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@xxxxxxx> --- fdisk/fdiskdoslabel.c | 2 +- include/randutils.h | 2 +- lib/randutils.c | 8 +++++--- libuuid/src/gen_uuid.c | 17 ++++++++++------- libuuid/src/uuidd.h | 2 +- misc-utils/uuidd.c | 4 ++-- 6 files changed, 20 insertions(+), 15 deletions(-) diff --git a/fdisk/fdiskdoslabel.c b/fdisk/fdiskdoslabel.c index 6a9a044..c6e4198 100644 --- a/fdisk/fdiskdoslabel.c +++ b/fdisk/fdiskdoslabel.c @@ -182,7 +182,7 @@ void create_doslabel(void) unsigned int id; /* random disk signature */ - random_get_bytes(&id, sizeof(id)); + random_get_bytes(&id, sizeof(id), -1); fprintf(stderr, _("Building a new DOS disklabel with disk identifier 0x%08x.\n"), id); diff --git a/include/randutils.h b/include/randutils.h index dec5e35..d5d00f4 100644 --- a/include/randutils.h +++ b/include/randutils.h @@ -7,6 +7,6 @@ #endif extern int random_get_fd(void); -extern void random_get_bytes(void *buf, size_t nbytes); +extern void random_get_bytes(void *buf, size_t nbytes, int fd); #endif diff --git a/lib/randutils.c b/lib/randutils.c index b90c886..0513798 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); } diff --git a/libuuid/src/gen_uuid.c b/libuuid/src/gen_uuid.c index 8ff4129..76f1bbd 100644 --- a/libuuid/src/gen_uuid.c +++ b/libuuid/src/gen_uuid.c @@ -277,7 +277,7 @@ static int get_clock(uint32_t *clock_high, uint32_t *clock_low, } if ((last.tv_sec == 0) && (last.tv_usec == 0)) { - random_get_bytes(&clock_seq, sizeof(clock_seq)); + random_get_bytes(&clock_seq, sizeof(clock_seq), -1); clock_seq &= 0x3FFF; gettimeofday(&last, 0); last.tv_sec--; @@ -434,7 +434,7 @@ int __uuid_generate_time(uuid_t out, int *num) if (!has_init) { if (get_node_id(node_id) <= 0) { - random_get_bytes(node_id, 6); + random_get_bytes(node_id, 6, -1); /* * Set multicast bit, to prevent conflicts * with IEEE 802 addresses obtained from @@ -520,7 +520,7 @@ int uuid_generate_time_safe(uuid_t out) } -void __uuid_generate_random(uuid_t out, int *num) +void __uuid_generate_random(uuid_t out, int *num, int fd) { uuid_t buf; struct uuid uu; @@ -532,7 +532,7 @@ void __uuid_generate_random(uuid_t out, int *num) n = *num; for (i = 0; i < n; i++) { - random_get_bytes(buf, sizeof(buf)); + random_get_bytes(buf, sizeof(buf), fd); uuid_unpack(buf, &uu); uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000; @@ -548,7 +548,7 @@ void uuid_generate_random(uuid_t out) int num = 1; /* No real reason to use the daemon for random uuid's -- yet */ - __uuid_generate_random(out, &num); + __uuid_generate_random(out, &num, -1); } @@ -560,8 +560,11 @@ void uuid_generate_random(uuid_t out) */ void uuid_generate(uuid_t out) { - if (random_get_fd() >= 0) - uuid_generate_random(out); + int fd; + int num = 1; + + if ((fd = random_get_fd()) >= 0) + __uuid_generate_random(out, &num, fd); else uuid_generate_time(out); } diff --git a/libuuid/src/uuidd.h b/libuuid/src/uuidd.h index 27b79c2..2e19522 100644 --- a/libuuid/src/uuidd.h +++ b/libuuid/src/uuidd.h @@ -49,6 +49,6 @@ #define UUIDD_MAX_OP UUIDD_OP_BULK_RANDOM_UUID extern int __uuid_generate_time(uuid_t out, int *num); -extern void __uuid_generate_random(uuid_t out, int *num); +extern void __uuid_generate_random(uuid_t out, int *num, int fd); #endif /* _UUID_UUID_H */ diff --git a/misc-utils/uuidd.c b/misc-utils/uuidd.c index d20526e..d3ed3eb 100644 --- a/misc-utils/uuidd.c +++ b/misc-utils/uuidd.c @@ -442,7 +442,7 @@ static void server_loop(const char *socket_path, const char *pidfile_path, break; case UUIDD_OP_RANDOM_UUID: num = 1; - __uuid_generate_random(uu, &num); + __uuid_generate_random(uu, &num, -1); if (uuidd_cxt->debug) { uuid_unparse(uu, str); fprintf(stderr, _("Generated random UUID: %s\n"), str); @@ -473,7 +473,7 @@ static void server_loop(const char *socket_path, const char *pidfile_path, if (num * UUID_LEN > (int) (sizeof(reply_buf) - sizeof(num))) num = (sizeof(reply_buf) - sizeof(num)) / UUID_LEN; __uuid_generate_random((unsigned char *) reply_buf + - sizeof(num), &num); + sizeof(num), &num, -1); if (uuidd_cxt->debug) { fprintf(stderr, P_("Generated %d UUID:\n", "Generated %d UUIDs:\n", num), num); -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
