commit ed6b0fe710b631b99ed9fc28cefedfe69a16dc55 Author: Brad Hubbard Date: Wed Mar 18 14:51:26 2015 +0530 Use calloc to allocate xports (BZ #17542) If xports is NULL in xprt_register we malloc it but if sock > _rpc_dtablesize() that memory does not get initialised and may in theory contain any value. Later we make a conditional jump in svc_getreq_common based on the uninitialised memory and this caused a general protection fault in rpc.statd on an older version of glibc but this code has not changed since that version. Following is the valgrind warning. ==26802== Conditional jump or move depends on uninitialised value(s) ==26802== at 0x5343A25: svc_getreq_common (in /lib64/libc-2.5.so) ==26802== by 0x534357B: svc_getreqset (in /lib64/libc-2.5.so) ==26802== by 0x10DE1F: ??? (in /sbin/rpc.statd) ==26802== by 0x10D0EF: main (in /sbin/rpc.statd) ==26802== Uninitialised value was created by a heap allocation ==26802== at 0x4C2210C: malloc (vg_replace_malloc.c:195) ==26802== by 0x53438BE: xprt_register (in /lib64/libc-2.5.so) ==26802== by 0x53450DF: svcudp_bufcreate (in /lib64/libc-2.5.so) ==26802== by 0x10FE32: ??? (in /sbin/rpc.statd) ==26802== by 0x10D13E: main (in /sbin/rpc.statd) diff --git glibc-2.17-c758a686/sunrpc/svc.c glibc-2.17-c758a686/sunrpc/svc.c index 8c4e8a5..c6ccf10 100644 --- glibc-2.17-c758a686/sunrpc/svc.c +++ glibc-2.17-c758a686/sunrpc/svc.c @@ -97,8 +97,8 @@ xprt_register (SVCXPRT *xprt) if (xports == NULL) { - xports = (SVCXPRT **) malloc (_rpc_dtablesize () * sizeof (SVCXPRT *)); - if (xports == NULL) /* Donīt add handle */ + xports = (SVCXPRT **) calloc (_rpc_dtablesize (), sizeof (SVCXPRT *)); + if (xports == NULL) /* Don't add handle */ return; }