From: Li Wang <liwang@xxxxxxxxxxx>
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@xxxxxxxxxxxxx: rewrite subject and commit message]
Signed-off-by: Li Wang <liwang@xxxxxxxxxxx>
Signed-off-by: Yunchuan Wen <wenyunchuan@xxxxxxxxxxxxxx>
Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxx>
---
fs/ecryptfs/read_write.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 3745f7c..ec3d936 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;
--
1.7.8.3
--
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