freebsd kernel buffer overflow patch

gerarra_at_tin.it
Date: 09/22/04

  • Next message: John Baldwin: "Re: Dell gx280 and acpi problems" 
    Date: Wed, 22 Sep 2004 21:08:00 +0200
To: freebsd-hackers@freebsd.org

    Hi,
    I've seen a potential problem in my patch; SYF_MPSAFE flag for MP safe syscalls
    is not managed; maybe something like that is better:

    ===================================
    kern/kern_syscalls.c:

    --- kern_syscalls.c Sat Sep 18 13:42:21 2004
    +++ kern_syscalls2.c Wed Sep 22 20:25:22 2004
    @@ -35,6 +35,7 @@
     #include <sys/mutex.h>
     #include <sys/sx.h>
     #include <sys/module.h>
    +#include <systm.h>

     /*
      * Acts like "nosys" but can be identified in sysent for dynamic call
    @@ -58,6 +59,17 @@
     syscall_register(int *offset, struct sysent *new_sysent,
                     struct sysent *old_sysent)
     {
    +#ifdef MAX_SYSCALL_ARGS
    + if ( (new_sysent->sy_narg & ~SYF_MPSAFE) < 0 ||
    + (new_sysent->sy_narg & ~SYF_MPSAFE) > MAX_SYSCALL_ARGS)
    + {
    + printf("Invalid sy_narg for syscall: boundary is [0 - %d]\n",
    + MAX_SYSCALL_ARGS);
    + return EINVAL;
    + }
    +#endif
    +
    +
            if (*offset == NO_SYSCALL) {
                    int i;

    complete diffs tree to http://www.gufi.org/~rookie/args-diff.tar.gz

    rookie

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  • Next message: John Baldwin: "Re: Dell gx280 and acpi problems"