Bug 674910 - avc: denied { sys_admin } comm="systemd-readahe" capability=21
Summary: avc: denied { sys_admin } comm="systemd-readahe" capability=21
Keywords:
Status: CLOSED RAWHIDE
Alias: None
Product: Fedora
Classification: Fedora
Component: systemd
Version: rawhide
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Lennart Poettering
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-02-03 17:49 UTC by John Reiser
Modified: 2011-02-08 23:00 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2011-02-08 23:00:58 UTC
Type: ---


Attachments (Terms of Use)

Description John Reiser 2011-02-03 17:49:18 UTC
Description of problem: systemd-readahead gets an avc from selinux.


Version-Release number of selected component (if applicable):
systemd-17-1.fc15.x86_64
selinux-policy-targeted-3.9.13-8.fc15.noarch
kernel-2.6.38-0.rc3.git0.1.fc15.x86_64


How reproducible: every time


Steps to Reproduce:
1. Fresh install DVD of today's rawhide (2011-02-03; Thursday).
2. boot
3.
  
Actual results: on text console and in output of dmesg:
[    8.670771] type=1400 audit(1296752507.393:4): avc:  denied  { sys_admin } for  pid=472 comm="systemd-readahe" capability=21  scontext=system_u:system_r:readahead_t:s0 tcontext=system_u:system_r:readahead_t:s0 tclass=capability


Expected results: no complaint


Additional info:

Comment 1 Lennart Poettering 2011-02-08 12:23:42 UTC
Dan, I don#t really understand this AVC, what is this about?

Comment 2 Daniel Walsh 2011-02-08 14:40:54 UTC
sys_admin is kind of the catchall of capabilities  Looking in 

/usr/include/linux/capabilty.h

sys_admin could mean:


/* Allow configuration of the secure attention key */
/* Allow administration of the random device */
/* Allow examination and configuration of disk quotas */
/* Allow setting the domainname */
/* Allow setting the hostname */
/* Allow calling bdflush() */
/* Allow mount() and umount(), setting up new smb connection */
/* Allow some autofs root ioctls */
/* Allow nfsservctl */
/* Allow VM86_REQUEST_IRQ */
/* Allow to read/write pci config on alpha */
/* Allow irix_prctl on mips (setstacksize) */
/* Allow flushing all cache on m68k (sys_cacheflush) */
/* Allow removing semaphores */
/* Used instead of CAP_CHOWN to "chown" IPC message queues, semaphores
   and shared memory */
/* Allow locking/unlocking of shared memory segment */
/* Allow turning swap on/off */
/* Allow forged pids on socket credentials passing */
/* Allow setting readahead and flushing buffers on block devices */
/* Allow setting geometry in floppy driver */
/* Allow turning DMA on/off in xd driver */
/* Allow administration of md devices (mostly the above, but some
   extra ioctls) */
/* Allow tuning the ide driver */
/* Allow access to the nvram device */
/* Allow administration of apm_bios, serial and bttv (TV) device */
/* Allow manufacturer commands in isdn CAPI support driver */
/* Allow reading non-standardized portions of pci configuration space */
/* Allow DDI debug ioctl on sbpcd driver */
/* Allow setting up serial ports */
/* Allow sending raw qic-117 commands */
/* Allow enabling/disabling tagged queuing on SCSI controllers and sending
   arbitrary SCSI commands */
/* Allow setting encryption key on loopback filesystem */
/* Allow setting zone reclaim policy */

Comment 3 Daniel Walsh 2011-02-08 14:41:50 UTC
Did you have a syscall record with that AVC?  That could tell you what it was doing when the AVC happened.

ausearch -m avc -ts recent 

Would return the complete messages.

Comment 4 John Reiser 2011-02-08 17:30:43 UTC
There was no syscall record then [or in a fresh re-creating] on the console or in the output of dmesg.  I do not see "systemd-read*" in the output from "ausearch -m avc -ts recent" :
----
time->Tue Feb  8 09:18:24 2011
type=AVC msg=audit(1297185504.817:58): avc:  denied  { link } for  pid=902 comm="plymouthd" name="boot.log" dev=sdd7 ino=656669 scontext=system_u:system_r:plymouthd_t:s0 tcontext=system_u:object_r:var_log_t:s0 tclass=file
----
time->Tue Feb  8 09:18:25 2011
type=SYSCALL msg=audit(1297185505.226:61): arch=c000003e syscall=6 success=no exit=-13 a0=7fe8fecbc587 a1=7fff64a8b200 a2=7fff64a8b200 a3=7fff64a8af70 items=0 ppid=1279 pid=1284 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="mount" exe="/bin/mount" subj=system_u:system_r:mount_t:s0 key=(null)
type=AVC msg=audit(1297185505.226:61): avc:  denied  { getattr } for  pid=1284 comm="mount" path="/etc/mtab" dev=sdd7 ino=525330 scontext=system_u:system_r:mount_t:s0 tcontext=system_u:object_r:etc_runtime_t:s0 tclass=lnk_file
----
time->Tue Feb  8 09:18:25 2011
type=SYSCALL msg=audit(1297185505.230:62): arch=c000003e syscall=2 success=no exit=-13 a0=7fe8fecbc587 a1=42 a2=1a4 a3=7fff64a8af60 items=0 ppid=1279 pid=1284 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="mount" exe="/bin/mount" subj=system_u:system_r:mount_t:s0 key=(null)
type=AVC msg=audit(1297185505.230:62): avc:  denied  { read } for  pid=1284 comm="mount" name="mtab" dev=sdd7 ino=525330 scontext=system_u:system_r:mount_t:s0 tcontext=system_u:object_r:etc_runtime_t:s0 tclass=lnk_file
-----

[Everything has been overwritten.  Today's rawhide fails to install: bug #676032
.  I re-ran the install with a DVD from Sat.Feb.5.]

More context from 'dmesg' [with stripped leading date and wall-clock time]:
-----
[   16.638494] systemd[1]: Startup finished in 821ms 703us (kernel) + 6s 898ms 674us (initrd) + 8s 918ms 99us (userspace) = 16s 638ms 476us.
[  125.747445] type=1400 audit(1297185499.467:22): avc:  denied  { create } for  pid=990 comm="system-setup-ke" name="00-system-setup-keyboard.conf" scontext=system_u:system_r:keyboardd_t:s0 tcontext=system_u:object_r:etc_runtime_t:s0 tclass=file
[  125.767718] type=1400 audit(1297185499.487:23): avc:  denied  { sys_admin } for  pid=991 comm="systemd-readahe" capability=21  scontext=system_u:system_r:readahead_t:s0 tcontext=system_u:system_r:readahead_t:s0 tclass=capability
[  125.777189] systemd-readahead-collect[991]: Failed to create fanotify object: Operation not permitted
[  125.779187] systemd[1]: systemd-readahead-collect.service: main process exited, code=exited, status=1
[  125.851175] type=1400 audit(1297185499.571:24): avc:  denied  { getattr } for  pid=1005 comm="mount" path="/etc/mtab" dev=sdd7 ino=525330 scontext=system_u:system_r:mount_t:s0 tcontext=system_u:object_r:etc_runtime_t:s0 tclass=lnk_file
-----

Comment 5 Daniel Walsh 2011-02-08 22:57:29 UTC
So it looks like fanotify is causing sys_admin capabilty to be required.  (I guess)

Mount access should be available in tonights update.

The boot.log access is an open bug on plymouthd, I have no idea why they want this as a hard link.

Comment 6 Daniel Walsh 2011-02-08 23:00:58 UTC
Fixed in selinux-policy-3.9.14-1.fc15


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