From: Eric Biggers <[email protected]>
Filesystem encryption ostensibly supported revoking a keyring key that
had been used to "unlock" encrypted files, causing those files to become
"locked" again. This was, however, buggy for several reasons, the most
severe of which was that when key revocation happened to be detected for
an inode, its fscrypt_info was immediately freed, even while other
threads could be using it for encryption or decryption concurrently.
This could be exploited to crash the kernel or worse.
This patch fixes the use-after-free by removing the code which detects
the keyring key having been revoked, invalidated, or expired. Instead,
an encrypted inode that is "unlocked" now simply remains unlocked until
it is evicted from memory. Note that this is no worse than the case for
block device-level encryption, e.g. dm-crypt, and it still remains
possible for a privileged user to evict unused pages, inodes, and
dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
simply unmounting the filesystem. In fact, one of those actions was
already needed anyway for key revocation to work even somewhat sanely.
This change is not expected to break any applications.
In the future I'd like to implement a real API for fscrypt key
revocation that interacts sanely with ongoing filesystem operations ---
waiting for existing operations to complete and blocking new operations,
and invalidating and sanitizing key material and plaintext from the VFS
caches. But this is a hard problem, and for now this bug must be fixed.
This bug affected almost all versions of ext4, f2fs, and ubifs
encryption, and it was potentially reachable in any kernel configured
with encryption support (CONFIG_EXT4_ENCRYPTION=y,
CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the
shared fs/crypto/ code, but due to the potential security implications
of this bug, it may still be worthwhile to backport this fix to them.
Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode")
Cc: [email protected] # v4.2+
Signed-off-by: Eric Biggers <[email protected]>
---
fs/crypto/crypto.c | 10 +--------
fs/crypto/fname.c | 2 +-
fs/crypto/fscrypt_private.h | 4 ----
fs/crypto/keyinfo.c | 52 ++++++++-------------------------------------
4 files changed, 11 insertions(+), 57 deletions(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 02a7a9286449..6d6eca394d4d 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -327,7 +327,6 @@ EXPORT_SYMBOL(fscrypt_decrypt_page);
static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
{
struct dentry *dir;
- struct fscrypt_info *ci;
int dir_has_key, cached_with_key;
if (flags & LOOKUP_RCU)
@@ -339,18 +338,11 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
return 0;
}
- ci = d_inode(dir)->i_crypt_info;
- if (ci && ci->ci_keyring_key &&
- (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
- (1 << KEY_FLAG_REVOKED) |
- (1 << KEY_FLAG_DEAD))))
- ci = NULL;
-
/* this should eventually be an flag in d_flags */
spin_lock(&dentry->d_lock);
cached_with_key = dentry->d_flags & DCACHE_ENCRYPTED_WITH_KEY;
spin_unlock(&dentry->d_lock);
- dir_has_key = (ci != NULL);
+ dir_has_key = (d_inode(dir)->i_crypt_info != NULL);
dput(dir);
/*
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 13052b85c393..37b49894c762 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -350,7 +350,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
fname->disk_name.len = iname->len;
return 0;
}
- ret = fscrypt_get_crypt_info(dir);
+ ret = fscrypt_get_encryption_info(dir);
if (ret && ret != -EOPNOTSUPP)
return ret;
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index fdbb8af32eaf..e39696e64494 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -67,7 +67,6 @@ struct fscrypt_info {
u8 ci_filename_mode;
u8 ci_flags;
struct crypto_skcipher *ci_ctfm;
- struct key *ci_keyring_key;
u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
};
@@ -101,7 +100,4 @@ extern int fscrypt_do_page_crypto(const struct inode *inode,
extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
gfp_t gfp_flags);
-/* keyinfo.c */
-extern int fscrypt_get_crypt_info(struct inode *);
-
#endif /* _FSCRYPT_PRIVATE_H */
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 02eb6b9e4438..cb3e82abf034 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -95,6 +95,7 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
kfree(description);
if (IS_ERR(keyring_key))
return PTR_ERR(keyring_key);
+ down_read(&keyring_key->sem);
if (keyring_key->type != &key_type_logon) {
printk_once(KERN_WARNING
@@ -102,11 +103,9 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
res = -ENOKEY;
goto out;
}
- down_read(&keyring_key->sem);
ukp = user_key_payload(keyring_key);
if (ukp->datalen != sizeof(struct fscrypt_key)) {
res = -EINVAL;
- up_read(&keyring_key->sem);
goto out;
}
master_key = (struct fscrypt_key *)ukp->data;
@@ -117,17 +116,11 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
"%s: key size incorrect: %d\n",
__func__, master_key->size);
res = -ENOKEY;
- up_read(&keyring_key->sem);
goto out;
}
res = derive_key_aes(ctx->nonce, master_key->raw, raw_key);
- up_read(&keyring_key->sem);
- if (res)
- goto out;
-
- crypt_info->ci_keyring_key = keyring_key;
- return 0;
out:
+ up_read(&keyring_key->sem);
key_put(keyring_key);
return res;
}
@@ -169,12 +162,11 @@ static void put_crypt_info(struct fscrypt_info *ci)
if (!ci)
return;
- key_put(ci->ci_keyring_key);
crypto_free_skcipher(ci->ci_ctfm);
kmem_cache_free(fscrypt_info_cachep, ci);
}
-int fscrypt_get_crypt_info(struct inode *inode)
+int fscrypt_get_encryption_info(struct inode *inode)
{
struct fscrypt_info *crypt_info;
struct fscrypt_context ctx;
@@ -184,21 +176,15 @@ int fscrypt_get_crypt_info(struct inode *inode)
u8 *raw_key = NULL;
int res;
+ if (inode->i_crypt_info)
+ return 0;
+
res = fscrypt_initialize(inode->i_sb->s_cop->flags);
if (res)
return res;
if (!inode->i_sb->s_cop->get_context)
return -EOPNOTSUPP;
-retry:
- crypt_info = ACCESS_ONCE(inode->i_crypt_info);
- if (crypt_info) {
- if (!crypt_info->ci_keyring_key ||
- key_validate(crypt_info->ci_keyring_key) == 0)
- return 0;
- fscrypt_put_encryption_info(inode, crypt_info);
- goto retry;
- }
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0) {
@@ -229,7 +215,6 @@ int fscrypt_get_crypt_info(struct inode *inode)
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
- crypt_info->ci_keyring_key = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
@@ -273,14 +258,8 @@ int fscrypt_get_crypt_info(struct inode *inode)
if (res)
goto out;
- kzfree(raw_key);
- raw_key = NULL;
- if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
- put_crypt_info(crypt_info);
- goto retry;
- }
- return 0;
-
+ if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) == NULL)
+ crypt_info = NULL;
out:
if (res == -ENOKEY)
res = 0;
@@ -288,6 +267,7 @@ int fscrypt_get_crypt_info(struct inode *inode)
kzfree(raw_key);
return res;
}
+EXPORT_SYMBOL(fscrypt_get_encryption_info);
void fscrypt_put_encryption_info(struct inode *inode, struct fscrypt_info *ci)
{
@@ -305,17 +285,3 @@ void fscrypt_put_encryption_info(struct inode *inode, struct fscrypt_info *ci)
put_crypt_info(ci);
}
EXPORT_SYMBOL(fscrypt_put_encryption_info);
-
-int fscrypt_get_encryption_info(struct inode *inode)
-{
- struct fscrypt_info *ci = inode->i_crypt_info;
-
- if (!ci ||
- (ci->ci_keyring_key &&
- (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
- (1 << KEY_FLAG_REVOKED) |
- (1 << KEY_FLAG_DEAD)))))
- return fscrypt_get_crypt_info(inode);
- return 0;
-}
-EXPORT_SYMBOL(fscrypt_get_encryption_info);
--
2.11.0.483.g087da7b7c-goog
On Tue, Feb 21, 2017 at 03:07:11PM -0800, Eric Biggers wrote:
> From: Eric Biggers <[email protected]>
>
> Filesystem encryption ostensibly supported revoking a keyring key
> that had been used to "unlock" encrypted files, causing those files
> to become "locked" again. This was, however, buggy for several
> reasons, the most severe of which was that when key revocation
> happened to be detected for an inode, its fscrypt_info was
> immediately freed, even while other threads could be using it for
> encryption or decryption concurrently. This could be exploited to
> crash the kernel or worse.
Removing the attempt at that functionality seems like the right
approach.
> This patch fixes the use-after-free by removing the code which
> detects the keyring key having been revoked, invalidated, or
> expired. Instead, an encrypted inode that is "unlocked" now simply
> remains unlocked until it is evicted from memory. Note that this is
> no worse than the case for block device-level encryption,
> e.g. dm-crypt, and it still remains possible for a privileged user
> to evict unused pages, inodes, and dentries by running 'sync; echo 3
> > /proc/sys/vm/drop_caches', or by simply unmounting the filesystem.
> In fact, one of those actions was already needed anyway for key
> revocation to work even somewhat sanely. This change is not
> expected to break any applications.
I don't see any problem with this reasoning.
> In the future I'd like to implement a real API for fscrypt key
> revocation that interacts sanely with ongoing filesystem operations ---
> waiting for existing operations to complete and blocking new operations,
> and invalidating and sanitizing key material and plaintext from the VFS
> caches. But this is a hard problem, and for now this bug must be fixed.
>
> This bug affected almost all versions of ext4, f2fs, and ubifs
> encryption, and it was potentially reachable in any kernel configured
> with encryption support (CONFIG_EXT4_ENCRYPTION=y,
> CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
> CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the
> shared fs/crypto/ code, but due to the potential security implications
> of this bug, it may still be worthwhile to backport this fix to them.
Agreed.
> Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode")
> Cc: [email protected] # v4.2+
> Signed-off-by: Eric Biggers <[email protected]>
Acked-by: Michael Halcrow <[email protected]>
> ---
> fs/crypto/crypto.c | 10 +--------
> fs/crypto/fname.c | 2 +-
> fs/crypto/fscrypt_private.h | 4 ----
> fs/crypto/keyinfo.c | 52 ++++++++-------------------------------------
> 4 files changed, 11 insertions(+), 57 deletions(-)
>
> diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
> index 02a7a9286449..6d6eca394d4d 100644
> --- a/fs/crypto/crypto.c
> +++ b/fs/crypto/crypto.c
> @@ -327,7 +327,6 @@ EXPORT_SYMBOL(fscrypt_decrypt_page);
> static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
> {
> struct dentry *dir;
> - struct fscrypt_info *ci;
> int dir_has_key, cached_with_key;
>
> if (flags & LOOKUP_RCU)
> @@ -339,18 +338,11 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
> return 0;
> }
>
> - ci = d_inode(dir)->i_crypt_info;
> - if (ci && ci->ci_keyring_key &&
> - (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
> - (1 << KEY_FLAG_REVOKED) |
> - (1 << KEY_FLAG_DEAD))))
> - ci = NULL;
> -
> /* this should eventually be an flag in d_flags */
> spin_lock(&dentry->d_lock);
> cached_with_key = dentry->d_flags & DCACHE_ENCRYPTED_WITH_KEY;
> spin_unlock(&dentry->d_lock);
> - dir_has_key = (ci != NULL);
> + dir_has_key = (d_inode(dir)->i_crypt_info != NULL);
> dput(dir);
>
> /*
> diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
> index 13052b85c393..37b49894c762 100644
> --- a/fs/crypto/fname.c
> +++ b/fs/crypto/fname.c
> @@ -350,7 +350,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
> fname->disk_name.len = iname->len;
> return 0;
> }
> - ret = fscrypt_get_crypt_info(dir);
> + ret = fscrypt_get_encryption_info(dir);
> if (ret && ret != -EOPNOTSUPP)
> return ret;
>
> diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
> index fdbb8af32eaf..e39696e64494 100644
> --- a/fs/crypto/fscrypt_private.h
> +++ b/fs/crypto/fscrypt_private.h
> @@ -67,7 +67,6 @@ struct fscrypt_info {
> u8 ci_filename_mode;
> u8 ci_flags;
> struct crypto_skcipher *ci_ctfm;
> - struct key *ci_keyring_key;
> u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
> };
>
> @@ -101,7 +100,4 @@ extern int fscrypt_do_page_crypto(const struct inode *inode,
> extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
> gfp_t gfp_flags);
>
> -/* keyinfo.c */
> -extern int fscrypt_get_crypt_info(struct inode *);
> -
> #endif /* _FSCRYPT_PRIVATE_H */
> diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
> index 02eb6b9e4438..cb3e82abf034 100644
> --- a/fs/crypto/keyinfo.c
> +++ b/fs/crypto/keyinfo.c
> @@ -95,6 +95,7 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
> kfree(description);
> if (IS_ERR(keyring_key))
> return PTR_ERR(keyring_key);
> + down_read(&keyring_key->sem);
>
> if (keyring_key->type != &key_type_logon) {
> printk_once(KERN_WARNING
> @@ -102,11 +103,9 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
> res = -ENOKEY;
> goto out;
> }
> - down_read(&keyring_key->sem);
> ukp = user_key_payload(keyring_key);
> if (ukp->datalen != sizeof(struct fscrypt_key)) {
> res = -EINVAL;
> - up_read(&keyring_key->sem);
> goto out;
> }
> master_key = (struct fscrypt_key *)ukp->data;
> @@ -117,17 +116,11 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
> "%s: key size incorrect: %d\n",
> __func__, master_key->size);
> res = -ENOKEY;
> - up_read(&keyring_key->sem);
> goto out;
> }
> res = derive_key_aes(ctx->nonce, master_key->raw, raw_key);
> - up_read(&keyring_key->sem);
> - if (res)
> - goto out;
> -
> - crypt_info->ci_keyring_key = keyring_key;
> - return 0;
> out:
> + up_read(&keyring_key->sem);
> key_put(keyring_key);
> return res;
> }
> @@ -169,12 +162,11 @@ static void put_crypt_info(struct fscrypt_info *ci)
> if (!ci)
> return;
>
> - key_put(ci->ci_keyring_key);
> crypto_free_skcipher(ci->ci_ctfm);
> kmem_cache_free(fscrypt_info_cachep, ci);
> }
>
> -int fscrypt_get_crypt_info(struct inode *inode)
> +int fscrypt_get_encryption_info(struct inode *inode)
> {
> struct fscrypt_info *crypt_info;
> struct fscrypt_context ctx;
> @@ -184,21 +176,15 @@ int fscrypt_get_crypt_info(struct inode *inode)
> u8 *raw_key = NULL;
> int res;
>
> + if (inode->i_crypt_info)
> + return 0;
> +
> res = fscrypt_initialize(inode->i_sb->s_cop->flags);
> if (res)
> return res;
>
> if (!inode->i_sb->s_cop->get_context)
> return -EOPNOTSUPP;
> -retry:
> - crypt_info = ACCESS_ONCE(inode->i_crypt_info);
> - if (crypt_info) {
> - if (!crypt_info->ci_keyring_key ||
> - key_validate(crypt_info->ci_keyring_key) == 0)
> - return 0;
> - fscrypt_put_encryption_info(inode, crypt_info);
> - goto retry;
> - }
>
> res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
> if (res < 0) {
> @@ -229,7 +215,6 @@ int fscrypt_get_crypt_info(struct inode *inode)
> crypt_info->ci_data_mode = ctx.contents_encryption_mode;
> crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
> crypt_info->ci_ctfm = NULL;
> - crypt_info->ci_keyring_key = NULL;
> memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
> sizeof(crypt_info->ci_master_key));
>
> @@ -273,14 +258,8 @@ int fscrypt_get_crypt_info(struct inode *inode)
> if (res)
> goto out;
>
> - kzfree(raw_key);
> - raw_key = NULL;
> - if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
> - put_crypt_info(crypt_info);
> - goto retry;
> - }
> - return 0;
> -
> + if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) == NULL)
> + crypt_info = NULL;
> out:
> if (res == -ENOKEY)
> res = 0;
> @@ -288,6 +267,7 @@ int fscrypt_get_crypt_info(struct inode *inode)
> kzfree(raw_key);
> return res;
> }
> +EXPORT_SYMBOL(fscrypt_get_encryption_info);
>
> void fscrypt_put_encryption_info(struct inode *inode, struct fscrypt_info *ci)
> {
> @@ -305,17 +285,3 @@ void fscrypt_put_encryption_info(struct inode *inode, struct fscrypt_info *ci)
> put_crypt_info(ci);
> }
> EXPORT_SYMBOL(fscrypt_put_encryption_info);
> -
> -int fscrypt_get_encryption_info(struct inode *inode)
> -{
> - struct fscrypt_info *ci = inode->i_crypt_info;
> -
> - if (!ci ||
> - (ci->ci_keyring_key &&
> - (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
> - (1 << KEY_FLAG_REVOKED) |
> - (1 << KEY_FLAG_DEAD)))))
> - return fscrypt_get_crypt_info(inode);
> - return 0;
> -}
> -EXPORT_SYMBOL(fscrypt_get_encryption_info);
> --
> 2.11.0.483.g087da7b7c-goog
>
On Tue, Feb 21, 2017 at 03:07:11PM -0800, Eric Biggers wrote:
> From: Eric Biggers <[email protected]>
>
> Filesystem encryption ostensibly supported revoking a keyring key that
> had been used to "unlock" encrypted files, causing those files to become
> "locked" again. This was, however, buggy for several reasons, the most
> severe of which was that when key revocation happened to be detected for
> an inode, its fscrypt_info was immediately freed, even while other
> threads could be using it for encryption or decryption concurrently.
> This could be exploited to crash the kernel or worse.
>
> This patch fixes the use-after-free by removing the code which detects
> the keyring key having been revoked, invalidated, or expired. Instead,
> an encrypted inode that is "unlocked" now simply remains unlocked until
> it is evicted from memory. Note that this is no worse than the case for
> block device-level encryption, e.g. dm-crypt, and it still remains
> possible for a privileged user to evict unused pages, inodes, and
> dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
> simply unmounting the filesystem. In fact, one of those actions was
> already needed anyway for key revocation to work even somewhat sanely.
> This change is not expected to break any applications.
>
> In the future I'd like to implement a real API for fscrypt key
> revocation that interacts sanely with ongoing filesystem operations ---
> waiting for existing operations to complete and blocking new operations,
> and invalidating and sanitizing key material and plaintext from the VFS
> caches. But this is a hard problem, and for now this bug must be fixed.
>
> This bug affected almost all versions of ext4, f2fs, and ubifs
> encryption, and it was potentially reachable in any kernel configured
> with encryption support (CONFIG_EXT4_ENCRYPTION=y,
> CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
> CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the
> shared fs/crypto/ code, but due to the potential security implications
> of this bug, it may still be worthwhile to backport this fix to them.
>
> Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode")
> Cc: [email protected] # v4.2+
> Signed-off-by: Eric Biggers <[email protected]>
Ted, can this be sent to Linus soon? This needs to be fixed as it's a security
vulnerability on some systems.
Eric
On Tue, Feb 21, 2017 at 03:07:11PM -0800, Eric Biggers wrote:
> From: Eric Biggers <[email protected]>
>
> Filesystem encryption ostensibly supported revoking a keyring key that
> had been used to "unlock" encrypted files, causing those files to become
> "locked" again. This was, however, buggy for several reasons, the most
> severe of which was that when key revocation happened to be detected for
> an inode, its fscrypt_info was immediately freed, even while other
> threads could be using it for encryption or decryption concurrently.
> This could be exploited to crash the kernel or worse.
>
> This patch fixes the use-after-free by removing the code which detects
> the keyring key having been revoked, invalidated, or expired. Instead,
> an encrypted inode that is "unlocked" now simply remains unlocked until
> it is evicted from memory. Note that this is no worse than the case for
> block device-level encryption, e.g. dm-crypt, and it still remains
> possible for a privileged user to evict unused pages, inodes, and
> dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
> simply unmounting the filesystem. In fact, one of those actions was
> already needed anyway for key revocation to work even somewhat sanely.
> This change is not expected to break any applications.
>
> In the future I'd like to implement a real API for fscrypt key
> revocation that interacts sanely with ongoing filesystem operations ---
> waiting for existing operations to complete and blocking new operations,
> and invalidating and sanitizing key material and plaintext from the VFS
> caches. But this is a hard problem, and for now this bug must be fixed.
>
> This bug affected almost all versions of ext4, f2fs, and ubifs
> encryption, and it was potentially reachable in any kernel configured
> with encryption support (CONFIG_EXT4_ENCRYPTION=y,
> CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
> CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the
> shared fs/crypto/ code, but due to the potential security implications
> of this bug, it may still be worthwhile to backport this fix to them.
>
> Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode")
> Cc: [email protected] # v4.2+
> Signed-off-by: Eric Biggers <[email protected]>
Thanks, applied.
- Ted
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot