Commit ba679017 authored Dec 01, 2016 by Eric Biggers Committed by Theodore Ts'o Dec 01, 2016

ext4: disable pwsalt ioctl when encryption disabled by config



On a CONFIG_EXT4_FS_ENCRYPTION=n kernel, the ioctls to get and set
encryption policies were disabled but EXT4_IOC_GET_ENCRYPTION_PWSALT was
not.  But there's no good reason to expose the pwsalt ioctl if the
kernel doesn't support encryption.  The pwsalt ioctl was also disabled
pre-4.8 (via ext4_sb_has_crypto() previously returning 0 when encryption
was disabled by config) and seems to have been enabled by mistake when
ext4 encryption was refactored to use fs/crypto/.  So let's disable it
again.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent 35997d1c

fs/ext4/ioctl.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -191,6 +191,7 @@ journal_err_out:
		return err;
		}

		#ifdef CONFIG_EXT4_FS_ENCRYPTION
		static int uuid_is_zero(__u8 u[16])
		{
		int i;
		@@ -200,6 +201,7 @@ static int uuid_is_zero(__u8 u[16])
		return 0;
		return 1;
		}
		#endif

		static int ext4_ioctl_setflags(struct inode *inode,
		unsigned int flags)
		@@ -802,6 +804,7 @@ resizefs_out:
		#endif
		}
		case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
		#ifdef CONFIG_EXT4_FS_ENCRYPTION
		int err, err2;
		struct ext4_sb_info *sbi = EXT4_SB(sb);
		handle_t *handle;
		@@ -836,6 +839,9 @@ resizefs_out:
		sbi->s_es->s_encrypt_pw_salt, 16))
		return -EFAULT;
		return 0;
		#else
		return -EOPNOTSUPP;
		#endif
		}
		case EXT4_IOC_GET_ENCRYPTION_POLICY: {
		#ifdef CONFIG_EXT4_FS_ENCRYPTION

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