From: Eric Biggers ebiggers@google.com
commit db717d8e26c2d1b0dba3e08668a1e6a7f665adde upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/crypto/policy.c | 34 +++++++++++++++++++++------------- fs/ext4/ext4.h | 4 ++-- fs/ext4/ioctl.c | 32 ++++---------------------------- fs/f2fs/f2fs.h | 4 ++-- fs/f2fs/file.c | 19 ++----------------- include/linux/fscrypto.h | 12 ++++++------ 6 files changed, 37 insertions(+), 68 deletions(-)
--- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -93,16 +93,19 @@ static int create_encryption_context_fro 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); @@ -122,9 +125,9 @@ int fscrypt_process_policy(struct file * 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__); @@ -136,11 +139,13 @@ int fscrypt_process_policy(struct file * 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 || @@ -153,15 +158,18 @@ int fscrypt_get_policy(struct inode *ino 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);
/** * fscrypt_has_permitted_context() - is a file's encryption policy permitted --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2354,8 +2354,8 @@ static inline void ext4_fname_free_filen #define fscrypt_pullback_bio_page fscrypt_notsupp_pullback_bio_page #define fscrypt_restore_control_page fscrypt_notsupp_restore_control_page #define fscrypt_zeroout_range fscrypt_notsupp_zeroout_range -#define fscrypt_process_policy fscrypt_notsupp_process_policy -#define fscrypt_get_policy fscrypt_notsupp_get_policy +#define fscrypt_ioctl_set_policy fscrypt_notsupp_ioctl_set_policy +#define fscrypt_ioctl_get_policy fscrypt_notsupp_ioctl_get_policy #define fscrypt_has_permitted_context fscrypt_notsupp_has_permitted_context #define fscrypt_inherit_context fscrypt_notsupp_inherit_context #define fscrypt_get_encryption_info fscrypt_notsupp_get_encryption_info --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -774,22 +774,12 @@ resizefs_out: } case EXT4_IOC_PRECACHE_EXTENTS: return ext4_ext_precache(inode); - case EXT4_IOC_SET_ENCRYPTION_POLICY: { -#ifdef CONFIG_EXT4_FS_ENCRYPTION - struct fscrypt_policy policy;
+ case EXT4_IOC_SET_ENCRYPTION_POLICY: if (!ext4_has_feature_encrypt(sb)) return -EOPNOTSUPP; + return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
- if (copy_from_user(&policy, - (struct fscrypt_policy __user *)arg, - sizeof(policy))) - return -EFAULT; - return fscrypt_process_policy(filp, &policy); -#else - return -EOPNOTSUPP; -#endif - } case EXT4_IOC_GET_ENCRYPTION_PWSALT: { int err, err2; struct ext4_sb_info *sbi = EXT4_SB(sb); @@ -826,23 +816,9 @@ resizefs_out: return -EFAULT; return 0; } - case EXT4_IOC_GET_ENCRYPTION_POLICY: { -#ifdef CONFIG_EXT4_FS_ENCRYPTION - struct fscrypt_policy policy; - int err = 0; + case EXT4_IOC_GET_ENCRYPTION_POLICY: + return fscrypt_ioctl_get_policy(filp, (void __user *)arg);
- if (!ext4_encrypted_inode(inode)) - return -ENOENT; - err = fscrypt_get_policy(inode, &policy); - if (err) - return err; - if (copy_to_user((void __user *)arg, &policy, sizeof(policy))) - return -EFAULT; - return 0; -#else - return -EOPNOTSUPP; -#endif - } case EXT4_IOC_FSGETXATTR: { struct fsxattr fa; --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2513,8 +2513,8 @@ static inline bool f2fs_may_encrypt(stru #define fscrypt_pullback_bio_page fscrypt_notsupp_pullback_bio_page #define fscrypt_restore_control_page fscrypt_notsupp_restore_control_page #define fscrypt_zeroout_range fscrypt_notsupp_zeroout_range -#define fscrypt_process_policy fscrypt_notsupp_process_policy -#define fscrypt_get_policy fscrypt_notsupp_get_policy +#define fscrypt_ioctl_set_policy fscrypt_notsupp_ioctl_set_policy +#define fscrypt_ioctl_get_policy fscrypt_notsupp_ioctl_get_policy #define fscrypt_has_permitted_context fscrypt_notsupp_has_permitted_context #define fscrypt_inherit_context fscrypt_notsupp_inherit_context #define fscrypt_get_encryption_info fscrypt_notsupp_get_encryption_info --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1774,31 +1774,16 @@ static bool uuid_is_nonzero(__u8 u[16])
static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg) { - struct fscrypt_policy policy; struct inode *inode = file_inode(filp);
- if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg, - sizeof(policy))) - return -EFAULT; - f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
- return fscrypt_process_policy(filp, &policy); + return fscrypt_ioctl_set_policy(filp, (const void __user *)arg); }
static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg) { - struct fscrypt_policy policy; - struct inode *inode = file_inode(filp); - int err; - - err = fscrypt_get_policy(inode, &policy); - if (err) - return err; - - if (copy_to_user((struct fscrypt_policy __user *)arg, &policy, sizeof(policy))) - return -EFAULT; - return 0; + return fscrypt_ioctl_get_policy(filp, (void __user *)arg); }
static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg) --- a/include/linux/fscrypto.h +++ b/include/linux/fscrypto.h @@ -249,8 +249,8 @@ extern void fscrypt_restore_control_page extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t, unsigned int); /* policy.c */ -extern int fscrypt_process_policy(struct file *, const struct fscrypt_policy *); -extern int fscrypt_get_policy(struct inode *, struct fscrypt_policy *); +extern int fscrypt_ioctl_set_policy(struct file *, const void __user *); +extern int fscrypt_ioctl_get_policy(struct file *, void __user *); extern int fscrypt_has_permitted_context(struct inode *, struct inode *); extern int fscrypt_inherit_context(struct inode *, struct inode *, void *, bool); @@ -318,14 +318,14 @@ static inline int fscrypt_notsupp_zeroou }
/* policy.c */ -static inline int fscrypt_notsupp_process_policy(struct file *f, - const struct fscrypt_policy *p) +static inline int fscrypt_notsupp_ioctl_set_policy(struct file *f, + const void __user *arg) { return -EOPNOTSUPP; }
-static inline int fscrypt_notsupp_get_policy(struct inode *i, - struct fscrypt_policy *p) +static inline int fscrypt_notsupp_ioctl_get_policy(struct file *f, + void __user *arg) { return -EOPNOTSUPP; }