[RFC,10/10] f2fs: fs-verity support

Message ID	20180824161642.1144-11-ebiggers@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-fsdevel-owner@kernel.org> From: Eric Biggers <ebiggers@kernel.org> To: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: linux-integrity@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org, Mimi Zohar <zohar@linux.vnet.ibm.com>, Dmitry Kasatkin <dmitry.kasatkin@gmail.com>, Michael Halcrow <mhalcrow@google.com>, Victor Hsieh <victorhsieh@google.com> Subject: [RFC PATCH 10/10] f2fs: fs-verity support Date: Fri, 24 Aug 2018 09:16:42 -0700 Message-Id: <20180824161642.1144-11-ebiggers@kernel.org> In-Reply-To: <20180824161642.1144-1-ebiggers@kernel.org> References: <20180824161642.1144-1-ebiggers@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk
Series	fs-verity: filesystem-level integrity protection \| expand [RFC,00/10] fs-verity: filesystem-level integrity protection [RFC,01/10] fs-verity: add setup code, UAPI, and Kconfig [RFC,02/10] fs-verity: add data verification hooks for ->readpages() [RFC,03/10] fs-verity: implement FS_IOC_ENABLE_VERITY ioctl [RFC,04/10] fs-verity: implement FS_IOC_MEASURE_VERITY ioctl [RFC,05/10] fs-verity: add SHA-512 support [RFC,06/10] fs-verity: add CRC-32C support [RFC,07/10] fs-verity: support builtin file signatures [RFC,08/10] ext4: add basic fs-verity support [RFC,09/10] ext4: add fs-verity read support [RFC,10/10] f2fs: fs-verity support

diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig index 9a20ef42fadde..c8396c7220f2a 100644 --- a/fs/f2fs/Kconfig +++ b/fs/f2fs/Kconfig @@ -81,6 +81,26 @@ config F2FS_FS_ENCRYPTION efficient since it avoids caching the encrypted and decrypted pages in the page cache. +config F2FS_FS_VERITY + bool "F2FS Verity" + depends on F2FS_FS + select FS_VERITY + help + This option enables fs-verity for f2fs. fs-verity is the + dm-verity mechanism implemented at the file level. Userspace + can append a Merkle tree (hash tree) to a file, then enable + fs-verity on the file. f2fs will then transparently verify + any data read from the file against the Merkle tree. The file + is also made read-only. + + This serves as an integrity check, but the availability of the + Merkle tree root hash also allows efficiently supporting + various use cases where normally the whole file would need to + be hashed at once, such as auditing and authenticity + verification (appraisal). + + If unsure, say N. + config F2FS_IO_TRACE bool "F2FS IO tracer" depends on F2FS_FS diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8f931d699287a..fc9ea831f7235 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -59,6 +59,7 @@ static bool __is_cp_guaranteed(struct page *page) enum bio_post_read_step { STEP_INITIAL = 0, STEP_DECRYPT, + STEP_VERITY, }; struct bio_post_read_ctx { @@ -103,8 +104,23 @@ static void decrypt_work(struct work_struct *work) bio_post_read_processing(ctx); } +static void verity_work(struct work_struct *work) +{ + struct bio_post_read_ctx *ctx = + container_of(work, struct bio_post_read_ctx, work); + + fsverity_verify_bio(ctx->bio); + + bio_post_read_processing(ctx); +} + static void bio_post_read_processing(struct bio_post_read_ctx *ctx) { + /* + * We use different work queues for decryption and for verity because + * verity may require reading metadata pages that need decryption, and + * we shouldn't recurse to the same workqueue. + */ switch (++ctx->cur_step) { case STEP_DECRYPT: if (ctx->enabled_steps & (1 << STEP_DECRYPT)) { @@ -114,6 +130,14 @@ static void bio_post_read_processing(struct bio_post_read_ctx *ctx) } ctx->cur_step++; /* fall-through */ + case STEP_VERITY: + if (ctx->enabled_steps & (1 << STEP_VERITY)) { + INIT_WORK(&ctx->work, verity_work); + fsverity_enqueue_verify_work(&ctx->work); + return; + } + ctx->cur_step++; + /* fall-through */ default: __read_end_io(ctx->bio); } @@ -534,7 +558,7 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio) } static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, - unsigned nr_pages) + unsigned nr_pages, pgoff_t first_idx) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct bio *bio; @@ -550,6 +574,11 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, if (f2fs_encrypted_file(inode)) post_read_steps |= 1 << STEP_DECRYPT; +#ifdef CONFIG_F2FS_FS_VERITY + if (inode->i_verity_info != NULL && + (first_idx < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT))) + post_read_steps |= 1 << STEP_VERITY; +#endif if (post_read_steps) { ctx = mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS); if (!ctx) { @@ -571,7 +600,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr, static int f2fs_submit_page_read(struct inode *inode, struct page *page, block_t blkaddr) { - struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1); + struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1, page->index); if (IS_ERR(bio)) return PTR_ERR(bio); @@ -1459,8 +1488,8 @@ static int f2fs_mpage_readpages(struct address_space *mapping, block_in_file = (sector_t)page->index; last_block = block_in_file + nr_pages; - last_block_in_file = (i_size_read(inode) + blocksize - 1) >> - blkbits; + last_block_in_file = (fsverity_full_i_size(inode) + + blocksize - 1) >> blkbits; if (last_block > last_block_in_file) last_block = last_block_in_file; @@ -1497,6 +1526,9 @@ static int f2fs_mpage_readpages(struct address_space *mapping, } } else { zero_user_segment(page, 0, PAGE_SIZE); + if (f2fs_verity_file(inode) && + !fsverity_verify_page(page)) + goto set_error_page; if (!PageUptodate(page)) SetPageUptodate(page); unlock_page(page); @@ -1514,7 +1546,8 @@ static int f2fs_mpage_readpages(struct address_space *mapping, bio = NULL; } if (bio == NULL) { - bio = f2fs_grab_read_bio(inode, block_nr, nr_pages); + bio = f2fs_grab_read_bio(inode, block_nr, nr_pages, + page->index); if (IS_ERR(bio)) { bio = NULL; goto set_error_page; diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 4d8b1de831439..e59781b13c5c8 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -29,6 +29,9 @@ #define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_F2FS_FS_ENCRYPTION) #include <linux/fscrypt.h> +#define __FS_HAS_VERITY IS_ENABLED(CONFIG_F2FS_FS_VERITY) +#include <linux/fsverity.h> + #ifdef CONFIG_F2FS_CHECK_FS #define f2fs_bug_on(sbi, condition) BUG_ON(condition) #else @@ -146,7 +149,7 @@ struct f2fs_mount_info { #define F2FS_FEATURE_QUOTA_INO 0x0080 #define F2FS_FEATURE_INODE_CRTIME 0x0100 #define F2FS_FEATURE_LOST_FOUND 0x0200 -#define F2FS_FEATURE_VERITY 0x0400 /* reserved */ +#define F2FS_FEATURE_VERITY 0x0400 #define F2FS_HAS_FEATURE(sb, mask) \ ((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0) @@ -598,7 +601,7 @@ enum { #define FADVISE_ENC_NAME_BIT 0x08 #define FADVISE_KEEP_SIZE_BIT 0x10 #define FADVISE_HOT_BIT 0x20 -#define FADVISE_VERITY_BIT 0x40 /* reserved */ +#define FADVISE_VERITY_BIT 0x40 #define file_is_cold(inode) is_file(inode, FADVISE_COLD_BIT) #define file_wrong_pino(inode) is_file(inode, FADVISE_LOST_PINO_BIT) @@ -616,6 +619,8 @@ enum { #define file_is_hot(inode) is_file(inode, FADVISE_HOT_BIT) #define file_set_hot(inode) set_file(inode, FADVISE_HOT_BIT) #define file_clear_hot(inode) clear_file(inode, FADVISE_HOT_BIT) +#define file_is_verity(inode) is_file(inode, FADVISE_VERITY_BIT) +#define file_set_verity(inode) set_file(inode, FADVISE_VERITY_BIT) #define DEF_DIR_LEVEL 0 @@ -3294,13 +3299,18 @@ static inline void f2fs_set_encrypted_inode(struct inode *inode) #endif } +static inline bool f2fs_verity_file(struct inode *inode) +{ + return file_is_verity(inode); +} + /* * Returns true if the reads of the inode's data need to undergo some * postprocessing step, like decryption or authenticity verification. */ static inline bool f2fs_post_read_required(struct inode *inode) { - return f2fs_encrypted_file(inode); + return f2fs_encrypted_file(inode) || f2fs_verity_file(inode); } #define F2FS_FEATURE_FUNCS(name, flagname) \ @@ -3318,6 +3328,7 @@ F2FS_FEATURE_FUNCS(flexible_inline_xattr, FLEXIBLE_INLINE_XATTR); F2FS_FEATURE_FUNCS(quota_ino, QUOTA_INO); F2FS_FEATURE_FUNCS(inode_crtime, INODE_CRTIME); F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND); +F2FS_FEATURE_FUNCS(verity, VERITY); #ifdef CONFIG_BLK_DEV_ZONED static inline int get_blkz_type(struct f2fs_sb_info *sbi, diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6880c6f78d58d..ea86dd35685ff 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -486,6 +486,12 @@ static int f2fs_file_open(struct inode *inode, struct file *filp) if (err) return err; + if (f2fs_verity_file(inode)) { + err = fsverity_file_open(inode, filp); + if (err) + return err; + } + filp->f_mode |= FMODE_NOWAIT; return dquot_file_open(inode, filp); @@ -684,6 +690,22 @@ int f2fs_getattr(const struct path *path, struct kstat *stat, struct f2fs_inode *ri; unsigned int flags; + if (f2fs_verity_file(inode)) { + /* + * For fs-verity we need to override i_size with the original + * data i_size. This requires I/O to the file which with + * fscrypt requires that the key be set up. But, if the key is + * unavailable just continue on without the i_size override. + */ + int err = fscrypt_require_key(inode); + + if (!err) { + err = fsverity_prepare_getattr(inode); + if (err) + return err; + } + } + if (f2fs_has_extra_attr(inode) && f2fs_sb_has_inode_crtime(inode->i_sb) && F2FS_FITS_IN_INODE(ri, fi->i_extra_isize, i_crtime)) { @@ -767,6 +789,12 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr) if (err) return err; + if (f2fs_verity_file(inode)) { + err = fsverity_prepare_setattr(dentry, attr); + if (err) + return err; + } + if (is_quota_modification(inode, attr)) { err = dquot_initialize(inode); if (err) @@ -2851,6 +2879,30 @@ static int f2fs_ioc_precache_extents(struct file *filp, unsigned long arg) return f2fs_precache_extents(file_inode(filp)); } +static int f2fs_ioc_enable_verity(struct file *filp, unsigned long arg) +{ + struct inode *inode = file_inode(filp); + + f2fs_update_time(F2FS_I_SB(inode), REQ_TIME); + + if (!f2fs_sb_has_verity(inode->i_sb)) { + f2fs_msg(inode->i_sb, KERN_WARNING, + "Can't enable fs-verity on inode %lu: the fs-verity feature is disabled on this filesystem.\n", + inode->i_ino); + return -EOPNOTSUPP; + } + + return fsverity_ioctl_enable(filp, (const void __user *)arg); +} + +static int f2fs_ioc_measure_verity(struct file *filp, unsigned long arg) +{ + if (!f2fs_sb_has_verity(file_inode(filp)->i_sb)) + return -EOPNOTSUPP; + + return fsverity_ioctl_measure(filp, (void __user *)arg); +} + long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp))))) @@ -2907,6 +2959,10 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return f2fs_ioc_set_pin_file(filp, arg); case F2FS_IOC_PRECACHE_EXTENTS: return f2fs_ioc_precache_extents(filp, arg); + case FS_IOC_ENABLE_VERITY: + return f2fs_ioc_enable_verity(filp, arg); + case FS_IOC_MEASURE_VERITY: + return f2fs_ioc_measure_verity(filp, arg); default: return -ENOTTY; } @@ -3013,6 +3069,8 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case F2FS_IOC_GET_PIN_FILE: case F2FS_IOC_SET_PIN_FILE: case F2FS_IOC_PRECACHE_EXTENTS: + case FS_IOC_ENABLE_VERITY: + case FS_IOC_MEASURE_VERITY: break; default: return -ENOIOCTLCMD; diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index f121c864f4c0d..e363e9f0c699e 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -407,7 +407,7 @@ void f2fs_update_inode(struct inode *inode, struct page *node_page) ri->i_uid = cpu_to_le32(i_uid_read(inode)); ri->i_gid = cpu_to_le32(i_gid_read(inode)); ri->i_links = cpu_to_le32(inode->i_nlink); - ri->i_size = cpu_to_le64(i_size_read(inode)); + ri->i_size = cpu_to_le64(fsverity_full_i_size(inode)); ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1); if (et) { @@ -618,6 +618,7 @@ void f2fs_evict_inode(struct inode *inode) } out_clear: fscrypt_put_encryption_info(inode); + fsverity_cleanup_inode(inode); clear_inode(inode); } diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 3995e926ba3a3..52a0de200fb79 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1943,6 +1943,25 @@ static const struct fscrypt_operations f2fs_cryptops = { }; #endif +#ifdef CONFIG_F2FS_FS_VERITY +static int f2fs_set_verity(struct inode *inode, loff_t data_i_size) +{ + int err; + + err = f2fs_convert_inline_inode(inode); + if (err) + return err; + + file_set_verity(inode); + f2fs_mark_inode_dirty_sync(inode, true); + return 0; +} + +static const struct fsverity_operations f2fs_verityops = { + .set_verity = f2fs_set_verity, +}; +#endif /* CONFIG_F2FS_FS_VERITY */ + static struct inode *f2fs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) { @@ -2758,6 +2777,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) sb->s_op = &f2fs_sops; #ifdef CONFIG_F2FS_FS_ENCRYPTION sb->s_cop = &f2fs_cryptops; +#endif +#ifdef CONFIG_F2FS_FS_VERITY + sb->s_vop = &f2fs_verityops; #endif sb->s_xattr = f2fs_xattr_handlers; sb->s_export_op = &f2fs_export_ops; diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 2e7e611deaef2..f11aa34a8be18 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -119,6 +119,9 @@ static ssize_t features_show(struct f2fs_attr *a, if (f2fs_sb_has_lost_found(sb)) len += snprintf(buf + len, PAGE_SIZE - len, "%s%s", len ? ", " : "", "lost_found"); + if (f2fs_sb_has_verity(sb)) + len += snprintf(buf + len, PAGE_SIZE - len, "%s%s", + len ? ", " : "", "verity"); len += snprintf(buf + len, PAGE_SIZE - len, "\n"); return len; } @@ -333,6 +336,7 @@ enum feat_id { FEAT_QUOTA_INO, FEAT_INODE_CRTIME, FEAT_LOST_FOUND, + FEAT_VERITY, }; static ssize_t f2fs_feature_show(struct f2fs_attr *a, @@ -349,6 +353,7 @@ static ssize_t f2fs_feature_show(struct f2fs_attr *a, case FEAT_QUOTA_INO: case FEAT_INODE_CRTIME: case FEAT_LOST_FOUND: + case FEAT_VERITY: return snprintf(buf, PAGE_SIZE, "supported\n"); } return 0; @@ -429,6 +434,9 @@ F2FS_FEATURE_RO_ATTR(flexible_inline_xattr, FEAT_FLEXIBLE_INLINE_XATTR); F2FS_FEATURE_RO_ATTR(quota_ino, FEAT_QUOTA_INO); F2FS_FEATURE_RO_ATTR(inode_crtime, FEAT_INODE_CRTIME); F2FS_FEATURE_RO_ATTR(lost_found, FEAT_LOST_FOUND); +#ifdef CONFIG_F2FS_FS_VERITY +F2FS_FEATURE_RO_ATTR(verity, FEAT_VERITY); +#endif #define ATTR_LIST(name) (&f2fs_attr_##name.attr) static struct attribute *f2fs_attrs[] = { @@ -485,6 +493,9 @@ static struct attribute *f2fs_feat_attrs[] = { ATTR_LIST(quota_ino), ATTR_LIST(inode_crtime), ATTR_LIST(lost_found), +#ifdef CONFIG_F2FS_FS_VERITY + ATTR_LIST(verity), +#endif NULL, };

[RFC,10/10] f2fs: fs-verity support

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