CVE-2024-26902: perf: RISCV: Fix panic on pmu overflow handler

Description

In the Linux kernel, the following vulnerability has been resolved:

perf: RISCV: Fix panic on pmu overflow handler

(1 << idx) of int is not desired when setting bits in unsigned long
overflowed_ctrs, use BIT() instead. This panic happens when running
'perf record -e branches' on sophgo sg2042.

[ 273.311852] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098
[ 273.320851] Oops [#1]
[ 273.323179] Modules linked in:
[ 273.326303] CPU: 0 PID: 1475 Comm: perf Not tainted 6.6.0-rc3+ #9
[ 273.332521] Hardware name: Sophgo Mango (DT)
[ 273.336878] epc : riscv_pmu_ctr_get_width_mask+0x8/0x62
[ 273.342291] ra : pmu_sbi_ovf_handler+0x2e0/0x34e
[ 273.347091] epc : ffffffff80aecd98 ra : ffffffff80aee056 sp : fffffff6e36928b0
[ 273.354454] gp : ffffffff821f82d0 tp : ffffffd90c353200 t0 : 0000002ade4f9978
[ 273.361815] t1 : 0000000000504d55 t2 : ffffffff8016cd8c s0 : fffffff6e3692a70
[ 273.369180] s1 : 0000000000000020 a0 : 0000000000000000 a1 : 00001a8e81800000
[ 273.376540] a2 : 0000003c00070198 a3 : 0000003c00db75a4 a4 : 0000000000000015
[ 273.383901] a5 : ffffffd7ff8804b0 a6 : 0000000000000015 a7 : 000000000000002a
[ 273.391327] s2 : 000000000000ffff s3 : 0000000000000000 s4 : ffffffd7ff8803b0
[ 273.398773] s5 : 0000000000504d55 s6 : ffffffd905069800 s7 : ffffffff821fe210
[ 273.406139] s8 : 000000007fffffff s9 : ffffffd7ff8803b0 s10: ffffffd903f29098
[ 273.413660] s11: 0000000080000000 t3 : 0000000000000003 t4 : ffffffff...

Classification

CVE ID: CVE-2024-26902

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/3ede8e94de6b834b48b0643385e66363e7a04be9
https://git.kernel.org/stable/c/9f599ba3b9cc4bdb8ec1e3f0feddd41bf9d296d6
https://git.kernel.org/stable/c/34b567868777e9fd39ec5333969728a7f0cf179c

Timeline