Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

usbip: deletion of incorrect socket descriptor checking

Browse source 
This patch removes checking of socket descriptor value in daemons.

It was checked to be less than FD_SETSIZE(1024 usually) but it's not
correct.

To be exact, the maximum value of descriptor comes from
rlimit(RLIMIT_NOFILE).

Following kernel code determines the value :
    get_unused_fd_flags() : fs/files.c
    __alloc_fd() : fs/files.c
    expand_files() : fs/files.c

The defalut (soft limit) is defines as INR_OPEN_CUR(1024) in
include/linux/fs.h which is referenced form INIT_RLIMS in
include/asm-generic/resource.h. The value may be modified with ulimt,
sysctl, security configuration and etc.

With the kernel code above, when socket() system call returns positive
value, the value must be within rlimit(RLIMIT_NOFILE). No extra
checking is needed when socket() returns positive.

Without 'usbip: vhci number of ports extension' patch set, there's no
practical problem because of number of USB port restriction. With the
patch set, the value of socket descriptor can exceed FD_SETSIZE(1024
usually) if the rlimit is changed.

Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nobuo Iwata 2016-09-30 14:44:04 +09:00 committed by Greg Kroah-Hartman
parent cbfff98a62
commit 220c61b6f7
1 changed files with 0 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
tools/usb/usbip/src/usbipd.c
View file

@ -398,13 +398,6 @@ static int listen_all_addrinfo(struct addrinfo *ai_head, int sockfdlist[],
* (see do_standalone_mode()) */
usbip_net_set_v6only(sock);
if (sock >= FD_SETSIZE) {
err("FD_SETSIZE: %s: sock=%d, max=%d",
ai_buf, sock, FD_SETSIZE);
close(sock);
continue;
}
ret = bind(sock, ai->ai_addr, ai->ai_addrlen);
if (ret < 0) {
err("bind: %s: %d (%s)",