The patch titled
ecryptfs: Change the maximum size check when writing header
has been removed from the -mm tree. Its filename is
ecryptfs-change-the-maximum-size-check-when-writing-header.patch
This patch was dropped because it was folded into ecryptfs-fs-makefile-and-fs-kconfig.patch
------------------------------------------------------
Subject: ecryptfs: Change the maximum size check when writing header
From: Stephan Mueller <smueller@xxxxxxxxxx>
When generating an encrypted file, the first page contains the header
information. ecryptfs allocates one page to be filled with the meta
information. ecryptfs_write_headers_virt() writes the header into the page.
The code in this function up to the call of ecryptfs_generate_key_packet_set()
already writes some bytes into the page and moves the pointer forward
accordingly.
This patch now tells ecryptfs_generate_key_packet_set() exactly how many bytes
it is allowed to write. Prior to that, the function would allow PAGE_MAX_SIZE
to be written which is longer than the allocated space (remember, some bytes
are already filled).
This problem does not really materialize in the current code as
ecryptfs_generate_key_packet_set() only writes a Tag 3 and Tag 11 with less
than 100 bytes. But this fix ensures that when development continues, nobody
stumbles over the problem without being warned.
Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
Acked-by: Michael Halcrow <mhalcrow@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/ecryptfs/crypto.c | 3 ++-
fs/ecryptfs/ecryptfs_kernel.h | 3 ++-
fs/ecryptfs/keystore.c | 15 +++++++++++----
3 files changed, 15 insertions(+), 6 deletions(-)
diff -puN fs/ecryptfs/crypto.c~ecryptfs-change-the-maximum-size-check-when-writing-header fs/ecryptfs/crypto.c
--- a/fs/ecryptfs/crypto.c~ecryptfs-change-the-maximum-size-check-when-writing-header
+++ a/fs/ecryptfs/crypto.c
@@ -1240,7 +1240,8 @@ int ecryptfs_write_headers_virt(char *pa
write_header_metadata((page_virt + offset), crypt_stat, &written);
offset += written;
rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat,
- ecryptfs_dentry, &written);
+ ecryptfs_dentry, &written,
+ PAGE_CACHE_SIZE - offset);
if (rc)
ecryptfs_printk(KERN_WARNING, "Error generating key packet "
"set; rc = [%d]\n", rc);
diff -puN fs/ecryptfs/ecryptfs_kernel.h~ecryptfs-change-the-maximum-size-check-when-writing-header fs/ecryptfs/ecryptfs_kernel.h
--- a/fs/ecryptfs/ecryptfs_kernel.h~ecryptfs-change-the-maximum-size-check-when-writing-header
+++ a/fs/ecryptfs/ecryptfs_kernel.h
@@ -451,7 +451,8 @@ int ecryptfs_cipher_code_to_string(char
void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
int ecryptfs_generate_key_packet_set(char *dest_base,
struct ecryptfs_crypt_stat *crypt_stat,
- struct dentry *ecryptfs_dentry, int *len);
+ struct dentry *ecryptfs_dentry, int *len,
+ int max);
int process_request_key_err(long err_code);
int
ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
diff -puN fs/ecryptfs/keystore.c~ecryptfs-change-the-maximum-size-check-when-writing-header fs/ecryptfs/keystore.c
--- a/fs/ecryptfs/keystore.c~ecryptfs-change-the-maximum-size-check-when-writing-header
+++ a/fs/ecryptfs/keystore.c
@@ -982,6 +982,7 @@ out:
* @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
* for the global parameters
* @len: The amount written
+ * @max: The maximum amount of data allowed to be written
*
* Generates a key packet set and writes it to the virtual address
* passed in.
@@ -991,7 +992,8 @@ out:
int
ecryptfs_generate_key_packet_set(char *dest_base,
struct ecryptfs_crypt_stat *crypt_stat,
- struct dentry *ecryptfs_dentry, int *len)
+ struct dentry *ecryptfs_dentry, int *len,
+ int max)
{
int rc = 0;
struct ecryptfs_auth_tok *auth_tok;
@@ -1006,7 +1008,7 @@ ecryptfs_generate_key_packet_set(char *d
auth_tok = mount_crypt_stat->global_auth_tok;
if (ECRYPTFS_CHECK_FLAG(auth_tok->flags, ECRYPTFS_PASSWORD)) {
rc = write_tag_3_packet((dest_base + (*len)),
- PAGE_CACHE_SIZE, auth_tok,
+ max, auth_tok,
crypt_stat, &key_rec,
&written);
if (rc) {
@@ -1018,7 +1020,7 @@ ecryptfs_generate_key_packet_set(char *d
/* Write auth tok signature packet */
rc = write_tag_11_packet(
(dest_base + (*len)),
- (PAGE_CACHE_SIZE - (*len)),
+ (max - (*len)),
key_rec.sig, ECRYPTFS_SIG_SIZE, &written);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error writing "
@@ -1042,7 +1044,12 @@ ecryptfs_generate_key_packet_set(char *d
}
} else
BUG();
- dest_base[(*len)] = 0x00;
+ if (likely((max - (*len)) > 0)) {
+ dest_base[(*len)] = 0x00;
+ } else {
+ ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
+ rc = -EIO;
+ }
out:
if (rc)
(*len) = 0;
_
Patches currently in -mm which might be from smueller@xxxxxxxxxx are
ecryptfs-fs-makefile-and-fs-kconfig.patch
ecryptfs-change-the-maximum-size-check-when-writing-header.patch
ecryptfs-print-the-actual-option-that-is-problematic.patch
ecryptfs-partial-signed-integer-to-size_t-conversion-updated-ii.patch
-
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