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. klogd will only change the console log level if `-c' is supplied

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. klogd.c by Troels Walsted Hansen <troels@thule.no>

   I found a bug in the sysklogd package version 1.4. When it
   encounters a zero byte in the kernel logging output, the text
   parser enters a busy loop. I came upon it when the 3c59x driver
   from kernel 2.4.0 started outputting two zero bytes for the product
   code of my laptop's 3Com card. It could be argued that the kernel
   should never output zero bytes in the logging info, but obviously
   that will happen from time to time.

   I fear this bug might be considered a security issue as well, if
   the kernel can be coerced to output a zero byte somehow, all kernel
   logging will stop.

   Wolfgang Oertl <Wolfgang.Oertl@uibk.ac.at> had a similar bugfix
   idea

 . klogd.c by Thomas Roessler <roessler@does-not-exist.org>

   Additionally, the patch prevents LogLine from being invoked with a
   negative counter as an argument.
This commit is contained in:
Joey Schulze 2001-03-11 19:35:51 +00:00
parent 728d79d925
commit dffa03bda1
1 changed files with 27 additions and 8 deletions
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35
klogd.c
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@ -233,6 +233,16 @@
* Added patch to fix priority decoding after moving kernel
* messgages into "%s". Thanks to Solar Designer
* <solar@false.com> for the patch.
*
* Sun Mar 11 20:23:44 CET 2001: Martin Schulze <joey@infodrom.ffis.de>
* Stop LogLine() from being called with wrong argument when a
* former calculation failed already. Thanks to Thomas Roessler
* <roessler@does-not-exist.org> for providing a patch.
*
* Ignore zero bytes, no busy loop is entered anymore. Several
* people have submitted patches: Troels Walsted Hansen
* <troels@thule.no>, Wolfgang Oertl <Wolfgang.Oertl@uibk.ac.at>
* and Thomas Roessler.
*/
@ -281,7 +291,7 @@ static int kmsg,
terminate = 0,
caught_TSTP = 0,
reload_symbols = 0,
console_log_level = 6;
console_log_level = -1;
static int use_syscall = 0,
one_shot = 0,
@ -499,7 +509,8 @@ static enum LOGSRC GetKernelLogSrc(void)
/* Set level of kernel console messaging.. */
if ( (ksyslog(8, NULL, console_log_level) < 0) && \
if ( (console_log_level != -1)
&& (ksyslog(8, NULL, console_log_level) < 0) && \
(errno == EINVAL) )
{
/*
@ -509,10 +520,9 @@ static enum LOGSRC GetKernelLogSrc(void)
* logging completely.
*/
Syslog(LOG_WARNING, "Cannot set console log level - disabling "
"console output.");
"console output.");
ksyslog(6, NULL, 0);
}
/*
* First do a stat to determine whether or not the proc based
@ -739,6 +749,15 @@ static void LogLine(char *ptr, int len)
break; /* full line_buff or end of input buffer */
}
if( *ptr == '\0' ) /* zero byte */
{
ptr++; /* skip zero byte */
space -= 1;
len -= 1;
break;
}
if( *ptr == '\n' ) /* newline */
{
ptr++; /* skip newline */
@ -926,8 +945,8 @@ static void LogKernelLine(void)
fprintf(stderr, "klogd: Error return from sys_sycall: " \
"%d - %s\n", errno, strerror(errno));
}
LogLine(log_buffer, rdcnt);
else
LogLine(log_buffer, rdcnt);
return;
}
@ -951,8 +970,8 @@ static void LogProcLine(void)
Syslog(LOG_ERR, "Cannot read proc file system: %d - %s.", \
errno, strerror(errno));
}
LogLine(log_buffer, rdcnt);
else
LogLine(log_buffer, rdcnt);
return;
}