Re: Fw: [Bug 42012] New: regression on 2.6.39.3 with socket/bind; still there in 3.0.4

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mardi 30 août 2011 à 08:47 -0700, Stephen Hemminger a écrit :
> Interesting? Does the kernel ABI include supporting buggy old proprietary
> programs?
> 
> Begin forwarded message:
> 
> Date: Tue, 30 Aug 2011 02:59:32 GMT
> From: bugzilla-daemon@bugzilla.kernel.org
> To: shemminger@linux-foundation.org
> Subject: [Bug 42012] New: regression on 2.6.39.3 with socket/bind; still there in 3.0.4
> 
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=42012
> 
>            Summary: regression on 2.6.39.3 with socket/bind; still there
>                     in 3.0.4
>            Product: Networking
>            Version: 2.5
>     Kernel Version: 2.6.39.3 - 3.0.4
>           Platform: All
>         OS/Version: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: IPV4
>         AssignedTo: shemminger@linux-foundation.org
>         ReportedBy: r_meier@freenet.de
>         Regression: Yes
> 
> 
> Hi,
> 
> the regression has been introduced in 2.6.39.3 with commit
> d0733d2e29b652b2e7b1438ececa732e4eed98eb. I experience this with a proprietary
> binary program. So I cant give you the source code which fails. This program
> used to work before but fails after applying this patch. As far as I understand
> the programm is using this code for ipc communication. I have recorded the
> strace output of the relevant part of the program.
> strace without d0733d2e29b652b2e7b1438ececa732e4eed98eb on kernel 2.6.39.2
> ---------------
> 2056  socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 4
> 2056  bind(4, {sa_family=AF_UNSPEC, sa_data="\0\0\0\0\0\0\0\0\0\0\0\0\0\0"},
> 16) = 0
> 2056  getsockname(4, {sa_family=AF_INET, sin_port=htons(33537),
> sin_addr=inet_addr("0.0.0.0")}, [16]) = 0
> 2056  listen(4, 5)                      = 0
> 2056  setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0
> ---------------
> 
> strace with d0733d2e29b652b2e7b1438ececa732e4eed98eb on kernel 2.6.39.2
> ---------------
> 6190  socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 4
> 6190  bind(4, {sa_family=AF_UNSPEC, sa_data="\0\0\0\0\0\0\0\0\0\0\0\0\0\0"},
> 16) = -1 EINVAL (Invalid argument)
> 6190  dup(2)                            = 11
> 6190  fcntl64(11, F_GETFL)              = 0x8002 (flags O_RDWR|O_LARGEFILE)
> 6190  fstat64(11, {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 3), ...}) = 0
> 6190  mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
> = 0x576ac000
> 6190  _llseek(11, 0, 0xffa03de4, SEEK_CUR) = -1 ESPIPE (Illegal seek)
> 6190  write(11, "ERROR: Failed to bind to interne"..., 66) = 66
> 6190  close(11)                         = 0
> ---------------
> 
> Btw, i have not enough knowledge on this topic to decide whether its the
> programs fault or the kernels fault. The binary program is sybyl8.1 from
> tripos.
> 
> Best regards, Rene
> 

Yep, we should relax the check and accept AF_UNSPEC.

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 1b745d4..60fd64e 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -465,7 +465,7 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	if (addr_len < sizeof(struct sockaddr_in))
 		goto out;
 
-	if (addr->sin_family != AF_INET) {
+	if (addr->sin_family != AF_INET && addr->sin_family != AF_UNSPEC) {
 		err = -EAFNOSUPPORT;
 		goto out;
 	}