MySQL Bugs: #96433: incorrect length in read_ok

Bug #96433	incorrect length in read_ok_ex()
Submitted:	6 Aug 2019 9:28	Modified:	13 Aug 2019 16:33
Reporter:	Przemysław Skibiński (OCA)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Compiling	Severity:	S3 (Non-critical)
Version:	5.7.27	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
clang-8 found a bug in mysql-5.7.27/sql-common/client.c:805
 
size_t length = data->length > (sizeof(charset_name) - 1)
                                  ? sizeof(charset_name - 1)
                                  : data->length;

sizeof(charset_name - 1), which is always 4, should be replaced with (sizeof(charset_name) - 1)

How to repeat:
the error is obvious

HI,

Would you be so kind and provide very detailed analysis on OS, it's version, cmake version, make version, compiler make and version. Last, but not least which source tarball did you exactly download.

Also, how did you run cmake, with which option. In other words , we need the entire procedure in detail.

Thanks in advance.

hi!

Thanks for your report!

Verified by:

$ export CC=/usr/bin/clang-8
$ export CXX=/usr/bin/clang++-8

$ mkdir b && cd b
$ cmake ..
$ cd libmysql
$ make VERBOSE=1
...

cd /work/mysql-5.7-clean/b/libmysql && /usr/bin/clang-8 -DHAVE_CONFIG_H -DHAVE_LIBEVENT2 -DHAVE_OPENSSL -DHAVE_TLSv13 -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -I/work/mysql-5.7-clean/b/include -I/work/mysql-5.7-clean/extra/rapidjson/include -I/work/mysql-5.7-clean/b/libbinlogevents/include -I/work/mysql-5.7-clean/libbinlogevents/export -I/work/mysql-5.7-clean/include -I/work/mysql-5.7-clean/libmysql -I/work/mysql-5.7-clean/regex -I/work/mysql-5.7-clean/sql -I/work/mysql-5.7-clean/strings -isystem /work/mysql-5.7-clean/zlib -isystem /work/mysql-5.7-clean/b/zlib  -Wall -Wextra -Wformat-security -Wvla -Wwrite-strings -Wdeclaration-after-statement -O3 -g -fno-omit-frame-pointer -fno-strict-aliasing -DDBUG_OFF -fPIC   -D CLIENT_PROTOCOL_TRACING -o CMakeFiles/clientlib.dir/__/sql-common/client.c.o   -c /work/mysql-5.7-clean/sql-common/client.c
/work/mysql-5.7-clean/sql-common/client.c:817:57: warning: sizeof on pointer operation will return size of 'char *' instead of 'char [256]'
      [-Wsizeof-array-decay]
                                  ? sizeof(charset_name - 1)
                                           ~~~~~~~~~~~~ ^

current head of 5.7:

sql-common/client.c:817:57: error: sizeof on pointer operation will return size of 'char *'
      instead of 'char [256]' [-Werror,-Wsizeof-array-decay]
                                  ? sizeof(charset_name - 1)

Posted by developer:
 
Fixed in 5.7.28, 8.0.19.

Code cleanup. No changelog entry needed.