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authorAl Viro <viro@zeniv.linux.org.uk>2014-02-02 07:05:05 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2014-02-09 15:21:16 -0500
commitc9efe51165fa0aff57be54e3cb0201ac87f68980 (patch)
tree2c956f57a8c176d0df62a16adc33a2d31b78a929 /drivers/char
parentd311d79de305f1ada47cadd672e6ed1b28a949eb (diff)
downloadlinux-linaro-stable-c9efe51165fa0aff57be54e3cb0201ac87f68980.tar.gz
fix a kmap leak in virtio_console
While we are at it, don't do kmap() under kmap_atomic(), *especially* for a page we'd allocated with GFP_KERNEL. It's spelled "page_address", and had that been more than that, we'd have a real trouble - kmap_high() can block, and doing that while holding kmap_atomic() is a Bad Idea(tm). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/virtio_console.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index feea87cc6b8f..6928d094451d 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -890,12 +890,10 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
} else {
/* Failback to copying a page */
struct page *page = alloc_page(GFP_KERNEL);
- char *src = buf->ops->map(pipe, buf, 1);
- char *dst;
+ char *src;
if (!page)
return -ENOMEM;
- dst = kmap(page);
offset = sd->pos & ~PAGE_MASK;
@@ -903,9 +901,8 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
if (len + offset > PAGE_SIZE)
len = PAGE_SIZE - offset;
- memcpy(dst + offset, src + buf->offset, len);
-
- kunmap(page);
+ src = buf->ops->map(pipe, buf, 1);
+ memcpy(page_address(page) + offset, src + buf->offset, len);
buf->ops->unmap(pipe, buf, src);
sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);