Bug 1393013
| Summary: | SELinux is preventing /usr/bin/perl from read access on the file unix. | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Brian J. Murrell <brian> |
| Component: | selinux-policy | Assignee: | Lukas Vrabec <lvrabec> |
| Status: | CLOSED WONTFIX | QA Contact: | Milos Malik <mmalik> |
| Severity: | high | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.2 | CC: | lvrabec, mgrepl, mmalik, plautrba, pvrabec, ssekidde, zpytela |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-10-12 12:17:01 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 1393066 | ||
Hi Brian, bugs 1393013, 1393015, 1393020, 1393030 have most likely the same cause. Unfortunately, I don't know it. I would appreciate if you could help me find it. Thanks for the report. So, this is what is happening I believe, at least in this case:
13191 open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 9
13191 fstat(9, {st_mode=S_IFREG|0644, st_size=149, ...}) = 0
13191 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fa417261000
13191 read(9, "# Generated by NetworkManager\nse"..., 1024) = 149
13191 access("/proc/net", R_OK) = 0
13191 access("/proc/net/unix", R_OK) = 0
13191 socket(PF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 10
13191 ioctl(10, SIOCGIFINDEX, {ifr_name="enp1s7", ifr_index=2}) = 0
13191 close(10) = 0
13191 read(9, "", 1024) = 0
13191 close(9) = 0
It's that access("/proc/net/unix", R_OK) that is causing the AVC. It is worth noting that after allowing that, a new AVC comes up:
SELinux is preventing /usr/bin/perl from create access on the unix_dgram_socket Unknown.
***** Plugin catchall (100. confidence) suggests **************************
If you believe that perl should be allowed create access on the Unknown unix_dgram_socket by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# grep sa-update /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp
Additional Information:
Source Context system_u:system_r:spamd_update_t:s0-s0:c0.c1023
Target Context system_u:system_r:spamd_update_t:s0-s0:c0.c1023
Target Objects Unknown [ unix_dgram_socket ]
Source sa-update
Source Path /usr/bin/perl
Port <Unknown>
Host server.interlinx.bc.ca
Source RPM Packages perl-5.16.3-286.el7.x86_64
Target RPM Packages
Policy RPM selinux-policy-3.13.1-60.el7_2.9.noarch
Selinux Enabled True
Policy Type targeted
Enforcing Mode Enforcing
Host Name server.interlinx.bc.ca
Platform Linux server.interlinx.bc.ca
3.10.0-327.36.3.el7.x86_64 #1 SMP Mon Oct 24
16:09:20 UTC 2016 x86_64 x86_64
Alert Count 17
First Seen 2016-11-09 04:10:04 EST
Last Seen 2016-11-10 09:51:04 EST
Local ID 5ed92169-a7df-4b7e-ae1e-f0bf8a9906c4
Raw Audit Messages
type=AVC msg=audit(1478789464.291:68659): avc: denied { create } for pid=13148 comm="sa-update" scontext=system_u:system_r:spamd_update_t:s0-s0:c0.c1023 tcontext=system_u:system_r:spamd_update_t:s0-s0:c0.c1023 tclass=unix_dgram_socket
type=SYSCALL msg=audit(1478789464.291:68659): arch=x86_64 syscall=socket success=no exit=EACCES a0=1 a1=80002 a2=0 a3=3 items=0 ppid=13140 pid=13148 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=7854 comm=sa-update exe=/usr/bin/perl subj=system_u:system_r:spamd_update_t:s0-s0:c0.c1023 key=(null)
Hash: sa-update,spamd_update_t,spamd_update_t,unix_dgram_socket,create
Which is clearly the socket(PF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0) right afterwards.
Why all of these processes are following this pattern of wanting access to /proc/net/unix "all of a sudden", I am not quite sure.
We're going to close this bug as WONTFIX because * of limited capacity of selinux-policy developers * the bug is related to EPEL component or 3rd party SW only * the bug appears in unsupported configuration We believe this bug can be fixed via a local policy module. For more information please see: * https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/selinux_users_and_administrators_guide/sect-security-enhanced_linux-troubleshooting-fixing_problems#sect-Security-Enhanced_Linux-Fixing_Problems-Allowing_Access_audit2allow If you disagree, please re-open the bug. We're going to close this bug as WONTFIX because * of limited capacity of selinux-policy developers * the bug is related to EPEL component or 3rd party SW only * the bug appears in unsupported configuration We believe this bug can be fixed via a local policy module. For more information please see: * https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/selinux_users_and_administrators_guide/sect-security-enhanced_linux-troubleshooting-fixing_problems#sect-Security-Enhanced_Linux-Fixing_Problems-Allowing_Access_audit2allow If you disagree, please re-open the bug. |
SELinux is preventing /usr/bin/perl from read access on the file unix. ***** Plugin catchall (100. confidence) suggests ************************** If you believe that perl should be allowed read access on the unix file by default. Then you should report this as a bug. You can generate a local policy module to allow this access. Do allow this access for now by executing: # grep sa-update /var/log/audit/audit.log | audit2allow -M mypol # semodule -i mypol.pp Additional Information: Source Context system_u:system_r:spamd_update_t:s0-s0:c0.c1023 Target Context system_u:object_r:proc_net_t:s0 Target Objects unix [ file ] Source sa-update Source Path /usr/bin/perl Port <Unknown> Host server.interlinx.bc.ca Source RPM Packages curl-7.29.0-25.el7.x86_64 Target RPM Packages Policy RPM selinux-policy-3.13.1-60.el7_2.9.noarch Selinux Enabled True Policy Type targeted Enforcing Mode Enforcing Host Name server.interlinx.bc.ca Platform Linux server.interlinx.bc.ca 3.10.0-327.36.3.el7.x86_64 #1 SMP Mon Oct 24 16:09:20 UTC 2016 x86_64 x86_64 Alert Count 29 First Seen 2016-10-27 04:10:05 EDT Last Seen 2016-11-08 04:58:26 EST Local ID eb43fe5b-eb64-4477-8945-3a20ee72adf8 Raw Audit Messages type=AVC msg=audit(1478599106.67:59249): avc: denied { read } for pid=14648 comm="curl" name="unix" dev="proc" ino=4026532002 scontext=system_u:system_r:spamd_update_t:s0-s0:c0.c1023 tcontext=system_u:object_r:proc_net_t:s0 tclass=file type=SYSCALL msg=audit(1478599106.67:59249): arch=x86_64 syscall=access success=no exit=EACCES a0=7f8773f7b7f0 a1=4 a2=7f8773f7b7fe a3=3 items=0 ppid=14631 pid=14648 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=6575 comm=curl exe=/usr/bin/curl subj=system_u:system_r:spamd_update_t:s0-s0:c0.c1023 key=(null) Hash: sa-update,spamd_update_t,proc_net_t,file,read This would presumably be SpamAssassin updating it's spam signature database.