I have a problem compiling the following exploit code:
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
I am using "gcc file.c" and "gcc -O2 file.c", but both of them results in the following errors:
sorbolinux-exec.c: In function ‘sc’:
sorbolinux-exec.c:76: error: stray ‘\302’ in program
sorbolinux-exec.c:76: error: stray ‘\244’ in program
sorbolinux-exec.c:76: error: ‘t’ undeclared (first use in this function)
sorbolinux-exec.c:76: error: (Each undeclared identifier is reported only once
sorbolinux-exec.c:76: error: for each function it appears in.)
I tried compiling them on both Kali Linux and Ubuntu 10.04 (Lucid Lynx) and got the same result.
You have an invalid character on that line. This is what I saw:
You have invalid characters in your source. If you don't have any valid non-ASCII characters in your source, maybe in a double quoted string literal, you can simply convert your file back to ASCII with:
tr -cd '\11\12\15\40-\176' < old.c > new.c
The method with iconv will stop at wrong characters which makes no sense. The above command line is working with the example file.
Sure, convert the file to ASCII and blast all Unicode characters away.
It will probably work... But...
You won't know what you fixed.
It will also destroy any Unicode comments. Example: //: A²+B²=C²
It could potentially damage obvious logic and the code will still be broken,
but the solution less obvious.
For example: A string with "Smart-Quotes" (“ & ”) or a pointer with a full-width asterisk (＊). Now “SOME_THING” looks like a #define (SOME_THING) and ＊SomeType is the wrong type (SomeType).
Two more surgical approaches to fixing the problem:
Switch fonts to see the character. (It might be invisible in your current font)
Regular expression search all Unicode characters not part of non-extended ASCII.
In Notepad++ I can search up to FFFF, which hasn't failed me yet.
[\x{80}-\x{FFFF}]
80 is hex for 128, the first extended ASCII character.
After hitting "find next" and highlighting what appears to be empty space, you can close your search dialog and press Ctrl + C to copy to clipboard.
Then paste the character into a Unicode search tool.
I usually use an online one.
http://unicode.scarfboy.com/
Example:
I had a bullet point (•) in my code somehow.
The Unicode value is 2022 (hex), but when read as ASCII by the compiler
you get \342 \200 \242 (3 octal values). It's not as simple as converting each octal values to hex and smashing them together. So "E2 80 A2" is not the hexadecimal Unicode point in your code.
I got the same with a character that visibly appeared as an asterisk, but it was a UTF-8 sequence instead:
Encoder * st;
When compiled, it returned:
g.c:2:1: error: stray ‘\342’ in program
g.c:2:1: error: stray ‘\210’ in program
g.c:2:1: error: stray ‘\227’ in program
342 210 227 turns out to be UTF-8 for ASTERISK OPERATOR (Unicode code point U+2217).
Deleting the '*' and typing it again fixed the problem.
Whenever the compiler found a special character, it gives these kind of compile errors. The error I found is as follows:
error: stray '\302' in program and error: stray '\240' in program
....
It is some piece of code I copied from a chat messenger. In Facebook Messenger, it was a special character only. After copying into the Vim editor it changed to the correct character only. But the compiler was giving the above error .. then .. that statement I wrote manually after .. it got resolved... :)
It's perhaps because you copied code from the Internet (from a site which has perhaps not an ASCII encoded page, but a UTF-8 encoded page), so you can convert the code to ASCII from this site:
"http://www.percederberg.net/tools/text_converter.html"
There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.
This problem comes when you have copied some text from an HTML page or you have done modification in a Windows environment and are trying to compile in a Unix/Solaris environment.
Please do "dos2unix" to remove the special characters from the file:
dos2unix fileName.ext fileName.ext
Invalid character in your code.
It is a common copy-paste error, especially when code is copied from Microsoft Word documents or PDF files.
I noticed an issue in using the above tr command. The tr command COMPLETELY removes the "smart quotes". It would be better to replace the "smart quotes" with something like this.
This will give you a quick preview of what will be replaced.
sed s/[”“]/'"'/g File.txt
This will do the replacements and put the replacement in a new file called WithoutSmartQuotes.txt.
sed s/[”“]/'"'/g File.txt > WithoutSmartQuotes.txt
This will overwrite the original file.
sed -i ".bk" s/[”“]/'"'/g File.txt
http://developmentality.wordpress.com/2010/10/11/how-to-remove-smart-quotes-from-a-text-file/
Codo was exactly right on Oct. 5 that ¤t[i] is the intended text (with the currency symbol inadvertently introduced when the source was put into HTML (see original):
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
Codo's change makes this exploit code compile without error. I did that and was able to use the exploit on Ubuntu 12.04 (Precise Pangolin) to escalate to root privilege.
The explanations given here are correct. I just wanted to add that this problem might be because you copied the code from somewhere, from a website or a PDF file due to which there are some invalid characters in the code.
Try to find those invalid characters, or just retype the code if you can't. It will definitely compile then.
Source: stray error reason
With me, this error occurred when I copied and pasted code in text format to my editor (gedit).
The code was in a text document (.odt). I copied it and pasted it into gedit.
If you did the same, you have manually rewrite the code.
Related
I have a problem compiling the following exploit code:
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
I am using "gcc file.c" and "gcc -O2 file.c", but both of them results in the following errors:
sorbolinux-exec.c: In function ‘sc’:
sorbolinux-exec.c:76: error: stray ‘\302’ in program
sorbolinux-exec.c:76: error: stray ‘\244’ in program
sorbolinux-exec.c:76: error: ‘t’ undeclared (first use in this function)
sorbolinux-exec.c:76: error: (Each undeclared identifier is reported only once
sorbolinux-exec.c:76: error: for each function it appears in.)
I tried compiling them on both Kali Linux and Ubuntu 10.04 (Lucid Lynx) and got the same result.
You have an invalid character on that line. This is what I saw:
You have invalid characters in your source. If you don't have any valid non-ASCII characters in your source, maybe in a double quoted string literal, you can simply convert your file back to ASCII with:
tr -cd '\11\12\15\40-\176' < old.c > new.c
The method with iconv will stop at wrong characters which makes no sense. The above command line is working with the example file.
Sure, convert the file to ASCII and blast all Unicode characters away.
It will probably work... But...
You won't know what you fixed.
It will also destroy any Unicode comments. Example: //: A²+B²=C²
It could potentially damage obvious logic and the code will still be broken,
but the solution less obvious.
For example: A string with "Smart-Quotes" (“ & ”) or a pointer with a full-width asterisk (＊). Now “SOME_THING” looks like a #define (SOME_THING) and ＊SomeType is the wrong type (SomeType).
Two more surgical approaches to fixing the problem:
Switch fonts to see the character. (It might be invisible in your current font)
Regular expression search all Unicode characters not part of non-extended ASCII.
In Notepad++ I can search up to FFFF, which hasn't failed me yet.
[\x{80}-\x{FFFF}]
80 is hex for 128, the first extended ASCII character.
After hitting "find next" and highlighting what appears to be empty space, you can close your search dialog and press Ctrl + C to copy to clipboard.
Then paste the character into a Unicode search tool.
I usually use an online one.
http://unicode.scarfboy.com/
Example:
I had a bullet point (•) in my code somehow.
The Unicode value is 2022 (hex), but when read as ASCII by the compiler
you get \342 \200 \242 (3 octal values). It's not as simple as converting each octal values to hex and smashing them together. So "E2 80 A2" is not the hexadecimal Unicode point in your code.
I got the same with a character that visibly appeared as an asterisk, but it was a UTF-8 sequence instead:
Encoder * st;
When compiled, it returned:
g.c:2:1: error: stray ‘\342’ in program
g.c:2:1: error: stray ‘\210’ in program
g.c:2:1: error: stray ‘\227’ in program
342 210 227 turns out to be UTF-8 for ASTERISK OPERATOR (Unicode code point U+2217).
Deleting the '*' and typing it again fixed the problem.
Whenever the compiler found a special character, it gives these kind of compile errors. The error I found is as follows:
error: stray '\302' in program and error: stray '\240' in program
....
It is some piece of code I copied from a chat messenger. In Facebook Messenger, it was a special character only. After copying into the Vim editor it changed to the correct character only. But the compiler was giving the above error .. then .. that statement I wrote manually after .. it got resolved... :)
It's perhaps because you copied code from the Internet (from a site which has perhaps not an ASCII encoded page, but a UTF-8 encoded page), so you can convert the code to ASCII from this site:
"http://www.percederberg.net/tools/text_converter.html"
There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.
This problem comes when you have copied some text from an HTML page or you have done modification in a Windows environment and are trying to compile in a Unix/Solaris environment.
Please do "dos2unix" to remove the special characters from the file:
dos2unix fileName.ext fileName.ext
Invalid character in your code.
It is a common copy-paste error, especially when code is copied from Microsoft Word documents or PDF files.
I noticed an issue in using the above tr command. The tr command COMPLETELY removes the "smart quotes". It would be better to replace the "smart quotes" with something like this.
This will give you a quick preview of what will be replaced.
sed s/[”“]/'"'/g File.txt
This will do the replacements and put the replacement in a new file called WithoutSmartQuotes.txt.
sed s/[”“]/'"'/g File.txt > WithoutSmartQuotes.txt
This will overwrite the original file.
sed -i ".bk" s/[”“]/'"'/g File.txt
http://developmentality.wordpress.com/2010/10/11/how-to-remove-smart-quotes-from-a-text-file/
Codo was exactly right on Oct. 5 that ¤t[i] is the intended text (with the currency symbol inadvertently introduced when the source was put into HTML (see original):
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
Codo's change makes this exploit code compile without error. I did that and was able to use the exploit on Ubuntu 12.04 (Precise Pangolin) to escalate to root privilege.
The explanations given here are correct. I just wanted to add that this problem might be because you copied the code from somewhere, from a website or a PDF file due to which there are some invalid characters in the code.
Try to find those invalid characters, or just retype the code if you can't. It will definitely compile then.
Source: stray error reason
With me, this error occurred when I copied and pasted code in text format to my editor (gedit).
The code was in a text document (.odt). I copied it and pasted it into gedit.
If you did the same, you have manually rewrite the code.
I am new to Linux OS and i am trying to compile a simpe c program
, I wrote it in using text editor
#include<stdio.h>
void main(){
printf("Hello!");
}
I typed gcc -o main main.c
and the following issue shows up
main.c:1:1: error: stray '\377' in program
# i n c l u d e < s t d i o . h >
main.c:1:2: error: stray '\376' in program
This happens whenever i run c or c++ program
\377 and \376 are an octal representation of the bytes that constitute the value 0xFEFF, the UTF-16 byte order marker. Your compiler doesn't expect those characters in your source code.
You need to change the encoding of your source file to either be UTF-8 or ASCII. Given the number of text editors that exist and the lack of that information in your question I cannot list every possibility for how to do that.
You could just do this in a bash shell:
cat > program.c
// File content here
^D
This will create a file called "program.c" with "// File content here" as its content, in UTF-8.
Your text editor is saving the program in the wrong character encoding. Save it as ASCII plain text and try again.
There is no text but encoded text.
With your editor, you have chosen to save your text file with the UTF-16LE character encoding (presumably).
Any program that reads a text file must know the character encoding of the text file. It could accept one documented character encoding (only or default) and/or allow you to tell it which you used.
This could work
gcc -finput-charset=UTF16-LE main.c
but since you have include files, the include files must use the same character encoding. On my system, they use UTF-8 (and include ©, which is good because gcc chokes on the bytes for that, letting me know that I've messed up).
Note: It's not very common to save a C source file (or most any text file) with UTF-16. UTF-8 is very common for all types of text files. (ASCII is also not very common, either. You might not find it as an option in many text editors. Historically, MS-DOS did not support it and Windows only got it very late and only for the sake of completeness.)
Here is my code
int main()
{
float avg, age[] = { 23.4, 55, 22.6, 3, 40.5, 18 };
avg = average(age); /* Only name of array is passed as argument. */
printf("Average age=%.2f", avg);
return 0;
}
Compilation error in int main():
error: stray '\342' in program
error: stray '\200' in program
error: stray '\213' in program
You have "crap characters" in your source file.
\342 \200 \213 is octal for 0xE2 0x80 0x8B which is a zero width space in UTF-8 (Unicode U+200B), something no C compiler can make sense of (and something you can't see, zero-width after all, when UTF-8 is displayed correctly).
-> Use a text or code editor (even Windows' Notepad should do, if not saving as UTF-8, but any other editor would be better) and/or an integrated development environment to write your code. Don't ever use word processors or the like, that might introduce unwanted characters.
The code looks fine.
According to my personal experience, stray '\xxx' is often caused by using invalid characters in your code (except in string literals), which happens more frequently if your language is not English.
For example, this code generates such an error:
int main（）｛return 0；｝
I can't find what's wrong, so my only suggestion is make sure your IME is switched to English, then type the code again.
This seem to be a problem with bad characters in your code. Characters that are non-printable like ╚ or something. Open your code for example in Notepad++, select menu option to view all characters, menu View → Show invisible characters → Show all characters and remove any bad characters from your code.
Use the following website. It will show you bad characters and then remove them:
View non-printable Unicode characters
I have a problem compiling the following exploit code:
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
I am using "gcc file.c" and "gcc -O2 file.c", but both of them results in the following errors:
sorbolinux-exec.c: In function ‘sc’:
sorbolinux-exec.c:76: error: stray ‘\302’ in program
sorbolinux-exec.c:76: error: stray ‘\244’ in program
sorbolinux-exec.c:76: error: ‘t’ undeclared (first use in this function)
sorbolinux-exec.c:76: error: (Each undeclared identifier is reported only once
sorbolinux-exec.c:76: error: for each function it appears in.)
I tried compiling them on both Kali Linux and Ubuntu 10.04 (Lucid Lynx) and got the same result.
You have an invalid character on that line. This is what I saw:
You have invalid characters in your source. If you don't have any valid non-ASCII characters in your source, maybe in a double quoted string literal, you can simply convert your file back to ASCII with:
tr -cd '\11\12\15\40-\176' < old.c > new.c
The method with iconv will stop at wrong characters which makes no sense. The above command line is working with the example file.
Sure, convert the file to ASCII and blast all Unicode characters away.
It will probably work... But...
You won't know what you fixed.
It will also destroy any Unicode comments. Example: //: A²+B²=C²
It could potentially damage obvious logic and the code will still be broken,
but the solution less obvious.
For example: A string with "Smart-Quotes" (“ & ”) or a pointer with a full-width asterisk (＊). Now “SOME_THING” looks like a #define (SOME_THING) and ＊SomeType is the wrong type (SomeType).
Two more surgical approaches to fixing the problem:
Switch fonts to see the character. (It might be invisible in your current font)
Regular expression search all Unicode characters not part of non-extended ASCII.
In Notepad++ I can search up to FFFF, which hasn't failed me yet.
[\x{80}-\x{FFFF}]
80 is hex for 128, the first extended ASCII character.
After hitting "find next" and highlighting what appears to be empty space, you can close your search dialog and press Ctrl + C to copy to clipboard.
Then paste the character into a Unicode search tool.
I usually use an online one.
http://unicode.scarfboy.com/
Example:
I had a bullet point (•) in my code somehow.
The Unicode value is 2022 (hex), but when read as ASCII by the compiler
you get \342 \200 \242 (3 octal values). It's not as simple as converting each octal values to hex and smashing them together. So "E2 80 A2" is not the hexadecimal Unicode point in your code.
I got the same with a character that visibly appeared as an asterisk, but it was a UTF-8 sequence instead:
Encoder * st;
When compiled, it returned:
g.c:2:1: error: stray ‘\342’ in program
g.c:2:1: error: stray ‘\210’ in program
g.c:2:1: error: stray ‘\227’ in program
342 210 227 turns out to be UTF-8 for ASTERISK OPERATOR (Unicode code point U+2217).
Deleting the '*' and typing it again fixed the problem.
Whenever the compiler found a special character, it gives these kind of compile errors. The error I found is as follows:
error: stray '\302' in program and error: stray '\240' in program
....
It is some piece of code I copied from a chat messenger. In Facebook Messenger, it was a special character only. After copying into the Vim editor it changed to the correct character only. But the compiler was giving the above error .. then .. that statement I wrote manually after .. it got resolved... :)
It's perhaps because you copied code from the Internet (from a site which has perhaps not an ASCII encoded page, but a UTF-8 encoded page), so you can convert the code to ASCII from this site:
"http://www.percederberg.net/tools/text_converter.html"
There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.
This problem comes when you have copied some text from an HTML page or you have done modification in a Windows environment and are trying to compile in a Unix/Solaris environment.
Please do "dos2unix" to remove the special characters from the file:
dos2unix fileName.ext fileName.ext
Invalid character in your code.
It is a common copy-paste error, especially when code is copied from Microsoft Word documents or PDF files.
I noticed an issue in using the above tr command. The tr command COMPLETELY removes the "smart quotes". It would be better to replace the "smart quotes" with something like this.
This will give you a quick preview of what will be replaced.
sed s/[”“]/'"'/g File.txt
This will do the replacements and put the replacement in a new file called WithoutSmartQuotes.txt.
sed s/[”“]/'"'/g File.txt > WithoutSmartQuotes.txt
This will overwrite the original file.
sed -i ".bk" s/[”“]/'"'/g File.txt
http://developmentality.wordpress.com/2010/10/11/how-to-remove-smart-quotes-from-a-text-file/
Codo was exactly right on Oct. 5 that ¤t[i] is the intended text (with the currency symbol inadvertently introduced when the source was put into HTML (see original):
http://downloads.securityfocus.com/vulnerabilities/exploits/59846-1.c
Codo's change makes this exploit code compile without error. I did that and was able to use the exploit on Ubuntu 12.04 (Precise Pangolin) to escalate to root privilege.
The explanations given here are correct. I just wanted to add that this problem might be because you copied the code from somewhere, from a website or a PDF file due to which there are some invalid characters in the code.
Try to find those invalid characters, or just retype the code if you can't. It will definitely compile then.
Source: stray error reason
With me, this error occurred when I copied and pasted code in text format to my editor (gedit).
The code was in a text document (.odt). I copied it and pasted it into gedit.
If you did the same, you have manually rewrite the code.
I couldn't find anything on this, but probably its just because I don't know how to search, because i don't know how to call it.
I tried to compile some C-Code and got the following error:
/path/to/file.h:55:32: error: path/to/include.h: No such file or directory
I know the error and i know that the problem is in file.h at line 55 - where's an include, which doesn't exist.
But what does the 32 stand for?
Marty
It's the number of the character within line 55.
This might also be referred to as "column number" (see comment) but I find that slightly misleading, as e.g. a tab character will generally take up more than one column in your editor, but still count as only one character for the compiler.