To be able to compile rsbac kernel CONFIG_UIDGIT_STRICT_TYPE_CHECKS and CONFIG_USER_NS have to be disabled in kernel config. To apply PaX patch fixation patch in kernel 3.10 with PaX Patch to this kernel, a #include<sched/sysctl.h> have to be included in mprotect.c
2013/7/29 Javier Juan Martínez Cabezón <[email protected]> > Tomwij, blueness, as rsbac_sources maintainers, if you want to test > fixation Patch with the source I have pointed in my initial mail, expect > some troubles in compilation (conflicting types with k_uidt. I think it's > not related with fixation Patch, but with rsbac instead, and git in > particular an something puntual :-S. So when I could make it compile (I > have asked about this to ao, tested with rsbac 3.10 too...with same result) > I will tell you, > > Rsbac git is now (as I have seen this night) with troubles and I could > only get rsbac sources from webgit clicking in "snapshot" > > > > > > > 2013/7/29 Javier Juan Martínez Cabezón <[email protected]> > >> Hi and thanks for your answer, in rsbac code in namei.c this code: >> >> >> rsbac_name = rsbac_symlink_redirect(dentry- >> >d_inode, link, buflen); >> >> assigns to rsbac_name the result of rsbac_symlink_redirect() >> >> the part I have found about rsbac_symlink_redirect definition is this >> (from adf_main.c, rsbac only code) >> >> ( >> http://git.rsbac.org/cgi-bin/gitweb.cgi?p=linux-3.8.y.git;a=blob;f=rsbac/adf/adf_main.c;h=decb72b3648cf4353deead1b880048bbfa17a035;hb=HEAD: >> >> #ifdef CONFIG_RSBAC_SYM_REDIR >> 2741 EXPORT_SYMBOL(rsbac_symlink_redirect); >> 2742 >> 2743 /* This function changes the symlink content by adding a suffix, if >> 2744 * requested. It returns NULL, if unchanged, or a pointer to a >> 2745 * kmalloc'd new char * otherwise, which has to be kfree'd after use. >> 2746 */ >> 2747 *char * rsbac_symlink_redirect( >> 2748 struct inode * inode_p, >> 2749 const char * name, >> 2750 u_int maxlen)* >> 2751 { >> 2752 #if defined(CONFIG_RSBAC_SYM_REDIR_REMOTE_IP) || >> defined(CONFIG_RSBAC_SYM_REDIR_MAC) || defined(CONFIG_RSBAC_SYM_REDIR_RC) >> || defined(CONFIG_RSBAC_SYM_REDIR_UID) >> 2753 * union rsbac_target_id_t * i_tid_p; >> 2754 int err; >> 2755 union rsbac_attribute_value_t i_attr_val;* >> 2756 #endif >> . >> . >> . >> #if defined(CONFIG_RSBAC_SYM_REDIR_REMOTE_IP) || >> defined(CONFIG_RSBAC_SYM_REDIR_MAC) || defined(CONFIG_RSBAC_SYM_REDIR_RC) >> || defined(CONFIG_RSBAC_SYM_REDIR_UID) >> 2793 * i_tid_p = kmalloc(sizeof(*i_tid_p), GFP_KERNEL);* >> 2794 if(!i_tid_p) >> 2795 { >> 2796 rsbac_printk(KERN_DEBUG >> 2797 "rsbac_symlink_redirect(): not enough memory for symlink >> redir remote ip inode %u on dev %02u:%02u!\n", >> 2798 inode_p->i_ino, >> 2799 RSBAC_MAJOR(inode_p->i_sb->s_dev), >> RSBAC_MINOR(inode_p->i_sb->s_dev) ); >> 2800 return NULL; >> 2801 } >> 2802 i_tid_p->symlink.device = inode_p->i_sb->s_dev; >> 2803 i_tid_p->symlink.inode = inode_p->i_ino; >> 2804 i_tid_p->symlink.dentry_p = NULL; >> 2805 #endif >> >> >> So, Would be safe maintain the namei.c related part from fixation patch >> as is isn't it? >> >> This in particular: >> >> >> #ifdef CONFIG_RSBAC_SYM_REDIR >> rsbac_name = rsbac_symlink_redirect(dentry->d_inode, link, buflen); >> if (rsbac_name) { >> len = strlen(rsbac_name); >> if (copy_to_user(buffer, rsbac_name, len)) >> len = -EFAULT; >> kfree(rsbac_name); >> } >> else >> #endif >> if (len < sizeof(tmpbuf)) { >> memcpy(tmpbuf, link, len); >> newlink = tmpbuf; >> } else >> newlink = link; >> >> if (copy_to_user(buffer, newlink, len)) >> len = -EFAULT; >> out: >> return len; >> } >> >> This piece of code doesn't change usually change in rsbac as I would had >> seen, so fixation patch should stay equal towards (if switched correct PaX >> patch and rsbac patch it only rejects in this four positions and always the >> same ones, so fixation patch should work for another versions too.. >> >> Thanks a lot pageexec. >> >> >> >> 2013/7/29 PaX Team <[email protected]> >> >>> On 29 Jul 2013 at 6:23, Javier Juan Martínez Cabezón wrote: >>> >>> > PaX tries to do this modification to rsbac git code: >>> > >>> > --- fs/namei.c 2013-03-19 01:53:21.091281869 +0100 >>> > +++ fs/namei.c 2013-03-19 01:53:31.251281326 +0100 >>> > @@ -3954,7 +3956,14 @@ >>> > len = strlen(link); >>> > if (len > (unsigned) buflen) >>> > len = buflen; >>> > - if (copy_to_user(buffer, link, len)) >>> > + >>> > + if (len < sizeof(tmpbuf)) { >>> > + memcpy(tmpbuf, link, len); >>> > + newlink = tmpbuf; >>> > + } else >>> > + newlink = link; >>> > + >>> > + if (copy_to_user(buffer, newlink, len)) >>> > len = -EFAULT; >>> > out: >>> > return len; >>> >>> this change is done for USERCOPY to prevent false positive reports when >>> the >>> name comes from a dentry field (vs. a normal kmalloc slab) or something >>> like that. if you want to enable USERCOPY under RSBAC as well then you'll >>> have to ensure that either rsbac_name is allocated by a normal kmalloc >>> (this >>> seems to be the case already from a quick look) or you'll have to do the >>> temporary stack copy as done in the above snippet. >>> >>> >>> >>> >> >
