From: Victor Stinner Date: Tue, 20 Sep 2016 20:49:52 +0000 (+0200) Subject: (Merge 3.5) Catch EPERM error in py_getrandom() X-Git-Tag: v3.6.0b2~153 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=75024c6589539f72af69ce61cd6493b193989c2d;p=python (Merge 3.5) Catch EPERM error in py_getrandom() Issue #27955: Fallback on reading /dev/urandom device when the getrandom() syscall fails with EPERM, for example when blocked by SECCOMP. --- 75024c6589539f72af69ce61cd6493b193989c2d diff --cc Misc/NEWS index 0a021ea155,f5efee1d1a..97f669d665 --- a/Misc/NEWS +++ b/Misc/NEWS @@@ -10,10 -10,9 +10,13 @@@ What's New in Python 3.6.0 beta Core and Builtins ----------------- + - Issue #27955: Fallback on reading /dev/urandom device when the getrandom() + syscall fails with EPERM, for example when blocked by SECCOMP. + +- Issue #28192: Don't import readline in isolated mode. + +- Upgrade internal unicode databases to Unicode version 9.0.0. + - Issue #28131: Fix a regression in zipimport's compile_source(). zipimport should use the same optimization level as the interpreter. diff --cc Python/random.c index ea506eeeb2,f2ada5f0d8..6f9f711074 --- a/Python/random.c +++ b/Python/random.c @@@ -128,14 -128,19 +128,14 @@@ py_getentropy(char *buffer, Py_ssize_t getrandom() failed with EINTR and the Python signal handler raised an exception, or getrandom() failed with a different error. */ static int -py_getrandom(void *buffer, Py_ssize_t size, int raise) +py_getrandom(void *buffer, Py_ssize_t size, int blocking, int raise) { /* Is getrandom() supported by the running kernel? Set to 0 if getrandom() - fails with ENOSYS. Need Linux kernel 3.17 or newer, or Solaris 11.3 - or newer */ + failed with ENOSYS or EPERM. Need Linux kernel 3.17 or newer, or Solaris + 11.3 or newer */ static int getrandom_works = 1; - - /* getrandom() on Linux will block if called before the kernel has - * initialized the urandom entropy pool. This will cause Python - * to hang on startup if called very early in the boot process - - * see https://bugs.python.org/issue26839. To avoid this, use the - * GRND_NONBLOCK flag. */ - const int flags = GRND_NONBLOCK; + int flags; + char *dest; long n; if (!getrandom_works) { @@@ -246,74 -302,61 +249,74 @@@ dev_urandom(char *buffer, Py_ssize_t si if (res == 1) { return 0; } - /* getrandom() is not supported by the running kernel, fall back - on reading /dev/urandom */ + /* getrandom() failed with ENOSYS or EPERM, + fall back on reading /dev/urandom */ #endif - if (urandom_cache.fd >= 0) { - /* Does the fd point to the same thing as before? (issue #21207) */ - if (_Py_fstat_noraise(urandom_cache.fd, &st) - || st.st_dev != urandom_cache.st_dev - || st.st_ino != urandom_cache.st_ino) { - /* Something changed: forget the cached fd (but don't close it, - since it probably points to something important for some - third-party code). */ - urandom_cache.fd = -1; - } - } - if (urandom_cache.fd >= 0) - fd = urandom_cache.fd; - else { - fd = _Py_open("/dev/urandom", O_RDONLY); - if (fd < 0) { - if (errno == ENOENT || errno == ENXIO || - errno == ENODEV || errno == EACCES) - PyErr_SetString(PyExc_NotImplementedError, - "/dev/urandom (or equivalent) not found"); - /* otherwise, keep the OSError exception raised by _Py_open() */ - return -1; - } + + if (raise) { + struct _Py_stat_struct st; + if (urandom_cache.fd >= 0) { - /* urandom_fd was initialized by another thread while we were - not holding the GIL, keep it. */ - close(fd); - fd = urandom_cache.fd; + /* Does the fd point to the same thing as before? (issue #21207) */ + if (_Py_fstat_noraise(urandom_cache.fd, &st) + || st.st_dev != urandom_cache.st_dev + || st.st_ino != urandom_cache.st_ino) { + /* Something changed: forget the cached fd (but don't close it, + since it probably points to something important for some + third-party code). */ + urandom_cache.fd = -1; + } } + if (urandom_cache.fd >= 0) + fd = urandom_cache.fd; else { - if (_Py_fstat(fd, &st)) { - close(fd); + fd = _Py_open("/dev/urandom", O_RDONLY); + if (fd < 0) { + if (errno == ENOENT || errno == ENXIO || + errno == ENODEV || errno == EACCES) + PyErr_SetString(PyExc_NotImplementedError, + "/dev/urandom (or equivalent) not found"); + /* otherwise, keep the OSError exception raised by _Py_open() */ return -1; } + if (urandom_cache.fd >= 0) { + /* urandom_fd was initialized by another thread while we were + not holding the GIL, keep it. */ + close(fd); + fd = urandom_cache.fd; + } else { - urandom_cache.fd = fd; - urandom_cache.st_dev = st.st_dev; - urandom_cache.st_ino = st.st_ino; + if (_Py_fstat(fd, &st)) { + close(fd); + return -1; + } + else { + urandom_cache.fd = fd; + urandom_cache.st_dev = st.st_dev; + urandom_cache.st_ino = st.st_ino; + } } } - } - do { - n = _Py_read(fd, buffer, (size_t)size); - if (n == -1) { - return -1; - } - if (n == 0) { - PyErr_Format(PyExc_RuntimeError, - "Failed to read %zi bytes from /dev/urandom", - size); + do { + n = _Py_read(fd, buffer, (size_t)size); + if (n == -1) + return -1; + if (n == 0) { + PyErr_Format(PyExc_RuntimeError, + "Failed to read %zi bytes from /dev/urandom", + size); + return -1; + } + + buffer += n; + size -= n; + } while (0 < size); + } + else { + fd = _Py_open_noraise("/dev/urandom", O_RDONLY); + if (fd < 0) { return -1; }