security_change_sid(9)

📦 version 7.3.1, in nixpkgs unstable

👑 security_change_sid — like, the Kernel API Manual energy, bestie (section 9) ✨

Okay so this is a page straight out of the Kernel API Manual, section 9, and it's all about one lil function that does one very specific glow-up job: computing a SID for relabeling an object. That's it. That's the whole vibe. Let's get into it 🫶

✨ NAME ✨

security_change_sid — compute the SID for object relabeling 💅

Like, it literally computes a SID so you can relabel an object. Iconic, lowkey essential, no cap.

🦋 SYNOPSIS 🦋

int security_change_sid (u32 ssid , u32 tsid , u16 tclass , u32 *out_sid
);

That's the whole signature, copied exactly, don't come for me about the spacing 😭

🎀 ARGUMENTS 🎀

  • ssid — the source security identifier. Like, where we're coming from, bestie.
  • tsid — the target security identifier. Where we're headed. Main character destination energy.
  • tclass — the target security class. Gotta know what kind of object we're talking about.
  • out_sid — the security identifier for the selected member. This is where the answer lands, so keep it safe 💖

🌸 DESCRIPTION 🌸

So here's the tea: security_change_sid computes a SID to use for relabeling an object of class tclass, and it does that based on a SID pair — (ssid, tsid). Cute, right? Pair 'em up and get your relabel SID ✨

And the return values? Let's do a vibe check:

  • Returns -EINVAL if any of the parameters are invalid — so, bad input, bestie, it's giving "try again".
  • Returns -ENOMEM if insufficient memory is available — literally not enough memory to go around 😭
  • Returns 0 if the SID was computed successfully — slay! That's the win condition. Ate. 👑
So yeah, check your params, make sure there's memory, and then you get that sweet, sweet 0. Periodt.

🔥 SEE ALSO 🔥

Okay this list is long long, so buckle up. But every single one of these is here for a reason and I'm not skipping a single one, iykyk:

Obsessed with this friend group tbh 🌈

And that's the whole page, bestie 💜 Quick cute sign-off: this one comes from ./security/selinux/ss, dated October 2026, and yeah — it's security_change_sid(9) all the way down. 🧚‍♀️✨

📦 where this page comes from