Bug 758429
| Summary: | file command incorrectly identifies a JPEG file as being a Minix filesystem | ||||||||
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| Product: | Red Hat Enterprise Linux 5 | Reporter: | Alan Staples <alan.staples> | ||||||
| Component: | file | Assignee: | Jan Kaluža <jkaluza> | ||||||
| Status: | CLOSED ERRATA | QA Contact: | BaseOS QE Security Team <qe-baseos-security> | ||||||
| Severity: | low | Docs Contact: | |||||||
| Priority: | low | ||||||||
| Version: | 5.5 | CC: | ksrot, mmalik, ovasik | ||||||
| Target Milestone: | rc | ||||||||
| Target Release: | 5.5 | ||||||||
| Hardware: | All | ||||||||
| OS: | Linux | ||||||||
| Whiteboard: | |||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||
| Doc Text: |
Cause: Minix magic pattern has the same beginning as the JPEG magic pattern and File tries to match Minix magic pattern before JPEG.
Consequence: This causes some JPEG files are detected as Minix filesystem.
Fix: Order of JPEG and Minix magic patterns have been changed, because JPEG magic pattern is longer and therefore stronger.
Result: File now tries to match JPEG magic pattern before Minix magic pattern, so it detects JPEG files properly.
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Story Points: | --- | ||||||
| Clone Of: | Environment: | ||||||||
| Last Closed: | 2012-02-21 05:46:40 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: | |||||||||
| Bug Depends On: | |||||||||
| Bug Blocks: | 771700, 772019 | ||||||||
| Attachments: |
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Created attachment 538461 [details]
proposed patch
Check JPEG before minix FS since JPEG pattern is stronger
(In reply to comment #2) > Created attachment 538461 [details] > proposed patch > > Check JPEG before minix FS since JPEG pattern is stronger I tried "file -k" and indeed this does identify that the file is either a "Minix file system" or "JPEG image data, JFIF standard 1.01". I can parse the output of this command for "JPEG image data" systematically now. Thank you for your help.
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New Contents:
Cause: Minix magic pattern has the same beginning as the JPEG magic pattern and File tries to match Minix magic pattern before JPEG.
Consequence: This causes some JPEG files are detected as Minix filesystem.
Fix: Order of JPEG and Minix magic patterns have been changed, because JPEG magic pattern is longer and therefore stronger.
Result: File now tries to match JPEG magic pattern before Minix magic pattern, so it detects JPEG files properly.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2012-0201.html |
Created attachment 538200 [details] 2 JPEG image files - 1 normal and 1 that causes this issue Description of problem: The "file" utility incorrectly identifies a JPEG file as being of type "Minix filesystem" Version-Release number of selected component (if applicable): Red Hat Enterprise Linux 5 Update 5 64-bit file-4.17-15.el5_3.1 How reproducible: consistently, but only for some JPEG files Steps to Reproduce: 1. extract the attached "jpeg_examples.tgz" file 2. copy extracted files to /tmp 2. execute "file /tmp/funky.jpeg" Actual results: The utility outputs: "Minix filesystem, 30 char names" Expected results: The utility outputs: "JPEG image data, JFIF standard 1.01" Additional info: I've also included a "normal.jpeg" file within the attachment, which I have generated the same way as the attached "funky.jpeg", yet the file command works as expected on this JPEG.