On Wed, Sep 19, 2007 at 10:38:50PM -0700, Andrew Morton wrote:
> > +   offset = (page_for_lower->index << PAGE_CACHE_SHIFT) + offset_in_page;
> 
> bug.  You need to cast page.index to loff_t before shifting.
> 
> I'd fix it on the spot, but this would be a good time to review the
> whole patchset and perhaps the whole fs for this easy-to-do,
> hard-to-find bug.

Update data types and add casts in order to avoid potential overflow
issues.

Signed-off-by: Michael Halcrow <[EMAIL PROTECTED]>
---
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 5d27cf9..4bf1a95 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -149,7 +149,7 @@ out:
  * ecryptfs_derive_iv
  * @iv: destination for the derived iv vale
  * @crypt_stat: Pointer to crypt_stat struct for the current inode
- * @offset: Offset of the page whose's iv we are to derive
+ * @offset: Offset of the extent whose IV we are to derive
  *
  * Generate the initialization vector from the given root IV and page
  * offset.
@@ -157,7 +157,7 @@ out:
  * Returns zero on success; non-zero on error.
  */
 static int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat,
-                             pgoff_t offset)
+                             loff_t offset)
 {
        int rc = 0;
        char dst[MD5_DIGEST_SIZE];
@@ -173,7 +173,7 @@ static int ecryptfs_derive_iv(char *iv, struct 
ecryptfs_crypt_stat *crypt_stat,
         * hashing business. -Halcrow */
        memcpy(src, crypt_stat->root_iv, crypt_stat->iv_bytes);
        memset((src + crypt_stat->iv_bytes), 0, 16);
-       snprintf((src + crypt_stat->iv_bytes), 16, "%ld", offset);
+       snprintf((src + crypt_stat->iv_bytes), 16, "%lld", offset);
        if (unlikely(ecryptfs_verbosity > 0)) {
                ecryptfs_printk(KERN_DEBUG, "source:\n");
                ecryptfs_dump_hex(src, (crypt_stat->iv_bytes + 16));
@@ -384,11 +384,11 @@ static int ecryptfs_encrypt_extent(struct page 
*enc_extent_page,
                                   struct page *page,
                                   unsigned long extent_offset)
 {
-       unsigned long extent_base;
+       loff_t extent_base;
        char extent_iv[ECRYPTFS_MAX_IV_BYTES];
        int rc;
 
-       extent_base = (page->index
+       extent_base = (((loff_t)page->index)
                       * (PAGE_CACHE_SIZE / crypt_stat->extent_size));
        rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
                                (extent_base + extent_offset));
@@ -492,8 +492,9 @@ int ecryptfs_encrypt_page(struct page *page)
                        goto out;
                }
                ecryptfs_lower_offset_for_extent(
-                       &offset, ((page->index * (PAGE_CACHE_SIZE
-                                                 / crypt_stat->extent_size))
+                       &offset, ((((loff_t)page->index)
+                                  * (PAGE_CACHE_SIZE
+                                     / crypt_stat->extent_size))
                                  + extent_offset), crypt_stat);
                rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt,
                                          offset, crypt_stat->extent_size);
@@ -515,11 +516,11 @@ static int ecryptfs_decrypt_extent(struct page *page,
                                   struct page *enc_extent_page,
                                   unsigned long extent_offset)
 {
-       unsigned long extent_base;
+       loff_t extent_base;
        char extent_iv[ECRYPTFS_MAX_IV_BYTES];
        int rc;
 
-       extent_base = (page->index
+       extent_base = (((loff_t)page->index)
                       * (PAGE_CACHE_SIZE / crypt_stat->extent_size));
        rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
                                (extent_base + extent_offset));
@@ -1320,7 +1321,7 @@ ecryptfs_write_metadata_to_contents(struct 
ecryptfs_crypt_stat *crypt_stat,
        while (current_header_page < header_pages) {
                loff_t offset;
 
-               offset = (current_header_page << PAGE_CACHE_SHIFT);
+               offset = (((loff_t)current_header_page) << PAGE_CACHE_SHIFT);
                if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode,
                                               page_virt, offset,
                                               PAGE_CACHE_SIZE))) {
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index c6a8a33..4eb09c1 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -127,7 +127,8 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
        int rc = 0;
 
        while (extent_num_in_page < num_extents_per_page) {
-               loff_t view_extent_num = ((page->index * num_extents_per_page)
+               loff_t view_extent_num = ((((loff_t)page->index)
+                                          * num_extents_per_page)
                                          + extent_num_in_page);
 
                if (view_extent_num < crypt_stat->num_header_extents_at_front) {
@@ -418,7 +419,7 @@ static int ecryptfs_commit_write(struct file *file, struct 
page *page,
                                "index [0x%.16x])\n", page->index);
                goto out;
        }
-       pos = (page->index << PAGE_CACHE_SHIFT) + to;
+       pos = (((loff_t)page->index) << PAGE_CACHE_SHIFT) + to;
        if (pos > i_size_read(ecryptfs_inode)) {
                i_size_write(ecryptfs_inode, pos);
                ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index ccd2599..272eaeb 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -87,7 +87,8 @@ int ecryptfs_write_lower_page_segment(struct inode 
*ecryptfs_inode,
        loff_t offset;
        int rc;
 
-       offset = (page_for_lower->index << PAGE_CACHE_SHIFT) + offset_in_page;
+       offset = ((((off_t)page_for_lower->index) << PAGE_CACHE_SHIFT)
+                 + offset_in_page);
        virt = kmap(page_for_lower);
        rc = ecryptfs_write_lower(ecryptfs_inode, virt, offset, size);
        kunmap(page_for_lower);
@@ -117,7 +118,8 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, 
loff_t offset,
 {
        struct page *ecryptfs_page;
        char *ecryptfs_page_virt;
-       u64 ecryptfs_file_size = i_size_read(ecryptfs_file->f_dentry->d_inode);
+       loff_t ecryptfs_file_size =
+               i_size_read(ecryptfs_file->f_dentry->d_inode);
        loff_t data_offset = 0;
        loff_t pos;
        int rc = 0;
@@ -277,7 +279,7 @@ int ecryptfs_read_lower_page_segment(struct page 
*page_for_ecryptfs,
        loff_t offset;
        int rc;
 
-       offset = ((page_index << PAGE_CACHE_SHIFT) + offset_in_page);
+       offset = ((((loff_t)page_index) << PAGE_CACHE_SHIFT) + offset_in_page);
        virt = kmap(page_for_ecryptfs);
        rc = ecryptfs_read_lower(virt, offset, size, ecryptfs_inode);
        kunmap(page_for_ecryptfs);
@@ -306,7 +308,8 @@ int ecryptfs_read(char *data, loff_t offset, size_t size,
 {
        struct page *ecryptfs_page;
        char *ecryptfs_page_virt;
-       u64 ecryptfs_file_size = i_size_read(ecryptfs_file->f_dentry->d_inode);
+       loff_t ecryptfs_file_size =
+               i_size_read(ecryptfs_file->f_dentry->d_inode);
        loff_t data_offset = 0;
        loff_t pos;
        int rc = 0;
-
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