[PATCH] scsi: ufs: ufshcd-pltfrm: fix memory leak due to probe defer

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: alim.akhtar@samsung.com, avri.altman@wdc.com, jejb@linux.ibm.com,
	martin.petersen@oracle.com
Cc: draviv@codeaurora.org, sthumma@codeaurora.org,
	linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
	bjorn.andersson@linaro.org,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: [PATCH] scsi: ufs: ufshcd-pltfrm: fix memory leak due to probe defer
Date: Tue, 14 Sep 2021 10:22:14 +0100	[thread overview]
Message-ID: <20210914092214.6468-1-srinivas.kandagatla@linaro.org> (raw)

UFS drivers that probe defer will endup leaking memory allocated for
clk and regulator names via kstrdup because the structure that is
holding this memory is allocated via devm_* variants which will be
freed during probe defer but the names are never freed.

Use same devm_* variant of kstrdup to free the memory allocated to
name when driver probe defers.

Kmemleak found around 11 leaks on Qualcomm Dragon Board RB5:

unreferenced object 0xffff66f243fb2c00 (size 128):
  comm "kworker/u16:0", pid 7, jiffies 4294893319 (age 94.848s)
  hex dump (first 32 bytes):
    63 6f 72 65 5f 63 6c 6b 00 76 69 72 74 75 61 6c  core_clk.virtual
    2f 77 6f 72 6b 71 75 65 75 65 2f 73 63 73 69 5f  /workqueue/scsi_
  backtrace:
    [<000000006f788cd1>] slab_post_alloc_hook+0x88/0x410
    [<00000000cfd1372b>] __kmalloc_track_caller+0x138/0x230
    [<00000000a92ab17b>] kstrdup+0xb0/0x110
    [<0000000037263ab6>] ufshcd_pltfrm_init+0x1a8/0x500
    [<00000000a20a5caa>] ufs_qcom_probe+0x20/0x58
    [<00000000a5e43067>] platform_probe+0x6c/0x118
    [<00000000ef686e3f>] really_probe+0xc4/0x330
    [<000000005b18792c>] __driver_probe_device+0x88/0x118
    [<00000000a5d295e8>] driver_probe_device+0x44/0x158
    [<000000007e83f58d>] __device_attach_driver+0xb4/0x128
    [<000000004bfa4470>] bus_for_each_drv+0x68/0xd0
    [<00000000b89a83bc>] __device_attach+0xec/0x170
    [<00000000ada2beea>] device_initial_probe+0x14/0x20
    [<0000000079921612>] bus_probe_device+0x9c/0xa8
    [<00000000d268bf7c>] deferred_probe_work_func+0x90/0xd0
    [<000000009ef64bfa>] process_one_work+0x29c/0x788
unreferenced object 0xffff66f243fb2c80 (size 128):
  comm "kworker/u16:0", pid 7, jiffies 4294893319 (age 94.848s)
  hex dump (first 32 bytes):
    62 75 73 5f 61 67 67 72 5f 63 6c 6b 00 00 00 00  bus_aggr_clk....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

with this patch no memory leaks are reported.
Fixes: aa4976130934 ("ufs: Add regulator enable support")
Fixes: c6e79dacd86f ("ufs: Add clock initialization support")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/scsi/ufs/ufshcd-pltfrm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 8859c13f4e09..eaeae83b999f 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -91,7 +91,7 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
 
 		clki->min_freq = clkfreq[i];
 		clki->max_freq = clkfreq[i+1];
-		clki->name = kstrdup(name, GFP_KERNEL);
+		clki->name = devm_kstrdup(dev, name, GFP_KERNEL);
 		if (!strcmp(name, "ref_clk"))
 			clki->keep_link_active = true;
 		dev_dbg(dev, "%s: min %u max %u name %s\n", "freq-table-hz",
@@ -126,7 +126,7 @@ static int ufshcd_populate_vreg(struct device *dev, const char *name,
 	if (!vreg)
 		return -ENOMEM;
 
-	vreg->name = kstrdup(name, GFP_KERNEL);
+	vreg->name = devm_kstrdup(dev, name, GFP_KERNEL);
 
 	snprintf(prop_name, MAX_PROP_SIZE, "%s-max-microamp", name);
 	if (of_property_read_u32(np, prop_name, &vreg->max_uA)) {
-- 
2.21.0

