linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: trix@redhat.com
To: dhowells@redhat.com, jlayton@kernel.org
Cc: linux-kernel@vger.kernel.org, Tom Rix <trix@redhat.com>
Subject: [PATCH] vfs: samples: fix memory leak
Date: Sun,  9 Aug 2020 10:06:36 -0700	[thread overview]
Message-ID: <20200809170636.22133-1-trix@redhat.com> (raw)

From: Tom Rix <trix@redhat.com>

clang static analysis reports this represenative problem

test-fsinfo.c:615:3: warning: Potential leak of memory pointed to by 'r'
                memset(r, 0xbd, buf_size);
                ^~~~~~

r dynamically allocated in a loop an increasing size.

	for (;;) {
		r = malloc(buf_size);
...
		buf_size = (ret + 4096 - 1) & ~(4096 - 1);
	}

The problem is that r is never freed at the bottom of the loop.
So free r.

Signed-off-by: Tom Rix <trix@redhat.com>
---
 samples/vfs/test-fsinfo.c  | 1 +
 samples/vfs/test-mntinfo.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c
index aa122fb555b6..d669201d03ac 100644
--- a/samples/vfs/test-fsinfo.c
+++ b/samples/vfs/test-fsinfo.c
@@ -622,6 +622,7 @@ static ssize_t get_fsinfo(const char *file, const char *name,
 		if (ret <= buf_size - 1)
 			break;
 		buf_size = (ret + 4096 - 1) & ~(4096 - 1);
+		free(r);
 	}
 
 	if (debug)
diff --git a/samples/vfs/test-mntinfo.c b/samples/vfs/test-mntinfo.c
index 40125ad81f17..54a6abf4a8b0 100644
--- a/samples/vfs/test-mntinfo.c
+++ b/samples/vfs/test-mntinfo.c
@@ -105,6 +105,7 @@ static void *get_attr_alloc(unsigned int mnt_id, unsigned int attr,
 			break;
 		}
 		buf_size = (ret + 4096 - 1) & ~(4096 - 1);
+		free(r);
 	}
 
 	return r;
-- 
2.18.1


                 reply	other threads:[~2020-08-09 17:07 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200809170636.22133-1-trix@redhat.com \
    --to=trix@redhat.com \
    --cc=dhowells@redhat.com \
    --cc=jlayton@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).