Bug 81644
| Summary: | /usr/bin/strip generates garbage from valid ELF executables | ||||||||||||
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| Product: | [Retired] Red Hat Linux | Reporter: | John Reiser <jreiser> | ||||||||||
| Component: | binutils | Assignee: | Jakub Jelinek <jakub> | ||||||||||
| Status: | CLOSED CURRENTRELEASE | QA Contact: | |||||||||||
| Severity: | medium | Docs Contact: | |||||||||||
| Priority: | medium | ||||||||||||
| Version: | 8.0 | CC: | jjackson, mitr | ||||||||||
| Target Milestone: | --- | ||||||||||||
| Target Release: | --- | ||||||||||||
| Hardware: | i386 | ||||||||||||
| OS: | Linux | ||||||||||||
| Whiteboard: | |||||||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||||||
| Doc Text: | Story Points: | --- | |||||||||||
| Clone Of: | Environment: | ||||||||||||
| Last Closed: | 2004-10-07 13:40:47 UTC | Type: | --- | ||||||||||
| Regression: | --- | Mount Type: | --- | ||||||||||
| Documentation: | --- | CRM: | |||||||||||
| Verified Versions: | Category: | --- | |||||||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||||||
| Embargoed: | |||||||||||||
| Attachments: |
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Created attachment 89309 [details] ELF executable with empty "linking view" /bin/date compressed by UPX (http://upx.sourceforge.net) Created attachment 89310 [details]
result of stripping date.upx.no_shdr
92-bytes of headers, and nothing else; 'strip' gutted the file
Created attachment 89311 [details]
ELF executable with non-empty, compatible, linking view
Output from a test version of UPX that supplies a linking view for compressed
output executables.
Created attachment 89312 [details]
result of stripping date.upx.shdr
The second PT_LOAD has been scrambled: p_align changed from 0x1000 to 4;
p_offset changed to inhibit mmap().
Why would 'strip' be applied to output from UPX? rpmbuild does it by default when building a binary package .rpm, and it's not obvious how to turn it off. *** Bug 76780 has been marked as a duplicate of this bug. *** binutils-2.15.91.0.2-8 issues warnings: strip date.upx.no_shdr BFD: date.upx.no_shdr: warning: Empty loadable segment detected, is this intentional ? BFD: date.upx.no_shdr: warning: Empty loadable segment detected, is this intentional ? strip: there are no sections to be copied! but doesn't change the binary. |
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020529 Description of problem: After applying /usr/bin/strip, executable ELF files that the kernel used to run, will not run anymore. In some cases I see "Illegal instruction", in other cases I see "bash: <a.elf>: cannot execute binary file". One broad case that fails is any ELF executable with e_shoff, e_shentsize, e_shnum, and e_shstrndx all zero. Such a file has an empty "linking view". This is no problem for executing, because execve() uses only the "execution view" [e_phnum, e_phoff, e_phentsize, e_entry], and totally ignores the "linking view". However, if the "linking view" is empty, then the output of 'strip' is just 92 bytes of headers, with no PT_LOAD at all; the file has been totally eviscerated. Trying to run it gets "cannot execute binary file". Instead, 'strip' should detect an empty "linking view", give a warning message, and leave the file alone. Another case that fails is an ELF executable with a second PT_LOAD having 0==.p_memsz, and that is not placed "next" after the first PT_LOAD. Such a PT_LOAD is useful for setting the value of brk(0). 'strip' changes p_vaddr to 0, and p_offset to "next", and also sets p_align to 4, even though the original value was 0x1000. Typically this destroys the relationship (0xfff & p_offset) == (0xfff & p_vaddr) which is required by execve(). Trying to run the result gets "Illegal instruction". 'strip' must preserve PT_LOAD.p_align and everything that it implies in conjunction with p_offset, p_vaddr, p_paddr. Version-Release number of selected component (if applicable): binutils-2.13.90.0.2-2 How reproducible: Always Steps to Reproduce: Using the date.upx.no_shdr and date.upx.shdr ELF executables that are attached to this bugreport: 1../a.elf # normal execution 2./usr/bin/strip ./a.elf # apply 'strip' 3../a.elf # try to execute the result of stripping Actual Results: $ ./date.upx.shdr.strip Illegal instruction $ ./date.upx.no_shdr.strip bash: ./date.upx.no_shdr.strip: cannot execute binary file Expected Results: $ ./date.upx.shdr Sat Jan 11 17:09:06 PST 2003 $ ./date.upx.no_shdr Sat Jan 11 17:09:09 PST 2003 Additional info: