vfs_splice_read() has a permission hook inside rw_verify_area() and it is called from splice_file_to_pipe(), which is called from do_splice() and do_sendfile(). do_sendfile() already has a rw_verify_area() check for the entire range. do_splice() has a rw_verify_check() for the splice to file case, not for the splice from file case. Add the rw_verify_area() check for splice from file case in do_splice() and use a variant of vfs_splice_read() without rw_verify_area() check in splice_file_to_pipe() to avoid the redundant rw_verify_area() checks. This is needed for fanotify "pre content" events. Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> --- fs/splice.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/splice.c b/fs/splice.c index 6fc2c27e9520..d4fdd44c0b32 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1239,7 +1239,7 @@ long splice_file_to_pipe(struct file *in, pipe_lock(opipe); ret = wait_for_space(opipe, flags); if (!ret) - ret = vfs_splice_read(in, offset, opipe, len, flags); + ret = do_splice_read(in, offset, opipe, len, flags); pipe_unlock(opipe); if (ret > 0) wakeup_pipe_readers(opipe); @@ -1316,6 +1316,10 @@ long do_splice(struct file *in, loff_t *off_in, struct file *out, offset = in->f_pos; } + ret = rw_verify_area(READ, in, &offset, len); + if (unlikely(ret < 0)) + return ret; + if (out->f_flags & O_NONBLOCK) flags |= SPLICE_F_NONBLOCK; -- 2.34.1
