evm_inode_setxattr(9)

💅 evm_inode_setxattr ✨

okay so this is a page from the Kernel API Manual, section 9 — aka the kernel-internals zone, bestie. it's giving "you're deep in the source tree now" energy 🧚

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🌸 NAME 🌸

evm_inode_setxattr — the bouncer at the club door of the EVM extended attribute 💅 like, it protects it, fr.

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🎀 SYNOPSIS 🎀

int evm_inode_setxattr (struct mnt_idmap *idmap , struct dentry *dentry
, const char *xattr_name , const void *xattr_value , size_t
xattr_value_len , int flags );

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🦋 ARGUMENTS 🦋

• idmap — the idmap of the mount, iykyk 🫶
• dentry — a pointer to the dentry that's being affected
• xattr_name — pointer to the name of the extended attribute we're messing with
• xattr_value — pointer to the new value for that extended attribute
• xattr_value_len — pointer to the length of that new extended attribute value
• flags — the flags that get passed on into filesystem operations 🔥

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⭐ DESCRIPTION ⭐

so before the kernel even thinks about letting the 'security.evm' protected xattr get updated, it verifies that the existing value is valid. vibe check first, always 💅

and here's the main character energy: only the kernel should have access to the EVM encrypted key that's needed to calculate the HMAC. so userspace is not allowed to write the HMAC value — no cap, that door is locked 🔒

also, writing 'security.evm' requires CAP_SYS_ADMIN privileges. periodt. 👑

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🔥 SEE ALSO 🔥

• Kernel file ./security/integrity/evm/evm_main.c
• evm_read_protected_xattrs(9)
• evm_verifyxattr(9)
• evm_inode_removexattr(9)
• evm_inode_set_acl(9)
• evm_inode_remove_acl(9)
• evm_metadata_changed(9)
• evm_revalidate_status(9)
• evm_fix_hmac(9)
• evm_inode_post_setxattr(9)
• evm_inode_post_set_acl(9)
• evm_inode_post_removexattr(9)
• evm_inode_post_remove_acl(9)
• evm_inode_setattr(9)
• evm_inode_post_setattr(9)

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ok that's the whole page bestie, go read the source if you want the real tea 🍓

anyway, this little icon comes from ./security/integrity/evm and it's dated October 2026 — mwah, love that for us 💖🎀🦋