|Summary:||devel/llvm12: overwriting static memory|
|Product:||Ports & Packages||Reporter:||Dirk Meyer <dinoex>|
|Component:||Individual Port(s)||Assignee:||Brooks Davis <brooks>|
|Status:||Closed Works As Intended|
|Severity:||Affects Only Me||Flags:||bugzilla:
Description Dirk Meyer 2021-09-17 10:41:42 UTC
With OpenSSL from ports I build a new version of tinyfuge (5.1.1): Sources: https://github.com/ingwarsw/tinyfugue The compiled code fails on starting the SSL connection. Output: % Trying to connect to ap: XXXX:f840::42 8889. % SSL: cert verify depth exceeded: allowed=0 actual=2 % SSL: cert verify error: err=22 'certificate chain too long' depth:2 cn:/C=US/O=Internet Security Research Group/CN=ISRG Root X1 % Intermediate connection to ap failed: SSL/lib: error:1416F086:SSL While debugging with gcc the static memory of the application gets overwritten. ssl_options is overwritten with bad data. The code of the application seems fine, -Wall does not show any hints. Once I enabled "-g" in CFLAGS the application runs. Output: % Trying to connect to ap: XXXX:f840::42 8889. % SSL: chain: depth:2 cn:/C=US/O=Internet Security Research Group/CN=ISRG Root X1 % SSL: chain: depth:1 cn:/C=US/O=Let's Encrypt/CN=R3 % SSL: chain: depth:0 cn:/CN=ap.XXXX.org % SSL: cert verified: OK ret=0 % Connected to ap using cipher TLS_AES_256_GCM_SHA384. I tested a few compilers: clang version 10.0.1 (base) clang version 12.0.1 (devel/llvm12) gcc10 (FreeBSD Ports Collection) 10.3.0 The Problem happens with: clang clang12 clang -O1 clang12 -O1 The application runs with: clang -g clang -O0 clang12 -O0 gcc10 -O2 gcc10 -O3 The structure on FreeBSD 12.2 has an address of: 0x7fffffffe4c0 (fail) 0x7fffffffe340 (ok) I guess there is something going wrong with the memory mapping.
Comment 2 Brooks Davis 2021-09-17 20:08:50 UTC
Could you try compiling with clang12 adding -fsanitize=address,undefined? While compiler bugs are certainly possible it seems more likely that clang is finding some undefined behavior and optimizing it into a broken executable.
Comment 3 Dirk Meyer 2021-09-19 06:42:04 UTC
Thanks, the Sanitizer found the alignment problems at run time. Fixing the application soled all the issues.