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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jens Axboe <axboe@kernel.dk>,
	Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	linux-block@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
	Bart Van Assche <bvanassche@acm.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 6.2 11/21] trace/blktrace: fix memory leak with using debugfs_lookup()
Date: Sat, 25 Feb 2023 22:41:40 -0500	[thread overview]
Message-ID: <20230226034150.771411-11-sashal@kernel.org> (raw)
In-Reply-To: <20230226034150.771411-1-sashal@kernel.org>

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 83e8864fee26f63a7435e941b7c36a20fd6fe93e ]

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230202141956.2299521-1-gregkh@linuxfoundation.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/trace/blktrace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 918a7d12df8ff..5743be5594153 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -320,8 +320,8 @@ static void blk_trace_free(struct request_queue *q, struct blk_trace *bt)
 	 * under 'q->debugfs_dir', thus lookup and remove them.
 	 */
 	if (!bt->dir) {
-		debugfs_remove(debugfs_lookup("dropped", q->debugfs_dir));
-		debugfs_remove(debugfs_lookup("msg", q->debugfs_dir));
+		debugfs_lookup_and_remove("dropped", q->debugfs_dir);
+		debugfs_lookup_and_remove("msg", q->debugfs_dir);
 	} else {
 		debugfs_remove(bt->dir);
 	}
-- 
2.39.0


  parent reply	other threads:[~2023-02-26  3:42 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-26  3:41 [PATCH AUTOSEL 6.2 01/21] ARM: OMAP2+: omap4-common: Fix refcount leak bug Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 02/21] arm64: dts: qcom: msm8996: Add additional A2NoC clocks Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 03/21] udf: Define EFSCORRUPTED error code Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 04/21] context_tracking: Fix noinstr vs KASAN Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 05/21] exit: Detect and fix irq disabled state in oops Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 06/21] ARM: dts: exynos: Use Exynos5420 compatible for the MIPI video phy Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 07/21] fs: Use CHECK_DATA_CORRUPTION() when kernel bugs are detected Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 08/21] blk-iocost: fix divide by 0 error in calc_lcoefs() Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 09/21] blk-cgroup: dropping parent refcount after pd_free_fn() is done Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 10/21] blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy() Sasha Levin
2023-02-26  3:41 ` Sasha Levin [this message]
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 12/21] fs/super.c: stop calling fscrypt_destroy_keyring() from __put_super() Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 13/21] sched/fair: sanitize vruntime of entity being placed Sasha Levin
2023-03-01 13:03   ` Zhang Qiao
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 14/21] btrfs: scrub: improve tree block error reporting Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 15/21] arm64: zynqmp: Enable hs termination flag for USB dwc3 controller Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 16/21] cpuidle, intel_idle: Fix CPUIDLE_FLAG_INIT_XSTATE Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 17/21] entry, kasan, x86: Disallow overriding mem*() functions Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 18/21] x86/fpu: Don't set TIF_NEED_FPU_LOAD for PF_IO_WORKER threads Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 19/21] cpuidle: drivers: firmware: psci: Dont instrument suspend code Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 20/21] cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG Sasha Levin
2023-02-26  3:41 ` [PATCH AUTOSEL 6.2 21/21] perf/x86/intel/uncore: Add Meteor Lake support Sasha Levin

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