[PATCH v5] evm: Correct inode_init_security hooks behaviors

[Mimi Zohar]

On Fri, 2022-11-25 at 16:57 +0100, Nicolas Bouchinet wrote:
> From: Nicolas Bouchinet <nicolas.bouchinet at ssi.gouv.fr>
> 
> Fixes a NULL pointer dereference occurring in the
> `evm_protected_xattr_common` function of the EVM LSM. The bug is
> triggered if a `inode_init_security` hook returns 0 without initializing
> the given `struct xattr` fields (which is the case of BPF) and if no
> other LSM overrides thoses fields after. This also leads to memory
> leaks.
> 
> The `call_int_hook_xattr` macro has been inlined into the
> `security_inode_init_security` hook in order to check hooks return
> values and skip ones who doesn't init `xattrs`.
> 
> Modify `evm_init_hmac` function to init the EVM hmac using every
> entry of the given xattr array.
> 
> The `MAX_LSM_EVM_XATTR` value is now based on the security modules
> compiled in, which gives room for SMACK, SELinux, Apparmor, BPF and
> IMA/EVM security attributes.
> 
> Changes the default return value of the `inode_init_security` hook
> definition to `-EOPNOTSUPP`.
> 
> Changes the hook documentation to match the behavior of the LSMs using
> it (only xattr->value is initialised with kmalloc and thus is the only
> one that should be kfreed by the caller).
> 
> Cc: roberto.sassu at huaweicloud.com
> Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet at ssi.gouv.fr>

What  is the relationship between this patch and Roberto's patch set? 
Roberto, if there is an overlap, then at minimum there should be a
Reported-by tag indicating that your patch set addresses a bug reported
by Nicolas.

-- 
thanks,

Mimi