From patchwork Mon Nov 25 14:09:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 13884963 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8969A192B7F; Mon, 25 Nov 2024 14:10:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732543821; cv=none; b=f/F/1A4x+rcVSXuMieDsoUYISazkXG68E0nilqkuLFR+s64IQRpy9mDXNi4MvukrPQhNtcPZqY9jp1Jg/1eRoyaXFBdk0S+2EuF/ab9oCiUjZCFQIC2UKVzDXyQWqIPcyvqKY1XJmQnkNIebp0aBJ0OZ3P0NXMrs+c9to6ksVx8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732543821; c=relaxed/simple; bh=lZvVNtEbq/joGnuPDT54Ur4lHMroM/AsKH4ca1Rb2jw=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=rsw0qYolE/TmOFk996JrfxfpTKhnkrOljJpnOhodR4+peJDwPkxlhsmsziRCiJlLanD6uQ9J1GEARdHSTL6KHo9tAacBOu6O49Bq3cWuWFl12B0WEaH0n2aZYg095Qzcel9mR29nF0sApilI8Dc9Q2XASWPNryT2Ek/S0Awn9RA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WYkJpU4f; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WYkJpU4f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5948CC4CECE; Mon, 25 Nov 2024 14:10:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1732543821; bh=lZvVNtEbq/joGnuPDT54Ur4lHMroM/AsKH4ca1Rb2jw=; h=From:Subject:Date:To:Cc:From; b=WYkJpU4fOMfXxXSpHo5HCdil8kw2CZEmFPGhTEAAaLw1C8fXHLRRvukJaUGoX+77l oN2GpxyCMKa49aRTX6G6e8zTUk4QsEIOf6YedP20ytgtgkSUS+Ms/ZOwgNnZGkgUQ/ FItudqn+mTJRjmQ29/FMvTorM2rtu3szyWSV4jm2sZT69R675NmS5kzd7X6IIoCzfr LyfFTGeofohlgCumrA+1ZzEY+uK6MTpRFzSlJVRzwzYbxGia3qkwnPqtguRxLFJye9 ezhxbta/JurORZJKwMwchhzWMqvsnyYW2N8ytXTbrfj7VvkNc5Pr8UHDUIgWSfENBD ZONEWmZg45+UA== From: Christian Brauner Subject: [PATCH v2 00/29] cred: rework {override,revert}_creds() Date: Mon, 25 Nov 2024 15:09:56 +0100 Message-Id: <20241125-work-cred-v2-0-68b9d38bb5b2@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIADWFRGcC/22NwQ6CMBBEf8X07JJ2KSqe/A/DoZQFGrQ1W4Iaw r/bcvb4MjNvVhGJHUVxPayCaXHRBZ8AjwdhR+MHAtclFihRK4Ua3oEnsEwdlLpuT5WupLygSP0 XU+8+u+veJG5NJGjZeDtmw9PEmbjIIlAKUOfN6OIc+LvfLyov/z0tCiT0ZYUpsWV9lreJ2NOjC DyIZtu2H2SUPNDHAAAA X-Change-ID: 20241124-work-cred-349b65450082 To: Linus Torvalds Cc: Amir Goldstein , Miklos Szeredi , Al Viro , Jens Axboe , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christian Brauner X-Mailer: b4 0.15-dev-355e8 X-Developer-Signature: v=1; a=openpgp-sha256; l=3601; i=brauner@kernel.org; h=from:subject:message-id; bh=lZvVNtEbq/joGnuPDT54Ur4lHMroM/AsKH4ca1Rb2jw=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaS7tHqwli0uDjK8fPNkYxGflf1nO9nJt2+LaH7dFPFif 8nXvZuvdJSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAEykYTojw8RLFXN8mTIt7+RP N77u+2myZu+e8ob6nazCJ5+f++09+xrDP3uFrKB38ZovVs1cWaTnWa+vOO0r04uaP+73e5odHbW 6GAA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 For the v6.13 cycle we switched overlayfs to a variant of override_creds() that doesn't take an extra reference. To this end I suggested introducing {override,revert}_creds_light() which overlayfs could use. This seems to work rather well. This series follow Linus advice and unifies the separate helpers and simply makes {override,revert}_creds() do what {override,revert}_creds_light() currently does. Caller's that really need the extra reference count can take it manually. Acked-by: Chuck Lever --- Changes in v2: - Remove confusion around dangling pointer. - Use the revert_creds(old) + put_cred(new) pattern instead of put_cred(revert_creds(old)). - Fill in missing justifications in various commit message why not using a separate reference count is safe. - Make get_new_cred() argument const to easily use it during the conversion. - Get rid of get_new_cred() completely at the end of the series. - Link to v1: https://lore.kernel.org/r/20241124-work-cred-v1-0-f352241c3970@kernel.org --- Christian Brauner (29): tree-wide: s/override_creds()/override_creds_light(get_new_cred())/g cred: return old creds from revert_creds_light() tree-wide: s/revert_creds()/put_cred(revert_creds_light())/g cred: remove old {override,revert}_creds() helpers tree-wide: s/override_creds_light()/override_creds()/g tree-wide: s/revert_creds_light()/revert_creds()/g firmware: avoid pointless reference count bump sev-dev: avoid pointless cred reference count bump target_core_configfs: avoid pointless cred reference count bump aio: avoid pointless cred reference count bump binfmt_misc: avoid pointless cred reference count bump coredump: avoid pointless cred reference count bump nfs/localio: avoid pointless cred reference count bumps nfs/nfs4idmap: avoid pointless reference count bump nfs/nfs4recover: avoid pointless cred reference count bump nfsfh: avoid pointless cred reference count bump open: avoid pointless cred reference count bump ovl: avoid pointless cred reference count bump cifs: avoid pointless cred reference count bump cifs: avoid pointless cred reference count bump smb: avoid pointless cred reference count bump io_uring: avoid pointless cred reference count bump acct: avoid pointless reference count bump cgroup: avoid pointless cred reference count bump trace: avoid pointless cred reference count bump dns_resolver: avoid pointless cred reference count bump cachefiles: avoid pointless cred reference count bump nfsd: avoid pointless cred reference count bump cred: remove unused get_new_cred() Documentation/security/credentials.rst | 5 ---- drivers/crypto/ccp/sev-dev.c | 2 +- fs/backing-file.c | 20 +++++++------- fs/nfsd/auth.c | 3 +- fs/nfsd/filecache.c | 2 +- fs/nfsd/nfs4recover.c | 3 +- fs/nfsd/nfsfh.c | 1 - fs/open.c | 11 ++------ fs/overlayfs/dir.c | 4 +-- fs/overlayfs/util.c | 4 +-- fs/smb/server/smb_common.c | 10 ++----- include/linux/cred.h | 26 ++++-------------- kernel/cred.c | 50 ---------------------------------- 13 files changed, 27 insertions(+), 114 deletions(-) --- base-commit: e7675238b9bf4db0b872d5dbcd53efa31914c98f change-id: 20241124-work-cred-349b65450082