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| author | Petr Uzel <petr.uzel@suse.cz> | 2012-05-03 21:02:01 +0200 |
|---|---|---|
| committer | Karel Zak <kzak@redhat.com> | 2012-05-04 15:14:24 +0200 |
| commit | 6126f7a53c57485a9a29ddd772765695f23c92e6 (patch) | |
| tree | b4f93a19a5459e69a7fa43b773590f42eb927b43 /lib/randutils.c | |
| parent | 881a0f6b286f034c99214c17c81d58b447d5908c (diff) | |
| download | util-linux-6126f7a53c57485a9a29ddd772765695f23c92e6.tar.gz | |
libuuid: avoid double open and leaking descriptor
We are opening /dev/urandom twice in uuid_generate(): first to check if
the file is available and then later __uuid_generate_random() again to
actually get the random data. Moreover, descriptor from the first open
is leaking.
Fix by passign the descriptor down the stack and reusing it there.
References: http://marc.info/?l=util-linux-ng&m=133406051131131&w=2
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
Diffstat (limited to 'lib/randutils.c')
| -rw-r--r-- | lib/randutils.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/randutils.c b/lib/randutils.c index b90c8869..0513798a 100644 --- a/lib/randutils.c +++ b/lib/randutils.c @@ -58,13 +58,15 @@ int random_get_fd(void) * Use /dev/urandom if possible, and if not, * use glibc pseudo-random functions. */ -void random_get_bytes(void *buf, size_t nbytes) +void random_get_bytes(void *buf, size_t nbytes, int fd) { size_t i, n = nbytes; - int fd = random_get_fd(); int lose_counter = 0; unsigned char *cp = (unsigned char *) buf; + if (fd < 0) + fd = random_get_fd(); + if (fd >= 0) { while (n > 0) { ssize_t x = read(fd, cp, n); @@ -111,7 +113,7 @@ int main(int argc, char *argv[]) /* generate and print 10 random numbers */ for (i = 0; i < 10; i++) { - random_get_bytes(&v, sizeof(v)); + random_get_bytes(&v, sizeof(v), -1); printf("%d\n", v); } |