avc_lookup(9)

💅 avc_lookup — aka the Kernel API Manual's avc_lookup(9) page 🎀

Okay bestie, gather round, because this one is a little lookup function that has main character energy and honestly? It eats. ✨

---

🌸 NAME 🌸

avc_lookup — literally just: look up an AVC entry. That's the whole vibe check. 👑

---

✨ SYNOPSIS ✨

struct avc_node * avc_lookup (u32 ssid , u32 tsid , u16 tclass );

Yes, it returns a struct avc_node *. Yes, it takes three args. No, we're not skipping any of them, keep reading. 🫶

---

🦋 ARGUMENTS 🦋

• ssid — the source security identifier. Like, who's the one doing the thing. 🌈
• tsid — the target security identifier. Like, who's on the receiving end. 🎯
• tclass — the target security class. It's giving "what kind of object are we even talking about". 💜

---

🌸 DESCRIPTION 🌸

So here's the tea, bestie: this function goes looking for an AVC entry that's valid for the (ssid, tsid) pair, and it interprets the permissions based on tclass. Not me explaining permissions as if they're a personality trait 😭

If a valid AVC entry exists, then this function returns the avc_node. Slay. Iconic. Returned.

Otherwise? This function returns NULL. 💀 That's it, that's the whole twist. No drama, just NULL.

---

🧚 SEE ALSO 🧚

Kernel file ./security/selinux/avc.c — plus the whole friend group:

• avc_init(9)
• avc_insert(9)
• avc_audit_pre_callback(9)
• avc_audit_post_callback(9)
• avc_add_callback(9)
• avc_update_node(9)
• avc_flush(9)
• avc_ss_reset(9)
• avc_compute_av(9)
• avc_perm_nonode(9)
• avc_has_perm_noaudit(9)
• avc_has_perm(9)

Fr fr, that's the entire invite list. 💖

---

Okay byeee, this page is brought to you by ./security/selinux and it's dated October 2026 — and honestly, avc_lookup(9) said "periodt". 💅🔥