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authorJan Blunck <j.blunck@tu-harburg.de>2005-08-27 11:07:52 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-08-27 11:22:27 -0700
commit729d70f5dfd663b44bca68a4479c96bde7e535d6 (patch)
treef92ee98a709264984ef6e3e8d6c3ee4f3462797f
parent8126fdbc76351bdf99c6737ef4fecf88a22fa538 (diff)
downloadlinux-stericsson-729d70f5dfd663b44bca68a4479c96bde7e535d6.tar.gz
[PATCH] sg.c: fix a memory leak in devices seq_file implementation
I know that scsi procfs is legacy code but this is a fix for a memory leak. While reading through sg.c I realized that the implementation of /proc/scsi/sg/devices with seq_file is leaking memory due to freeing the pointer returned by the next() iterator method. Since next() might return NULL or an error this is wrong. This patch fixes it through using the seq_files private field for holding the reference to the iterator object. Here is a small bash script to trigger the leak. Use slabtop to watch the size-32 usage grow and grow. #!/bin/sh while true; do cat /proc/scsi/sg/devices > /dev/null done Signed-off-by: Jan Blunck <j.blunck@tu-harburg.de> Acked-by: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/scsi/sg.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 51292f269ce5..e822ca0e97cf 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -2971,23 +2971,22 @@ static void * dev_seq_start(struct seq_file *s, loff_t *pos)
{
struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
+ s->private = it;
if (! it)
return NULL;
+
if (NULL == sg_dev_arr)
- goto err1;
+ return NULL;
it->index = *pos;
it->max = sg_last_dev();
if (it->index >= it->max)
- goto err1;
+ return NULL;
return it;
-err1:
- kfree(it);
- return NULL;
}
static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
- struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
+ struct sg_proc_deviter * it = s->private;
*pos = ++it->index;
return (it->index < it->max) ? it : NULL;
@@ -2995,7 +2994,7 @@ static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
static void dev_seq_stop(struct seq_file *s, void *v)
{
- kfree (v);
+ kfree(s->private);
}
static int sg_proc_open_dev(struct inode *inode, struct file *file)