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From:   Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
To:     Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Cc:     Dan Carpenter <error27@gmail.com>, Takashi Iwai <tiwai@suse.de>,
        Kees Cook <keescook@chromium.org>,
        "Luis R . Rodriguez" <mcgrof@kernel.org>,
        Brian Norris <computersforpeace@gmail.com>,
        stable@vger.kernel.org
Subject: [PATCH v3 2/2] test_firmware: return ENOMEM instead of ENOSPC on failed memory allocation
Date:   Thu,  3 Aug 2023 18:53:06 +0200
Message-Id: <20230803165304.9200-2-mirsad.todorovac@alu.unizg.hr>
In-Reply-To: <20230803165304.9200-1-mirsad.todorovac@alu.unizg.hr>
References: <20230803165304.9200-1-mirsad.todorovac@alu.unizg.hr>
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[ Upstream commit 7dae593cd226a0bca61201cf85ceb9335cf63682 ]

In a couple of situations like

	name = kstrndup(buf, count, GFP_KERNEL);
	if (!name)
		return -ENOSPC;

the error is not actually "No space left on device", but "Out of memory".

It is semantically correct to return -ENOMEM in all failed kstrndup()
and kzalloc() cases in this driver, as it is not a problem with disk
space, but with kernel memory allocator failing allocation.

The semantically correct should be:

        name = kstrndup(buf, count, GFP_KERNEL);
        if (!name)
                return -ENOMEM;

Cc: Dan Carpenter <error27@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: stable@vger.kernel.org # 5.4
Fixes: c92316bf8e948 ("test_firmware: add batched firmware tests")
Fixes: 0a8adf584759c ("test: add firmware_class loader test")
Fixes: eb910947c82f9 ("test: firmware_class: add asynchronous request trigger")
Fixes: 061132d2b9c95 ("test_firmware: add test custom fallback trigger")
Fixes: 7feebfa487b92 ("test_firmware: add support for request_firmware_into_buf")
Link: https://lore.kernel.org/all/20230606070808.9300-1-mirsad.todorovac@alu.unizg.hr/
Signed-off-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>

[ This is the backport of the patch to specific to the 5.4 branch. There are no		]
[ semantic differences in the commit when compared to upstream, only fewer instances	]
[ of error code replacement. Backport is provided for completeness sake			]
[ so it would apply to all of the supported LTS kernels.				]
---
 v3:
	fixed a minor typo. no change to commit.

 v2:
	tested on 5.4 stable build.

 lib/test_firmware.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 92d7195d5b5b..dd3850ec1dfa 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -173,7 +173,7 @@ static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
 {
 	*dst = kstrndup(name, count, gfp);
 	if (!*dst)
-		return -ENOSPC;
+		return -ENOMEM;
 	return count;
 }
 
@@ -509,7 +509,7 @@ static ssize_t trigger_request_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("loading '%s'\n", name);
 
@@ -552,7 +552,7 @@ static ssize_t trigger_async_request_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("loading '%s'\n", name);
 
@@ -597,7 +597,7 @@ static ssize_t trigger_custom_fallback_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("loading '%s' using custom fallback mechanism\n", name);
 
@@ -648,7 +648,7 @@ static int test_fw_run_batch_request(void *data)
 
 		test_buf = kzalloc(TEST_FIRMWARE_BUF_SIZE, GFP_KERNEL);
 		if (!test_buf)
-			return -ENOSPC;
+			return -ENOMEM;
 
 		req->rc = request_firmware_into_buf(&req->fw,
 						    req->name,
-- 
2.34.1