Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitca32594

Browse files
committed
Check return values of sensitive system library calls.
PostgreSQL already checked the vast majority of these, missing thishandful that nearly cannot fail. If putenv() failed with ENOMEM inpg_GSS_recvauth(), authentication would proceed with the wrong keytabfile. If strftime() returned zero in cache_locale_time(), using theunspecified buffer contents could lead to information exposure or acrash. Back-patch to 9.0 (all supported versions).Other unchecked calls to these functions, especially those in frontendcode, pose negligible security concern. This patch does not addressthem. Nonetheless, it is always better to check return values whosespecification provides for indicating an error.In passing, fix an off-by-one error in strftime_win32()'s invocation ofWideCharToMultiByte(). Upon retrieving a value of exactly MAX_L10N_DATAbytes, strftime_win32() would overrun the caller's buffer by one byte.MAX_L10N_DATA is chosen to exceed the length of every possible value, sothe vulnerable scenario probably does not arise.Security:CVE-2015-3166
1 parent2e3bd06 commitca32594

File tree

2 files changed

+48
-33
lines changed

2 files changed

+48
-33
lines changed

‎src/backend/libpq/auth.c

Lines changed: 4 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -817,15 +817,16 @@ pg_GSS_recvauth(Port *port)
817817
size_tkt_len=strlen(pg_krb_server_keyfile)+14;
818818
char*kt_path=malloc(kt_len);
819819

820-
if (!kt_path)
820+
if (!kt_path||
821+
snprintf(kt_path,kt_len,"KRB5_KTNAME=%s",
822+
pg_krb_server_keyfile)!=kt_len-2||
823+
putenv(kt_path)!=0)
821824
{
822825
ereport(LOG,
823826
(errcode(ERRCODE_OUT_OF_MEMORY),
824827
errmsg("out of memory")));
825828
returnSTATUS_ERROR;
826829
}
827-
snprintf(kt_path,kt_len,"KRB5_KTNAME=%s",pg_krb_server_keyfile);
828-
putenv(kt_path);
829830
}
830831
}
831832

‎src/backend/utils/adt/pg_locale.c

Lines changed: 44 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -575,22 +575,32 @@ PGLC_localeconv(void)
575575
* pg_strftime(), which isn't locale-aware and does not need to be replaced.
576576
*/
577577
staticsize_t
578-
strftime_win32(char*dst,size_tdstlen,constwchar_t*format,conststructtm*tm)
578+
strftime_win32(char*dst,size_tdstlen,
579+
constchar*format,conststructtm*tm)
579580
{
580581
size_tlen;
582+
wchar_twformat[8];/* formats used below need 3 bytes */
581583
wchar_twbuf[MAX_L10N_DATA];
582584

583-
len=wcsftime(wbuf,MAX_L10N_DATA,format,tm);
585+
/* get a wchar_t version of the format string */
586+
len=MultiByteToWideChar(CP_UTF8,0,format,-1,
587+
wformat,lengthof(wformat));
588+
if (len==0)
589+
elog(ERROR,"could not convert format string from UTF-8: error code %lu",
590+
GetLastError());
591+
592+
len=wcsftime(wbuf,MAX_L10N_DATA,wformat,tm);
584593
if (len==0)
585594
{
586595
/*
587-
* strftimecallfailed - return 0 with the contents of dst
588-
* unspecified
596+
* strftime failed, possibly because the result would not fit in
597+
*MAX_L10N_DATA. Return 0 with the contents of dstunspecified.
589598
*/
590599
return0;
591600
}
592601

593-
len=WideCharToMultiByte(CP_UTF8,0,wbuf,len,dst,dstlen,NULL,NULL);
602+
len=WideCharToMultiByte(CP_UTF8,0,wbuf,len,dst,dstlen-1,
603+
NULL,NULL);
594604
if (len==0)
595605
elog(ERROR,"could not convert string to UTF-8: error code %lu",
596606
GetLastError());
@@ -612,9 +622,33 @@ strftime_win32(char *dst, size_t dstlen, const wchar_t *format, const struct tm
612622
}
613623

614624
/* redefine strftime() */
615-
#definestrftime(a,b,c,d) strftime_win32(a,b,L##c,d)
625+
#definestrftime(a,b,c,d) strftime_win32(a,b,c,d)
616626
#endif/* WIN32 */
617627

628+
/* Subroutine for cache_locale_time(). */
629+
staticvoid
630+
cache_single_time(char**dst,constchar*format,conststructtm*tm)
631+
{
632+
charbuf[MAX_L10N_DATA];
633+
char*ptr;
634+
635+
/*
636+
* MAX_L10N_DATA is sufficient buffer space for every known locale, and
637+
* POSIX defines no strftime() errors. (Buffer space exhaustion is not an
638+
* error.) An implementation might report errors (e.g. ENOMEM) by
639+
* returning 0 (or, less plausibly, a negative value) and setting errno.
640+
* Report errno just in case the implementation did that, but clear it in
641+
* advance of the call so we don't emit a stale, unrelated errno.
642+
*/
643+
errno=0;
644+
if (strftime(buf,MAX_L10N_DATA,format,tm) <=0)
645+
elog(ERROR,"strftime(%s) failed: %m",format);
646+
647+
ptr=MemoryContextStrdup(TopMemoryContext,buf);
648+
if (*dst)
649+
pfree(*dst);
650+
*dst=ptr;
651+
}
618652

619653
/*
620654
* Update the lc_time localization cache variables if needed.
@@ -625,8 +659,6 @@ cache_locale_time(void)
625659
char*save_lc_time;
626660
time_ttimenow;
627661
structtm*timeinfo;
628-
charbuf[MAX_L10N_DATA];
629-
char*ptr;
630662
inti;
631663

632664
#ifdefWIN32
@@ -673,35 +705,17 @@ cache_locale_time(void)
673705
for (i=0;i<7;i++)
674706
{
675707
timeinfo->tm_wday=i;
676-
strftime(buf,MAX_L10N_DATA,"%a",timeinfo);
677-
ptr=MemoryContextStrdup(TopMemoryContext,buf);
678-
if (localized_abbrev_days[i])
679-
pfree(localized_abbrev_days[i]);
680-
localized_abbrev_days[i]=ptr;
681-
682-
strftime(buf,MAX_L10N_DATA,"%A",timeinfo);
683-
ptr=MemoryContextStrdup(TopMemoryContext,buf);
684-
if (localized_full_days[i])
685-
pfree(localized_full_days[i]);
686-
localized_full_days[i]=ptr;
708+
cache_single_time(&localized_abbrev_days[i],"%a",timeinfo);
709+
cache_single_time(&localized_full_days[i],"%A",timeinfo);
687710
}
688711

689712
/* localized months */
690713
for (i=0;i<12;i++)
691714
{
692715
timeinfo->tm_mon=i;
693716
timeinfo->tm_mday=1;/* make sure we don't have invalid date */
694-
strftime(buf,MAX_L10N_DATA,"%b",timeinfo);
695-
ptr=MemoryContextStrdup(TopMemoryContext,buf);
696-
if (localized_abbrev_months[i])
697-
pfree(localized_abbrev_months[i]);
698-
localized_abbrev_months[i]=ptr;
699-
700-
strftime(buf,MAX_L10N_DATA,"%B",timeinfo);
701-
ptr=MemoryContextStrdup(TopMemoryContext,buf);
702-
if (localized_full_months[i])
703-
pfree(localized_full_months[i]);
704-
localized_full_months[i]=ptr;
717+
cache_single_time(&localized_abbrev_months[i],"%b",timeinfo);
718+
cache_single_time(&localized_full_months[i],"%B",timeinfo);
705719
}
706720

707721
/* try to restore internal settings */

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp