PATCH [1/1]: Bug with sockaddr size in net/af_unix/test_unix_oob.c

PATCH [1/1]: Bug with sockaddr size in net/af_unix/test_unix_oob.c

[Mirsad Goran Todorovac]

Hi all,

There is a minor issue that prevents self test net/af_unix to run on my platform:

# ./test_unix_oob
Connect failed: No such file or directory
Terminated

Tracing reveals that bind tried to open a shorter AF_UNIX socket address:

# strace -f ./test_unix_oob
.
.
.
socket(AF_UNIX, SOCK_STREAM, 0)         = 3
getpid()                                = 453059
unlink("unix_oob_453059")               = -1 ENOENT (No such file or directory)
bind(3, {sa_family=AF_UNIX, sun_path="unix_oob_453059"}, 110) = 0
pipe2([4, 5], 0)                        = 0
listen(3, 1)                            = 0
clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fa6a6577a10) = 453060
rt_sigaction(SIGURG, {sa_handler=0x5601e2d014c9, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, 
sa_restorer=0x7fa6a623bcf0}, NULL, 8) = 0
write(5, "S", 1)                        = 1
accept(3, strace: Process 453060 attached
  <unfinished ...>
[pid 453060] set_robust_list(0x7fa6a6577a20, 24) = 0
[pid 453060] socket(AF_UNIX, SOCK_STREAM, 0) = 6
[pid 453060] read(4, "S", 5)            = 1
[pid 453060] connect(6, {sa_family=AF_UNIX, sun_path="unix_oob_45305"}, 16) = -1 ENOENT (No such file or directory)
.
.
.

NOTE: bind used UNIX_AF addr "unix_oob_453059", while producer tries to connect to "unix_oob_45305".

When pids were up to 5 digits it probably did not manifest, but logically the size of the
consumer_addr is sizeof(struct sockaddr_un).

Please find the patch attached:

Thanks,
Mirsad

------------------------------------------------------------------------------------------------
diff --git a/tools/testing/selftests/net/af_unix/test_unix_oob.c b/tools/testing/selftests/net/af_unix/test_unix_oob.c
index b57e91e1c3f2..7ea733239cd9 100644
--- a/tools/testing/selftests/net/af_unix/test_unix_oob.c
+++ b/tools/testing/selftests/net/af_unix/test_unix_oob.c
@@ -124,7 +124,7 @@ void producer(struct sockaddr_un *consumer_addr)

  	wait_for_signal(pipefd[0]);
  	if (connect(cfd, (struct sockaddr *)consumer_addr,
-		     sizeof(struct sockaddr)) != 0) {
+		     sizeof(struct sockaddr_un)) != 0) {
  		perror("Connect failed");
  		kill(0, SIGTERM);
  		exit(1);

--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
-- 
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union

Re: PATCH [1/1]: Bug with sockaddr size in net/af_unix/test_unix_oob.c

[Kuniyuki Iwashima]

From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Date:   Tue, 3 Jan 2023 11:28:19 +0100
> Hi all,
> 
> There is a minor issue that prevents self test net/af_unix to run on my platform:

Hi,

Thanks for the report and fix.

The diff looks good.
Could you post a patch formally following these?

  https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/Documentation/process/maintainer-netdev.rst
  https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/tree/Documentation/process/submitting-patches.rst

Subject should be like

  [PATCH net v1] af_unix: Correct addr size for connect() in test_unix_oob.c.

and please add this tag just before your Signed-off-by tag.

  Fixes: 314001f0bf92 ("af_unix: Add OOB support")


> 
> # ./test_unix_oob
> Connect failed: No such file or directory
> Terminated
> 
> Tracing reveals that bind tried to open a shorter AF_UNIX socket address:

s/bind/connect/


> 
> # strace -f ./test_unix_oob
> .
> .
> .
> socket(AF_UNIX, SOCK_STREAM, 0)         = 3
> getpid()                                = 453059
> unlink("unix_oob_453059")               = -1 ENOENT (No such file or directory)
> bind(3, {sa_family=AF_UNIX, sun_path="unix_oob_453059"}, 110) = 0
> pipe2([4, 5], 0)                        = 0
> listen(3, 1)                            = 0
> clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fa6a6577a10) = 453060
> rt_sigaction(SIGURG, {sa_handler=0x5601e2d014c9, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, 
> sa_restorer=0x7fa6a623bcf0}, NULL, 8) = 0
> write(5, "S", 1)                        = 1
> accept(3, strace: Process 453060 attached
>   <unfinished ...>
> [pid 453060] set_robust_list(0x7fa6a6577a20, 24) = 0
> [pid 453060] socket(AF_UNIX, SOCK_STREAM, 0) = 6
> [pid 453060] read(4, "S", 5)            = 1
> [pid 453060] connect(6, {sa_family=AF_UNIX, sun_path="unix_oob_45305"}, 16) = -1 ENOENT (No such file or directory)
> .
> .
> .
> 
> NOTE: bind used UNIX_AF addr "unix_oob_453059", while producer tries to connect to "unix_oob_45305".
> 
> When pids were up to 5 digits it probably did not manifest, but logically the size of the
> consumer_addr is sizeof(struct sockaddr_un).
> 
> Please find the patch attached:
> 
> Thanks,
> Mirsad
> 
> ------------------------------------------------------------------------------------------------
> diff --git a/tools/testing/selftests/net/af_unix/test_unix_oob.c b/tools/testing/selftests/net/af_unix/test_unix_oob.c
> index b57e91e1c3f2..7ea733239cd9 100644
> --- a/tools/testing/selftests/net/af_unix/test_unix_oob.c
> +++ b/tools/testing/selftests/net/af_unix/test_unix_oob.c
> @@ -124,7 +124,7 @@ void producer(struct sockaddr_un *consumer_addr)
> 
>   	wait_for_signal(pipefd[0]);
>   	if (connect(cfd, (struct sockaddr *)consumer_addr,
> -		     sizeof(struct sockaddr)) != 0) {
> +		     sizeof(struct sockaddr_un)) != 0) {

While at it, please fix the indent.


>   		perror("Connect failed");
>   		kill(0, SIGTERM);
>   		exit(1);
> 
> --
> Mirsad Goran Todorovac
> Sistem inženjer
> Grafički fakultet | Akademija likovnih umjetnosti
> Sveučilište u Zagrebu
> -- 
> System engineer
> Faculty of Graphic Arts | Academy of Fine Arts
> University of Zagreb, Republic of Croatia
> The European Union