Created attachment 1303540 [details] Triggered by "./sassc POC Description of problem: There is a heap based buffer overflow in libsass Version-Release number of selected component (if applicable): <= latest version How reproducible: ./sassc POC Steps to Reproduce: ➜ sumary ../../../../origin/libsass/sassc/bin/sassc POC ================================================================= ==29485==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb50007b6 at pc 0x0859139e bp 0xbf99cdd8 sp 0xbf99cdcc READ of size 1 at 0xb50007b6 thread T0 #0 0x859139d (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x859139d) #1 0x85b7572 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b7572) #2 0x85b746e (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b746e) #3 0x85b8bd0 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b8bd0) #4 0x85b81a2 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b81a2) #5 0x85b5f26 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b5f26) #6 0x85a1f5e (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85a1f5e) #7 0x8485ff4 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x8485ff4) #8 0x845f606 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x845f606) #9 0x8454eb2 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x8454eb2) #10 0x8450b1f (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x8450b1f) #11 0x829f371 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x829f371) #12 0x82ba1ec (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82ba1ec) #13 0x82501e1 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82501e1) #14 0x824f0ae (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x824f0ae) #15 0x824f460 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x824f460) #16 0x823ab42 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x823ab42) #17 0x823ba7a (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x823ba7a) #18 0xb73ab636 (/lib/i386-linux-gnu/libc.so.6+0x18636) #19 0x81666cb (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x81666cb) 0xb50007b6 is located 0 bytes to the right of 6-byte region [0xb50007b0,0xb50007b6) allocated by thread T0 here: #0 0x820aa04 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x820aa04) #1 0x840e182 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x840e182) #2 0x82b8e7b (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82b8e7b) #3 0x82501e1 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82501e1) #4 0x824f0ae (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x824f0ae) SUMMARY: AddressSanitizer: heap-buffer-overflow (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x859139d) Shadow bytes around the buggy address: 0x36a000a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36a000b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36a000c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa 00 00 0x36a000d0: fa fa fd fa fa fa 04 fa fa fa 04 fa fa fa 00 fa 0x36a000e0: fa fa 04 fa fa fa 00 fa fa fa 04 fa fa fa fd fa =>0x36a000f0: fa fa 04 fa fa fa[06]fa fa fa 04 fa fa fa fd fa 0x36a00100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36a00110: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36a00120: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36a00130: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36a00140: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Heap right redzone: fb Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==29485==ABORTING The GDB debugging information is as follows: (gdb) b lexer.cpp:150 Breakpoint 1 at 0x8449e4b: file src/lexer.cpp, line 150. (gdb) r POC Starting program: /home/osboxes/Desktop/origin/libsass/sassc/bin/sassc POC [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1". Breakpoint 1, Sass::Prelexer::re_linebreak (src=0xb59007b5 "") at src/lexer.cpp:151 151 if (*src == 0 || *src == '\n') return src + 1; (gdb) n 156 } (gdb) Sass::Prelexer::alternatives<&Sass::Prelexer::sequence<&Sass::Prelexer::exactly<(char)92>, &Sass::Prelexer::re_linebreak>, &Sass::Prelexer::escape_seq, &Sass::Prelexer::unicode_seq, &Sass::Prelexer::interpolant, &Sass::Prelexer::any_char_but<(char)34> > (src=<optimised out>) at src/lexer.hpp:202 202 if ((rslt = mx1(src))) return rslt; (gdb) Sass::Prelexer::zero_plus<&Sass::Prelexer::alternatives<&Sass::Prelexer::sequence<&Sass::Prelexer::exactly<(char)92>, &Sass::Prelexer::re_linebreak>, &Sass::Prelexer::escape_seq, &Sass::Prelexer::unicode_seq, &Sass::Prelexer::interpolant, &Sass::Prelexer::any_char_but<(char)34> > > ( src=<optimised out>) at src/lexer.hpp:236 236 while (p) src = p, p = mx(src); (gdb) ================================================================= ==15322==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb59007b6 at pc 0x0859139e bp 0xbfffd1d8 sp 0xbfffd1cc READ of size 1 at 0xb59007b6 thread T0 #0 0x859139d (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x859139d) #1 0x85b7572 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b7572) #2 0x85b746e (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b746e) #3 0x85b8bd0 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b8bd0) #4 0x85b81a2 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b81a2) #5 0x85b5f26 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85b5f26) #6 0x85a1f5e (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x85a1f5e) #7 0x8485ff4 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x8485ff4) #8 0x845f606 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x845f606) #9 0x8454eb2 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x8454eb2) #10 0x8450b1f (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x8450b1f) #11 0x829f371 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x829f371) #12 0x82ba1ec (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82ba1ec) #13 0x82501e1 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82501e1) #14 0x824f0ae (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x824f0ae) #15 0x824f460 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x824f460) #16 0x823ab42 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x823ab42) #17 0x823ba7a (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x823ba7a) #18 0xb7c00636 (/lib/i386-linux-gnu/libc.so.6+0x18636) #19 0x81666cb (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x81666cb) 0xb59007b6 is located 0 bytes to the right of 6-byte region [0xb59007b0,0xb59007b6) allocated by thread T0 here: #0 0x820aa04 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x820aa04) #1 0x840e182 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x840e182) #2 0x82b8e7b (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82b8e7b) #3 0x82501e1 (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x82501e1) #4 0x824f0ae (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x824f0ae) SUMMARY: AddressSanitizer: heap-buffer-overflow (/home/osboxes/Desktop/origin/libsass/sassc/bin/sassc+0x859139d) Shadow bytes around the buggy address: 0x36b200a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36b200b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36b200c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa 00 00 0x36b200d0: fa fa fd fa fa fa 04 fa fa fa 04 fa fa fa 00 fa 0x36b200e0: fa fa 04 fa fa fa 00 fa fa fa 04 fa fa fa fd fa =>0x36b200f0: fa fa 04 fa fa fa[06]fa fa fa 04 fa fa fa fd fa 0x36b20100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36b20110: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36b20120: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36b20130: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x36b20140: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Heap right redzone: fb Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==15322==ABORTING Actual results: crash Expected results: crash Additional info:
I updated libsass & sassc to 3.4.5, can you try again with this version? On my computer with the updated sassc I get: $ sassc POC Internal Error: Invalid UTF-8
This bug appears to have been reported against 'rawhide' during the Fedora 27 development cycle. Changing version to '27'.
This message is a reminder that Fedora 27 is nearing its end of life. On 2018-Nov-30 Fedora will stop maintaining and issuing updates for Fedora 27. 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 '27'. 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 27 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.
Fedora 27 changed to end-of-life (EOL) status on 2018-11-30. Fedora 27 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.