CVE-2024-26902

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 : ffffffff8017a0ca [ 273.421022] t5 : ffffffff8023cfc2 t6 : ffffffd9040780e8 [ 273.426437] status: 0000000200000100 badaddr: 0000000000000098 cause: 000000000000000d [ 273.434512] [] riscv_pmu_ctr_get_width_mask+0x8/0x62 [ 273.441169] [] handle_percpu_devid_irq+0x98/0x1ee [ 273.447562] [] generic_handle_domain_irq+0x28/0x36 [ 273.454151] [] riscv_intc_irq+0x36/0x4e [ 273.459659] [] handle_riscv_irq+0x4a/0x74 [ 273.465442] [] do_irq+0x62/0x92 [ 273.470360] Code: 0420 60a2 6402 5529 0141 8082 0013 0000 0013 0000 (6d5c) b783 [ 273.477921] —[ end trace 0000000000000000 ]— [ 273.482630] Kernel panic - not syncing: Fatal exception in interrupt

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

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