bpf: Don't predict JMP32 pointer vs zero comparisons
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7epss 0.1%
exploitation probability
0.1%top 97% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
bpf: Don't predict JMP32 pointer vs zero comparisons
Consider the following program:
r1 = map_value; /* low 32 bits are zero at runtime */
r6 = 0xdead000000000000;
if w1 != 0 goto l1;
l0: r1 += r6;
r2 = *(u64 *)(r1 + 0);
exit;
l1: r6 = 0;
goto l0;
At the moment is_branch_taken() reports the jump as always taken,
because it does not distinguish between BPF_JMP and BPF_JMP32
comparisons when processing 'if w1 != 0 ...'.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
Linux · Linux