linux-kernel - Re: [PATCH 1/3] ima: Remove inode lock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHQche-W2VxB+EJQRHUAWr4=850sX1ZfzzZUFJChUx8j6dW9Hw@mail.gmail.com>
Date: Wed, 9 Oct 2024 23:59:35 +0800
From: Shu Han <ebpqwerty472123@...il.com>
To: Roberto Sassu <roberto.sassu@...weicloud.com>
Cc: zohar@...ux.ibm.com, dmitry.kasatkin@...il.com, eric.snowberg@...cle.com, 
	paul@...l-moore.com, jmorris@...ei.org, serge@...lyn.com, 
	linux-integrity@...r.kernel.org, linux-security-module@...r.kernel.org, 
	linux-kernel@...r.kernel.org, bpf@...r.kernel.org, 
	Roberto Sassu <roberto.sassu@...wei.com>
Subject: Re: [PATCH 1/3] ima: Remove inode lock

> 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().

I am not familiar with this, so the following statement may be inaccurate:

I suspect that modifying the `i_flags` field through
`inode->i_flags |= S_IMA;` in `ima_inode_get` may cause a
race, as this patch removes the write lock for inodes in
process_measurement().

For example, swapon() adds the S_SWAPFILE tag under inode write lock's
protection.

Perhaps this initialization tag(`S_IMA`) can also be moved into inode's
security blob.