* [musl] [PATCH 1/2] Avoid out-of-bounds read for invalid quoted timezone
@ 2020-02-22 22:01 Samuel Holland
2020-02-22 22:01 ` [musl] [PATCH 2/2] Fix parsing offsets after long timezone names Samuel Holland
0 siblings, 1 reply; 2+ messages in thread
From: Samuel Holland @ 2020-02-22 22:01 UTC (permalink / raw)
To: musl; +Cc: Samuel Holland
Parsing the timezone name must stop when reaching the null terminator.
In that case, there is no '>' to skip.
---
This was found while investigating the bug fixed by patch 2.
# env -i TZ="<" date
Sat Feb 22 22:34:06 ate 2020
# env -i TZ="UTC0" date
Sat Feb 22 21:34:09 UTC 2020
---
src/time/__tz.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/time/__tz.c b/src/time/__tz.c
index 185642e8..a962960e 100644
--- a/src/time/__tz.c
+++ b/src/time/__tz.c
@@ -86,9 +86,9 @@ static void getname(char *d, const char **p)
int i;
if (**p == '<') {
++*p;
- for (i=0; (*p)[i]!='>' && i<TZNAME_MAX; i++)
+ for (i=0; (*p)[i] && (*p)[i]!='>' && i<TZNAME_MAX; i++)
d[i] = (*p)[i];
- ++*p;
+ if ((*p)[i]) ++*p;
} else {
for (i=0; ((*p)[i]|32)-'a'<26U && i<TZNAME_MAX; i++)
d[i] = (*p)[i];
--
2.24.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* [musl] [PATCH 2/2] Fix parsing offsets after long timezone names
2020-02-22 22:01 [musl] [PATCH 1/2] Avoid out-of-bounds read for invalid quoted timezone Samuel Holland
@ 2020-02-22 22:01 ` Samuel Holland
0 siblings, 0 replies; 2+ messages in thread
From: Samuel Holland @ 2020-02-22 22:01 UTC (permalink / raw)
To: musl; +Cc: Samuel Holland
TZ containg a timezone name with >TZNAME_MAX characters currently breaks
musl's timezone parsing. getname() stops after TZNAME_MAX characters.
getoff() will consume no characters (because the next character is not a
digit) and incorrectly return 0. Then, because there are remaining
alphabetic characters, __daylight == 1, and dst_off == -3600.
getname() must consume the entire timezone name, even if it will not fit
in d/__tzname, so when it returns, s points to the offset digits.
---
This was causing a failure in gnulib test-parse-datetime, which tries
to use a timezone of 2000 "X"s followed by "0".
---
src/time/__tz.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/src/time/__tz.c b/src/time/__tz.c
index a962960e..49a7371e 100644
--- a/src/time/__tz.c
+++ b/src/time/__tz.c
@@ -86,15 +86,15 @@ static void getname(char *d, const char **p)
int i;
if (**p == '<') {
++*p;
- for (i=0; (*p)[i] && (*p)[i]!='>' && i<TZNAME_MAX; i++)
- d[i] = (*p)[i];
+ for (i=0; (*p)[i] && (*p)[i]!='>'; i++)
+ if (i<TZNAME_MAX) d[i] = (*p)[i];
if ((*p)[i]) ++*p;
} else {
- for (i=0; ((*p)[i]|32)-'a'<26U && i<TZNAME_MAX; i++)
- d[i] = (*p)[i];
+ for (i=0; ((*p)[i]|32)-'a'<26U; i++)
+ if (i<TZNAME_MAX) d[i] = (*p)[i];
}
*p += i;
- d[i] = 0;
+ d[i<TZNAME_MAX?i:TZNAME_MAX] = 0;
}
#define VEC(...) ((const unsigned char[]){__VA_ARGS__})
--
2.24.1
^ permalink raw reply [flat|nested] 2+ messages in thread
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