[committed] fortify: Fix spurious warning with realpath
Commit Message
The length and object size arguments were swapped around for realpath.
Also add a smoke test so that any changes in this area get caught in
future.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
---
debug/Makefile | 3 ++-
debug/tst-realpath-chk.c | 37 +++++++++++++++++++++++++++++++++++++
stdlib/bits/stdlib.h | 2 +-
3 files changed, 40 insertions(+), 2 deletions(-)
create mode 100644 debug/tst-realpath-chk.c
Comments
Thank Siddhesh,
This seems to fix the issue I reported.
On Fri, Dec 17, 2021 at 5:58 AM Siddhesh Poyarekar via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> The length and object size arguments were swapped around for realpath.
> Also add a smoke test so that any changes in this area get caught in
> future.
>
> Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> debug/Makefile | 3 ++-
> debug/tst-realpath-chk.c | 37 +++++++++++++++++++++++++++++++++++++
> stdlib/bits/stdlib.h | 2 +-
> 3 files changed, 40 insertions(+), 2 deletions(-)
> create mode 100644 debug/tst-realpath-chk.c
>
> diff --git a/debug/Makefile b/debug/Makefile
> index 357f888246..bc37e466ee 100644
> --- a/debug/Makefile
> +++ b/debug/Makefile
> @@ -108,6 +108,7 @@ CFLAGS-tst-longjmp_chk2.c += -fexceptions -fasynchronous-unwind-tables
> CPPFLAGS-tst-longjmp_chk2.c += -D_FORTIFY_SOURCE=1
> CFLAGS-tst-longjmp_chk3.c += -fexceptions -fasynchronous-unwind-tables
> CPPFLAGS-tst-longjmp_chk3.c += -D_FORTIFY_SOURCE=1
> +CPPFLAGS-tst-realpath-chk.c += -D_FORTIFY_SOURCE=2
>
> # We know these tests have problems with format strings, this is what
> # we are testing. Disable that warning. They are also testing
> @@ -155,7 +156,7 @@ tests = backtrace-tst tst-longjmp_chk tst-chk1 tst-chk2 tst-chk3 \
> tst-lfschk1 tst-lfschk2 tst-lfschk3 test-strcpy_chk test-stpcpy_chk \
> tst-chk4 tst-chk5 tst-chk6 tst-chk7 tst-chk8 tst-lfschk4 tst-lfschk5 \
> tst-lfschk6 tst-longjmp_chk2 tst-backtrace2 tst-backtrace3 \
> - tst-backtrace4 tst-backtrace5 tst-backtrace6
> + tst-backtrace4 tst-backtrace5 tst-backtrace6 tst-realpath-chk
>
> ifeq ($(have-ssp),yes)
> tests += tst-ssp-1
> diff --git a/debug/tst-realpath-chk.c b/debug/tst-realpath-chk.c
> new file mode 100644
> index 0000000000..a8fcb327c4
> --- /dev/null
> +++ b/debug/tst-realpath-chk.c
> @@ -0,0 +1,37 @@
> +/* Smoke test to verify that realpath does not cause spurious warnings.
> + Copyright The GNU Toolchain Authors.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <limits.h>
> +#include <stdlib.h>
> +
> +#include <support/check.h>
> +#include <support/support.h>
> +
> +static int
> +do_test (void)
> +{
> +#ifdef PATH_MAX
> + char buf[PATH_MAX + 1];
> + char *res = realpath (".", buf);
> + TEST_VERIFY (res == buf);
> +#endif
> +
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/stdlib/bits/stdlib.h b/stdlib/bits/stdlib.h
> index 067115eeca..ccacbdf76a 100644
> --- a/stdlib/bits/stdlib.h
> +++ b/stdlib/bits/stdlib.h
> @@ -42,7 +42,7 @@ __NTH (realpath (const char *__restrict __name, char *__restrict __resolved))
> return __realpath_alias (__name, __resolved);
>
> #if defined _LIBC_LIMITS_H_ && defined PATH_MAX
> - if (__glibc_unsafe_len (sz, sizeof (char), PATH_MAX))
> + if (__glibc_unsafe_len (PATH_MAX, sizeof (char), sz))
> return __realpath_chk_warn (__name, __resolved, sz);
> #endif
> return __realpath_chk (__name, __resolved, sz);
> --
> 2.31.1
>
@@ -108,6 +108,7 @@ CFLAGS-tst-longjmp_chk2.c += -fexceptions -fasynchronous-unwind-tables
CPPFLAGS-tst-longjmp_chk2.c += -D_FORTIFY_SOURCE=1
CFLAGS-tst-longjmp_chk3.c += -fexceptions -fasynchronous-unwind-tables
CPPFLAGS-tst-longjmp_chk3.c += -D_FORTIFY_SOURCE=1
+CPPFLAGS-tst-realpath-chk.c += -D_FORTIFY_SOURCE=2
# We know these tests have problems with format strings, this is what
# we are testing. Disable that warning. They are also testing
@@ -155,7 +156,7 @@ tests = backtrace-tst tst-longjmp_chk tst-chk1 tst-chk2 tst-chk3 \
tst-lfschk1 tst-lfschk2 tst-lfschk3 test-strcpy_chk test-stpcpy_chk \
tst-chk4 tst-chk5 tst-chk6 tst-chk7 tst-chk8 tst-lfschk4 tst-lfschk5 \
tst-lfschk6 tst-longjmp_chk2 tst-backtrace2 tst-backtrace3 \
- tst-backtrace4 tst-backtrace5 tst-backtrace6
+ tst-backtrace4 tst-backtrace5 tst-backtrace6 tst-realpath-chk
ifeq ($(have-ssp),yes)
tests += tst-ssp-1
new file mode 100644
@@ -0,0 +1,37 @@
+/* Smoke test to verify that realpath does not cause spurious warnings.
+ Copyright The GNU Toolchain Authors.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <limits.h>
+#include <stdlib.h>
+
+#include <support/check.h>
+#include <support/support.h>
+
+static int
+do_test (void)
+{
+#ifdef PATH_MAX
+ char buf[PATH_MAX + 1];
+ char *res = realpath (".", buf);
+ TEST_VERIFY (res == buf);
+#endif
+
+ return 0;
+}
+
+#include <support/test-driver.c>
@@ -42,7 +42,7 @@ __NTH (realpath (const char *__restrict __name, char *__restrict __resolved))
return __realpath_alias (__name, __resolved);
#if defined _LIBC_LIMITS_H_ && defined PATH_MAX
- if (__glibc_unsafe_len (sz, sizeof (char), PATH_MAX))
+ if (__glibc_unsafe_len (PATH_MAX, sizeof (char), sz))
return __realpath_chk_warn (__name, __resolved, sz);
#endif
return __realpath_chk (__name, __resolved, sz);