From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/smb/client/link.c | 642 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 642 insertions(+) create mode 100644 fs/smb/client/link.c (limited to 'fs/smb/client/link.c') diff --git a/fs/smb/client/link.c b/fs/smb/client/link.c new file mode 100644 index 000000000..8d5d6aca7 --- /dev/null +++ b/fs/smb/client/link.c @@ -0,0 +1,642 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * + * Copyright (C) International Business Machines Corp., 2002,2008 + * Author(s): Steve French (sfrench@us.ibm.com) + * + */ +#include +#include +#include +#include +#include +#include "cifsfs.h" +#include "cifsglob.h" +#include "cifsproto.h" +#include "cifs_debug.h" +#include "cifs_fs_sb.h" +#include "cifs_unicode.h" +#include "smb2proto.h" +#include "cifs_ioctl.h" +#include "fs_context.h" +#include "reparse.h" + +/* + * M-F Symlink Functions - Begin + */ + +#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1) +#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1)) +#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1)) +#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024) +#define CIFS_MF_SYMLINK_FILE_SIZE \ + (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN) + +#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n" +#define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n" +#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash + +static int +parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len, + char **_link_str) +{ + int rc; + unsigned int link_len; + const char *md5_str1; + const char *link_str; + u8 md5_hash[16]; + char md5_str2[34]; + + if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE) + return -EINVAL; + + md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET]; + link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET]; + + rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len); + if (rc != 1) + return -EINVAL; + + if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN) + return -EINVAL; + + md5(link_str, link_len, md5_hash); + + scnprintf(md5_str2, sizeof(md5_str2), + CIFS_MF_SYMLINK_MD5_FORMAT, + CIFS_MF_SYMLINK_MD5_ARGS(md5_hash)); + + if (strncmp(md5_str1, md5_str2, 17) != 0) + return -EINVAL; + + if (_link_str) { + *_link_str = kstrndup(link_str, link_len, GFP_KERNEL); + if (!*_link_str) + return -ENOMEM; + } + + *_link_len = link_len; + return 0; +} + +static int +format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str) +{ + unsigned int link_len; + unsigned int ofs; + u8 md5_hash[16]; + + if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE) + return -EINVAL; + + link_len = strlen(link_str); + + if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN) + return -ENAMETOOLONG; + + md5(link_str, link_len, md5_hash); + + scnprintf(buf, buf_len, + CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT, + link_len, + CIFS_MF_SYMLINK_MD5_ARGS(md5_hash)); + + ofs = CIFS_MF_SYMLINK_LINK_OFFSET; + memcpy(buf + ofs, link_str, link_len); + + ofs += link_len; + if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) { + buf[ofs] = '\n'; + ofs++; + } + + while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) { + buf[ofs] = ' '; + ofs++; + } + + return 0; +} + +bool +couldbe_mf_symlink(const struct cifs_fattr *fattr) +{ + if (!S_ISREG(fattr->cf_mode)) + /* it's not a symlink */ + return false; + + if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE) + /* it's not a symlink */ + return false; + + return true; +} + +static int +create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const char *fromName, + const char *toName) +{ + int rc; + u8 *buf; + unsigned int bytes_written = 0; + + buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName); + if (rc) + goto out; + + if (tcon->ses->server->ops->create_mf_symlink) + rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, + cifs_sb, fromName, buf, &bytes_written); + else + rc = -EOPNOTSUPP; + + if (rc) + goto out; + + if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE) + rc = smb_EIO2(smb_eio_trace_symlink_file_size, + bytes_written, CIFS_MF_SYMLINK_FILE_SIZE); +out: + kfree(buf); + return rc; +} + +int +check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr, + const unsigned char *path) +{ + int rc; + u8 *buf = NULL; + unsigned int link_len = 0; + unsigned int bytes_read = 0; + char *symlink = NULL; + + if (!couldbe_mf_symlink(fattr)) + /* it's not a symlink */ + return 0; + + buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (tcon->ses->server->ops->query_mf_symlink) + rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon, + cifs_sb, path, buf, &bytes_read); + else + rc = -ENOSYS; + + if (rc) + goto out; + + if (bytes_read == 0) /* not a symlink */ + goto out; + + rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink); + if (rc == -EINVAL) { + /* it's not a symlink */ + rc = 0; + goto out; + } + + if (rc != 0) + goto out; + + /* it is a symlink */ + fattr->cf_eof = link_len; + fattr->cf_mode &= ~S_IFMT; + fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO; + fattr->cf_dtype = DT_LNK; + fattr->cf_symlink_target = symlink; +out: + kfree(buf); + return rc; +} + +#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY +/* + * SMB 1.0 Protocol specific functions + */ + +int +cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const unsigned char *path, + char *pbuf, unsigned int *pbytes_read) +{ + int rc; + int oplock = 0; + struct cifs_fid fid; + struct cifs_open_parms oparms; + struct cifs_io_parms io_parms = {0}; + int buf_type = CIFS_NO_BUFFER; + struct cifs_open_info_data query_data = {}; + + oparms = (struct cifs_open_parms) { + .tcon = tcon, + .cifs_sb = cifs_sb, + .desired_access = GENERIC_READ, + .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR), + .disposition = FILE_OPEN, + .path = path, + .fid = &fid, + }; + + rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, &query_data); + if (rc) + return rc; + + if (query_data.fi.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) { + rc = -ENOENT; + /* it's not a symlink */ + goto out; + } + + io_parms.netfid = fid.netfid; + io_parms.pid = current->tgid; + io_parms.tcon = tcon; + io_parms.offset = 0; + io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE; + + rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type); +out: + CIFSSMBClose(xid, tcon, fid.netfid); + return rc; +} + +int +cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const unsigned char *path, + char *pbuf, unsigned int *pbytes_written) +{ + int rc; + int oplock = 0; + struct cifs_fid fid; + struct cifs_open_parms oparms; + struct cifs_io_parms io_parms = {0}; + + oparms = (struct cifs_open_parms) { + .tcon = tcon, + .cifs_sb = cifs_sb, + .desired_access = GENERIC_WRITE, + .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR), + .disposition = FILE_CREATE, + .path = path, + .fid = &fid, + }; + + rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL); + if (rc) + return rc; + + io_parms.netfid = fid.netfid; + io_parms.pid = current->tgid; + io_parms.tcon = tcon; + io_parms.offset = 0; + io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE; + + rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf); + CIFSSMBClose(xid, tcon, fid.netfid); + return rc; +} +#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ + +/* + * SMB 2.1/SMB3 Protocol specific functions + */ +int +smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const unsigned char *path, + char *pbuf, unsigned int *pbytes_read) +{ + int rc; + struct cifs_fid fid; + struct cifs_open_parms oparms; + struct cifs_io_parms io_parms = {0}; + int buf_type = CIFS_NO_BUFFER; + __le16 *utf16_path; + __u8 oplock = SMB2_OPLOCK_LEVEL_NONE; + struct cifs_open_info_data data = {}; + + oparms = (struct cifs_open_parms) { + .tcon = tcon, + .cifs_sb = cifs_sb, + .path = path, + .desired_access = GENERIC_READ, + .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR), + .disposition = FILE_OPEN, + .fid = &fid, + }; + + utf16_path = cifs_convert_path_to_utf16(path, cifs_sb); + if (utf16_path == NULL) + return -ENOMEM; + + rc = SMB2_open(xid, &oparms, utf16_path, &oplock, &data, NULL, + NULL, NULL); + if (rc) + goto qmf_out_open_fail; + + if (data.fi.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) { + /* it's not a symlink */ + rc = -ENOENT; /* Is there a better rc to return? */ + goto qmf_out; + } + + io_parms.netfid = fid.netfid; + io_parms.pid = current->tgid; + io_parms.tcon = tcon; + io_parms.offset = 0; + io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE; + io_parms.persistent_fid = fid.persistent_fid; + io_parms.volatile_fid = fid.volatile_fid; + rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type); +qmf_out: + SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); +qmf_out_open_fail: + kfree(utf16_path); + return rc; +} + +int +smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const unsigned char *path, + char *pbuf, unsigned int *pbytes_written) +{ + int rc; + struct cifs_fid fid; + struct cifs_open_parms oparms; + struct cifs_io_parms io_parms = {0}; + __le16 *utf16_path; + __u8 oplock = SMB2_OPLOCK_LEVEL_NONE; + struct kvec iov[2]; + + cifs_dbg(FYI, "%s: path: %s\n", __func__, path); + + utf16_path = cifs_convert_path_to_utf16(path, cifs_sb); + if (!utf16_path) + return -ENOMEM; + + oparms = (struct cifs_open_parms) { + .tcon = tcon, + .cifs_sb = cifs_sb, + .path = path, + .desired_access = GENERIC_WRITE, + .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR), + .disposition = FILE_CREATE, + .fid = &fid, + .mode = 0644, + }; + + rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, + NULL, NULL); + if (rc) { + kfree(utf16_path); + return rc; + } + + io_parms.netfid = fid.netfid; + io_parms.pid = current->tgid; + io_parms.tcon = tcon; + io_parms.offset = 0; + io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE; + io_parms.persistent_fid = fid.persistent_fid; + io_parms.volatile_fid = fid.volatile_fid; + + /* iov[0] is reserved for smb header */ + iov[1].iov_base = pbuf; + iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE; + + rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1); + + /* Make sure we wrote all of the symlink data */ + if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE)) + rc = smb_EIO2(smb_eio_trace_short_symlink_write, + *pbytes_written, CIFS_MF_SYMLINK_FILE_SIZE); + + SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); + + kfree(utf16_path); + return rc; +} + +/* + * M-F Symlink Functions - End + */ + +int +cifs_hardlink(struct dentry *old_file, struct inode *inode, + struct dentry *direntry) +{ + int rc = -EACCES; + unsigned int xid; + const char *from_name, *to_name; + void *page1, *page2; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct tcon_link *tlink; + struct cifs_tcon *tcon; + struct TCP_Server_Info *server; + struct cifsInodeInfo *cifsInode; + + if (unlikely(cifs_forced_shutdown(cifs_sb))) + return smb_EIO(smb_eio_trace_forced_shutdown); + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + tcon = tlink_tcon(tlink); + + xid = get_xid(); + page1 = alloc_dentry_path(); + page2 = alloc_dentry_path(); + + from_name = build_path_from_dentry(old_file, page1); + if (IS_ERR(from_name)) { + rc = PTR_ERR(from_name); + goto cifs_hl_exit; + } + to_name = build_path_from_dentry(direntry, page2); + if (IS_ERR(to_name)) { + rc = PTR_ERR(to_name); + goto cifs_hl_exit; + } + +#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY + if (tcon->unix_ext) + rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name, + cifs_sb->local_nls, + cifs_remap(cifs_sb)); + else { +#else + { +#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ + server = tcon->ses->server; + if (!server->ops->create_hardlink) { + rc = -ENOSYS; + goto cifs_hl_exit; + } + rc = server->ops->create_hardlink(xid, tcon, old_file, + from_name, to_name, cifs_sb); + if ((rc == -EIO) || (rc == -EINVAL)) + rc = -EOPNOTSUPP; + } + + d_drop(direntry); /* force new lookup from server of target */ + + /* + * if source file is cached (oplocked) revalidate will not go to server + * until the file is closed or oplock broken so update nlinks locally + */ + if (d_really_is_positive(old_file)) { + cifsInode = CIFS_I(d_inode(old_file)); + if (rc == 0) { + clear_bit(CIFS_INO_TMPFILE, &cifsInode->flags); + spin_lock(&d_inode(old_file)->i_lock); + inc_nlink(d_inode(old_file)); + spin_unlock(&d_inode(old_file)->i_lock); + + /* + * parent dir timestamps will update from srv within a + * second, would it really be worth it to set the parent + * dir cifs inode time to zero to force revalidate + * (faster) for it too? + */ + } + /* + * if not oplocked will force revalidate to get info on source + * file from srv. Note Samba server prior to 4.2 has bug - + * not updating src file ctime on hardlinks but Windows servers + * handle it properly + */ + cifsInode->time = 0; + + /* + * Will update parent dir timestamps from srv within a second. + * Would it really be worth it to set the parent dir (cifs + * inode) time field to zero to force revalidate on parent + * directory faster ie + * + * CIFS_I(inode)->time = 0; + */ + } + +cifs_hl_exit: + free_dentry_path(page1); + free_dentry_path(page2); + free_xid(xid); + cifs_put_tlink(tlink); + return rc; +} + +int +cifs_symlink(struct mnt_idmap *idmap, struct inode *inode, + struct dentry *direntry, const char *symname) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(inode); + struct inode *newinode = NULL; + struct tcon_link *tlink; + struct cifs_tcon *pTcon; + const char *full_path; + int rc = -EOPNOTSUPP; + unsigned int sbflags; + unsigned int xid; + void *page; + + if (unlikely(cifs_forced_shutdown(cifs_sb))) + return smb_EIO(smb_eio_trace_forced_shutdown); + + page = alloc_dentry_path(); + if (!page) + return -ENOMEM; + + xid = get_xid(); + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + /* BB could be clearer if skipped put_tlink on error here, but harmless */ + goto symlink_exit; + } + pTcon = tlink_tcon(tlink); + + full_path = build_path_from_dentry(direntry, page); + if (IS_ERR(full_path)) { + rc = PTR_ERR(full_path); + goto symlink_exit; + } + + cifs_dbg(FYI, "Full path: %s\n", full_path); + cifs_dbg(FYI, "symname is %s\n", symname); + + /* BB what if DFS and this volume is on different share? BB */ + sbflags = cifs_sb_flags(cifs_sb); + rc = -EOPNOTSUPP; + switch (cifs_symlink_type(cifs_sb)) { + case CIFS_SYMLINK_TYPE_UNIX: +#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY + if (pTcon->unix_ext) { + rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, + symname, + cifs_sb->local_nls, + cifs_remap(cifs_sb)); + } +#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ + break; + + case CIFS_SYMLINK_TYPE_MFSYMLINKS: + if (sbflags & CIFS_MOUNT_MF_SYMLINKS) { + rc = create_mf_symlink(xid, pTcon, cifs_sb, + full_path, symname); + } + break; + + case CIFS_SYMLINK_TYPE_SFU: + if (sbflags & CIFS_MOUNT_UNX_EMUL) { + rc = __cifs_sfu_make_node(xid, inode, direntry, pTcon, + full_path, S_IFLNK, + 0, symname); + } + break; + + case CIFS_SYMLINK_TYPE_NATIVE: + case CIFS_SYMLINK_TYPE_NFS: + case CIFS_SYMLINK_TYPE_WSL: + if (CIFS_REPARSE_SUPPORT(pTcon)) { + rc = create_reparse_symlink(xid, inode, direntry, pTcon, + full_path, symname); + goto symlink_exit; + } + break; + default: + break; + } + + if (rc == 0) { + if (pTcon->posix_extensions) { + rc = smb311_posix_get_inode_info(&newinode, full_path, + NULL, inode->i_sb, xid); + } else if (pTcon->unix_ext) { + rc = cifs_get_inode_info_unix(&newinode, full_path, + inode->i_sb, xid); + } else { + rc = cifs_get_inode_info(&newinode, full_path, NULL, + inode->i_sb, xid, NULL); + } + + if (rc != 0) { + cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n", + rc); + } else { + d_instantiate(direntry, newinode); + } + } +symlink_exit: + free_dentry_path(page); + cifs_put_tlink(tlink); + free_xid(xid); + return rc; +} -- cgit v1.3.1