Bug 1471780
| Summary: | There is a stack-overflow in the sassc of libsass library. | ||||||
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| Product: | [Fedora] Fedora | Reporter: | owl337 <v.owl337> | ||||
| Component: | sassc | Assignee: | Aurelien Bompard <aurelien> | ||||
| Status: | CLOSED EOL | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||
| Severity: | urgent | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 27 | CC: | aurelien, jkurik | ||||
| Target Milestone: | --- | ||||||
| Target Release: | --- | ||||||
| Hardware: | x86_64 | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2018-11-30 17:53:16 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | |||||||
| Bug Blocks: | 1474937 | ||||||
| Attachments: |
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Reported upstream as https://github.com/sass/libsass/issues/2445 This bug appears to have been reported against 'rawhide' during the Fedora 27 development cycle. Changing version to '27'. More information and reason for this action is here: https://fedoraproject.org/wiki/Releases/27/HouseKeeping#Rawhide_Rebase 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 It is Fedora's policy to close all bug reports from releases that are no longer maintained.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. |
Created attachment 1299840 [details] Triggered by "./sassc POC3" Description of problem: There is a stack-overflow in the sassc of libsass library. Version-Release number of selected component (if applicable): <= latest version How reproducible: ./sassc POC3 Steps to Reproduce: $ ./sassc POC3 Segmentation fault ASAN debugging information: $ ./sassc POC3 ================================================================= ==17056==ERROR: AddressSanitizer: stack-overflow on address 0x7ffd3045ee10 (pc 0x7f92503b9437 bp 0x7ffd3045f180 sp 0x7ffd3045ee00 T0) #0 0x7f92503b9436 (/home/icy/libsass/install/lib/libsass.so.1+0x182436) #1 0x7f9250397ac9 (/home/icy/libsass/install/lib/libsass.so.1+0x160ac9) #2 0x7f9250398cd9 (/home/icy/libsass/install/lib/libsass.so.1+0x161cd9) #3 0x7f92503996b9 (/home/icy/libsass/install/lib/libsass.so.1+0x1626b9) #4 0x7f9250399ffa (/home/icy/libsass/install/lib/libsass.so.1+0x162ffa) #5 0x7f92503a0858 (/home/icy/libsass/install/lib/libsass.so.1+0x169858) #6 0x7f92503a14ef (/home/icy/libsass/install/lib/libsass.so.1+0x16a4ef) #7 0x7f92503b5a14 (/home/icy/libsass/install/lib/libsass.so.1+0x17ea14) #8 0x7f92503b725b (/home/icy/libsass/install/lib/libsass.so.1+0x18025b) #9 0x7f92503b8a19 (/home/icy/libsass/install/lib/libsass.so.1+0x181a19) #10 0x7f92503b94f9 (/home/icy/libsass/install/lib/libsass.so.1+0x1824f9) #11 0x7f9250397ac9 (/home/icy/libsass/install/lib/libsass.so.1+0x160ac9) #12 0x7f9250398cd9 (/home/icy/libsass/install/lib/libsass.so.1+0x161cd9) #13 0x7f92503996b9 (/home/icy/libsass/install/lib/libsass.so.1+0x1626b9) ... ... #251 0x7f9250397ac9 (/home/icy/libsass/install/lib/libsass.so.1+0x160ac9) ==17056==ABORTING GDB debugging information: (gdb) set args POC3 (gdb) b parser.hpp:150 (gdb) r The program being debugged has been started already. ... Breakpoint 1, Sass::Parser::lex<&Sass::Prelexer::block_comment> (force=false, lazy=true, this=0x7fffffffdd30) at parser.hpp:150 150 const char* it_after_token = mx(it_before_token); (gdb) c 9224 Will ignore next 9223 crossings of breakpoint 2. Continuing. Breakpoint 2, Sass::Parser::lex<&Sass::Prelexer::css_comments> (force=false, lazy=false, this=0x7fffffffdd30) at parser.hpp:150 150 const char* it_after_token = mx(it_before_token); (gdb) x/5i $pc => 0x7ffff7a8e940 <Sass::Parser::advanceToNextToken()+48>: mov %rbp,%rdi 0x7ffff7a8e943 <Sass::Parser::advanceToNextToken()+51>: callq 0x7ffff79e7830 <_ZN4Sass8Prelexer12css_commentsEPKc@plt> 0x7ffff7a8e948 <Sass::Parser::advanceToNextToken()+56>: cmp 0xa0(%rbx),%rax 0x7ffff7a8e94f <Sass::Parser::advanceToNextToken()+63>: mov %rax,%r12 0x7ffff7a8e952 <Sass::Parser::advanceToNextToken()+66>: seta %dl (gdb) si 0x00007ffff7a8e943 150 const char* it_after_token = mx(it_before_token); (gdb) si Program received signal SIGSEGV, Segmentation fault. 0x00007ffff7a8e943 in Sass::Parser::lex<&Sass::Prelexer::css_comments> (force=false, lazy=false, this=0x7fffffffdd30) at parser.hpp:150 150 const char* it_after_token = mx(it_before_token); (gdb) c Continuing. ASAN:SIGSEGV ================================================================= ==4332==ERROR: AddressSanitizer: stack-overflow on address 0x7fffff7fef98 (pc 0x7ffff7a8e943 bp 0x61c00000fe05 sp 0x7fffff7fefa0 T0) #0 0x7ffff7a8e942 (/home/icy/libsass/install/lib/libsass.so.1+0x159942) #1 0x7ffff7ab7454 (/home/icy/libsass/install/lib/libsass.so.1+0x182454) #2 0x7ffff7a95ac9 (/home/icy/libsass/install/lib/libsass.so.1+0x160ac9) #3 0x7ffff7a96cd9 (/home/icy/libsass/install/lib/libsass.so.1+0x161cd9) #4 0x7ffff7a976b9 (/home/icy/libsass/install/lib/libsass.so.1+0x1626b9) #5 0x7ffff7a97ffa (/home/icy/libsass/install/lib/libsass.so.1+0x162ffa) #6 0x7ffff7a9e858 (/home/icy/libsass/install/lib/libsass.so.1+0x169858) #7 0x7ffff7a9f4ef (/home/icy/libsass/install/lib/libsass.so.1+0x16a4ef) #8 0x7ffff7ab3a14 (/home/icy/libsass/install/lib/libsass.so.1+0x17ea14) #9 0x7ffff7ab525b (/home/icy/libsass/install/lib/libsass.so.1+0x18025b) ... ... #251 0x7ffff7ab74f9 (/home/icy/libsass/install/lib/libsass.so.1+0x1824f9) ==4332==ABORTING This vulnerability was triggered in function char* lex()at line /libsass/src/parser.hpp:150: 134 template <Prelexer::prelexer mx> 135 const char* lex(bool lazy = true, bool force = false) 136 { 137 138 if (*position == 0) return 0; 139 140 // position considered before lexed token 141 // we can skip whitespace or comments for 142 // lazy developers (but we need control) 143 const char* it_before_token = position; 144 145 // sneak up to the actual token we want to lex 146 // this should skip over white-space if desired 147 if (lazy) it_before_token = sneak < mx >(position); 148 149 // now call matcher to get position after token 150 const char* it_after_token = mx(it_before_token); 151 152 // check if match is in valid range 153 if (it_after_token > end) return 0; 154 ... 177 178 } 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.