[patch] x86-64 ext2/ext3 datestamp problem

[Markus Rechberger]

Hi,

there is an issue with ext2/ext3 date stamps, if someone creates a file
with a timestamp between 1902 and 1970(epoch 0) it will overflow and
result in a higher date than 2038.

$ touch --date "1905-01-01" test
$ ls -lah test
-rw-r--r-- 1 root root 0 Jan  1  1905 test (this is a cached value here)
(remount the partition/clear the cache)
$ ls -lah test
-rw-r--r-- 1 root root 0 Feb  6  2041 test

10000101101111001100011001110000 .. -2051226000 (1905)
10000101101111001100011001110000 .. 2243741296 (2041)

this was tested against linus git tree

Markus

-- 
Markus Rechberger
Operating System Research Center
AMD Saxony LLC & Co. KG

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index dd4e14c..9fa1bd6 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1079,9 +1079,9 @@ void ext2_read_inode (struct inode * inode)
 	}
 	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
 	inode->i_size = le32_to_cpu(raw_inode->i_size);
-	inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
-	inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
-	inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
+	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
+	inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
+	inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
 	inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
 	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
 	/* We now have enough fields to check if the inode was active or not.
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index beaf25f..5d171c0 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -2673,9 +2673,9 @@ void ext3_read_inode(struct inode * inode)
 	}
 	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
 	inode->i_size = le32_to_cpu(raw_inode->i_size);
-	inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
-	inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
-	inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
+	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
+	inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
+	inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
 	inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
 
 	ei->i_state = 0;