[patch] PM / Hibernate: NULL dereferences on error paths

Dan Carpenter
2011-10-07T13:24:53Z

These lines break if "data" is NULL.
if (data[thr].thr)
kthread_stop(data[thr].thr);
I rearranged it so the checks for NULL in the error handling code
aren't needed anymore. And anyway both vfree() and free_page()
handle NULL pointers so the checks were redundant.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index d692842..32a17e0 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -528,15 +528,14 @@ static int save_image_lzo(struct swap_map_handle *handle,
page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
if (!page) {
printk(KERN_ERR "PM: Failed to allocate LZO page\n");
- ret = -ENOMEM;
- goto out_clean;
+ return -ENOMEM;
}

data = vmalloc(sizeof(*data) * nr_threads);
if (!data) {
printk(KERN_ERR "PM: Failed to allocate LZO data\n");
ret = -ENOMEM;
- goto out_clean;
+ goto out_page;
}
for (thr = 0; thr < nr_threads; thr++)
memset(&data[thr], 0, offsetof(struct cmp_data, go));
@@ -664,8 +663,9 @@ out_clean:
if (data[thr].thr)
kthread_stop(data[thr].thr);
}
- if (data) vfree(data);
- if (page) free_page((unsigned long)page);
+ vfree(data);
+out_page:
+ free_page((unsigned long)page);

return ret;
}
@@ -978,15 +978,14 @@ static int load_image_lzo(struct swap_map_handle *handle,
page = vmalloc(sizeof(*page) * LZO_READ_PAGES);
if (!page) {
printk(KERN_ERR "PM: Failed to allocate LZO page\n");
- error = -ENOMEM;
- goto out_clean;
+ return -ENOMEM;
}

data = vmalloc(sizeof(*data) * nr_threads);
if (!data) {
printk(KERN_ERR "PM: Failed to allocate LZO data\n");
error = -ENOMEM;
- goto out_clean;
+ goto out_page;
}
for (thr = 0; thr < nr_threads; thr++)
memset(&data[thr], 0, offsetof(struct dec_data, go));
@@ -1183,8 +1182,9 @@ out_clean:
if (data[thr].thr)
kthread_stop(data[thr].thr);
}
- if (data) vfree(data);
- if (page) vfree(page);
+ vfree(data);
+out_page:
+ vfree(page);

return error;
}