CVSS 7.1 · High EPSS 0,16%
Kerentanan Out-of-bounds Read pada linux kernel. Skor CVSS 3.1 7.1 (High) menurut NVD.
In the Linux kernel, the following vulnerability has been resolved: rcu: Fix rcu_read_unlock() deadloop due to IRQ work During rcu_read_unlock_special(), if this happens during irq_exit(), we can lockup if an IPI is issued. This is because the IPI itself triggers the irq_exit() path causing a recursive lock up. This is precisely what Xiongfeng found when invoking a BPF program on the trace_tick_stop() tracepoint As shown in the trace below. Fix by managing the irq_work state correctly. irq_exit() __irq_exit_rcu() /* in_hardirq() returns false after this */ preempt_count_sub(HARDIRQ_OFFSET) tick_irq_exit() tick_nohz_irq_exit() tick_nohz_stop_sched_tick() trace_tick_stop() /* a bpf prog is hooked on this trace point */ __bpf_trace_tick_stop() bpf_trace_run2() rcu_read_unlock_special() /* will send a IPI to itself */ irq_work_queue_on(&rdp->defer_qs_iw, rdp->cpu); A simple reproducer can also be obtained by doing the following in tick_irq_exit(). It will hang on boot without the patch: static inline void tick_irq_exit(void) { + rcu_read_lock(); + WRITE_ONCE(current->rcu_read_unlock_special.b.need_qs, true); + rcu_read_unlock(); + [neeraj: Apply Frederic's suggested fix for PREEMPT_RT]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Semua versi sebelum 6.6.103 |
| linux | linux kernel | Versi 6.7 hingga sebelum 6.12.43 |
| linux | linux kernel | Versi 6.13 hingga sebelum 6.15.11 |
| linux | linux kernel | Versi 6.16 hingga sebelum 6.16.2 |