diff options
Diffstat (limited to 'community-testing/multipath-tools/log_enquery_overflow.patch')
| -rw-r--r-- | community-testing/multipath-tools/log_enquery_overflow.patch | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/community-testing/multipath-tools/log_enquery_overflow.patch b/community-testing/multipath-tools/log_enquery_overflow.patch new file mode 100644 index 000000000..67367c9f4 --- /dev/null +++ b/community-testing/multipath-tools/log_enquery_overflow.patch @@ -0,0 +1,69 @@ +From e1d69df0cdd1627676501df3a533b25ffadaeff0 Mon Sep 17 00:00:00 2001 +From: Arkadiusz Miskiewicz <arekm@maven.pl> +Date: Sat, 27 Nov 2010 19:21:21 +0100 +Subject: [PATCH] multipath-tools overflow + +On Saturday 27 of November 2010, you wrote: + +[...] + +> the whole logarea is memset to 0 by logarea_init(), and each dequeued +> message is also memset to 0 by log_dequeue(), so it seems normal that +> msg->str value is 0x0, but it's really its address that matters. + +Ok, got it. Pointers, memory areas in my debugging session - are looking +good then. + +> +> It's not clear to me : are you actually hitting a bug or is it your +> debug session that puzzles you ? + +I'm hitting a bug. multipathd dies for me at that strcpy(). Now I think +the bug is strcpy usage instead of memcpy because I'm building with +-O2 -D_FORTIFY_SOURCE=2 which turns on special glibc overflow +detection. + +That detection seem to be smart enough to know that &str area is not +a string memory and aborts the program. + +Found similar problem discussed here +http://sourceware.org/ml/binutils/2005-11/msg00308.html + +glibc aborts the program: +[pid 13432] writev(2, [{"*** ", 4}, {"buffer overflow detected", 24}, +{" ***: ", 6}, {"/home/users/arekm/rpm/BUILD/multipath-tools-0.4.9 +/multipathd/multipathd", 71}, {" terminated\n", 12}], 5) = 117 + +same for valgrind: +**13436** *** strcpy_chk: buffer overflow detected ***: program terminated +==13436== at 0x4024997: VALGRIND_PRINTF_BACKTRACE (valgrind.h:4477) +==13436== by 0x40265F8: __strcpy_chk (mc_replace_strmem.c:781) +==13436== by 0x40EDC06: log_enqueue (string3.h:107) +==13436== by 0x40ED68A: log_safe (log_pthread.c:24) +==13436== by 0x40E296A: dlog (debug.c:36) +==13436== by 0x804ECEC: pidfile_create (pidfile.c:37) +==13436== by 0x804E731: main (main.c:1424) + +The bug is not visible if I run multipathd in debug mode (-d). + +This patch fixes the problem for me by avoiding false positive on strcpy_chk. +--- + libmultipath/log.c | 2 +- + 1 files changed, 1 insertions(+), 1 deletions(-) + +diff --git a/libmultipath/log.c b/libmultipath/log.c +index e56e46b..57b7696 100644 +--- a/libmultipath/log.c ++++ b/libmultipath/log.c +@@ -142,7 +142,7 @@ int log_enqueue (int prio, const char * fmt, va_list ap) + la->empty = 0; + msg = (struct logmsg *)la->tail; + msg->prio = prio; +- strcpy((void *)&msg->str, buff); ++ memcpy((void *)&msg->str, buff, strlen(buff) + 1); + lastmsg->next = la->tail; + msg->next = la->head; + +-- +1.7.6.5 + |