diff options
authorLi Wang <liwang@nudt.edu.cn>2012-01-19 09:44:36 +0800
committerTyler Hicks <tyhicks@canonical.com>2012-01-25 14:43:40 -0600
commit684a3ff7e69acc7c678d1a1394fe9e757993fd34 (patch)
parent48399c0b0e6172888a2e2e36df1595ab1e049ba8 (diff)
eCryptfs: Infinite loop due to overflow in ecryptfs_write()
ecryptfs_write() can enter an infinite loop when truncating a file to a size larger than 4G. This only happens on architectures where size_t is represented by 32 bits. This was caused by a size_t overflow due to it incorrectly being used to store the result of a calculation which uses potentially large values of type loff_t. [tyhicks@canonical.com: rewrite subject and commit message] Signed-off-by: Li Wang <liwang@nudt.edu.cn> Signed-off-by: Yunchuan Wen <wenyunchuan@kylinos.com.cn> Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 3745f7c2b9c2..ec3d9368dc5b 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -130,13 +130,13 @@ int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset,
pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT);
size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK);
size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page);
- size_t total_remaining_bytes = ((offset + size) - pos);
+ loff_t total_remaining_bytes = ((offset + size) - pos);
if (num_bytes > total_remaining_bytes)
num_bytes = total_remaining_bytes;
if (pos < offset) {
/* remaining zeros to write, up to destination offset */
- size_t total_remaining_zeros = (offset - pos);
+ loff_t total_remaining_zeros = (offset - pos);
if (num_bytes > total_remaining_zeros)
num_bytes = total_remaining_zeros;