[rsbac] Random "file not found" errors

Oliver Breuer oliverbreuer at web.de
Thu May 12 14:56:07 CEST 2005


 Hi all,

when using the 2.6.11-Kernel with RSBAC 1.2.4, at random times random files are not found when trying to access them. But this occures only at random times. The next try (just one second later), the file can be accessed. There are no log messages generated from RSBAC.

After a lot of trying I found one reproducible case:

- tmpfs mounted on /sysmnt/shmtmp/shm
  -> unix-mode: rwxrwxrwt
- symlink /shm -> /sysmnt/shmtmp/shm
- normal user "testuser"
  -> no RC-writing rights to / (only CHDIR, CLOSE, GET_PERMISSIONS_DATA, GET_STATUS_DATA, READ, READ_OPEN, SEARCH)
  -> RC-writing rights to /sysmnt/shmtmp (APPEND, CHDIR, CLOSE, CREATE, DELETE, GET_PERMISSIONS_DATA, GET_STATUS_DATA, LINK_HARD, MODIFY_ACCESS_DATA, MODIFY_PERMISSIONS_DATA, READ, READ_WRITE_OPEN, READ_OPEN, RENAME, SEARCH, TRUNCATE, WRITE, WRITE_OPEN)
- as user "testuser":
  -> mkdir /shm/test1
  -> mkdir /shm/test1/test2
  -> mkdir /home/testuser/test3
  -> cd /home/testuser/test3
  -> ln -s /shm/test1/test2 test4
  -> ls test4/
    => no such file or directory!
  -> ls /shm/test1/test2/
    => no problems

The access through the symlink "/shm -> /sysmnt/shmtmp/shm" somehow doesn't work. When I boot a kernel compiled the same .config-file but without the rsbac-patch, there are no problems.


In the following example there are no problems with the rsbac-kernel:
- as user "testuser"
  -> cd /home/testuser
  -> ln -s /sysmnt/shmtmp/shm test10
  -> cd test3
  -> ln -s /home/testuser/test10/test1/test2 test11
  -> ls test11/
    => no problems

Probably this error results from the user not having RC-writing-rights to the directory where the symlink "/shm -> /sysmnt/shmtmp/shm" is located (in the second case, the link to /sysmnt/shmtmp/shm is created in a directory with rc-write-rights)? I have no idea if this case is related to the random "file not found" errors mentioned at the beginning.

Thanks for any help about this.
Oliver



______________________________________________________________
Verschicken Sie romantische, coole und witzige Bilder per SMS!
Jetzt bei WEB.DE FreeMail: http://f.web.de/?mc=021193



More information about the rsbac mailing list