6667a78c9b
mbedtls_net_poll() and mbedtls_net_recv_timeout() rely on select(), which represents sets of file descriptors through the fd_set type. This type cannot hold file descriptors larger than FD_SETSIZE. Make sure that these functions identify this failure code. Without a proper range check of the file descriptor in the mbedtls_net_xxx function, this test fails when running with UBSan: ``` net_poll beyond FD_SETSIZE ........................................ source/library/net_sockets.c:482:9: runtime error: index 16 out of bounds for type '__fd_mask [16]' SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior source/library/net_sockets.c:482:9 in ``` This is a non-regression test for https://github.com/ARMmbed/mbedtls/issues/4169 . The implementation of this test is specific to Unix-like platforms. Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
132 lines
4 KiB
Text
132 lines
4 KiB
Text
/* BEGIN_HEADER */
|
|
|
|
#include "mbedtls/net_sockets.h"
|
|
|
|
#if defined(unix) || defined(__unix__) || defined(__unix) || \
|
|
defined(__APPLE__) || defined(__QNXNTO__) || \
|
|
defined(__HAIKU__) || defined(__midipix__)
|
|
#define MBEDTLS_PLATFORM_IS_UNIXLIKE
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PLATFORM_IS_UNIXLIKE)
|
|
#include <sys/fcntl.h>
|
|
#include <sys/resource.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/time.h>
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
#endif
|
|
|
|
|
|
#if defined(MBEDTLS_PLATFORM_IS_UNIXLIKE)
|
|
/** Open a file on the given file descriptor.
|
|
*
|
|
* This is disruptive if there is already something open on that descriptor.
|
|
* Caller beware.
|
|
*
|
|
* \param ctx An initialized, but unopened socket context.
|
|
* On success, it refers to the opened file (\p wanted_fd).
|
|
* \param wanted_fd The desired file descriptor.
|
|
*
|
|
* \return \c 0 on succes, a negative error code on error.
|
|
*/
|
|
static int open_file_on_fd( mbedtls_net_context *ctx, int wanted_fd )
|
|
{
|
|
int got_fd = open( "/dev/null", O_RDONLY );
|
|
TEST_ASSERT( got_fd >= 0 );
|
|
if( got_fd != wanted_fd )
|
|
{
|
|
TEST_ASSERT( dup2( got_fd, wanted_fd ) >= 0 );
|
|
TEST_ASSERT( close( got_fd ) >= 0 );
|
|
}
|
|
ctx->fd = wanted_fd;
|
|
return( 0 );
|
|
exit:
|
|
return( -1 );
|
|
}
|
|
#endif /* MBEDTLS_PLATFORM_IS_UNIXLIKE */
|
|
|
|
/* END_HEADER */
|
|
|
|
/* BEGIN_DEPENDENCIES
|
|
* depends_on:MBEDTLS_NET_C
|
|
* END_DEPENDENCIES
|
|
*/
|
|
|
|
/* BEGIN_CASE */
|
|
void context_init_free( int reinit )
|
|
{
|
|
mbedtls_net_context ctx;
|
|
|
|
mbedtls_net_init( &ctx );
|
|
mbedtls_net_free( &ctx );
|
|
|
|
if( reinit )
|
|
mbedtls_net_init( &ctx );
|
|
mbedtls_net_free( &ctx );
|
|
|
|
/* This test case always succeeds, functionally speaking. A plausible
|
|
* bug might trigger an invalid pointer dereference or a memory leak. */
|
|
goto exit;
|
|
}
|
|
/* END_CASE */
|
|
|
|
/* BEGIN_CASE depends_on:MBEDTLS_PLATFORM_IS_UNIXLIKE */
|
|
void poll_beyond_fd_setsize( )
|
|
{
|
|
/* Test that mbedtls_net_poll does not misbehave when given a file
|
|
* descriptor beyond FD_SETSIZE. This code is specific to platforms
|
|
* with a Unix-like select() function. */
|
|
|
|
struct rlimit rlim_nofile;
|
|
int restore_rlim_nofile = 0;
|
|
int ret;
|
|
mbedtls_net_context ctx;
|
|
uint8_t buf[1];
|
|
|
|
mbedtls_net_init( &ctx );
|
|
|
|
/* On many systems, by default, the maximum permitted file descriptor
|
|
* number is less or equal to FD_SETSIZE. If so, raise the limit if
|
|
* possible.
|
|
*
|
|
* If the limit can't be raised, a newly open file descriptor
|
|
* won't be higher than FD_SETSIZE, so the test is not necessary and we
|
|
* mark it as skipped.
|
|
*/
|
|
TEST_ASSERT( getrlimit( RLIMIT_NOFILE, &rlim_nofile ) == 0 );
|
|
if( rlim_nofile.rlim_cur <= FD_SETSIZE + 1 )
|
|
{
|
|
rlim_t old_rlim_cur = rlim_nofile.rlim_cur;
|
|
rlim_nofile.rlim_cur = FD_SETSIZE + 1;
|
|
TEST_ASSUME( setrlimit( RLIMIT_NOFILE, &rlim_nofile ) == 0 );
|
|
rlim_nofile.rlim_cur = old_rlim_cur;
|
|
restore_rlim_nofile = 1;
|
|
}
|
|
|
|
TEST_ASSERT( open_file_on_fd( &ctx, FD_SETSIZE ) == 0 );
|
|
|
|
/* In principle, mbedtls_net_poll() with valid arguments should succeed.
|
|
* However, we know that on Unix-like platforms (and others), this function
|
|
* is implemented on top of select() and fd_set, which do not support
|
|
* file descriptors beyond FD_SETSIZE. So we expect to hit this platform
|
|
* limitation.
|
|
*
|
|
* If mbedtls_net_poll() does not proprely check that ctx.fd is in range,
|
|
* it may still happen to return the expected failure code, but if this
|
|
* is problematic on the particular platform where the code is running,
|
|
* a memory sanitizer such as UBSan should catch it.
|
|
*/
|
|
ret = mbedtls_net_poll( &ctx, MBEDTLS_NET_POLL_READ, 0 );
|
|
TEST_EQUAL( ret, MBEDTLS_ERR_NET_POLL_FAILED );
|
|
|
|
/* mbedtls_net_recv_timeout() uses select() and fd_set in the same way. */
|
|
ret = mbedtls_net_recv_timeout( &ctx, buf, sizeof( buf ), 0 );
|
|
TEST_EQUAL( ret, MBEDTLS_ERR_NET_POLL_FAILED );
|
|
|
|
exit:
|
|
mbedtls_net_free( &ctx );
|
|
if( restore_rlim_nofile )
|
|
setrlimit( RLIMIT_NOFILE, &rlim_nofile );
|
|
}
|
|
/* END_CASE */
|