user/sven/linux.git/include, branch v5.15.52

fs: fix acl translation

2022-07-02T14:41:17Z

commit 705191b03d507744c7e097f78d583621c14988ac upstream. Last cycle we extended the idmapped mounts infrastructure to support idmapped mounts of idmapped filesystems (No such filesystem yet exist.). Since then, the meaning of an idmapped mount is a mount whose idmapping is different from the filesystems idmapping. While doing that work we missed to adapt the acl translation helpers. They still assume that checking for the identity mapping is enough. But they need to use the no_idmapping() helper instead. Note, POSIX ACLs are always translated right at the userspace-kernel boundary using the caller's current idmapping and the initial idmapping. The order depends on whether we're coming from or going to userspace. The filesystem's idmapping doesn't matter at the border. Consequently, if a non-idmapped mount is passed we need to make sure to always pass the initial idmapping as the mount's idmapping and not the filesystem idmapping. Since it's irrelevant here it would yield invalid ids and prevent setting acls for filesystems that are mountable in a userns and support posix acls (tmpfs and fuse). I verified the regression reported in [1] and verified that this patch fixes it. A regression test will be added to xfstests in parallel. Link: https://bugzilla.kernel.org/show_bug.cgi?id=215849 [1] Fixes: bd303368b776 ("fs: support mapped mounts of mapped filesystems") Cc: Seth Forshee Cc: Christoph Hellwig Cc: # 5.15+ Cc: Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Linus Torvalds Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: support mapped mounts of mapped filesystems

2022-07-02T14:41:17Z

commit bd303368b776eead1c29e6cdda82bde7128b82a7 upstream. In previous patches we added new and modified existing helpers to handle idmapped mounts of filesystems mounted with an idmapping. In this final patch we convert all relevant places in the vfs to actually pass the filesystem's idmapping into these helpers. With this the vfs is in shape to handle idmapped mounts of filesystems mounted with an idmapping. Note that this is just the generic infrastructure. Actually adding support for idmapped mounts to a filesystem mountable with an idmapping is follow-up work. In this patch we extend the definition of an idmapped mount from a mount that that has the initial idmapping attached to it to a mount that has an idmapping attached to it which is not the same as the idmapping the filesystem was mounted with. As before we do not allow the initial idmapping to be attached to a mount. In addition this patch prevents that the idmapping the filesystem was mounted with can be attached to a mount created based on this filesystem. This has multiple reasons and advantages. First, attaching the initial idmapping or the filesystem's idmapping doesn't make much sense as in both cases the values of the i_{g,u}id and other places where k{g,u}ids are used do not change. Second, a user that really wants to do this for whatever reason can just create a separate dedicated identical idmapping to attach to the mount. Third, we can continue to use the initial idmapping as an indicator that a mount is not idmapped allowing us to continue to keep passing the initial idmapping into the mapping helpers to tell them that something isn't an idmapped mount even if the filesystem is mounted with an idmapping. Link: https://lore.kernel.org/r/20211123114227.3124056-11-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-11-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-11-brauner@kernel.org Cc: Seth Forshee Cc: Amir Goldstein Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: add i_user_ns() helper

2022-07-02T14:41:16Z

commit a1ec9040a2a9122605ac26e5725c6de019184419 upstream. Since we'll be passing the filesystem's idmapping in even more places in the following patches and we do already dereference struct inode to get to the filesystem's idmapping multiple times add a tiny helper. Link: https://lore.kernel.org/r/20211123114227.3124056-10-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-10-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-10-brauner@kernel.org Cc: Seth Forshee Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: port higher-level mapping helpers

2022-07-02T14:41:16Z

commit 209188ce75d0d357c292f6bb81d712acdd4e7db7 upstream. Enable the mapped_fs{g,u}id() helpers to support filesystems mounted with an idmapping. Apart from core mapping helpers that use mapped_fs{g,u}id() to initialize struct inode's i_{g,u}id fields xfs is the only place that uses these low-level helpers directly. The patch only extends the helpers to be able to take the filesystem idmapping into account. Since we don't actually yet pass the filesystem's idmapping in no functional changes happen. This will happen in a final patch. Link: https://lore.kernel.org/r/20211123114227.3124056-9-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-9-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-9-brauner@kernel.org Cc: Seth Forshee Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: remove unused low-level mapping helpers

2022-07-02T14:41:16Z

commit 02e4079913500f24ceb082d8d87d8665f044b298 upstream. Now that we ported all places to use the new low-level mapping helpers that are able to support filesystems mounted with an idmapping we can remove the old low-level mapping helpers. With the removal of these old helpers we also conclude the renaming of the mapping helpers we started in commit a65e58e791a1 ("fs: document and rename fsid helpers"). Link: https://lore.kernel.org/r/20211123114227.3124056-8-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-8-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-8-brauner@kernel.org Cc: Seth Forshee Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: account for filesystem mappings

2022-07-02T14:41:15Z

commit 1ac2a4104968e0a60b4b3572216a92aab5c1b025 upstream. Currently we only support idmapped mounts for filesystems mounted without an idmapping. This was a conscious decision mentioned in multiple places (cf. e.g. [1]). As explained at length in [3] it is perfectly fine to extend support for idmapped mounts to filesystem's mounted with an idmapping should the need arise. The need has been there for some time now. Various container projects in userspace need this to run unprivileged and nested unprivileged containers (cf. [2]). Before we can port any filesystem that is mountable with an idmapping to support idmapped mounts we need to first extend the mapping helpers to account for the filesystem's idmapping. This again, is explained at length in our documentation at [3] but I'll give an overview here again. Currently, the low-level mapping helpers implement the remapping algorithms described in [3] in a simplified manner. Because we could rely on the fact that all filesystems supporting idmapped mounts are mounted without an idmapping the translation step from or into the filesystem idmapping could be skipped. In order to support idmapped mounts of filesystem's mountable with an idmapping the translation step we were able to skip before cannot be skipped anymore. A filesystem mounted with an idmapping is very likely to not use an identity mapping and will instead use a non-identity mapping. So the translation step from or into the filesystem's idmapping in the remapping algorithm cannot be skipped for such filesystems. More details with examples can be found in [3]. This patch adds a few new and prepares some already existing low-level mapping helpers to perform the full translation algorithm explained in [3]. The low-level helpers can be written in a way that they only perform the additional translation step when the filesystem is indeed mounted with an idmapping. If the low-level helpers detect that they are not dealing with an idmapped mount they can simply return the relevant k{g,u}id unchanged; no remapping needs to be performed at all. The no_idmapping() helper detects whether the shortcut can be used. If the low-level helpers detected that they are dealing with an idmapped mount but the underlying filesystem is mounted without an idmapping we can rely on the previous shorcut and can continue to skip the translation step from or into the filesystem's idmapping. These checks guarantee that only the minimal amount of work is performed. As before, if idmapped mounts aren't used the low-level helpers are idempotent and no work is performed at all. This patch adds the helpers mapped_k{g,u}id_fs() and mapped_k{g,u}id_user(). Following patches will port all places to replace the old k{g,u}id_into_mnt() and k{g,u}id_from_mnt() with these two new helpers. After the conversion is done k{g,u}id_into_mnt() and k{g,u}id_from_mnt() will be removed. This also concludes the renaming of the mapping helpers we started in [4]. Now, all mapping helpers will started with the "mapped_" prefix making everything nice and consistent. The mapped_k{g,u}id_fs() helpers replace the k{g,u}id_into_mnt() helpers. They are to be used when k{g,u}ids are to be mapped from the vfs, e.g. from from struct inode's i_{g,u}id. Conversely, the mapped_k{g,u}id_user() helpers replace the k{g,u}id_from_mnt() helpers. They are to be used when k{g,u}ids are to be written to disk, e.g. when entering from a system call to change ownership of a file. This patch only introduces the helpers. It doesn't yet convert the relevant places to account for filesystem mounted with an idmapping. [1]: commit 2ca4dcc4909d ("fs/mount_setattr: tighten permission checks") [2]: https://github.com/containers/podman/issues/10374 [3]: Documentations/filesystems/idmappings.rst [4]: commit a65e58e791a1 ("fs: document and rename fsid helpers") Link: https://lore.kernel.org/r/20211123114227.3124056-5-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-5-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-5-brauner@kernel.org Cc: Seth Forshee Cc: Amir Goldstein Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: tweak fsuidgid_has_mapping()

2022-07-02T14:41:15Z

commit 476860b3eb4a50958243158861d5340066df5af2 upstream. If the caller's fs{g,u}id aren't mapped in the mount's idmapping we can return early and skip the check whether the mapped fs{g,u}id also have a mapping in the filesystem's idmapping. If the fs{g,u}id aren't mapped in the mount's idmapping they consequently can't be mapped in the filesystem's idmapping. So there's no point in checking that. Link: https://lore.kernel.org/r/20211123114227.3124056-4-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-4-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-4-brauner@kernel.org Cc: Seth Forshee Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: move mapping helpers

2022-07-02T14:41:15Z

commit a793d79ea3e041081cd7cbd8ee43d0b5e4914a2b upstream. The low-level mapping helpers were so far crammed into fs.h. They are out of place there. The fs.h header should just contain the higher-level mapping helpers that interact directly with vfs objects such as struct super_block or struct inode and not the bare mapping helpers. Similarly, only vfs and specific fs code shall interact with low-level mapping helpers. And so they won't be made accessible automatically through regular {g,u}id helpers. Link: https://lore.kernel.org/r/20211123114227.3124056-3-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-3-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-3-brauner@kernel.org Cc: Seth Forshee Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

fs: add is_idmapped_mnt() helper

2022-07-02T14:41:14Z

commit bb49e9e730c2906a958eee273a7819f401543d6c upstream. Multiple places open-code the same check to determine whether a given mount is idmapped. Introduce a simple helper function that can be used instead. This allows us to get rid of the fragile open-coding. We will later change the check that is used to determine whether a given mount is idmapped. Introducing a helper allows us to do this in a single place instead of doing it for multiple places. Link: https://lore.kernel.org/r/20211123114227.3124056-2-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-2-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-2-brauner@kernel.org Cc: Seth Forshee Cc: Christoph Hellwig Cc: Al Viro CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein Reviewed-by: Seth Forshee Signed-off-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Greg Kroah-Hartman

sock: redo the psock vs ULP protection check

2022-06-29T07:03:25Z

[ Upstream commit e34a07c0ae3906f97eb18df50902e2a01c1015b6 ] Commit 8a59f9d1e3d4 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()") has moved the inet_csk_has_ulp(sk) check from sk_psock_init() to the new tcp_bpf_update_proto() function. I'm guessing that this was done to allow creating psocks for non-inet sockets. Unfortunately the destruction path for psock includes the ULP unwind, so we need to fail the sk_psock_init() itself. Otherwise if ULP is already present we'll notice that later, and call tcp_update_ulp() with the sk_proto of the ULP itself, which will most likely result in the ULP looping its callbacks. Fixes: 8a59f9d1e3d4 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()") Signed-off-by: Jakub Kicinski Reviewed-by: John Fastabend Reviewed-by: Jakub Sitnicki Tested-by: Jakub Sitnicki Link: https://lore.kernel.org/r/20220620191353.1184629-2-kuba@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin