diff options
Diffstat (limited to 'patches/source/rpcbind/0002-rpcbind-pair-all-svc_getargs-calls-with-svc_freeargs.patch')
| -rw-r--r-- | patches/source/rpcbind/0002-rpcbind-pair-all-svc_getargs-calls-with-svc_freeargs.patch | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/patches/source/rpcbind/0002-rpcbind-pair-all-svc_getargs-calls-with-svc_freeargs.patch b/patches/source/rpcbind/0002-rpcbind-pair-all-svc_getargs-calls-with-svc_freeargs.patch new file mode 100644 index 000000000..060614cc9 --- /dev/null +++ b/patches/source/rpcbind/0002-rpcbind-pair-all-svc_getargs-calls-with-svc_freeargs.patch @@ -0,0 +1,218 @@ +From 7ea36eeece56b59f98e469934e4c20b4da043346 Mon Sep 17 00:00:00 2001 +From: Doran Moppert <dmoppert@redhat.com> +Date: Thu, 11 May 2017 11:42:54 -0400 +Subject: [PATCH 2/6] rpcbind: pair all svc_getargs() calls with svc_freeargs() + to avoid memory leak + +This patch is to address CVE-2017-8779 "rpcbomb" in rpcbind, discussed +at [1], [2], [3]. The last link suggests this issue is actually a bug +in rpcbind, which led me here. + +The leak caused by the reproducer at [4] appears to come from +rpcb_service_4(), in the case where svc_getargs() returns false and the +function had an early return, rather than passing through the cleanup +path at done:, as would otherwise occur. + +It also addresses a couple of other locations where the same fault seems +to exist, though I haven't been able to exercise those. I hope someone +more intimate with rpc(3) can confirm my understanding is correct, and +that I haven't introduced any new bugs. + +Without this patch, using the reproducer (and variants) repeatedly +against rpcbind with a numBytes argument of 1_000_000_000, /proc/$(pidof +rpcbind)/status reports VmSize increase of 976564 kB each call, and +VmRSS increase of around 260 kB every 33 calls - the specific numbers +are probably an artifact of my rhel/glibc version. With the patch, +there is a small (~50 kB) VmSize increase with the first message, but +thereafter both VmSize and VmRSS remain steady. + +[1]: http://seclists.org/oss-sec/2017/q2/209 +[2]: https://bugzilla.redhat.com/show_bug.cgi?id=1448124 +[3]: https://sourceware.org/ml/libc-alpha/2017-05/msg00129.html +[4]: https://github.com/guidovranken/rpcbomb/ + +Signed-off-by: Doran Moppert <dmoppert@redhat.com> +Signed-off-by: Steve Dickson <steved@redhat.com> +--- + src/pmap_svc.c | 56 +++++++++++++++++++++++++++++++++++++++++++++--------- + src/rpcb_svc.c | 2 +- + src/rpcb_svc_4.c | 2 +- + src/rpcb_svc_com.c | 8 ++++++++ + 4 files changed, 57 insertions(+), 11 deletions(-) + +diff --git a/src/pmap_svc.c b/src/pmap_svc.c +index 4c744fe..e926cdc 100644 +--- a/src/pmap_svc.c ++++ b/src/pmap_svc.c +@@ -175,6 +175,7 @@ pmapproc_change(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt, unsigned long + long ans; + uid_t uid; + char uidbuf[32]; ++ int rc = TRUE; + + /* + * Can't use getpwnam here. We might end up calling ourselves +@@ -194,7 +195,8 @@ pmapproc_change(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt, unsigned long + + if (!svc_getargs(xprt, (xdrproc_t) xdr_pmap, (char *)®)) { + svcerr_decode(xprt); +- return (FALSE); ++ rc = FALSE; ++ goto done; + } + #ifdef RPCBIND_DEBUG + if (debugging) +@@ -205,7 +207,8 @@ pmapproc_change(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt, unsigned long + + if (!check_access(xprt, op, reg.pm_prog, PMAPVERS)) { + svcerr_weakauth(xprt); +- return (FALSE); ++ rc = (FALSE); ++ goto done; + } + + rpcbreg.r_prog = reg.pm_prog; +@@ -258,7 +261,16 @@ done_change: + rpcbs_set(RPCBVERS_2_STAT, ans); + else + rpcbs_unset(RPCBVERS_2_STAT, ans); +- return (TRUE); ++done: ++ if (!svc_freeargs(xprt, (xdrproc_t) xdr_pmap, (char *)®)) { ++ if (debugging) { ++ (void) xlog(LOG_DEBUG, "unable to free arguments\n"); ++ if (doabort) { ++ rpcbind_abort(); ++ } ++ } ++ } ++ return (rc); + } + + /* ARGSUSED */ +@@ -272,15 +284,18 @@ pmapproc_getport(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt) + #ifdef RPCBIND_DEBUG + char *uaddr; + #endif ++ int rc = TRUE; + + if (!svc_getargs(xprt, (xdrproc_t) xdr_pmap, (char *)®)) { + svcerr_decode(xprt); +- return (FALSE); ++ rc = FALSE; ++ goto done; + } + + if (!check_access(xprt, PMAPPROC_GETPORT, reg.pm_prog, PMAPVERS)) { + svcerr_weakauth(xprt); +- return FALSE; ++ rc = FALSE; ++ goto done; + } + + #ifdef RPCBIND_DEBUG +@@ -330,21 +345,34 @@ pmapproc_getport(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt) + pmap_ipprot2netid(reg.pm_prot) ?: "<unknown>", + port ? udptrans : ""); + +- return (TRUE); ++done: ++ if (!svc_freeargs(xprt, (xdrproc_t) xdr_pmap, (char *)®)) { ++ if (debugging) { ++ (void) xlog(LOG_DEBUG, "unable to free arguments\n"); ++ if (doabort) { ++ rpcbind_abort(); ++ } ++ } ++ } ++ return (rc); + } + + /* ARGSUSED */ + static bool_t + pmapproc_dump(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt) + { ++ int rc = TRUE; ++ + if (!svc_getargs(xprt, (xdrproc_t)xdr_void, NULL)) { + svcerr_decode(xprt); +- return (FALSE); ++ rc = FALSE; ++ goto done; + } + + if (!check_access(xprt, PMAPPROC_DUMP, 0, PMAPVERS)) { + svcerr_weakauth(xprt); +- return FALSE; ++ rc = FALSE; ++ goto done; + } + + if ((!svc_sendreply(xprt, (xdrproc_t) xdr_pmaplist_ptr, +@@ -354,7 +382,17 @@ pmapproc_dump(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt) + rpcbind_abort(); + } + } +- return (TRUE); ++ ++done: ++ if (!svc_freeargs(xprt, (xdrproc_t) xdr_pmap, (char *)NULL)) { ++ if (debugging) { ++ (void) xlog(LOG_DEBUG, "unable to free arguments\n"); ++ if (doabort) { ++ rpcbind_abort(); ++ } ++ } ++ } ++ return (rc); + } + + int pmap_netid2ipprot(const char *netid) +diff --git a/src/rpcb_svc.c b/src/rpcb_svc.c +index 709e3fb..091f530 100644 +--- a/src/rpcb_svc.c ++++ b/src/rpcb_svc.c +@@ -166,7 +166,7 @@ rpcb_service_3(struct svc_req *rqstp, SVCXPRT *transp) + svcerr_decode(transp); + if (debugging) + (void) xlog(LOG_DEBUG, "rpcbind: could not decode"); +- return; ++ goto done; + } + + if (rqstp->rq_proc == RPCBPROC_SET +diff --git a/src/rpcb_svc_4.c b/src/rpcb_svc_4.c +index 5094879..eebbbbe 100644 +--- a/src/rpcb_svc_4.c ++++ b/src/rpcb_svc_4.c +@@ -218,7 +218,7 @@ rpcb_service_4(struct svc_req *rqstp, SVCXPRT *transp) + svcerr_decode(transp); + if (debugging) + (void) xlog(LOG_DEBUG, "rpcbind: could not decode\n"); +- return; ++ goto done; + } + + if (rqstp->rq_proc == RPCBPROC_SET +diff --git a/src/rpcb_svc_com.c b/src/rpcb_svc_com.c +index 5862c26..cb63afd 100644 +--- a/src/rpcb_svc_com.c ++++ b/src/rpcb_svc_com.c +@@ -927,6 +927,14 @@ error: + if (call_msg.rm_xid != 0) + (void) free_slot_by_xid(call_msg.rm_xid); + out: ++ if (!svc_freeargs(transp, (xdrproc_t) xdr_rmtcall_args, (char *) &a)) { ++ if (debugging) { ++ (void) xlog(LOG_DEBUG, "unable to free arguments\n"); ++ if (doabort) { ++ rpcbind_abort(); ++ } ++ } ++ } + if (local_uaddr) + free(local_uaddr); + if (buf_alloc) +-- +2.13.0 + |