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authorLinus Torvalds <torvalds@linux-foundation.org>2016-09-10 19:18:33 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-09-10 19:18:33 +0300
commit6905732c80bc7f85602abbe27f7bdc3fe81f56d0 (patch)
tree8d181da54cd9e57e1004553a0e76f30606bf6142 /fs
parentd0acc7dfd90eb97e90ccd42a567034017ec60fb8 (diff)
parentba63f23d69a3a10e7e527a02702023da68ef8a6d (diff)
downloadlinux-6905732c80bc7f85602abbe27f7bdc3fe81f56d0.tar.xz
Merge tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull fscrypto fixes fromTed Ts'o: "Fix some brown-paper-bag bugs for fscrypto, including one one which allows a malicious user to set an encryption policy on an empty directory which they do not own" * tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: fscrypto: require write access to mount to set encryption policy fscrypto: only allow setting encryption policy on directories fscrypto: add authorization check for setting encryption policy
Diffstat (limited to 'fs')
-rw-r--r--fs/crypto/policy.c41
-rw-r--r--fs/ext4/ioctl.c2
-rw-r--r--fs/f2fs/file.c9
3 files changed, 31 insertions, 21 deletions
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index 0f9961eede1e..ed115acb5dee 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -11,6 +11,7 @@
#include <linux/random.h>
#include <linux/string.h>
#include <linux/fscrypto.h>
+#include <linux/mount.h>
static int inode_has_encryption_context(struct inode *inode)
{
@@ -92,26 +93,42 @@ static int create_encryption_context_from_policy(struct inode *inode,
return inode->i_sb->s_cop->set_context(inode, &ctx, sizeof(ctx), NULL);
}
-int fscrypt_process_policy(struct inode *inode,
+int fscrypt_process_policy(struct file *filp,
const struct fscrypt_policy *policy)
{
+ struct inode *inode = file_inode(filp);
+ int ret;
+
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
if (policy->version != 0)
return -EINVAL;
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
if (!inode_has_encryption_context(inode)) {
- if (!inode->i_sb->s_cop->empty_dir)
- return -EOPNOTSUPP;
- if (!inode->i_sb->s_cop->empty_dir(inode))
- return -ENOTEMPTY;
- return create_encryption_context_from_policy(inode, policy);
+ if (!S_ISDIR(inode->i_mode))
+ ret = -EINVAL;
+ else if (!inode->i_sb->s_cop->empty_dir)
+ ret = -EOPNOTSUPP;
+ else if (!inode->i_sb->s_cop->empty_dir(inode))
+ ret = -ENOTEMPTY;
+ else
+ ret = create_encryption_context_from_policy(inode,
+ policy);
+ } else if (!is_encryption_context_consistent_with_policy(inode,
+ policy)) {
+ printk(KERN_WARNING
+ "%s: Policy inconsistent with encryption context\n",
+ __func__);
+ ret = -EINVAL;
}
- if (is_encryption_context_consistent_with_policy(inode, policy))
- return 0;
-
- printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n",
- __func__);
- return -EINVAL;
+ mnt_drop_write_file(filp);
+ return ret;
}
EXPORT_SYMBOL(fscrypt_process_policy);
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 10686fd67fb4..1bb7df5e4536 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -776,7 +776,7 @@ resizefs_out:
(struct fscrypt_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
- return fscrypt_process_policy(inode, &policy);
+ return fscrypt_process_policy(filp, &policy);
#else
return -EOPNOTSUPP;
#endif
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 47abb96098e4..28f4f4cbb8d8 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1757,21 +1757,14 @@ static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
{
struct fscrypt_policy policy;
struct inode *inode = file_inode(filp);
- int ret;
if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
- ret = mnt_want_write_file(filp);
- if (ret)
- return ret;
-
f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
- ret = fscrypt_process_policy(inode, &policy);
- mnt_drop_write_file(filp);
- return ret;
+ return fscrypt_process_policy(filp, &policy);
}
static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg)