+Sai
On 4/13/2020 2:43 AM, David Binderman wrote:
> Hello there,
>
> Source code is
>
> while (fgets(temp, 1024, fp)) {
>
> but
>
> char *token_array[8], temp[512];
>
> Use of compiler flag -D_FORTIFY_SOURCE=2 would have found the problem.
> For example:
>
> # include <stdio.h>
>
> extern void g( int);
>
> void
> f( FILE * fp)
> {
> char buf[ 100];
>
> while (fgets( buf, 200, fp) != 0)
> {
> g( 1);
> }
> }
>
> gives
>
> $ /home/dcb/gcc/results/bin/gcc -c -g -O2 -D_FORTIFY_SOURCE=2 apr13c.cc
> In file included from /usr/include/stdio.h:867,
> from apr13c.cc:2:
> In function ‘char* fgets(char*, int, FILE*)’,
> inlined from ‘void f(FILE*)’ at apr13c.cc:11:14:
> /usr/include/bits/stdio2.h:263:26: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer [-Wattribute-warning]
>
> I suggest switch on compiler flag -D_FORTIFY_SOURCE=2 in
> all development builds.
>
Thank you very much for catching this David.
Sai: could you include this fix in your upcoming series of fixes? Using
the pattern of "fgets(buf, sizeof(buf), ...)" instead of hard coding the
size should be helpful here.
Reinette
While running seccomp_bpf, kill_after_ptrace() gets stuck if we run it
via /usr/bin/timeout (that is the default), until the timeout expires.
This is because /usr/bin/timeout is preventing to properly deliver
signals to ptrace'd children (SIGSYS in this case).
This problem can be easily reproduced by running:
$ sudo make TARGETS=seccomp kselftest
...
# [ RUN ] TRACE_syscall.skip_a#
not ok 1 selftests: seccomp: seccomp_bpf # TIMEOUT
The test is hanging at this point until the timeout expires and then it
reports the timeout error.
Prevent this problem by passing --foreground to /usr/bin/timeout,
allowing to properly deliver signals to children processes.
Signed-off-by: Andrea Righi <andrea.righi(a)canonical.com>
---
tools/testing/selftests/kselftest/runner.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh
index e84d901f8567..676b3a8b114d 100644
--- a/tools/testing/selftests/kselftest/runner.sh
+++ b/tools/testing/selftests/kselftest/runner.sh
@@ -33,7 +33,7 @@ tap_timeout()
{
# Make sure tests will time out if utility is available.
if [ -x /usr/bin/timeout ] ; then
- /usr/bin/timeout "$kselftest_timeout" "$1"
+ /usr/bin/timeout --foreground "$kselftest_timeout" "$1"
else
"$1"
fi
--
2.25.1