Bug 194452
| Summary: | Grub fails with execmem AVC denied | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Mark McLoughlin <markmc> |
| Component: | selinux-policy-targeted | Assignee: | Daniel Walsh <dwalsh> |
| Status: | CLOSED CURRENTRELEASE | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | rawhide | CC: | drepper, pb--bugzilla, pjones |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Current | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2007-08-22 14:14:39 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Is this required by grub? IE Is there another way to do this. We can define a context of uncofined_execmem_exec_t for grub which would allow this. chcon -t uncofined_execmem_exec_t /sbin/grub Fixed in 2.2.47-3 I still see this problem on FC6 T1
Vigor14:~: rpm -q selinux-policy-targeted
selinux-policy-targeted-2.3.1-1
Vigor14:~:
audit(1152250446.486:6): avc: denied { execmem } for pid=2177 comm="grub"
scontext=system_u:system_r:unconfined_t:s0
tcontext=system_u:system_r:unconfined_t:s0 tclass=process
Fixed in selinux-policy-targeted-2.3.2-2 Should be fixed in the current release |
Doing the following: $> cat > grubscript.tmp << EOF root (hd1,0) install /grub/stage1 d (hd1) /grub/stage2 p /grub/grub.conf EOF $> grub --batch --no-floppy --device-map=device.map < grubscript.tmp grub: asmstub.c:214: grub_stage2: Assertion `simstack_alloc_base != ((void *) -1)' failed. Aborted Fails with this AVC denied: avc: denied { execmem } for pid=3093 comm="grub" scontext=root:system_r:unconfined_t:s0-s0:c0.c255 tcontext=root:system_r:unconfined_t:s0-s0:c0.c255 tclass=process Running with allow_execmem set to 1 makes it work. Best I can make out is that our grub simulates an executable stack my mmaping a chunk of memory and marking it executable ... presumably so grub can be built without an executable stack. CVS log of the patch: $> cvs log grub-0.95-nxstack.patch date: 2005/02/11 08:16:53; author: pjones; state: Exp; vroomfondel:~$ eu-readelf -l /sbin/grub | grep STACK GNU_STACK 0x000000 0x00000000 0x00000000 0x000000 0x000000 RW 0x4 ^ yay This may be one of the worst atrocities I've ever committed to disk. :-) Do we need to modify the policy to allow_execmem for grub?