From d55f90e9b243faa5bcd5c8a323a8f43040500106 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 16 Apr 2024 12:08:51 +0200 Subject: ntfs3: enforce read-only when used as legacy ntfs driver Ensure that ntfs3 is mounted read-only when it is used to provide the legacy ntfs driver. Signed-off-by: Christian Brauner --- fs/ntfs3/ntfs_fs.h | 2 ++ fs/ntfs3/super.c | 36 ++++++++++++++++++++++++++++++++---- 2 files changed, 34 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h index 79356fd29a141..184c8bc76b927 100644 --- a/fs/ntfs3/ntfs_fs.h +++ b/fs/ntfs3/ntfs_fs.h @@ -1154,4 +1154,6 @@ static inline void le64_sub_cpu(__le64 *var, u64 val) *var = cpu_to_le64(le64_to_cpu(*var) - val); } +bool is_legacy_ntfs(struct super_block *sb); + #endif /* _LINUX_NTFS3_NTFS_FS_H */ diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c index 8d2e51bae2cbc..b26d95a8d3274 100644 --- a/fs/ntfs3/super.c +++ b/fs/ntfs3/super.c @@ -408,6 +408,12 @@ static int ntfs_fs_reconfigure(struct fs_context *fc) struct ntfs_mount_options *new_opts = fc->fs_private; int ro_rw; + /* If ntfs3 is used as legacy ntfs enforce read-only mode. */ + if (is_legacy_ntfs(sb)) { + fc->sb_flags |= SB_RDONLY; + goto out; + } + ro_rw = sb_rdonly(sb) && !(fc->sb_flags & SB_RDONLY); if (ro_rw && (sbi->flags & NTFS_FLAGS_NEED_REPLAY)) { errorf(fc, @@ -427,8 +433,6 @@ static int ntfs_fs_reconfigure(struct fs_context *fc) fc, "ntfs3: Cannot use different iocharset when remounting!"); - sync_filesystem(sb); - if (ro_rw && (sbi->volume.flags & VOLUME_FLAG_DIRTY) && !new_opts->force) { errorf(fc, @@ -436,6 +440,8 @@ static int ntfs_fs_reconfigure(struct fs_context *fc) return -EINVAL; } +out: + sync_filesystem(sb); swap(sbi->options, fc->fs_private); return 0; @@ -1613,6 +1619,8 @@ load_root: } #endif + if (is_legacy_ntfs(sb)) + sb->s_flags |= SB_RDONLY; return 0; put_inode_out: @@ -1730,7 +1738,7 @@ static const struct fs_context_operations ntfs_context_ops = { * This will called when mount/remount. We will first initialize * options so that if remount we can use just that. */ -static int ntfs_init_fs_context(struct fs_context *fc) +static int __ntfs_init_fs_context(struct fs_context *fc) { struct ntfs_mount_options *opts; struct ntfs_sb_info *sbi; @@ -1778,6 +1786,11 @@ free_opts: return -ENOMEM; } +static int ntfs_init_fs_context(struct fs_context *fc) +{ + return __ntfs_init_fs_context(fc); +} + static void ntfs3_kill_sb(struct super_block *sb) { struct ntfs_sb_info *sbi = sb->s_fs_info; @@ -1800,10 +1813,20 @@ static struct file_system_type ntfs_fs_type = { }; #if IS_ENABLED(CONFIG_NTFS_FS) +static int ntfs_legacy_init_fs_context(struct fs_context *fc) +{ + int ret; + + ret = __ntfs_init_fs_context(fc); + /* If ntfs3 is used as legacy ntfs enforce read-only mode. */ + fc->sb_flags |= SB_RDONLY; + return ret; +} + static struct file_system_type ntfs_legacy_fs_type = { .owner = THIS_MODULE, .name = "ntfs", - .init_fs_context = ntfs_init_fs_context, + .init_fs_context = ntfs_legacy_init_fs_context, .parameters = ntfs_fs_parameters, .kill_sb = ntfs3_kill_sb, .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, @@ -1821,9 +1844,14 @@ static inline void unregister_as_ntfs_legacy(void) { unregister_filesystem(&ntfs_legacy_fs_type); } +bool is_legacy_ntfs(struct super_block *sb) +{ + return sb->s_type == &ntfs_legacy_fs_type; +} #else static inline void register_as_ntfs_legacy(void) {} static inline void unregister_as_ntfs_legacy(void) {} +bool is_legacy_ntfs(struct super_block *sb) { return false; } #endif -- cgit 1.2.3-korg