Answer in brief
CVE-2025-39744 records a High severity (CVSS 7.1) vulnerability in rcu: Fix rcu_read_unlock() deadloop due to IRQ work. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=0864f057b050bc6dd68106b3185e02db5140012d <6b552ffd21f9be57806ade167a757f32dd66a98d || >=0864f057b050bc6dd68106b3185e02db5140012d <e7a375453cca2b8a0d2fa1b82b913f3fed7c0507 || >=0864f057b050bc6dd68106b3185e02db5140012d <1cfa244f7198d325594e627574930b7b91df5bfe || >=0864f057b050bc6dd68106b3185e02db5140012d <ddebb2a7677673cf4438a04e1a48b8ed6b0c8e9a || >=0864f057b050bc6dd68106b3185e02db5140012d <56c5ef194f4509df63fc0f7a91ea5973ce479b1e || >=0864f057b050bc6dd68106b3185e02db5140012d <b41642c87716bbd09797b1e4ea7d904f06c39b7b | 6b552ffd21f9be57806ade167a757f32dd66a98d, e7a375453cca2b8a0d2fa1b82b913f3fed7c0507, 1cfa244f7198d325594e627574930b7b91df5bfe, ddebb2a7677673cf4438a04e1a48b8ed6b0c8e9a, 56c5ef194f4509df63fc0f7a91ea5973ce479b1e, b41642c87716bbd09797b1e4ea7d904f06c39b7b |
| Linux/Linuxgeneric | 5.3 | Not reported |
Published upstream
Sep 11, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
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]
Quoted source text, attributed separately from HOL analysis.