[v4,2/5] ima: use fs method to read integrity data [updated]

Message ID	1501619070.3204.4.camel@linux.vnet.ibm.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-fsdevel-owner@kernel.org> Gateway: Authorized Use Only! Violators will be prosecuted for <linux-fsdevel@vger.kernel.org> from <zohar@linux.vnet.ibm.com>; Wed, 2 Aug 2017 06:24:50 +1000 Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 2 Aug 2017 06:24:47 +1000 Subject: Re: [PATCH v4 2/5] ima: use fs method to read integrity data [updated] From: Mimi Zohar <zohar@linux.vnet.ibm.com> To: Christoph Hellwig <hch@lst.de>, Al Viro <viro@zeniv.linux.org.uk> Cc: James Morris <jmorris@namei.org>, linux-fsdevel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, Matthew Garrett <matthew.garrett@nebula.com>, Jan Kara <jack@suse.com>, "Theodore Ts'o" <tytso@mit.edu>, Andreas Dilger <adilger.kernel@dilger.ca>, Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <yuchao0@huawei.com>, Steven Whitehouse <swhiteho@redhat.com>, Bob Peterson <rpeterso@redhat.com>, David Woodhouse <dwmw2@infradead.org>, Dave Kleikamp <shaggy@kernel.org>, Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>, Mark Fasheh <mfasheh@versity.com>, Joel Becker <jlbec@evilplan.org>, Richard Weinberger <richard@nod.at>, "Darrick J. Wong" <darrick.wong@oracle.com>, Hugh Dickins <hughd@google.com>, Chris Mason <clm@fb.com> Date: Tue, 01 Aug 2017 16:24:30 -0400 In-Reply-To: <1501075375-29469-3-git-send-email-zohar@linux.vnet.ibm.com> References: <1501075375-29469-1-git-send-email-zohar@linux.vnet.ibm.com> <1501075375-29469-3-git-send-email-zohar@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Message-Id: <1501619070.3204.4.camel@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 9e75d8a39aac..2542dc66c85c 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3125,6 +3125,7 @@ const struct file_operations btrfs_file_operations = { #endif .clone_file_range = btrfs_clone_file_range, .dedupe_file_range = btrfs_dedupe_file_range, + .integrity_read = generic_file_read_iter, }; void btrfs_auto_defrag_exit(void) diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c index 5f22e74bbade..17955a92a5b3 100644 --- a/fs/efivarfs/file.c +++ b/fs/efivarfs/file.c @@ -64,9 +64,10 @@ static ssize_t efivarfs_file_write(struct file *file, return bytes; } -static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, - size_t count, loff_t *ppos) +static ssize_t efivarfs_file_read_iter(struct kiocb *iocb, + struct iov_iter *iter) { + struct file *file = iocb->ki_filp; struct efivar_entry *var = file->private_data; unsigned long datasize = 0; u32 attributes; @@ -96,8 +97,8 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, goto out_free; memcpy(data, &attributes, sizeof(attributes)); - size = simple_read_from_buffer(userbuf, count, ppos, - data, datasize + sizeof(attributes)); + size = simple_read_iter_from_buffer(iocb, iter, data, + datasize + sizeof(attributes)); out_free: kfree(data); @@ -174,8 +175,9 @@ efivarfs_file_ioctl(struct file *file, unsigned int cmd, unsigned long p) const struct file_operations efivarfs_file_operations = { .open = simple_open, - .read = efivarfs_file_read, + .read_iter = efivarfs_file_read_iter, .write = efivarfs_file_write, .llseek = no_llseek, .unlocked_ioctl = efivarfs_file_ioctl, + .integrity_read = efivarfs_file_read_iter, }; diff --git a/fs/ext2/file.c b/fs/ext2/file.c index d34d32bdc944..111069de1973 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -192,6 +192,22 @@ static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to) return generic_file_read_iter(iocb, to); } +static ssize_t ext2_file_integrity_read_iter(struct kiocb *iocb, + struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + lockdep_assert_held(&inode->i_rwsem); +#ifdef CONFIG_FS_DAX + if (!iov_iter_count(to)) + return 0; /* skip atime */ + + if (IS_DAX(iocb->ki_filp->f_mapping->host)) + return dax_iomap_rw(iocb, to, &ext2_iomap_ops); +#endif + return generic_file_read_iter(iocb, to); +} + static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { #ifdef CONFIG_FS_DAX @@ -216,6 +232,7 @@ const struct file_operations ext2_file_operations = { .get_unmapped_area = thp_get_unmapped_area, .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, + .integrity_read = ext2_file_integrity_read_iter, }; const struct inode_operations ext2_file_inode_operations = { diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 58294c9a7e1d..cb423fff935f 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -74,6 +74,28 @@ static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to) return generic_file_read_iter(iocb, to); } +static ssize_t ext4_file_integrity_read_iter(struct kiocb *iocb, + struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + int o_direct = iocb->ki_flags & IOCB_DIRECT; + + lockdep_assert_held(&inode->i_rwsem); + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + +#ifdef CONFIG_FS_DAX + if (IS_DAX(inode)) + return dax_iomap_rw(iocb, to, &ext4_iomap_ops); +#endif + if (o_direct) + return -EINVAL; + return generic_file_read_iter(iocb, to); +} + /* * Called when an inode is released. Note that this is different * from ext4_file_open: open gets called at every open, but release @@ -747,6 +769,7 @@ const struct file_operations ext4_file_operations = { .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .fallocate = ext4_fallocate, + .integrity_read = ext4_file_integrity_read_iter, }; const struct inode_operations ext4_file_inode_operations = { diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 2706130c261b..82ea81da0b2d 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2514,4 +2514,5 @@ const struct file_operations f2fs_file_operations = { #endif .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, + .integrity_read = generic_file_read_iter, }; diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index c12476e309c6..5a63034cccf5 100644 --- a/fs/jffs2/file.c +++ b/fs/jffs2/file.c @@ -57,6 +57,7 @@ const struct file_operations jffs2_file_operations = .mmap = generic_file_readonly_mmap, .fsync = jffs2_fsync, .splice_read = generic_file_splice_read, + .integrity_read = generic_file_read_iter, }; /* jffs2_file_inode_operations */ diff --git a/fs/jfs/file.c b/fs/jfs/file.c index 739492c7a3fd..423512a810e4 100644 --- a/fs/jfs/file.c +++ b/fs/jfs/file.c @@ -162,4 +162,5 @@ const struct file_operations jfs_file_operations = { #ifdef CONFIG_COMPAT .compat_ioctl = jfs_compat_ioctl, #endif + .integrity_read = generic_file_read_iter, }; diff --git a/fs/libfs.c b/fs/libfs.c index 3aabe553fc45..99333264a0a7 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -16,6 +16,7 @@ #include <linux/exportfs.h> #include <linux/writeback.h> #include <linux/buffer_head.h> /* sync_mapping_buffers */ +#include <linux/uio.h> #include <linux/uaccess.h> @@ -676,6 +677,37 @@ ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, EXPORT_SYMBOL(simple_write_to_buffer); /** + * simple_read_iter_from_buffer - copy data from the buffer to user space + * @iocb: struct containing the file, the current position and other info + * @to: the user space buffer to read to + * @from: the buffer to read from + * @available: the size of the buffer + * + * The simple_read_iter_from_buffer() function reads up to @available bytes + * from the current buffer into the user space buffer. + * + * On success, the current buffer offset is advanced by the number of bytes + * read, or a negative value is returned on error. + **/ +ssize_t simple_read_iter_from_buffer(struct kiocb *iocb, struct iov_iter *to, + const void *from, size_t available) +{ + loff_t pos = iocb->ki_pos; + size_t ret; + + if (pos < 0) + return -EINVAL; + if (pos >= available) + return 0; + ret = copy_to_iter(from + pos, available - pos, to); + if (!ret && iov_iter_count(to)) + return -EFAULT; + iocb->ki_pos = pos + ret; + return ret; +} +EXPORT_SYMBOL(simple_read_iter_from_buffer); + +/** * memory_read_from_buffer - copy data from the buffer * @to: the kernel space buffer to read to * @count: the maximum number of bytes to read diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c index c5fa3dee72fc..55e058ac487f 100644 --- a/fs/nilfs2/file.c +++ b/fs/nilfs2/file.c @@ -150,6 +150,7 @@ const struct file_operations nilfs_file_operations = { /* .release = nilfs_release_file, */ .fsync = nilfs_sync_file, .splice_read = generic_file_splice_read, + .integrity_read = generic_file_read_iter, }; const struct inode_operations nilfs_file_inode_operations = { diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c index 12af0490322f..4f24d1b589b1 100644 --- a/fs/ramfs/file-mmu.c +++ b/fs/ramfs/file-mmu.c @@ -47,6 +47,7 @@ const struct file_operations ramfs_file_operations = { .splice_write = iter_file_splice_write, .llseek = generic_file_llseek, .get_unmapped_area = ramfs_mmu_get_unmapped_area, + .integrity_read = generic_file_read_iter, }; const struct inode_operations ramfs_file_inode_operations = { diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 2ef7ce75c062..5ee704fa84e0 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -50,6 +50,7 @@ const struct file_operations ramfs_file_operations = { .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .llseek = generic_file_llseek, + .integrity_read = generic_file_read_iter, }; const struct inode_operations ramfs_file_inode_operations = { diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 8cad0b19b404..5e52a315e18b 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1747,4 +1747,5 @@ const struct file_operations ubifs_file_operations = { #ifdef CONFIG_COMPAT .compat_ioctl = ubifs_compat_ioctl, #endif + .integrity_read = generic_file_read_iter, }; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index c4893e226fd8..0a6704b563d6 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -292,6 +292,26 @@ xfs_file_read_iter( return ret; } +static ssize_t +xfs_integrity_read( + struct kiocb *iocb, + struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + struct xfs_mount *mp = XFS_I(inode)->i_mount; + + lockdep_assert_held(&inode->i_rwsem); + + XFS_STATS_INC(mp, xs_read_calls); + + if (XFS_FORCED_SHUTDOWN(mp)) + return -EIO; + + if (IS_DAX(inode)) + return dax_iomap_rw(iocb, to, &xfs_iomap_ops); + return generic_file_read_iter(iocb, to); +} + /* * Zero any on disk space between the current EOF and the new, larger EOF. * @@ -1175,6 +1195,7 @@ const struct file_operations xfs_file_operations = { .fallocate = xfs_file_fallocate, .clone_file_range = xfs_file_clone_range, .dedupe_file_range = xfs_file_dedupe_range, + .integrity_read = xfs_integrity_read, }; const struct file_operations xfs_dir_file_operations = { diff --git a/include/linux/fs.h b/include/linux/fs.h index 6e1fd5d21248..8d0d10e1dd93 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1699,6 +1699,7 @@ struct file_operations { u64); ssize_t (*dedupe_file_range)(struct file *, u64, u64, struct file *, u64); + ssize_t (*integrity_read)(struct kiocb *, struct iov_iter *); } __randomize_layout; struct inode_operations { @@ -3097,6 +3098,8 @@ extern void simple_release_fs(struct vfsmount **mount, int *count); extern ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, const void *from, size_t available); +extern ssize_t simple_read_iter_from_buffer(struct kiocb *iocb, + struct iov_iter *to, const void *from, size_t available); extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, const void __user *from, size_t count); diff --git a/mm/shmem.c b/mm/shmem.c index b0aa6075d164..805d99011ca4 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3849,6 +3849,7 @@ static const struct file_operations shmem_file_operations = { .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .fallocate = shmem_fallocate, + .integrity_read = shmem_file_read_iter, #endif }; diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 6fc888ca468e..df04f35a1d40 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -21,6 +21,7 @@ #include <linux/rbtree.h> #include <linux/file.h> #include <linux/uaccess.h> +#include <linux/uio.h> #include "integrity.h" static struct rb_root integrity_iint_tree = RB_ROOT; @@ -184,18 +185,25 @@ security_initcall(integrity_iintcache_init); int integrity_kernel_read(struct file *file, loff_t offset, void *addr, unsigned long count) { - mm_segment_t old_fs; - char __user *buf = (char __user *)addr; + struct inode *inode = file_inode(file); + struct kvec iov = { .iov_base = addr, .iov_len = count }; + struct kiocb kiocb; + struct iov_iter iter; ssize_t ret; + lockdep_assert_held(&inode->i_rwsem); + if (!(file->f_mode & FMODE_READ)) return -EBADF; + if (!file->f_op->integrity_read) + return -EBADF; - old_fs = get_fs(); - set_fs(get_ds()); - ret = __vfs_read(file, buf, count, &offset); - set_fs(old_fs); + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = offset; + iov_iter_kvec(&iter, READ | ITER_KVEC, &iov, 1, count); + ret = file->f_op->integrity_read(&kiocb, &iter); + BUG_ON(ret == -EIOCBQUEUED); return ret; }

[v4,2/5] ima: use fs method to read integrity data [updated]

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