is a conditional jump and currently verifier.c:can_jump()
does not know about that. This can lead to incorrect live registers
and SCC computation.

E.g. in the following example:

   1: r0 = 1;
   2: r2 = 2;
   3: if r1 & 0x7 goto +1;
   4: exit;
   5: r0 = r2;
   6: exit;

W/o this fix insn_successors(3) will return only (4), a jump to (5)
would be missed and r2 won't be marked as alive at (3).
Comment 1 Jon Moroney 2025-08-19 21:53:15 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025081922-CVE-2025-38607-c6ce@gregkh/T