commit 0e0cf4abd80249faa23f2bbdb89e62ba96c898f0 Author: Nick Mathewson <nickm@torproject.org> Date: Wed May 29 09:38:32 2019 -0400 Tweak comments in tor_vasprintf(), and add a changes file for 30651 --- changes/bug30561 | 6 ++++++ src/common/compat.c | 10 ++++++---- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/changes/bug30561 b/changes/bug30561 new file mode 100644 index 000000000..afb3f02c6 --- /dev/null +++ b/changes/bug30561 @@ -0,0 +1,6 @@ + o Minor bugfixes (portability): + - Avoid crashing in our tor_vasprintf() implementation on systems that + define neither vasprintf() nor _vscprintf(). (This bug has been here + long enough that we question whether people are running Tor on such + systems, but we're applying the fix out of caution.) Fixes bug 30561; + bugfix on 0.2.8.2-alpha. Found and fixed by Tobias Stoeckmann. diff --git a/src/common/compat.c b/src/common/compat.c index d3bc2f5fe..ee3bf0fd5 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -554,13 +554,16 @@ tor_vasprintf(char **strp, const char *fmt, va_list args) * characters we need. We give it a try on a short buffer first, since * it might be nice to avoid the second vsnprintf call. */ + /* XXXX This code spent a number of years broken (see bug 30651). It is + * possible that no Tor users actually run on systems without vasprintf() or + * _vscprintf(). If so, we should consider removing this code. */ char buf[128]; int len, r; va_list tmp_args; va_copy(tmp_args, args); - /* Use vsnprintf to retrieve needed length. tor_vsnprintf() is not an option - * here because it will simply return -1 if buf is not large enough to hold the - * complete string. + /* Use vsnprintf to retrieve needed length. tor_vsnprintf() is not an + * option here because it will simply return -1 if buf is not large enough + * to hold the complete string. */ len = vsnprintf(buf, sizeof(buf), fmt, tmp_args); va_end(tmp_args); @@ -3550,4 +3553,3 @@ tor_get_avail_disk_space(const char *path) return -1; #endif } -