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path: root/fs/smb/client/reparse.c
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Diffstat (limited to 'fs/smb/client/reparse.c')
-rw-r--r--fs/smb/client/reparse.c157
1 files changed, 148 insertions, 9 deletions
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
index 90da1e2b6217..e81d2d78ddb7 100644
--- a/fs/smb/client/reparse.c
+++ b/fs/smb/client/reparse.c
@@ -378,8 +378,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
memset(iov, 0, sizeof(*iov));
- /* Exclude $LXDEV xattr for sockets and fifos */
- if (S_ISSOCK(_mode) || S_ISFIFO(_mode))
+ /* Exclude $LXDEV xattr for non-device files */
+ if (!S_ISBLK(_mode) && !S_ISCHR(_mode))
num_xattrs = ARRAY_SIZE(xattrs) - 1;
else
num_xattrs = ARRAY_SIZE(xattrs);
@@ -535,9 +535,95 @@ static int parse_reparse_posix(struct reparse_posix_data *buf,
return 0;
}
+int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len,
+ bool unicode, bool relative,
+ const char *full_path,
+ struct cifs_sb_info *cifs_sb)
+{
+ char sep = CIFS_DIR_SEP(cifs_sb);
+ char *linux_target = NULL;
+ char *smb_target = NULL;
+ int levels;
+ int rc;
+ int i;
+
+ /* Check that length it valid for unicode/non-unicode mode */
+ if (!len || (unicode && (len % 2))) {
+ cifs_dbg(VFS, "srv returned malformed symlink buffer\n");
+ rc = -EIO;
+ goto out;
+ }
+
+ /*
+ * Check that buffer does not contain UTF-16 null codepoint in unicode
+ * mode or null byte in non-unicode mode because Linux cannot process
+ * symlink with null byte.
+ */
+ if ((unicode && UniStrnlen((wchar_t *)buf, len/2) != len/2) ||
+ (!unicode && strnlen(buf, len) != len)) {
+ cifs_dbg(VFS, "srv returned null byte in native symlink target location\n");
+ rc = -EIO;
+ goto out;
+ }
+
+ smb_target = cifs_strndup_from_utf16(buf, len, unicode, cifs_sb->local_nls);
+ if (!smb_target) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ if (smb_target[0] == sep && relative) {
+ /*
+ * This is a relative SMB symlink from the top of the share,
+ * which is the top level directory of the Linux mount point.
+ * Linux does not support such relative symlinks, so convert
+ * it to the relative symlink from the current directory.
+ * full_path is the SMB path to the symlink (from which is
+ * extracted current directory) and smb_target is the SMB path
+ * where symlink points, therefore full_path must always be on
+ * the SMB share.
+ */
+ int smb_target_len = strlen(smb_target)+1;
+ levels = 0;
+ for (i = 1; full_path[i]; i++) { /* i=1 to skip leading sep */
+ if (full_path[i] == sep)
+ levels++;
+ }
+ linux_target = kmalloc(levels*3 + smb_target_len, GFP_KERNEL);
+ if (!linux_target) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ for (i = 0; i < levels; i++) {
+ linux_target[i*3 + 0] = '.';
+ linux_target[i*3 + 1] = '.';
+ linux_target[i*3 + 2] = sep;
+ }
+ memcpy(linux_target + levels*3, smb_target+1, smb_target_len); /* +1 to skip leading sep */
+ } else {
+ linux_target = smb_target;
+ smb_target = NULL;
+ }
+
+ if (sep == '\\')
+ convert_delimiter(linux_target, '/');
+
+ rc = 0;
+ *target = linux_target;
+
+ cifs_dbg(FYI, "%s: symlink target: %s\n", __func__, *target);
+
+out:
+ if (rc != 0)
+ kfree(linux_target);
+ kfree(smb_target);
+ return rc;
+}
+
static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
u32 plen, bool unicode,
struct cifs_sb_info *cifs_sb,
+ const char *full_path,
struct cifs_open_info_data *data)
{
unsigned int len;
@@ -552,20 +638,64 @@ static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
return -EIO;
}
- data->symlink_target = cifs_strndup_from_utf16(sym->PathBuffer + offs,
- len, unicode,
+ return smb2_parse_native_symlink(&data->symlink_target,
+ sym->PathBuffer + offs,
+ len,
+ unicode,
+ le32_to_cpu(sym->Flags) & SYMLINK_FLAG_RELATIVE,
+ full_path,
+ cifs_sb);
+}
+
+static int parse_reparse_wsl_symlink(struct reparse_wsl_symlink_data_buffer *buf,
+ struct cifs_sb_info *cifs_sb,
+ struct cifs_open_info_data *data)
+{
+ int len = le16_to_cpu(buf->ReparseDataLength);
+ int symname_utf8_len;
+ __le16 *symname_utf16;
+ int symname_utf16_len;
+
+ if (len <= sizeof(buf->Flags)) {
+ cifs_dbg(VFS, "srv returned malformed wsl symlink buffer\n");
+ return -EIO;
+ }
+
+ /* PathBuffer is in UTF-8 but without trailing null-term byte */
+ symname_utf8_len = len - sizeof(buf->Flags);
+ /*
+ * Check that buffer does not contain null byte
+ * because Linux cannot process symlink with null byte.
+ */
+ if (strnlen(buf->PathBuffer, symname_utf8_len) != symname_utf8_len) {
+ cifs_dbg(VFS, "srv returned null byte in wsl symlink target location\n");
+ return -EIO;
+ }
+ symname_utf16 = kzalloc(symname_utf8_len * 2, GFP_KERNEL);
+ if (!symname_utf16)
+ return -ENOMEM;
+ symname_utf16_len = utf8s_to_utf16s(buf->PathBuffer, symname_utf8_len,
+ UTF16_LITTLE_ENDIAN,
+ symname_utf16, symname_utf8_len * 2);
+ if (symname_utf16_len < 0) {
+ kfree(symname_utf16);
+ return symname_utf16_len;
+ }
+ symname_utf16_len *= 2; /* utf8s_to_utf16s() returns number of u16 items, not byte length */
+
+ data->symlink_target = cifs_strndup_from_utf16((u8 *)symname_utf16,
+ symname_utf16_len, true,
cifs_sb->local_nls);
+ kfree(symname_utf16);
if (!data->symlink_target)
return -ENOMEM;
- convert_delimiter(data->symlink_target, '/');
- cifs_dbg(FYI, "%s: target path: %s\n", __func__, data->symlink_target);
-
return 0;
}
int parse_reparse_point(struct reparse_data_buffer *buf,
u32 plen, struct cifs_sb_info *cifs_sb,
+ const char *full_path,
bool unicode, struct cifs_open_info_data *data)
{
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
@@ -580,12 +710,20 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
case IO_REPARSE_TAG_SYMLINK:
return parse_reparse_symlink(
(struct reparse_symlink_data_buffer *)buf,
- plen, unicode, cifs_sb, data);
+ plen, unicode, cifs_sb, full_path, data);
case IO_REPARSE_TAG_LX_SYMLINK:
+ return parse_reparse_wsl_symlink(
+ (struct reparse_wsl_symlink_data_buffer *)buf,
+ cifs_sb, data);
case IO_REPARSE_TAG_AF_UNIX:
case IO_REPARSE_TAG_LX_FIFO:
case IO_REPARSE_TAG_LX_CHR:
case IO_REPARSE_TAG_LX_BLK:
+ if (le16_to_cpu(buf->ReparseDataLength) != 0) {
+ cifs_dbg(VFS, "srv returned malformed buffer for reparse point: 0x%08x\n",
+ le32_to_cpu(buf->ReparseTag));
+ return -EIO;
+ }
break;
default:
cifs_tcon_dbg(VFS | ONCE, "unhandled reparse tag: 0x%08x\n",
@@ -596,6 +734,7 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
}
int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
+ const char *full_path,
struct kvec *rsp_iov,
struct cifs_open_info_data *data)
{
@@ -605,7 +744,7 @@ int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
buf = (struct reparse_data_buffer *)((u8 *)io +
le32_to_cpu(io->OutputOffset));
- return parse_reparse_point(buf, plen, cifs_sb, true, data);
+ return parse_reparse_point(buf, plen, cifs_sb, full_path, true, data);
}
static void wsl_to_fattr(struct cifs_open_info_data *data,
generated by cgit (git 2.34.1) at 2025-05-29 14:26:03 +0000