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| author | Eric Biggers <ebiggers@google.com> | 2016-11-27 01:07:49 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-12-11 22:26:07 +0100 |
| commit | db717d8e26c2d1b0dba3e08668a1e6a7f665adde (patch) | |
| tree | 43fd594156e48c3270f52125d5fe0e9e5e50d417 /fs/crypto/policy.c | |
| parent | fscrypto: remove unneeded Kconfig dependencies (diff) | |
| download | linux-db717d8e26c2d1b0dba3e08668a1e6a7f665adde.tar.xz linux-db717d8e26c2d1b0dba3e08668a1e6a7f665adde.zip | |
fscrypto: move ioctl processing more fully into common code
Multiple bugs were recently fixed in the "set encryption policy" ioctl.
To make it clear that fscrypt_process_policy() and fscrypt_get_policy()
implement ioctls and therefore their implementations must take standard
security and correctness precautions, rename them to
fscrypt_ioctl_set_policy() and fscrypt_ioctl_get_policy(). Make the
latter take in a struct file * to make it consistent with the former.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/crypto/policy.c')
| -rw-r--r-- | fs/crypto/policy.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 6865663aac69..b96a10e3cf78 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -93,16 +93,19 @@ 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 file *filp, - const struct fscrypt_policy *policy) +int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg) { + struct fscrypt_policy policy; struct inode *inode = file_inode(filp); int ret; + if (copy_from_user(&policy, arg, sizeof(policy))) + return -EFAULT; + if (!inode_owner_or_capable(inode)) return -EACCES; - if (policy->version != 0) + if (policy.version != 0) return -EINVAL; ret = mnt_want_write_file(filp); @@ -120,9 +123,9 @@ int fscrypt_process_policy(struct file *filp, ret = -ENOTEMPTY; else ret = create_encryption_context_from_policy(inode, - policy); + &policy); } else if (!is_encryption_context_consistent_with_policy(inode, - policy)) { + &policy)) { printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n", __func__); @@ -134,11 +137,13 @@ int fscrypt_process_policy(struct file *filp, mnt_drop_write_file(filp); return ret; } -EXPORT_SYMBOL(fscrypt_process_policy); +EXPORT_SYMBOL(fscrypt_ioctl_set_policy); -int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy) +int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg) { + struct inode *inode = file_inode(filp); struct fscrypt_context ctx; + struct fscrypt_policy policy; int res; if (!inode->i_sb->s_cop->get_context || @@ -151,15 +156,18 @@ int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy) if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1) return -EINVAL; - policy->version = 0; - policy->contents_encryption_mode = ctx.contents_encryption_mode; - policy->filenames_encryption_mode = ctx.filenames_encryption_mode; - policy->flags = ctx.flags; - memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor, + policy.version = 0; + policy.contents_encryption_mode = ctx.contents_encryption_mode; + policy.filenames_encryption_mode = ctx.filenames_encryption_mode; + policy.flags = ctx.flags; + memcpy(policy.master_key_descriptor, ctx.master_key_descriptor, FS_KEY_DESCRIPTOR_SIZE); + + if (copy_to_user(arg, &policy, sizeof(policy))) + return -EFAULT; return 0; } -EXPORT_SYMBOL(fscrypt_get_policy); +EXPORT_SYMBOL(fscrypt_ioctl_get_policy); int fscrypt_has_permitted_context(struct inode *parent, struct inode *child) { |