kernel_optimize_test/security/selinux
Ondrej Mosnacek fd75d73aa2 selinux: fix cond_list corruption when changing booleans
commit d8f5f0ea5b86300390b026b6c6e7836b7150814a upstream.

Currently, duplicate_policydb_cond_list() first copies the whole
conditional avtab and then tries to link to the correct entries in
cond_dup_av_list() using avtab_search(). However, since the conditional
avtab may contain multiple entries with the same key, this approach
often fails to find the right entry, potentially leading to wrong rules
being activated/deactivated when booleans are changed.

To fix this, instead start with an empty conditional avtab and add the
individual entries one-by-one while building the new av_lists. This
approach leads to the correct result, since each entry is present in the
av_lists exactly once.

The issue can be reproduced with Fedora policy as follows:

    # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True
    # setsebool ftpd_anon_write=off ftpd_connect_all_unreserved=off ftpd_connect_db=off ftpd_full_access=off

On fixed kernels, the sesearch output is the same after the setsebool
command:

    # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True

While on the broken kernels, it will be different:

    # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True

While there, also simplify the computation of nslots. This changes the
nslots values for nrules 2 or 3 to just two slots instead of 4, which
makes the sequence more consistent.

Cc: stable@vger.kernel.org
Fixes: c7c556f1e8 ("selinux: refactor changing booleans")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:41:57 +02:00
..
include selinux: fix variable scope issue in live sidtab conversion 2021-03-30 14:31:53 +02:00
ss selinux: fix cond_list corruption when changing booleans 2021-04-14 08:41:57 +02:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
avc.c selinux: add basic filtering for audit trace events 2020-08-21 17:07:29 -04:00
hooks.c selinux: fix inconsistency between inode_getxattr and inode_listsecurity 2021-03-04 11:38:28 +01:00
ibpkey.c selinux: Fix error return code in sel_ib_pkey_sid_slow() 2020-11-12 20:16:09 -05:00
Kconfig Documentation,selinux: deprecate setting checkreqprot to 1 2020-02-10 10:49:01 -05:00
Makefile selinux: hash context structure directly 2020-04-17 16:04:34 -04:00
netif.c selinux: Fix spelling mistakes in the comments 2020-07-08 12:15:52 -04:00
netlabel.c
netlink.c
netnode.c selinux: Fix spelling mistakes in the comments 2020-07-08 12:15:52 -04:00
netport.c selinux: Fix spelling mistakes in the comments 2020-07-08 12:15:52 -04:00
nlmsgtab.c net: bridge: vlan: add rtm definitions and dump support 2020-01-15 13:48:17 +01:00
selinuxfs.c selinux: fix variable scope issue in live sidtab conversion 2021-03-30 14:31:53 +02:00
status.c selinux: move status variables out of selinux_ss 2020-02-10 10:49:01 -05:00
xfrm.c