From e9bb1f9b12e33fc0b2169b3937dc50c44ad87dd5 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sat, 17 Oct 2015 16:26:08 -0500 Subject: [PATCH] fs/pipe.c: preserve alloc_file() error code If sys_pipe() was unable to allocate a 'struct file', it always failed with ENFILE, which means "The number of simultaneously open files in the system would exceed a system-imposed limit." However, alloc_file() actually returns an ERR_PTR value and might fail with other error codes. Currently, in addition to ENFILE, it can fail with ENOMEM, potentially when there are few open files in the system. Update sys_pipe() to preserve this error code. In a prior submission of a similar patch (1) some concern was raised about introducing a new error code for sys_pipe(). However, for most system calls, programs cannot assume that new error codes will never be introduced. In addition, ENOMEM was, in fact, already a possible error code for sys_pipe(), in the case where the file descriptor table could not be expanded due to insufficient memory. (1) http://comments.gmane.org/gmane.linux.kernel/1357942 Signed-off-by: Eric Biggers Signed-off-by: Al Viro --- fs/pipe.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 8865f7963700..997de3464479 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -693,17 +693,20 @@ int create_pipe_files(struct file **res, int flags) d_instantiate(path.dentry, inode); - err = -ENFILE; f = alloc_file(&path, FMODE_WRITE, &pipefifo_fops); - if (IS_ERR(f)) + if (IS_ERR(f)) { + err = PTR_ERR(f); goto err_dentry; + } f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)); f->private_data = inode->i_pipe; res[0] = alloc_file(&path, FMODE_READ, &pipefifo_fops); - if (IS_ERR(res[0])) + if (IS_ERR(res[0])) { + err = PTR_ERR(res[0]); goto err_file; + } path_get(&path); res[0]->private_data = inode->i_pipe; -- 2.20.1