From: Ryan Mallon Date: Thu, 9 Jan 2014 18:14:07 +0000 (+0100) Subject: fakeidentd: fix use-after-free X-Git-Tag: 1_23_0~228 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=89deb22f9745e145fdbb4fbe985cfa9e20e90024;p=oweals%2Fbusybox.git fakeidentd: fix use-after-free function old new delta do_rd 199 197 -2 Signed-off-by: Ryan Mallon Signed-off-by: Denys Vlasenko --- diff --git a/networking/isrv_identd.c b/networking/isrv_identd.c index a41405c33..c6b0f6528 100644 --- a/networking/isrv_identd.c +++ b/networking/isrv_identd.c @@ -51,19 +51,18 @@ static int do_rd(int fd, void **paramp) { identd_buf_t *buf = *paramp; char *cur, *p; - int retval = 0; /* session is ok (so far) */ int sz; cur = buf->buf + buf->pos; if (buf->fd_flag & O_NONBLOCK) fcntl(fd, F_SETFL, buf->fd_flag); - sz = safe_read(fd, cur, sizeof(buf->buf) - buf->pos); + sz = safe_read(fd, cur, sizeof(buf->buf) - 1 - buf->pos); if (sz < 0) { if (errno != EAGAIN) - goto term; /* terminate this session if !EAGAIN */ - goto ok; + goto term; + return 0; /* "session is ok" */ } buf->pos += sz; @@ -71,19 +70,19 @@ static int do_rd(int fd, void **paramp) p = strpbrk(cur, "\r\n"); if (p) *p = '\0'; - if (!p && sz && buf->pos <= (int)sizeof(buf->buf)) - goto ok; + if (!p && sz && buf->pos < (int)sizeof(buf->buf)) + return 0; /* "session is ok" */ + /* Terminate session. If we are in server mode, then * fd is still in nonblocking mode - we never block here */ - if (fd == 0) fd++; /* inetd mode? then write to fd 1 */ + if (fd == 0) + fd++; /* inetd mode? then write to fd 1 */ fdprintf(fd, "%s : USERID : UNIX : %s\r\n", buf->buf, bogouser); - term: - free(buf); - retval = 1; /* terminate */ - ok: if (buf->fd_flag & O_NONBLOCK) fcntl(fd, F_SETFL, buf->fd_flag & ~O_NONBLOCK); - return retval; + term: + free(buf); + return 1; /* "terminate" */ } static int do_timeout(void **paramp UNUSED_PARAM) @@ -120,7 +119,7 @@ int fakeidentd_main(int argc UNUSED_PARAM, char **argv) opt = getopt32(argv, "fiwb:", &bind_address); strcpy(bogouser, "nobody"); if (argv[optind]) - strncpy(bogouser, argv[optind], sizeof(bogouser)); + strncpy(bogouser, argv[optind], sizeof(bogouser) - 1); /* Daemonize if no -f and no -i and no -w */ if (!(opt & OPT_fiw))