| Message ID | 20190804095643.7393-1-chao@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | ext4 crypto: fix to check feature status before get policy | expand |
Hi, Is this change not necessary? A month has passed... Thanks, On 2019/8/4 17:56, Chao Yu wrote: > From: Chao Yu <yuchao0@huawei.com> > > When getting fscrypto policy via EXT4_IOC_GET_ENCRYPTION_POLICY, if > encryption feature is off, it's better to return EOPNOTSUPP instead > of ENODATA, so let's add ext4_has_feature_encrypt() to do the check > for that. > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > --- > fs/ext4/ioctl.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c > index 442f7ef873fc..bf87835c1237 100644 > --- a/fs/ext4/ioctl.c > +++ b/fs/ext4/ioctl.c > @@ -1112,9 +1112,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return -EOPNOTSUPP; > #endif > } > - case EXT4_IOC_GET_ENCRYPTION_POLICY: > + case EXT4_IOC_GET_ENCRYPTION_POLICY: { > + if (!ext4_has_feature_encrypt(sb)) > + return -EOPNOTSUPP; > return fscrypt_ioctl_get_policy(filp, (void __user *)arg); > - > + } > case EXT4_IOC_FSGETXATTR: > { > struct fsxattr fa; >
On Sat, Aug 31, 2019 at 06:32:28PM +0800, Chao Yu wrote: > Hi, > > Is this change not necessary? A month has passed... > > Thanks, > > On 2019/8/4 17:56, Chao Yu wrote: > > From: Chao Yu <yuchao0@huawei.com> > > > > When getting fscrypto policy via EXT4_IOC_GET_ENCRYPTION_POLICY, if > > encryption feature is off, it's better to return EOPNOTSUPP instead > > of ENODATA, so let's add ext4_has_feature_encrypt() to do the check > > for that. > > > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > > --- > > fs/ext4/ioctl.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c > > index 442f7ef873fc..bf87835c1237 100644 > > --- a/fs/ext4/ioctl.c > > +++ b/fs/ext4/ioctl.c > > @@ -1112,9 +1112,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > > return -EOPNOTSUPP; > > #endif > > } > > - case EXT4_IOC_GET_ENCRYPTION_POLICY: > > + case EXT4_IOC_GET_ENCRYPTION_POLICY: { > > + if (!ext4_has_feature_encrypt(sb)) > > + return -EOPNOTSUPP; > > return fscrypt_ioctl_get_policy(filp, (void __user *)arg); > > - > > + } > > case EXT4_IOC_FSGETXATTR: > > { > > struct fsxattr fa; > > Sorry, I was preoccupied with all the other fscrypt changes, and was thinking of waiting until 5.5 for this to avoid a potential extra merge conflict or a potentially breaking change. Looking at this again though, the new ioctl FS_IOC_GET_ENCRYPTION_POLICY_EX *does* do the feature check, which doesn't match the documentation, which implies the check isn't done. Also, f2fs does the check in FS_IOC_GET_ENCRYPTION_POLICY, so the filesystems are inconsistent. So, it makes some sense to apply this now. So I've gone ahead and applied the following to fscrypt.git#master, edited a bit from your original patch: From 0642ea2409f3bfa105570e12854b8e2628db6835 Mon Sep 17 00:00:00 2001 From: Chao Yu <yuchao0@huawei.com> Date: Sun, 4 Aug 2019 17:56:43 +0800 Subject: [PATCH] ext4 crypto: fix to check feature status before get policy When getting fscrypt policy via EXT4_IOC_GET_ENCRYPTION_POLICY, if encryption feature is off, it's better to return EOPNOTSUPP instead of ENODATA, so let's add ext4_has_feature_encrypt() to do the check for that. This makes it so that all fscrypt ioctls consistently check for the encryption feature, and makes ext4 consistent with f2fs in this regard. Signed-off-by: Chao Yu <yuchao0@huawei.com> [EB - removed unneeded braces, updated the documentation, and added more explanation to commit message] Signed-off-by: Eric Biggers <ebiggers@google.com> --- Documentation/filesystems/fscrypt.rst | 3 ++- fs/ext4/ioctl.c | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 4289c29d7c5a..8a0700af9596 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -562,7 +562,8 @@ FS_IOC_GET_ENCRYPTION_POLICY_EX can fail with the following errors: or this kernel is too old to support FS_IOC_GET_ENCRYPTION_POLICY_EX (try FS_IOC_GET_ENCRYPTION_POLICY instead) - ``EOPNOTSUPP``: the kernel was not configured with encryption - support for this filesystem + support for this filesystem, or the filesystem superblock has not + had encryption enabled on it - ``EOVERFLOW``: the file is encrypted and uses a recognized encryption policy version, but the policy struct does not fit into the provided buffer diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index fe5a4b13f939..5703d607f5af 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1113,6 +1113,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) #endif } case EXT4_IOC_GET_ENCRYPTION_POLICY: + if (!ext4_has_feature_encrypt(sb)) + return -EOPNOTSUPP; return fscrypt_ioctl_get_policy(filp, (void __user *)arg); case FS_IOC_GET_ENCRYPTION_POLICY_EX:
On 2019/8/31 23:02, Eric Biggers wrote: > On Sat, Aug 31, 2019 at 06:32:28PM +0800, Chao Yu wrote: >> Hi, >> >> Is this change not necessary? A month has passed... >> >> Thanks, >> >> On 2019/8/4 17:56, Chao Yu wrote: >>> From: Chao Yu <yuchao0@huawei.com> >>> >>> When getting fscrypto policy via EXT4_IOC_GET_ENCRYPTION_POLICY, if >>> encryption feature is off, it's better to return EOPNOTSUPP instead >>> of ENODATA, so let's add ext4_has_feature_encrypt() to do the check >>> for that. >>> >>> Signed-off-by: Chao Yu <yuchao0@huawei.com> >>> --- >>> fs/ext4/ioctl.c | 6 ++++-- >>> 1 file changed, 4 insertions(+), 2 deletions(-) >>> >>> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c >>> index 442f7ef873fc..bf87835c1237 100644 >>> --- a/fs/ext4/ioctl.c >>> +++ b/fs/ext4/ioctl.c >>> @@ -1112,9 +1112,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) >>> return -EOPNOTSUPP; >>> #endif >>> } >>> - case EXT4_IOC_GET_ENCRYPTION_POLICY: >>> + case EXT4_IOC_GET_ENCRYPTION_POLICY: { >>> + if (!ext4_has_feature_encrypt(sb)) >>> + return -EOPNOTSUPP; >>> return fscrypt_ioctl_get_policy(filp, (void __user *)arg); >>> - >>> + } >>> case EXT4_IOC_FSGETXATTR: >>> { >>> struct fsxattr fa; >>> > > Sorry, I was preoccupied with all the other fscrypt changes, and was thinking of > waiting until 5.5 for this to avoid a potential extra merge conflict or a > potentially breaking change. Looking at this again though, the new ioctl > FS_IOC_GET_ENCRYPTION_POLICY_EX *does* do the feature check, which doesn't match > the documentation, which implies the check isn't done. Also, f2fs does the > check in FS_IOC_GET_ENCRYPTION_POLICY, so the filesystems are inconsistent. > > So, it makes some sense to apply this now. So I've gone ahead and applied the > following to fscrypt.git#master, edited a bit from your original patch: > >>From 0642ea2409f3bfa105570e12854b8e2628db6835 Mon Sep 17 00:00:00 2001 > From: Chao Yu <yuchao0@huawei.com> > Date: Sun, 4 Aug 2019 17:56:43 +0800 > Subject: [PATCH] ext4 crypto: fix to check feature status before get policy > > When getting fscrypt policy via EXT4_IOC_GET_ENCRYPTION_POLICY, if > encryption feature is off, it's better to return EOPNOTSUPP instead of > ENODATA, so let's add ext4_has_feature_encrypt() to do the check for > that. > > This makes it so that all fscrypt ioctls consistently check for the > encryption feature, and makes ext4 consistent with f2fs in this regard. > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > [EB - removed unneeded braces, updated the documentation, and > added more explanation to commit message] The patch looks better now, thanks for the help. Thanks, > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > Documentation/filesystems/fscrypt.rst | 3 ++- > fs/ext4/ioctl.c | 2 ++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst > index 4289c29d7c5a..8a0700af9596 100644 > --- a/Documentation/filesystems/fscrypt.rst > +++ b/Documentation/filesystems/fscrypt.rst > @@ -562,7 +562,8 @@ FS_IOC_GET_ENCRYPTION_POLICY_EX can fail with the following errors: > or this kernel is too old to support FS_IOC_GET_ENCRYPTION_POLICY_EX > (try FS_IOC_GET_ENCRYPTION_POLICY instead) > - ``EOPNOTSUPP``: the kernel was not configured with encryption > - support for this filesystem > + support for this filesystem, or the filesystem superblock has not > + had encryption enabled on it > - ``EOVERFLOW``: the file is encrypted and uses a recognized > encryption policy version, but the policy struct does not fit into > the provided buffer > diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c > index fe5a4b13f939..5703d607f5af 100644 > --- a/fs/ext4/ioctl.c > +++ b/fs/ext4/ioctl.c > @@ -1113,6 +1113,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > #endif > } > case EXT4_IOC_GET_ENCRYPTION_POLICY: > + if (!ext4_has_feature_encrypt(sb)) > + return -EOPNOTSUPP; > return fscrypt_ioctl_get_policy(filp, (void __user *)arg); > > case FS_IOC_GET_ENCRYPTION_POLICY_EX: >
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 442f7ef873fc..bf87835c1237 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1112,9 +1112,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return -EOPNOTSUPP; #endif } - case EXT4_IOC_GET_ENCRYPTION_POLICY: + case EXT4_IOC_GET_ENCRYPTION_POLICY: { + if (!ext4_has_feature_encrypt(sb)) + return -EOPNOTSUPP; return fscrypt_ioctl_get_policy(filp, (void __user *)arg); - + } case EXT4_IOC_FSGETXATTR: { struct fsxattr fa;