From 0d91f0ad6a01c8c64a84c5255c5ab95133d0fed5 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 25 Aug 2022 09:31:09 -0400 Subject: [PATCH] ceph: handle fscrypt fields in cap messages from MDS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Handle the new fscrypt_file and fscrypt_auth fields in cap messages. Use them to populate new fields in cap_extra_info and update the inode with those values. Signed-off-by: Jeff Layton Reviewed-by: Xiubo Li Reviewed-and-tested-by: Luís Henriques Reviewed-by: Milind Changire Signed-off-by: Ilya Dryomov --- fs/ceph/caps.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 83 insertions(+), 2 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index aff256274415..ee61b539a8ec 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -3383,6 +3383,9 @@ struct cap_extra_info { /* currently issued */ int issued; struct timespec64 btime; + u8 *fscrypt_auth; + u32 fscrypt_auth_len; + u64 fscrypt_file_size; }; /* @@ -3415,6 +3418,14 @@ static void handle_cap_grant(struct inode *inode, bool deleted_inode = false; bool fill_inline = false; + /* + * If there is at least one crypto block then we'll trust + * fscrypt_file_size. If the real length of the file is 0, then + * ignore it (it has probably been truncated down to 0 by the MDS). + */ + if (IS_ENCRYPTED(inode) && size) + size = extra_info->fscrypt_file_size; + dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n", inode, cap, session->s_mds, seq, ceph_cap_string(newcaps)); dout(" size %llu max_size %llu, i_size %llu\n", size, max_size, @@ -3481,6 +3492,14 @@ static void handle_cap_grant(struct inode *inode, dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode, from_kuid(&init_user_ns, inode->i_uid), from_kgid(&init_user_ns, inode->i_gid)); +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + if (ci->fscrypt_auth_len != extra_info->fscrypt_auth_len || + memcmp(ci->fscrypt_auth, extra_info->fscrypt_auth, + ci->fscrypt_auth_len)) + pr_warn_ratelimited("%s: cap grant attempt to change fscrypt_auth on non-I_NEW inode (old len %d new len %d)\n", + __func__, ci->fscrypt_auth_len, + extra_info->fscrypt_auth_len); +#endif } if ((newcaps & CEPH_CAP_LINK_SHARED) && @@ -3897,7 +3916,8 @@ static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid, */ static bool handle_cap_trunc(struct inode *inode, struct ceph_mds_caps *trunc, - struct ceph_mds_session *session) + struct ceph_mds_session *session, + struct cap_extra_info *extra_info) { struct ceph_inode_info *ci = ceph_inode(inode); int mds = session->s_mds; @@ -3914,6 +3934,14 @@ static bool handle_cap_trunc(struct inode *inode, issued |= implemented | dirty; + /* + * If there is at least one crypto block then we'll trust + * fscrypt_file_size. If the real length of the file is 0, then + * ignore it (it has probably been truncated down to 0 by the MDS). + */ + if (IS_ENCRYPTED(inode) && size) + size = extra_info->fscrypt_file_size; + dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n", inode, mds, seq, truncate_size, truncate_seq); queue_trunc = ceph_fill_file_size(inode, issued, @@ -4135,6 +4163,52 @@ retry: *target_cap = cap; } +#ifdef CONFIG_FS_ENCRYPTION +static int parse_fscrypt_fields(void **p, void *end, + struct cap_extra_info *extra) +{ + u32 len; + + ceph_decode_32_safe(p, end, extra->fscrypt_auth_len, bad); + if (extra->fscrypt_auth_len) { + ceph_decode_need(p, end, extra->fscrypt_auth_len, bad); + extra->fscrypt_auth = kmalloc(extra->fscrypt_auth_len, + GFP_KERNEL); + if (!extra->fscrypt_auth) + return -ENOMEM; + ceph_decode_copy_safe(p, end, extra->fscrypt_auth, + extra->fscrypt_auth_len, bad); + } + + ceph_decode_32_safe(p, end, len, bad); + if (len >= sizeof(u64)) { + ceph_decode_64_safe(p, end, extra->fscrypt_file_size, bad); + len -= sizeof(u64); + } + ceph_decode_skip_n(p, end, len, bad); + return 0; +bad: + return -EIO; +} +#else +static int parse_fscrypt_fields(void **p, void *end, + struct cap_extra_info *extra) +{ + u32 len; + + /* Don't care about these fields unless we're encryption-capable */ + ceph_decode_32_safe(p, end, len, bad); + if (len) + ceph_decode_skip_n(p, end, len, bad); + ceph_decode_32_safe(p, end, len, bad); + if (len) + ceph_decode_skip_n(p, end, len, bad); + return 0; +bad: + return -EIO; +} +#endif + /* * Handle a caps message from the MDS. * @@ -4255,6 +4329,11 @@ void ceph_handle_caps(struct ceph_mds_session *session, ceph_decode_64_safe(&p, end, extra_info.nsubdirs, bad); } + if (msg_version >= 12) { + if (parse_fscrypt_fields(&p, end, &extra_info)) + goto bad; + } + /* lookup ino */ inode = ceph_find_inode(mdsc->fsc->sb, vino); dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino, @@ -4352,7 +4431,8 @@ void ceph_handle_caps(struct ceph_mds_session *session, break; case CEPH_CAP_OP_TRUNC: - queue_trunc = handle_cap_trunc(inode, h, session); + queue_trunc = handle_cap_trunc(inode, h, session, + &extra_info); spin_unlock(&ci->i_ceph_lock); if (queue_trunc) ceph_queue_vmtruncate(inode); @@ -4375,6 +4455,7 @@ out: if (close_sessions) ceph_mdsc_close_sessions(mdsc); + kfree(extra_info.fscrypt_auth); return; flush_cap_releases: