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Fri, 20 Feb 2026 01:36:15 -0800 (PST) Received: from aegis ([2001:fd8:f657:5202:3e11:bbb5:18b7:bbbb]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2ad1a741e5bsm184240445ad.40.2026.02.20.01.36.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Feb 2026 01:36:14 -0800 (PST) From: Daniel J Blueman To: Bartosz Golaszewski , Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org, Daniel J Blueman Subject: [PATCH] gpiolib: Fix shared GPIO memory leaks Date: Fri, 20 Feb 2026 17:34:51 +0800 Message-ID: <20260220093452.101655-1-daniel@quora.org> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On a Snapdragon X1 Elite laptop (Lenovo Yoga Slim 7x), kmemleak reports three sets of: unreferenced object 0xffff00080187f400 (size 1024): comm "swapper/0", pid 1, jiffies 4294667327 hex dump (first 32 bytes): 58 bd 70 01 08 00 ff ff 58 bd 70 01 08 00 ff ff X.p.....X.p..... 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................ backtrace (crc 1665d1f8): kmemleak_alloc+0xf4/0x12c __kmalloc_cache_noprof+0x370/0x49c gpio_shared_make_ref+0x70/0x16c gpio_shared_of_traverse+0x4e8/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_init+0x34/0x1c4 do_one_initcall+0x50/0x280 kernel_init_freeable+0x290/0x33c kernel_init+0x28/0x14c ret_from_fork+0x10/0x20 unreferenced object 0xffff00080170c140 (size 8): comm "swapper/0", pid 1, jiffies 4294667327 hex dump (first 8 bytes): 72 65 73 65 74 00 00 00 reset... backtrace (crc fc24536): kmemleak_alloc+0xf4/0x12c __kmalloc_node_track_caller_noprof+0x3c4/0x584 kstrdup+0x4c/0xcc gpio_shared_make_ref+0x8c/0x16c gpio_shared_of_traverse+0x4e8/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_of_traverse+0x200/0x5f4 gpio_shared_init+0x34/0x1c4 do_one_initcall+0x50/0x280 kernel_init_freeable+0x290/0x33c kernel_init+0x28/0x14c ret_from_fork+0x10/0x20 Fix this by decrementing the reference count of each list entry rather than only the first. Fix verified on the same laptop. Fixes: a060b8c511abb gpiolib: implement low-level, shared GPIO support Signed-off-by: Daniel J Blueman --- drivers/gpio/gpiolib-shared.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/gpiolib-shared.c b/drivers/gpio/gpiolib-shared.c index 9e6544203439..e16f467b72e7 100644 --- a/drivers/gpio/gpiolib-shared.c +++ b/drivers/gpio/gpiolib-shared.c @@ -753,14 +753,14 @@ static bool gpio_shared_entry_is_really_shared(struct= gpio_shared_entry *entry) static void gpio_shared_free_exclusive(void) { struct gpio_shared_entry *entry, *epos; + struct gpio_shared_ref *ref, *rpos; =20 list_for_each_entry_safe(entry, epos, &gpio_shared_list, list) { if (gpio_shared_entry_is_really_shared(entry)) continue; =20 - gpio_shared_drop_ref(list_first_entry(&entry->refs, - struct gpio_shared_ref, - list)); + list_for_each_entry_safe(ref, rpos, &entry->refs, list) + gpio_shared_drop_ref(ref); gpio_shared_drop_entry(entry); } } --=20 2.51.0