[PATCH 1/3] ima: Remove inode lock

[Paul Moore]

On Wed, Oct 9, 2024 at 11:36 AM Paul Moore <paul at paul-moore.com> wrote:
> On Tue, Oct 8, 2024 at 12:57 PM Roberto Sassu
> <roberto.sassu at huaweicloud.com> wrote:
> >
> > From: Roberto Sassu <roberto.sassu at huawei.com>
> >
> > Move out the mutex in the ima_iint_cache structure to a new structure
> > called ima_iint_cache_lock, so that a lock can be taken regardless of
> > whether or not inode integrity metadata are stored in the inode.
> >
> > Introduce ima_inode_security() to simplify accessing the new structure in
> > the inode security blob.
> >
> > Move the mutex initialization and annotation in the new function
> > ima_inode_alloc_security() and introduce ima_iint_lock() and
> > ima_iint_unlock() to respectively lock and unlock the mutex.
> >
> > Finally, expand the critical region in process_measurement() guarded by
> > iint->mutex up to where the inode was locked, use only one iint lock in
> > __ima_inode_hash(), since the mutex is now in the inode security blob, and
> > replace the inode_lock()/inode_unlock() calls in ima_check_last_writer().
> >
> > Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
> > ---
> >  security/integrity/ima/ima.h      | 26 ++++++++---
> >  security/integrity/ima/ima_api.c  |  4 +-
> >  security/integrity/ima/ima_iint.c | 77 ++++++++++++++++++++++++++-----
> >  security/integrity/ima/ima_main.c | 39 +++++++---------
> >  4 files changed, 104 insertions(+), 42 deletions(-)
>
> I'm not an IMA expert, but it looks reasonable to me, although
> shouldn't this carry a stable CC in the patch metadata?
>
> Reviewed-by: Paul Moore <paul at paul-moore.com>

Sorry, one more thing ... did you verify this patchset resolves the
syzbot problem?  I saw at least one reproducer.

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