kdumpctl_selinux(8)

📦
version 20250627+git412.dbf877ab7 · 7 versions
, in opensuse-leap 16.0

💖 kdumpctl_selinux — the whole vibe, explained by your favorite Unix bestie 💖

Okay so like, buckle up bestie, because this is the manual page for kdumpctl_selinux(8) and it's literally all about the SELinux policy for kdumpctl processes. It's giving security, it's giving mandatory access control, it's giving "your fave is protected." Let's get into it. ✨

🎀 NAME 🎀

kdumpctl_selinux — Security Enhanced Linux Policy for the kdumpctl processes. That's the whole name, that's the whole assignment. Periodt. 💅

🦋 DESCRIPTION 🦋

Security-Enhanced Linux secures the kdumpctl processes via flexible mandatory access control. Translation: SELinux is the bodyguard and kdumpctl is the celebrity. The bodyguard doesn't ask questions, it just enforces. Iconic behavior, honestly.

The kdumpctl processes execute with the kdumpctl_t SELinux type. That's its whole identity, its main character energy. You can check if you have these processes running by executing the ps command with the -Z qualifier. Like, just to make sure everything's actually working and not secretly broken. We've all been there.

For example:

ps -eZ | grep kdumpctl_t

Run that and you'll see if your kdumpctl processes are out here living their best life with the right label. Easy. Slay. 💖

🚪 ENTRYPOINTS 🚪

So like, the kdumpctl_t SELinux type can be entered via the kdumpctl_exec_t file type. Think of it as the VIP door — you can't just walk into the domain, you gotta come through the right entrance.

The default entrypoint paths for the kdumpctl_t domain are the following:

/usr/bin/kdumpctl

That's the one. The only one. The chosen one. No cap. ✨

👑 PROCESS TYPES 👑

SELinux defines process types (domains) for each process running on the system. So every process gets its own little kingdom, its own little fiefdom, and we respect that.

You can see the context of a process using the -Z option to ps. It's giving transparency. It's giving receipts. We love to see it.

Policy governs the access confined processes have to files. SELinux kdumpctl policy is very flexible allowing users to setup their kdumpctl processes in as secure a method as possible. And like, secure is the moment. Secure is the vibe. We're not out here being reckless, bestie.

The following process types are defined for kdumpctl:

  • kdumpctl_t

That's it. One process type. Solo act. No entourage. And honestly? Respect.

Note: semanage permissive -a kdumpctl_t can be used to make the process type kdumpctl_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. So like, it won't block anything, but it will still snitch on denials. FYI. Bestie behavior, honestly. 🫶

🎛️ BOOLEANS 🎛️

SELinux policy is customizable based on least access required. kdumpctl policy is extremely flexible and has several booleans that allow you to manipulate the policy and run kdumpctl with the tightest access possible. Tightest access = safest access. It's the "less is more" of security. Obsessed.

If you want to dontaudit all daemons scheduling requests (setsched, sys_nice), you must turn on the daemons_dontaudit_scheduling boolean. It's enabled by default, so it's already out here doing its thing.

setsebool -P daemons_dontaudit_scheduling 1

If you want to deny user domains applications to map a memory region as both executable and writable — okay so this is dangerous and the executable should be reported in bugzilla — you must turn on the deny_execmem boolean. It's disabled by default because, again, dangerous. We don't play with that.

setsebool -P deny_execmem 1

If you want to control the ability to mmap a low area of the address space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on the mmap_low_allowed boolean. Disabled by default. So it's off until you specifically need it, which is the whole point of security, bestie.

setsebool -P mmap_low_allowed 1

If you want to disable kernel module loading, you must turn on the secure_mode_insmod boolean. Disabled by default. Disabling module loading = keeping things locked down = keeping things secure. The math is mathing.

setsebool -P secure_mode_insmod 1

If you want to allow unconfined executables to make their heap memory executable, you must turn on the selinuxuser_execheap boolean. Doing this is a really bad idea. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla. It's disabled by default and honestly? Keep it that way unless you have a very good reason. Really bad idea, remember? We said what we said.

setsebool -P selinuxuser_execheap 1

If you want to allow unconfined executables to make their stack executable, you must turn on the selinuxuser_execstack boolean. This should never, ever be necessary. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla. Disabled by default, and that's literally the correct setting. Like, if you're turning this on, maybe rethink some choices? Just saying. 🙈

setsebool -P selinuxuser_execstack 1

📁 MANAGED FILES 📁

The SELinux process type kdumpctl_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions — so even though SELinux is holding the door, the UID still gotta have the key. Double security, double slay. 🔥

  • file_type — all files on the system. Literally all of them. The whole filesystem. It's giving "I have access to everything and I'm not afraid to use it" energy. But again, DAC permissions still apply, so it's not a free-for-all.

🏷️ FILE CONTEXTS 🏷️

SELinux requires files to have an extended attribute to define the file type. So every file gets a label, and that label is how SELinux knows what's what. It's like name tags at a party but for files. Cute, honestly.

You can see the context of a file using the -Z option to ls. Just add -Z and boom, labels galore. We love a transparent filesystem.

Policy governs the access confined processes have to these files. SELinux kdumpctl policy is very flexible allowing users to setup their kdumpctl processes in as secure a method as possible. Same energy as before: flexible but secure, which is the best combo. 💖

✨ STANDARD FILE CONTEXT ✨

SELinux defines the file context types for the kdumpctl. If you wanted to store files with these types in different paths, you need to execute the semanage command to specify alternate labeling and then use restorecon to put the labels on disk. Like this:

semanage fcontext -a -t kdumpctl_exec_t '/srv/kdumpctl/content(/.*)?'
restorecon -R -v /srv/mykdumpctl_content
Okay so like, the paths in those two commands don't match — one's /srv/kdumpctl/content and the other's /srv/mykdumpctl_content — but that's literally how it's written in the original page. I'm not fixing it, I'm just the messenger. Copy it exact, bestie. Don't come for me. 🙈

Note: SELinux often uses regular expressions to specify labels that match multiple files. That's why there's that (/.*)? situation — it's regex, it's matching multiple files, it's doing the most. We respect the hustle.

The following file types are defined for kdumpctl:

  • kdumpctl_exec_t — Set files with the kdumpctl_exec_t type, if you want to transition an executable to the kdumpctl_t domain. This is the entrypoint type, the one that opens the VIP door. If you're trying to get into the kdumpctl_t domain, this is your ride.
  • kdumpctl_tmp_t — Set files with the kdumpctl_tmp_t type, if you want to store kdumpctl temporary files in the /tmp directories. For all your temporary file needs. We love a /tmp moment. 🎀
Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels. So like, chcon is the fast fix, semanage fcontext is the permanent fix, and restorecon is the "actually put it on disk" fix. Three steps, one slay. 💅

🛠️ COMMANDS 🛠️

Here's the tools you can use to manipulate all this stuff, bestie:

  • semanage fcontext — can also be used to manipulate default file context mappings. This is how you change labels permanently, like we talked about.
  • semanage permissive — can also be used to manipulate whether or not a process type is permissive. Per the note earlier: permissive = no denials but AVC messages still get generated. It's the "I'm watching you but I won't stop you" of SELinux. 👀
  • semanage module — can also be used to enable/disable/install/remove policy modules. Policy modules, bestie. The whole module vibe.
  • semanage boolean — can also be used to manipulate the booleans. All those on/off switches we talked about earlier? This is how you manage them. Like a little control panel for all your security toggles. 🎛️
  • system-config-selinux — is a GUI tool available to customize SELinux policy settings. If you're a GUI person instead of a command-line person, this is for you. No shame in that game. 🦋

👑 AUTHOR 👑

This manual page was auto-generated using sepolicy manpage. Not by a human, by a script. Auto-generated, auto-iconic. The script ate and left no crumbs. 💅

👀 SEE ALSO 👀

You should also check out these pages if you need more info, bestie:

All the references, all the lore, all the reading material. Go forth and learn. 📚✨

And that's the whole page! This manual page is for kdumpctl, version 26-10-06, and it's the kdumpctl_selinux(8) page, so yeah, that's the one. Go forth and be secure, bestie. You got this. 💖✨🌈

📦 where this page comes from