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([2001:41d0:303:db6b::]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4924944fbbdsm187983235e9.12.2026.06.21.17.00.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 21 Jun 2026 17:00:22 -0700 (PDT) From: Tristan Madani To: Andrew Morton Cc: Tetsuo Handa , Ingo Molnar , Dave Hansen , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Tristan Madani Subject: [PATCH v2] profiling: don't free prof_cpu_mask on init failure Date: Mon, 22 Jun 2026 00:00:22 +0000 Message-ID: <20260622000022.3375262-1-tristmd@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260621192324.2062795-1-tristmd@gmail.com> References: <20260621192324.2062795-1-tristmd@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tristan Madani When profiling is enabled at runtime via /sys/kernel/profiling, profile_setup() sets prof_on and profile_init() allocates prof_cpu_mask then attempts to allocate prof_buffer. If all prof_buffer allocations fail, the error path frees prof_cpu_mask but leaves prof_on set. Since profile_tick() runs from timer interrupt context and checks cpumask_available(prof_cpu_mask), it can access the freed cpumask between the free and the next reboot. Remove the free_cpumask_var() call from the error path. The cpumask allocation already succeeded and is small; keeping it on this rare failure path is harmless. Fixes: 22b8ce94708f ("profiling: dynamically enable readprofile at runtime") Cc: stable@vger.kernel.org Suggested-by: Tetsuo Handa Signed-off-by: Tristan Madani --- Changes in v2: - Remove the free_cpumask_var() call instead of adding a prof_on guard in profile_tick(), which still raced with the free (Tetsuo Handa) kernel/profile.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/profile.c b/kernel/profile.c index 984f819b701c9..93180f9d21467 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -123,7 +123,6 @@ int __ref profile_init(void) if (prof_buffer) return 0; - free_cpumask_var(prof_cpu_mask); return -ENOMEM; } -- 2.47.3