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| author | Pedro Alves <palves@redhat.com> | 2016-05-03 12:16:56 +0100 |
|---|---|---|
| committer | Pedro Alves <palves@redhat.com> | 2016-05-03 12:16:56 +0100 |
| commit | 86f1abec458df24ea7d4a38a7b3e21861c5b9bd8 (patch) | |
| tree | c559abcd6d720378382bd750c7cc1e42918316e1 | |
| parent | 1aa96702887a9c0f66b5d7cab034bf6718796708 (diff) | |
| download | gdb-86f1abec458df24ea7d4a38a7b3e21861c5b9bd8.zip gdb-86f1abec458df24ea7d4a38a7b3e21861c5b9bd8.tar.gz gdb-86f1abec458df24ea7d4a38a7b3e21861c5b9bd8.tar.bz2 | |
Fix gdb/python/python.c use-after-free
Valgrind shows:
==26964== Invalid read of size 1
==26964== at 0x6E14100: __GI_strcmp (strcmp.S:180)
==26964== by 0x6DB55AA: setlocale (setlocale.c:238)
==26964== by 0x4E0455: _initialize_python() (python.c:1731)
==26964== by 0x786731: initialize_all_files() (init.c:319)
==26964== by 0x72EF0A: gdb_init(char*) (top.c:1929)
==26964== by 0x60BCAC: captured_main(void*) (main.c:863)
==26964== by 0x606AD5: catch_errors(int (*)(void*), void*, char*, return_mask) (exceptions.c:234)
==26964== by 0x60C608: gdb_main(captured_main_args*) (main.c:1165)
==26964== by 0x40CAEC: main (gdb.c:32)
==26964== Address 0x81d30a0 is 0 bytes inside a block of size 181 free'd
==26964== at 0x4C29CF0: free (vg_replace_malloc.c:530)
==26964== by 0x6DB5B65: setname (setlocale.c:201)
==26964== by 0x6DB5B65: setlocale (setlocale.c:388)
==26964== by 0x4E037F: _initialize_python() (python.c:1712)
==26964== by 0x786731: initialize_all_files() (init.c:319)
==26964== by 0x72EF0A: gdb_init(char*) (top.c:1929)
==26964== by 0x60BCAC: captured_main(void*) (main.c:863)
==26964== by 0x606AD5: catch_errors(int (*)(void*), void*, char*, return_mask) (exceptions.c:234)
==26964== by 0x60C608: gdb_main(captured_main_args*) (main.c:1165)
==26964== by 0x40CAEC: main (gdb.c:32)
The problem is doing this:
oldloc = setlocale (LC_ALL, NULL);
setlocale (LC_ALL, "");
...
setlocale (LC_ALL, oldloc);
I.e., the second setlocale call frees 'oldloc'.
From http://pubs.opengroup.org/onlinepubs/9699919799/functions/setlocale.html :
"The returned string pointer might be invalidated or the string
content might be overwritten by a subsequent call to setlocale()."
gdb/ChangeLog:
2016-05-03 Pedro Alves <palves@redhat.com>
PR python/20037
* python/python.c (_initialize_python) [IS_PY3K]: xstrdup/xfree
oldloc.
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/python/python.c | 5 |
2 files changed, 10 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c5b7325..8627cb7 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,11 @@ 2016-05-03 Pedro Alves <palves@redhat.com> + PR python/20037 + * python/python.c (_initialize_python) [IS_PY3K]: xstrdup/xfree + oldloc. + +2016-05-03 Pedro Alves <palves@redhat.com> + * python/python.c (_initialize_python) [IS_PY3K]: Remove dead code. diff --git a/gdb/python/python.c b/gdb/python/python.c index ea9cf85..c706644 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -1708,22 +1708,25 @@ message == an error message without a stack will be printed."), progname = concat (ldirname (python_libdir), SLASH_STRING, "bin", SLASH_STRING, "python", (char *) NULL); #ifdef IS_PY3K - oldloc = setlocale (LC_ALL, NULL); + oldloc = xstrdup (setlocale (LC_ALL, NULL)); setlocale (LC_ALL, ""); progsize = strlen (progname); progname_copy = (wchar_t *) PyMem_Malloc ((progsize + 1) * sizeof (wchar_t)); if (!progname_copy) { + xfree (oldloc); fprintf (stderr, "out of memory\n"); return; } count = mbstowcs (progname_copy, progname, progsize + 1); if (count == (size_t) -1) { + xfree (oldloc); fprintf (stderr, "Could not convert python path to string\n"); return; } setlocale (LC_ALL, oldloc); + xfree (oldloc); /* Note that Py_SetProgramName expects the string it is passed to remain alive for the duration of the program's execution, so |