Bug 203919 – sscanf - bad hex conversion value with sign bit set and %i conversion

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Bug 203919 - sscanf - bad hex conversion value with sign bit set and %i conversion

Summary:	sscanf - bad hex conversion value with sign bit set and %i conversion

Status:	CLOSED NOTABUG

Aliases:	None

Product:	Red Hat Enterprise Linux 4
Classification:	Red Hat
Component:	glibc (Show other bugs)
Sub Component:
Version:	4.2
Hardware:	i386 Linux

Priority	medium Severity medium
Target Milestone:	---
Target Release:	---
Assigned To:	Jakub Jelinek
QA Contact:	Brian Brock
Docs Contact:

URL:
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Depends On:
Blocks:
	Show dependency tree / graph

Reported:	2006-08-24 10:31 EDT by Rod Swenson
Modified:	2016-11-24 10:03 EST (History)
CC List:	2 users (show)

See Also:
Fixed In Version:
Doc Type:	Bug Fix
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2006-08-24 10:50:23 EDT
Type:	---
Regression:	---
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Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
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Attachments	(Terms of Use)
sscanf test case (2.02 KB, text/plain) 2006-08-24 10:31 EDT, Rod Swenson	no flags	Details
Add an attachment (proposed patch, testcase, etc.)

Groups: None (edit)

Description Rod Swenson 2006-08-24 10:31:38 EDT

Description of problem:
'sscanf' does not process hex (0x) values properly if the MSB (sign) bit is set
using "%i" conversion. I suspect that the conversion routines do not parse the
value as a hex bit pattern, but convert the value to decimal thus causing an
overflow condition. This would explain why the cases in question would return
the max positive value.

Version-Release number of selected component (if applicable):
RHEL4 U2

How reproducible:
test case attached. 

Steps to Reproduce:
Compile and execute test case
  
Additional info:

Using this test case on x86_64 the sscanf works fine.

Comment 1 Rod Swenson 2006-08-24 10:31:50 EDT

Created attachment 134817 [details]
sscanf test case

Comment 2 Jakub Jelinek 2006-08-24 10:50:23 EDT

Please read the standard:
http://www.opengroup.org/onlinepubs/009695399/functions/scanf.html
http://www.opengroup.org/onlinepubs/009695399/functions/strtol.html
0XFFFFFF00 is not in range of the int type (INT_MIN .. INT_MAX), so INT_MAX
should be returned.  If you want a negative number in hexadecimal notation,
write -0x100.

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