On Fri, Sep 23, 2011 at 2:00 PM, Abhijit Pawar <[email protected]>wrote:
> On 09/23/2011 01:01 PM, Rajat Sharma wrote: > >> Untidy way : - >>> Yes, you can do that by registering a new binary format handler. Whenever >>> exec is called, a list of registered binary format handlers is scanned, >>> in >>> the same way you can hook the load_binary& load_library function >>> pointers >>> of the already registered binary format handlers. >>> >> Challenge with this untidy way is to identify the correct format, for >> example if you are interested in only hooking ELF format, there is no >> special signature withing the registered format handler to identify >> that, however if one format handler recognizes the file header, its >> load_binary will return 0. This can give you the hint that you are >> sitting on top of correct file format. Long time back I had written >> the similar module in Linux to do the same, but can't share the code >> :) >> >> -Rajat >> >> On Thu, Sep 22, 2011 at 3:14 PM, rohan puri<[email protected]> >> wrote: >> >>> >>> On Thu, Sep 22, 2011 at 1:53 PM, Abhijit Pawar<[email protected]> >>> wrote: >>> >>>> hi list, >>>> Is there any way to hook the exec system call on Linux box apart from >>>> replacing the call in System Call table? >>>> >>>> Regards, >>>> Abhijit Pawar >>>> >>>> ______________________________**_________________ >>>> Kernelnewbies mailing list >>>> Kernelnewbies@kernelnewbies.**org <[email protected]> >>>> http://lists.kernelnewbies.**org/mailman/listinfo/**kernelnewbies<http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies> >>>> >>> Tidy way : - >>> >>> You can do that from LSM (Linux security module). >>> >>> Untidy way : - >>> Yes, you can do that by registering a new binary format handler. Whenever >>> exec is called, a list of registered binary format handlers is scanned, >>> in >>> the same way you can hook the load_binary& load_library function >>> pointers >>> of the already registered binary format handlers. >>> >>> Regards, >>> Rohan Puri >>> >>> ______________________________**_________________ >>> Kernelnewbies mailing list >>> Kernelnewbies@kernelnewbies.**org <[email protected]> >>> http://lists.kernelnewbies.**org/mailman/listinfo/**kernelnewbies<http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies> >>> >>> >>> So If I use the binary format handler, then I can hook the exec call. > however I need to register this. Does that mean that I need to return the > negative value so as to have actual ELF handler to be loaded? > > Regards, > Abhijit Pawar > > Read this, http://www.linux.it/~rubini/docs/binfmt/binfmt.html this might help Regards, Rohan Puri
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