From b66829b17f6385cc9ffbcbe2476d532d2e3121ad Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Tue, 5 May 2026 13:12:59 +0000 Subject: [PATCH] firmware: samsung: acpm: Fix mailbox channel leak on probe error Sashiko identified the leak at [1]. The ACPM driver allocates hardware mailbox channels using `mbox_request_channel()` during `acpm_channels_init()`. However, the driver lacked a `.remove` callback and did not free these channels on subsequent error paths inside `acpm_probe()`. Additionally, if `acpm_achan_alloc_cmds()` failed during the channel initialization loop, the function returned immediately, bypassing the manual cleanup and permanently leaking any channels successfully requested in previous loop iterations. Fix this by modifying `acpm_free_mbox_chans()` to match the `devres` action signature and registering it via `devm_add_action_or_reset()`. Cc: stable@vger.kernel.org Fixes: a88927b534ba ("firmware: add Exynos ACPM protocol driver") Closes: https://sashiko.dev/#/patchset/20260420-acpm-tmu-v3-0-3dc8e93f0b26%40linaro.org [1] Signed-off-by: Tudor Ambarus Link: https://patch.msgid.link/20260505-acpm-fixes-sashiko-reports-v5-2-43b5ee7f1674@linaro.org Signed-off-by: Krzysztof Kozlowski --- drivers/firmware/samsung/exynos-acpm.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/samsung/exynos-acpm.c b/drivers/firmware/samsung/exynos-acpm.c index e95edc350efa..9766425a44ab 100644 --- a/drivers/firmware/samsung/exynos-acpm.c +++ b/drivers/firmware/samsung/exynos-acpm.c @@ -527,10 +527,11 @@ static int acpm_achan_alloc_cmds(struct acpm_chan *achan) /** * acpm_free_mbox_chans() - free mailbox channels. - * @acpm: pointer to driver data. + * @data: pointer to driver data. */ -static void acpm_free_mbox_chans(struct acpm_info *acpm) +static void acpm_free_mbox_chans(void *data) { + struct acpm_info *acpm = data; int i; for (i = 0; i < acpm->num_chans; i++) @@ -558,6 +559,10 @@ static int acpm_channels_init(struct acpm_info *acpm) if (!acpm->chans) return -ENOMEM; + ret = devm_add_action_or_reset(dev, acpm_free_mbox_chans, acpm); + if (ret) + return dev_err_probe(dev, ret, "Failed to add mbox free action.\n"); + chans_shmem = acpm->sram_base + readl(&shmem->chans); for (i = 0; i < acpm->num_chans; i++) { @@ -579,10 +584,8 @@ static int acpm_channels_init(struct acpm_info *acpm) cl->dev = dev; achan->chan = mbox_request_channel(cl, 0); - if (IS_ERR(achan->chan)) { - acpm_free_mbox_chans(acpm); + if (IS_ERR(achan->chan)) return PTR_ERR(achan->chan); - } } return 0;