Date: Wed, 1 Feb 2012 10:26:40 +0400 (MSK) From: Yuri Pankov <yuri.pankov@gmail.com> To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/164684: [kern][patch] Zero out dynamically allocated sbufs Message-ID: <201202010626.q116QePw067371@sirius.xvoid.org> Resent-Message-ID: <201202010630.q116UEm5043386@freefall.freebsd.org>
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>Number: 164684 >Category: kern >Synopsis: [kern][patch] Zero out dynamically allocated sbufs >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Feb 01 06:30:14 UTC 2012 >Closed-Date: >Last-Modified: >Originator: Yuri Pankov >Release: FreeBSD 10.0-CURRENT amd64 >Organization: >Environment: System: FreeBSD sirius.xvoid.org 10.0-CURRENT FreeBSD 10.0-CURRENT #1 r230537: Wed Jan 25 16:28:58 MSK 2012 yuri@sirius.xvoid.org:/usr/obj/data/src/freebsd/head/sys/GENERIC amd64 >Description: Filing this against kernel (as the source is in sys/kern), but got the problem itself using libsbuf - sbuf_newbuf() and sbuf_extend() don't zero out the malloc'ed memory, leading to issues when malloc debugging is enabled. >How-To-Repeat: #include <sys/types.h> #include <sys/sbuf.h> #include <stdio.h> int main(void) { struct sbuf *sb = sbuf_new_auto(); sbuf_cat(sb, "TEST TEST"); printf("s_buf=%s\n", sbuf_data(sb)); return(0); } $ MALLOC_OPTIONS=J ./sbuf s_buf=TEST TEST▒▒▒▒▒▒▒ $ MALLOC_OPTIONS=j ./sbuf s_buf=TEST TEST >Fix: --- sbuf-dynamic.diff begins here --- Index: sys/kern/subr_sbuf.c =================================================================== --- sys/kern/subr_sbuf.c (revision 230853) +++ sys/kern/subr_sbuf.c (working copy) @@ -159,6 +159,7 @@ newbuf = SBMALLOC(newsize); if (newbuf == NULL) return (-1); + memset(newbuf, 0, newsize); memcpy(newbuf, s->s_buf, s->s_size); if (SBUF_ISDYNAMIC(s)) SBFREE(s->s_buf); @@ -197,6 +198,7 @@ s->s_buf = SBMALLOC(s->s_size); if (s->s_buf == NULL) return (NULL); + memset(s->s_buf, 0, s->s_size); SBUF_SETFLAG(s, SBUF_DYNAMIC); return (s); } --- sbuf-dynamic.diff ends here --- >Release-Note: >Audit-Trail: >Unformatted:
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