musl - setenv if value=NULL, what say standard? Bug?

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Message-ID: <553837F1.5080808@safe.ca>
Date: Wed, 22 Apr 2015 20:08:17 -0400
From: Jean-Marc Pigeon <jmp@...e.ca>
To: musl@...ts.openwall.com
Subject: setenv if value=NULL, what say standard? Bug?

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Hello,


hwclock (util-linux-2.26) is crashing, this is caused by
setenv.

#0  mktime_tz (tm=..., universal=1, valid_p=0x7fffffffea4c,
systime_p=0x7fffffffea30) at sys-utils/hwclock.c:411
#1  0x00000000004025f6 in read_hardware_clock (universal=1,
valid_p=0x7fffffffea4c, systime_p=0x7fffffffea30)
    at sys-utils/hwclock.c:476
#2  0x0000000000403bae in manipulate_clock (show=1, adjust=0,
noadjfile=0, set=0, set_time=0, hctosys=0,
    systohc=0, systz=0, startup_time=..., utc=0, local_opt=0,
update=0, testing=0, predict=0, get=0)
    at sys-utils/hwclock.c:1336
#3  0x0000000000404b37 in main (argc=0, argv=0x7fffffffebe8) at
sys-utils/hwclock.c:1965

src:
hwclock.c:411 setenv("TZ", getenv("TZUTC"), TRUE);

as TZUTC is undefined (NULL),
setenv is crashing

setenv.c:30 l2 = strlen(value);

fixing the hwclock code is a possibility,
but we could have other same-kind situation
far less obvious in other application, making
all sort of code to crash "randomly".

Tried to see what was saying standard,
about  (const char *value) to be NULL
when calling
setenv(const char *name, const char *value, int overwrite);
found nothing.

My guess, glibc code is 'blindly" setting the NULL (as "")
value to the variable.

Is the standard saying otherwise, or do we have a
a real bug in setenv??




- -- 

A bientôt
===========================================================
Jean-Marc Pigeon                        E-Mail: jmp@...e.ca
SAFE Inc.                             Phone: (514) 493-4280
  Clement, 'a kiss solution' to get rid of SPAM (at last)
     Clement' Home base <"http://www.clement.safe.ca">
===========================================================
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