Created attachment 1314586 [details] Triggered by "./sassc POC9" Description of problem: There is a stack-overflow in the sassc of libsass library. This vulnerability is triggered in function Sass::Eval::operator() . Version-Release number of selected component (if applicable): <= latest version How reproducible: ./sassc $POC Steps to Reproduce: The debugging information is as follows: $ ./sassc POC9 Segmentation fault ASAN debugging information: $ ./sassc POC9 (gdb) r The program being debugged has been started already. Start it from the beginning? (y or n) y Starting program: /home/icy/libsass-check/sassc-asan/install/bin/sassc id:000070,sig:11,src:009686,op:havoc,rep:4 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Breakpoint 1, Sass::Eval::operator() (this=<optimized out>, b_in=<optimized out>) at eval.cpp:542 542 Expression_Obj lhs = b_in->left(); (gdb) c 1194 Will ignore next 1193 crossings of breakpoint 1. Continuing. Breakpoint 1, Sass::Eval::operator() (this=<optimized out>, b_in=<optimized out>) at eval.cpp:542 542 Expression_Obj lhs = b_in->left(); (gdb) i b Num Type Disp Enb Address What 1 breakpoint keep y 0x00007ffff7819369 in Sass::Eval::operator()(Sass::Binary_Expression*) at eval.cpp:540 breakpoint already hit 1195 times ... (gdb) 567 Binary_Expression_Obj b = b_in; (gdb) Single stepping until exit from function Sass::Eval::operator()(Sass::Binary_Expression*), which has no line number information. Program received signal SIGSEGV, Segmentation fault. 0x00007ffff7818ffb in Sass::Eval::operator() (this=0x7fffffffd880, b_in=<optimized out>) at eval.cpp:540 540 { (gdb) 0x00000000004bfbd0 in __asan::AsanOnSIGSEGV(int, void*, void*) () (gdb) Single stepping until exit from function _ZN6__asan13AsanOnSIGSEGVEiPvS0_, which has no line number information. ASAN:SIGSEGV ================================================================= ==6364==ERROR: AddressSanitizer: stack-overflow on address 0x7fffff7fe930 (pc 0x7ffff7818ffb bp 0x7fffff800310 sp 0x7fffff7fe7c0 T0) #0 0x7ffff7818ffa (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x545ffa) #1 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #2 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #3 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #4 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #5 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #6 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #7 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #8 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #9 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #10 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #11 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #12 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #13 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #14 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #15 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #16 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #17 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #18 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #19 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #20 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #21 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #22 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #23 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #24 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #25 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #26 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #27 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #28 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #29 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) #30 0x7ffff781a67f (/home/icy/libsass-check/libsass-asan/install/lib/libsass.so.1+0x54767f) ... ==6364==ABORTING [Inferior 1 (process 6364) exited with code 01] This vulnerability was triggered in function Sass::Eval::operator() (this=<optimized out>, b_in=<optimized out>) at eval.cpp 539 Expression_Ptr Eval::operator()(Binary_Expression_Ptr b_in) 540 { 541 542 Expression_Obj lhs = b_in->left(); 543 Expression_Obj rhs = b_in->right(); 544 enum Sass_OP op_type = b_in->optype(); ... 559 // Evaluate variables as early o 560 while (Variable_Ptr l_v = Cast<Variable>(lhs)) { 561 lhs = operator()(l_v); 562 } 563 while (Variable_Ptr r_v = Cast<Variable>(rhs)) { 564 rhs = operator()(r_v); 565 } 566 567 Binary_Expression_Obj b = b_in; 568 Actual results: crash Expected results: crash Additional info: Credits: This vulnerability is detected by team OWL337, with our custom fuzzer collAFL. Please contact ganshuitao and chaoz.cn if you need more info about the team, the tool or the vulnerability.
This bug appears to have been reported against 'rawhide' during the Fedora 28 development cycle. Changing version to '28'.
This message is a reminder that Fedora 28 is nearing its end of life. On 2019-May-28 Fedora will stop maintaining and issuing updates for Fedora 28. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '28'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 28 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
Red Hat Bugzilla is not an appropriate forum for reporting security bugs in upstream components. As you can see, your bug report here has been ignored for three years, and will likely continue to be ignored, so I'm going to go ahead and close it. Please feel free to report this upstream if you want the developers to look at it.