Module Name: src
Committed By: kamil
Date: Tue Jun 12 00:42:17 UTC 2018
Modified Files:
src/usr.bin/gzip: gzip.c
Log Message:
Correct Undefined Behavior in gzip(1)
Unportable left shift reported with MKSANITIZER=yes USE_SANITIZER=undefined:
# progress -zf ./games.tgz tar -xp -C "./" -f -
/public/src.git/usr.bin/gzip/gzip.c:2126:33: runtime error: left shift of 251
by 24 places cannot be represented in type 'int'
100%
|****************************************************************************************************************|
44500 KiB 119.69 MiB/s 00:00 ETA
Refactor the following code into something that is more clear
and fix signed integer shift, by casting all buf[] elements to
(unsigned int):
unsigned char buf[8];
uint32_t usize;
[...]
else {
usize = buf[4] | buf[5] << 8 |
buf[6] << 16 | buf[7] << 24;
[...]
New version:
usize = buf[4];
usize |= (unsigned int)buf[5] << 8;
usize |= (unsigned int)buf[6] << 16;
usize |= (unsigned int)buf[7] << 24;
Only the "<< 24" part needs explicit cast, but for consistency make the
integer promotion explicit and clear to a code reader.
Sponsored by <The NetBSD Foundation>
To generate a diff of this commit:
cvs rdiff -u -r1.112 -r1.113 src/usr.bin/gzip/gzip.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
