linux/security/smack
José Bollo 9598f4c9e7 SMACK: Fix handling value==NULL in post setxattr
The function `smack_inode_post_setxattr` is called each
time that a setxattr is done, for any value of name.
The kernel allow to put value==NULL when size==0
to set an empty attribute value. The systematic
call to smk_import_entry was causing the dereference
of a NULL pointer hence a KERNEL PANIC!

The problem can be produced easily by issuing the
command `setfattr -n user.data file` under bash prompt
when SMACK is active.

Moving the call to smk_import_entry as proposed by this
patch is correcting the behaviour because the function
smack_inode_post_setxattr is called for the SMACK's
attributes only if the function smack_inode_setxattr validated
the value and its size (what will not be the case when size==0).

It also has a benefical effect to not fill the smack hash
with garbage values coming from any extended attribute
write.

Change-Id: Iaf0039c2be9bccb6cee11c24a3b44d209101fe47
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
2014-04-11 14:35:05 -07:00
..
Kconfig Smack: use select not depends in Kconfig 2012-12-14 10:57:10 -08:00
Makefile Smack: Simplified Mandatory Access Control Kernel 2008-02-05 09:44:20 -08:00
smack_access.c Smack: adds smackfs/ptrace interface 2014-04-11 14:34:35 -07:00
smack_lsm.c SMACK: Fix handling value==NULL in post setxattr 2014-04-11 14:35:05 -07:00
smack.h Smack: adds smackfs/ptrace interface 2014-04-11 14:34:35 -07:00
smackfs.c Smack: adds smackfs/ptrace interface 2014-04-11 14:34:35 -07:00