[PATCH] Allow auditctl_t to read bin_t symlinks.

[PATCH] Allow auditctl_t to read bin_t symlinks.

[David Sugar]

on RHEL7 insmod, rmmod, modprobe (and others?) are a symlinks
to ../bin/kmod.  But policy didn't allow auditctl_t to follow
that link.

type=AVC msg=audit(1543853530.925:141): avc:  denied  { read } for
pid=6937 comm="auditctl" name="insmod" dev="dm-1" ino=628383
scontext=system_u:system_r:auditctl_t:s0
tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=0
type=AVC msg=audit(1543853530.925:143): avc:  denied  { read } for
pid=6937 comm="auditctl" name="rmmod" dev="dm-1" ino=628387
scontext=system_u:system_r:auditctl_t:s0
tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=0
type=AVC msg=audit(1543853530.926:145): avc:  denied  { read } for
pid=6937 comm="auditctl" name="modprobe" dev="dm-1" ino=628386
scontext=system_u:system_r:auditctl_t:s0
tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=0
type=AVC msg=audit(1543853797.766:60): avc:  denied  { read } for
pid=6942 comm="auditctl" name="insmod" dev="dm-1" ino=628383
scontext=system_u:system_r:auditctl_t:s0
tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=1

Signed-off-by: Dave Sugar <dsugar@tresys.com>
---
 policy/modules/system/logging.te | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/policy/modules/system/logging.te b/policy/modules/system/logging.te
index 7020a476..483084a5 100644
--- a/policy/modules/system/logging.te
+++ b/policy/modules/system/logging.te
@@ -107,6 +107,8 @@ read_files_pattern(auditctl_t, auditd_etc_t, auditd_etc_t)
 allow auditctl_t auditd_etc_t:dir list_dir_perms;
 dontaudit auditctl_t auditd_etc_t:file map;
 
+corecmd_search_bin(auditctl_t)
+
 # Needed for adding watches
 files_getattr_all_dirs(auditctl_t)
 files_getattr_all_files(auditctl_t)
-- 
2.19.2

Re: [PATCH] Allow auditctl_t to read bin_t symlinks.

[Chris PeBenito]

On 12/6/18 7:20 PM, David Sugar wrote:
> on RHEL7 insmod, rmmod, modprobe (and others?) are a symlinks
> to ../bin/kmod.  But policy didn't allow auditctl_t to follow
> that link.
> 
> type=AVC msg=audit(1543853530.925:141): avc:  denied  { read } for
> pid=6937 comm="auditctl" name="insmod" dev="dm-1" ino=628383
> scontext=system_u:system_r:auditctl_t:s0
> tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=0
> type=AVC msg=audit(1543853530.925:143): avc:  denied  { read } for
> pid=6937 comm="auditctl" name="rmmod" dev="dm-1" ino=628387
> scontext=system_u:system_r:auditctl_t:s0
> tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=0
> type=AVC msg=audit(1543853530.926:145): avc:  denied  { read } for
> pid=6937 comm="auditctl" name="modprobe" dev="dm-1" ino=628386
> scontext=system_u:system_r:auditctl_t:s0
> tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=0
> type=AVC msg=audit(1543853797.766:60): avc:  denied  { read } for
> pid=6942 comm="auditctl" name="insmod" dev="dm-1" ino=628383
> scontext=system_u:system_r:auditctl_t:s0
> tcontext=system_u:object_r:bin_t:s0 tclass=lnk_file permissive=1
> 
> Signed-off-by: Dave Sugar <dsugar@tresys.com>
> ---
>   policy/modules/system/logging.te | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/policy/modules/system/logging.te b/policy/modules/system/logging.te
> index 7020a476..483084a5 100644
> --- a/policy/modules/system/logging.te
> +++ b/policy/modules/system/logging.te
> @@ -107,6 +107,8 @@ read_files_pattern(auditctl_t, auditd_etc_t, auditd_etc_t)
>   allow auditctl_t auditd_etc_t:dir list_dir_perms;
>   dontaudit auditctl_t auditd_etc_t:file map;
>   
> +corecmd_search_bin(auditctl_t)
> +
>   # Needed for adding watches
>   files_getattr_all_dirs(auditctl_t)
>   files_getattr_all_files(auditctl_t)

Merged.

-- 
Chris PeBenito