fs: ocfs2: replace strlcpy with sysfs_emit

strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with
sysfs_emit().

Direct replacement is safe here since its ok for `kernel_param_ops.get()`
to return -errno [3].

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
[3] https://elixir.bootlin.com/linux/v6.5/source/include/linux/moduleparam.h#L52

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Azeem Shaikh <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Joseph Qi <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Junxiao Bi <[email protected]>
Cc: Changwei Ge <[email protected]>
Cc: Gang He <[email protected]>
Cc: Jun Piao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index 81265123ce6c..b38776ba3306 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -80,8 +80,7 @@ static int param_set_dlmfs_capabilities(const char *val,
 static int param_get_dlmfs_capabilities(char *buffer,
 					const struct kernel_param *kp)
 {
-	return strlcpy(buffer, DLMFS_CAPABILITIES,
-		       strlen(DLMFS_CAPABILITIES) + 1);
+	return sysfs_emit(buffer, DLMFS_CAPABILITIES);
 }
 module_param_call(capabilities, param_set_dlmfs_capabilities,
 		  param_get_dlmfs_capabilities, NULL, 0444);