History log of /openbmc/linux/Documentation/filesystems/overlayfs.rst (Results 26 – 50 of 212)
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Revision tags: v6.0
# 305a72ef 01-Oct-2022 Dan Williams <dan.j.williams@intel.com>

Merge branch 'for-6.1/nvdimm' into libnvdimm-for-next

Add v6.1 content on top of some straggling updates that missed v6.0.


Revision tags: v5.15.71
# 70d1b1a7 27-Sep-2022 Leon Romanovsky <leonro@nvidia.com>

Merge branch 'mlx5-vfio' into mlx5-next

Merge net/mlx5 dependencies for device DMA logging.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>


# b3bbcc5d 24-Sep-2022 Dan Williams <dan.j.williams@intel.com>

Merge branch 'for-6.0/dax' into libnvdimm-fixes

Pick up another "Soft Reservation" fix for v6.0-final on top of some
straggling nvdimm fixes that missed v5.19.


Revision tags: v5.15.70
# 74656d03 21-Sep-2022 Ingo Molnar <mingo@kernel.org>

Merge tag 'v6.0-rc6' into locking/core, to refresh the branch

Signed-off-by: Ingo Molnar <mingo@kernel.org>


Revision tags: v5.15.69, v5.15.68
# a108772d 14-Sep-2022 Maxime Ripard <maxime@cerno.tech>

Merge drm/drm-next into drm-misc-next

We need 6.0-rc1 to merge the backlight rework PR.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>


Revision tags: v5.15.67, v5.15.66
# 2a906db2 06-Sep-2022 Tony Lindgren <tony@atomide.com>

Merge branch 'am5748-fix' into fixes


Revision tags: v5.15.65
# 10438976 02-Sep-2022 Ingo Molnar <mingo@kernel.org>

Merge branch 'linus' into x86/mm, to refresh the branch

This branch is ~14k commits behind upstream, and has an old merge base
from early into the merge window, refresh it to v6.0-rc3+fixes before
q

Merge branch 'linus' into x86/mm, to refresh the branch

This branch is ~14k commits behind upstream, and has an old merge base
from early into the merge window, refresh it to v6.0-rc3+fixes before
queueing up new commits.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...


Revision tags: v5.15.64
# 53aa930d 30-Aug-2022 Ingo Molnar <mingo@kernel.org>

Merge branch 'sched/warnings' into sched/core, to pick up WARN_ON_ONCE() conversion commit

Merge in the BUG_ON() => WARN_ON_ONCE() conversion commit.

Signed-off-by: Ingo Molnar <mingo@kernel.org>


# 917bda9a 29-Aug-2022 Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-next into drm-intel-next

Sync drm-intel-next with v6.0-rc as well as recent drm-intel-gt-next.

Since drm-next does not have commit f0c70d41e4e8 ("drm/i915/guc: remove
runtime info pri

Merge drm/drm-next into drm-intel-next

Sync drm-intel-next with v6.0-rc as well as recent drm-intel-gt-next.

Since drm-next does not have commit f0c70d41e4e8 ("drm/i915/guc: remove
runtime info printing from time stamp logging") yet, only
drm-intel-gt-next, will need to do that as part of the merge here to
build.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

show more ...


Revision tags: v5.15.63, v5.15.62
# 93fbff11 17-Aug-2022 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'i2c/make_remove_callback_void-immutable' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux into next

Sync up with the latest I2C code base to get updated prototype of I2C
bus

Merge branch 'i2c/make_remove_callback_void-immutable' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux into next

Sync up with the latest I2C code base to get updated prototype of I2C
bus remove() method.

show more ...


Revision tags: v5.15.61
# cf36ae3e 17-Aug-2022 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Backmerging for v6.0-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v5.15.60, v5.15.59
# aad26f55 02-Aug-2022 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'docs-6.0' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
"This was a moderately busy cycle for documentation, but nothing
all that earth-shaking:

- Mor

Merge tag 'docs-6.0' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
"This was a moderately busy cycle for documentation, but nothing
all that earth-shaking:

- More Chinese translations, and an update to the Italian
translations.

The Japanese, Korean, and traditional Chinese translations
are more-or-less unmaintained at this point, instead.

- Some build-system performance improvements.

- The removal of the archaic submitting-drivers.rst document,
with the movement of what useful material that remained into
other docs.

- Improvements to sphinx-pre-install to, hopefully, give more
useful suggestions.

- A number of build-warning fixes

Plus the usual collection of typo fixes, updates, and more"

* tag 'docs-6.0' of git://git.lwn.net/linux: (92 commits)
docs: efi-stub: Fix paths for x86 / arm stubs
Docs/zh_CN: Update the translation of sched-stats to 5.19-rc8
Docs/zh_CN: Update the translation of pci to 5.19-rc8
Docs/zh_CN: Update the translation of pci-iov-howto to 5.19-rc8
Docs/zh_CN: Update the translation of usage to 5.19-rc8
Docs/zh_CN: Update the translation of testing-overview to 5.19-rc8
Docs/zh_CN: Update the translation of sparse to 5.19-rc8
Docs/zh_CN: Update the translation of kasan to 5.19-rc8
Docs/zh_CN: Update the translation of iio_configfs to 5.19-rc8
doc:it_IT: align Italian documentation
docs: Remove spurious tag from admin-guide/mm/overcommit-accounting.rst
Documentation: process: Update email client instructions for Thunderbird
docs: ABI: correct QEMU fw_cfg spec path
doc/zh_CN: remove submitting-driver reference from docs
docs: zh_TW: align to submitting-drivers removal
docs: zh_CN: align to submitting-drivers removal
docs: ko_KR: howto: remove reference to removed submitting-drivers
docs: ja_JP: howto: remove reference to removed submitting-drivers
docs: it_IT: align to submitting-drivers removal
docs: process: remove outdated submitting-drivers.rst
...

show more ...


# 0fac198d 01-Aug-2022 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'fs.idmapped.overlay.acl.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull acl updates from Christian Brauner:
"Last cycle we introduced support for mounting over

Merge tag 'fs.idmapped.overlay.acl.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull acl updates from Christian Brauner:
"Last cycle we introduced support for mounting overlayfs on top of
idmapped mounts. While looking into additional testing we realized
that posix acls don't really work correctly with stacking filesystems
on top of idmapped layers.

We already knew what the fix were but it would require work that is
more suitable for the merge window so we turned off posix acls for
v5.19 for overlayfs on top of idmapped layers with Miklos routing my
patch upstream in 72a8e05d4f66 ("Merge tag 'ovl-fixes-5.19-rc7' [..]").

This contains the work to support posix acls for overlayfs on top of
idmapped layers. Since the posix acl fixes should use the new
vfs{g,u}id_t work the associated branch has been merged in. (We sent a
pull request for this earlier.)

We've also pulled in Miklos pull request containing my patch to turn
of posix acls on top of idmapped layers. This allowed us to avoid
rebasing the branch which we didn't like because we were already at
rc7 by then. Merging it in allows this branch to first fix posix acls
and then to cleanly revert the temporary fix it brought in by commit
4a47c6385bb4 ("ovl: turn of SB_POSIXACL with idmapped layers
temporarily").

The last patch in this series adds Seth Forshee as a co-maintainer for
idmapped mounts. Seth has been integral to all of this work and is
also the main architect behind the filesystem idmapping work which
ultimately made filesystems such as FUSE and overlayfs available in
containers. He continues to be active in both development and review.
I'm very happy he decided to help and he has my full trust. This
increases the bus factor which is always great for work like this. I'm
honestly very excited about this because I think in general we don't
do great in the bringing on new maintainers department"

For more explanations of the ACL issues, see

https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org/

* tag 'fs.idmapped.overlay.acl.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
Add Seth Forshee as co-maintainer for idmapped mounts
Revert "ovl: turn of SB_POSIXACL with idmapped layers temporarily"
ovl: handle idmappings in ovl_get_acl()
acl: make posix_acl_clone() available to overlayfs
acl: port to vfs{g,u}id_t
acl: move idmapped mount fixup into vfs_{g,s}etxattr()
mnt_idmapping: add vfs[g,u]id_into_k[g,u]id()

show more ...


Revision tags: v5.19
# 82b6c2e7 29-Jul-2022 Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Merge branches 'pm-cpufreq' and 'pm-cpuidle'

Merge processor power management changes for v5.20-rc1:

- Make cpufreq_show_cpus() more straightforward (Viresh Kumar).

- Drop unnecessary CPU hotplu

Merge branches 'pm-cpufreq' and 'pm-cpuidle'

Merge processor power management changes for v5.20-rc1:

- Make cpufreq_show_cpus() more straightforward (Viresh Kumar).

- Drop unnecessary CPU hotplug locking from store() used by cpufreq
sysfs attributes (Viresh Kumar).

- Make the ACPI cpufreq driver support the boost control interface on
Zhaoxin/Centaur processors (Tony W Wang-oc).

- Print a warning message on attempts to free an active cpufreq policy
which should never happen (Viresh Kumar).

- Fix grammar in the Kconfig help text for the loongson2 cpufreq
driver (Randy Dunlap).

- Use cpumask_var_t for an on-stack CPU mask in the ondemand cpufreq
governor (Zhao Liu).

- Add trace points for guest_halt_poll_ns grow/shrink to the haltpoll
cpuidle driver (Eiichi Tsukata).

- Modify intel_idle to treat C1 and C1E as independent idle states on
Sapphire Rapids (Artem Bityutskiy).

* pm-cpufreq:
cpufreq: ondemand: Use cpumask_var_t for on-stack cpu mask
cpufreq: loongson2: fix Kconfig "its" grammar
cpufreq: Warn users while freeing active policy
cpufreq: ACPI: Add Zhaoxin/Centaur turbo boost control interface support
cpufreq: Drop unnecessary cpus locking from store()
cpufreq: Optimize cpufreq_show_cpus()

* pm-cpuidle:
intel_idle: make SPR C1 and C1E be independent
cpuidle: haltpoll: Add trace points for guest_halt_poll_ns grow/shrink

show more ...


Revision tags: v5.15.58
# 3c69a99b 24-Jul-2022 Michael Ellerman <mpe@ellerman.id.au>

Merge tag 'v5.19-rc7' into fixes

Merge v5.19-rc7 into fixes to bring in:
d11219ad53dc ("amdgpu: disable powerpc support for the newer display engine")


# 4effe18f 24-Jul-2022 Jens Axboe <axboe@kernel.dk>

Merge branch 'for-5.20/io_uring' into for-5.20/io_uring-zerocopy-send

* for-5.20/io_uring: (716 commits)
io_uring: ensure REQ_F_ISREG is set async offload
net: fix compat pointer in get_compat_m

Merge branch 'for-5.20/io_uring' into for-5.20/io_uring-zerocopy-send

* for-5.20/io_uring: (716 commits)
io_uring: ensure REQ_F_ISREG is set async offload
net: fix compat pointer in get_compat_msghdr()
io_uring: Don't require reinitable percpu_ref
io_uring: fix types in io_recvmsg_multishot_overflow
io_uring: Use atomic_long_try_cmpxchg in __io_account_mem
io_uring: support multishot in recvmsg
net: copy from user before calling __get_compat_msghdr
net: copy from user before calling __copy_msghdr
io_uring: support 0 length iov in buffer select in compat
io_uring: fix multishot ending when not polled
io_uring: add netmsg cache
io_uring: impose max limit on apoll cache
io_uring: add abstraction around apoll cache
io_uring: move apoll cache to poll.c
io_uring: consolidate hash_locked io-wq handling
io_uring: clear REQ_F_HASH_LOCKED on hash removal
io_uring: don't race double poll setting REQ_F_ASYNC_DATA
io_uring: don't miss setting REQ_F_DOUBLE_POLL
io_uring: disable multishot recvmsg
io_uring: only trace one of complete or overflow
...

Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...


Revision tags: v5.15.57, v5.15.56
# dc14036f 18-Jul-2022 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge 5.19-rc7 into usb-next

We need the USB fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 0698461a 18-Jul-2022 Arnaldo Carvalho de Melo <acme@redhat.com>

Merge remote-tracking branch 'torvalds/master' into perf/core

To update the perf/core codebase.

Fix conflict by moving arch__post_evsel_config(evsel, attr) to the end
of evsel__config(), after what

Merge remote-tracking branch 'torvalds/master' into perf/core

To update the perf/core codebase.

Fix conflict by moving arch__post_evsel_config(evsel, attr) to the end
of evsel__config(), after what was added in:

49c692b7dfc9b6c0 ("perf offcpu: Accept allowed sample types only")

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...


Revision tags: v5.15.55
# 7c4d37c2 13-Jul-2022 Christian Brauner <brauner@kernel.org>

Revert "ovl: turn of SB_POSIXACL with idmapped layers temporarily"

This reverts commit 4a47c6385bb4e0786826e75bd4555aba32953653.

Now that we have a proper fix for POSIX ACLs with overlayfs on top o

Revert "ovl: turn of SB_POSIXACL with idmapped layers temporarily"

This reverts commit 4a47c6385bb4e0786826e75bd4555aba32953653.

Now that we have a proper fix for POSIX ACLs with overlayfs on top of
idmapped layers revert the temporary fix.

Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

show more ...


# 45598fd4 13-Jul-2022 Christian Brauner <brauner@kernel.org>

Merge tag 'ovl-fixes-5.19-rc7' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into fs.idmapped.overlay.acl

Bring in Miklos' tree which contains the temporary fix for POSIX ACLs
w

Merge tag 'ovl-fixes-5.19-rc7' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into fs.idmapped.overlay.acl

Bring in Miklos' tree which contains the temporary fix for POSIX ACLs
with overlayfs on top of idmapped layers. We will add a proper fix on
top of it and then revert the temporary fix.

Cc: Seth Forshee <sforshee@digitalocean.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

show more ...


# 816cd168 14-Jul-2022 Jakub Kicinski <kuba@kernel.org>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

include/net/sock.h
310731e2f161 ("net: Fix data-races around sysctl_mem.")
e70f3c701276 ("Revert "net: set SK_MEM_QUANTUM to 4096""

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

include/net/sock.h
310731e2f161 ("net: Fix data-races around sysctl_mem.")
e70f3c701276 ("Revert "net: set SK_MEM_QUANTUM to 4096"")
https://lore.kernel.org/all/20220711120211.7c8b7cba@canb.auug.org.au/

net/ipv4/fib_semantics.c
747c14307214 ("ip: fix dflt addr selection for connected nexthop")
d62607c3fe45 ("net: rename reference+tracking helpers")

net/tls/tls.h
include/net/tls.h
3d8c51b25a23 ("net/tls: Check for errors in tls_device_init")
587903142308 ("tls: create an internal header")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...


# 72a8e05d 12-Jul-2022 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'ovl-fixes-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fix from Miklos Szeredi:
"Add a temporary fix for posix acls on idmapped mounts introduce

Merge tag 'ovl-fixes-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fix from Miklos Szeredi:
"Add a temporary fix for posix acls on idmapped mounts introduced in
this cycle. A proper fix will be added in the next cycle"

* tag 'ovl-fixes-5.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: turn off SB_POSIXACL with idmapped layers temporarily

show more ...


Revision tags: v5.15.54, v5.15.53
# 4a47c638 06-Jul-2022 Christian Brauner <brauner@kernel.org>

ovl: turn of SB_POSIXACL with idmapped layers temporarily

This cycle we added support for mounting overlayfs on top of idmapped
mounts. Recently I've started looking into potential corner cases whe

ovl: turn of SB_POSIXACL with idmapped layers temporarily

This cycle we added support for mounting overlayfs on top of idmapped
mounts. Recently I've started looking into potential corner cases when
trying to add additional tests and I noticed that reporting for POSIX ACLs
is currently wrong when using idmapped layers with overlayfs mounted on top
of it.

I have sent out an patch that fixes this and makes POSIX ACLs work
correctly but the patch is a bit bigger and we're already at -rc5 so I
recommend we simply don't raise SB_POSIXACL when idmapped layers are
used. Then we can fix the VFS part described below for the next merge
window so we can have good exposure in -next.

I'm going to give a rather detailed explanation to both the origin of the
problem and mention the solution so people know what's going on.

Let's assume the user creates the following directory layout and they have
a rootfs /var/lib/lxc/c1/rootfs. The files in this rootfs are owned as you
would expect files on your host system to be owned. For example, ~/.bashrc
for your regular user would be owned by 1000:1000 and /root/.bashrc would
be owned by 0:0. IOW, this is just regular boring filesystem tree on an
ext4 or xfs filesystem.

The user chooses to set POSIX ACLs using the setfacl binary granting the
user with uid 4 read, write, and execute permissions for their .bashrc
file:

setfacl -m u:4:rwx /var/lib/lxc/c2/rootfs/home/ubuntu/.bashrc

Now they to expose the whole rootfs to a container using an idmapped
mount. So they first create:

mkdir -pv /vol/contpool/{ctrover,merge,lowermap,overmap}
mkdir -pv /vol/contpool/ctrover/{over,work}
chown 10000000:10000000 /vol/contpool/ctrover/{over,work}

The user now creates an idmapped mount for the rootfs:

mount-idmapped/mount-idmapped --map-mount=b:0:10000000:65536 \
/var/lib/lxc/c2/rootfs \
/vol/contpool/lowermap

This for example makes it so that
/var/lib/lxc/c2/rootfs/home/ubuntu/.bashrc which is owned by uid and gid
1000 as being owned by uid and gid 10001000 at
/vol/contpool/lowermap/home/ubuntu/.bashrc.

Assume the user wants to expose these idmapped mounts through an overlayfs
mount to a container.

mount -t overlay overlay \
-o lowerdir=/vol/contpool/lowermap, \
upperdir=/vol/contpool/overmap/over, \
workdir=/vol/contpool/overmap/work \
/vol/contpool/merge

The user can do this in two ways:

(1) Mount overlayfs in the initial user namespace and expose it to the
container.

(2) Mount overlayfs on top of the idmapped mounts inside of the container's
user namespace.

Let's assume the user chooses the (1) option and mounts overlayfs on the
host and then changes into a container which uses the idmapping
0:10000000:65536 which is the same used for the two idmapped mounts.

Now the user tries to retrieve the POSIX ACLs using the getfacl command

getfacl -n /vol/contpool/lowermap/home/ubuntu/.bashrc

and to their surprise they see:

# file: vol/contpool/merge/home/ubuntu/.bashrc
# owner: 1000
# group: 1000
user::rw-
user:4294967295:rwx
group::r--
mask::rwx
other::r--

indicating the uid wasn't correctly translated according to the idmapped
mount. The problem is how we currently translate POSIX ACLs. Let's inspect
the callchain in this example:

idmapped mount /vol/contpool/merge: 0:10000000:65536
caller's idmapping: 0:10000000:65536
overlayfs idmapping (ofs->creator_cred): 0:0:4k /* initial idmapping */

sys_getxattr()
-> path_getxattr()
-> getxattr()
-> do_getxattr()
|> vfs_getxattr()
| -> __vfs_getxattr()
| -> handler->get == ovl_posix_acl_xattr_get()
| -> ovl_xattr_get()
| -> vfs_getxattr()
| -> __vfs_getxattr()
| -> handler->get() /* lower filesystem callback */
|> posix_acl_fix_xattr_to_user()
{
4 = make_kuid(&init_user_ns, 4);
4 = mapped_kuid_fs(&init_user_ns /* no idmapped mount */, 4);
/* FAILURE */
-1 = from_kuid(0:10000000:65536 /* caller's idmapping */, 4);
}

If the user chooses to use option (2) and mounts overlayfs on top of
idmapped mounts inside the container things don't look that much better:

idmapped mount /vol/contpool/merge: 0:10000000:65536
caller's idmapping: 0:10000000:65536
overlayfs idmapping (ofs->creator_cred): 0:10000000:65536

sys_getxattr()
-> path_getxattr()
-> getxattr()
-> do_getxattr()
|> vfs_getxattr()
| -> __vfs_getxattr()
| -> handler->get == ovl_posix_acl_xattr_get()
| -> ovl_xattr_get()
| -> vfs_getxattr()
| -> __vfs_getxattr()
| -> handler->get() /* lower filesystem callback */
|> posix_acl_fix_xattr_to_user()
{
4 = make_kuid(&init_user_ns, 4);
4 = mapped_kuid_fs(&init_user_ns, 4);
/* FAILURE */
-1 = from_kuid(0:10000000:65536 /* caller's idmapping */, 4);
}

As is easily seen the problem arises because the idmapping of the lower
mount isn't taken into account as all of this happens in do_gexattr(). But
do_getxattr() is always called on an overlayfs mount and inode and thus
cannot possible take the idmapping of the lower layers into account.

This problem is similar for fscaps but there the translation happens as
part of vfs_getxattr() already. Let's walk through an fscaps overlayfs
callchain:

setcap 'cap_net_raw+ep' /var/lib/lxc/c2/rootfs/home/ubuntu/.bashrc

The expected outcome here is that we'll receive the cap_net_raw capability
as we are able to map the uid associated with the fscap to 0 within our
container. IOW, we want to see 0 as the result of the idmapping
translations.

If the user chooses option (1) we get the following callchain for fscaps:

idmapped mount /vol/contpool/merge: 0:10000000:65536
caller's idmapping: 0:10000000:65536
overlayfs idmapping (ofs->creator_cred): 0:0:4k /* initial idmapping */

sys_getxattr()
-> path_getxattr()
-> getxattr()
-> do_getxattr()
-> vfs_getxattr()
-> xattr_getsecurity()
-> security_inode_getsecurity() ________________________________
-> cap_inode_getsecurity() | |
{ V |
10000000 = make_kuid(0:0:4k /* overlayfs idmapping */, 10000000); |
10000000 = mapped_kuid_fs(0:0:4k /* no idmapped mount */, 10000000); |
/* Expected result is 0 and thus that we own the fscap. */ |
0 = from_kuid(0:10000000:65536 /* caller's idmapping */, 10000000); |
} |
-> vfs_getxattr_alloc() |
-> handler->get == ovl_other_xattr_get() |
-> vfs_getxattr() |
-> xattr_getsecurity() |
-> security_inode_getsecurity() |
-> cap_inode_getsecurity() |
{ |
0 = make_kuid(0:0:4k /* lower s_user_ns */, 0); |
10000000 = mapped_kuid_fs(0:10000000:65536 /* idmapped mount */, 0); |
10000000 = from_kuid(0:0:4k /* overlayfs idmapping */, 10000000); |
|____________________________________________________________________|
}
-> vfs_getxattr_alloc()
-> handler->get == /* lower filesystem callback */

And if the user chooses option (2) we get:

idmapped mount /vol/contpool/merge: 0:10000000:65536
caller's idmapping: 0:10000000:65536
overlayfs idmapping (ofs->creator_cred): 0:10000000:65536

sys_getxattr()
-> path_getxattr()
-> getxattr()
-> do_getxattr()
-> vfs_getxattr()
-> xattr_getsecurity()
-> security_inode_getsecurity() _______________________________
-> cap_inode_getsecurity() | |
{ V |
10000000 = make_kuid(0:10000000:65536 /* overlayfs idmapping */, 0); |
10000000 = mapped_kuid_fs(0:0:4k /* no idmapped mount */, 10000000); |
/* Expected result is 0 and thus that we own the fscap. */ |
0 = from_kuid(0:10000000:65536 /* caller's idmapping */, 10000000); |
} |
-> vfs_getxattr_alloc() |
-> handler->get == ovl_other_xattr_get() |
|-> vfs_getxattr() |
-> xattr_getsecurity() |
-> security_inode_getsecurity() |
-> cap_inode_getsecurity() |
{ |
0 = make_kuid(0:0:4k /* lower s_user_ns */, 0); |
10000000 = mapped_kuid_fs(0:10000000:65536 /* idmapped mount */, 0); |
0 = from_kuid(0:10000000:65536 /* overlayfs idmapping */, 10000000); |
|____________________________________________________________________|
}
-> vfs_getxattr_alloc()
-> handler->get == /* lower filesystem callback */

We can see how the translation happens correctly in those cases as the
conversion happens within the vfs_getxattr() helper.

For POSIX ACLs we need to do something similar. However, in contrast to
fscaps we cannot apply the fix directly to the kernel internal posix acl
data structure as this would alter the cached values and would also require
a rework of how we currently deal with POSIX ACLs in general which almost
never take the filesystem idmapping into account (the noteable exception
being FUSE but even there the implementation is special) and instead
retrieve the raw values based on the initial idmapping.

The correct values are then generated right before returning to
userspace. The fix for this is to move taking the mount's idmapping into
account directly in vfs_getxattr() instead of having it be part of
posix_acl_fix_xattr_to_user().

To this end we simply move the idmapped mount translation into a separate
step performed in vfs_{g,s}etxattr() instead of in
posix_acl_fix_xattr_{from,to}_user().

To see how this fixes things let's go back to the original example. Assume
the user chose option (1) and mounted overlayfs on top of idmapped mounts
on the host:

idmapped mount /vol/contpool/merge: 0:10000000:65536
caller's idmapping: 0:10000000:65536
overlayfs idmapping (ofs->creator_cred): 0:0:4k /* initial idmapping */

sys_getxattr()
-> path_getxattr()
-> getxattr()
-> do_getxattr()
|> vfs_getxattr()
| |> __vfs_getxattr()
| | -> handler->get == ovl_posix_acl_xattr_get()
| | -> ovl_xattr_get()
| | -> vfs_getxattr()
| | |> __vfs_getxattr()
| | | -> handler->get() /* lower filesystem callback */
| | |> posix_acl_getxattr_idmapped_mnt()
| | {
| | 4 = make_kuid(&init_user_ns, 4);
| | 10000004 = mapped_kuid_fs(0:10000000:65536 /* lower idmapped mount */, 4);
| | 10000004 = from_kuid(&init_user_ns, 10000004);
| | |_______________________
| | } |
| | |
| |> posix_acl_getxattr_idmapped_mnt() |
| { |
| V
| 10000004 = make_kuid(&init_user_ns, 10000004);
| 10000004 = mapped_kuid_fs(&init_user_ns /* no idmapped mount */, 10000004);
| 10000004 = from_kuid(&init_user_ns, 10000004);
| } |_________________________________________________
| |
| |
|> posix_acl_fix_xattr_to_user() |
{ V
10000004 = make_kuid(0:0:4k /* init_user_ns */, 10000004);
/* SUCCESS */
4 = from_kuid(0:10000000:65536 /* caller's idmapping */, 10000004);
}

And similarly if the user chooses option (1) and mounted overayfs on top of
idmapped mounts inside the container:

idmapped mount /vol/contpool/merge: 0:10000000:65536
caller's idmapping: 0:10000000:65536
overlayfs idmapping (ofs->creator_cred): 0:10000000:65536

sys_getxattr()
-> path_getxattr()
-> getxattr()
-> do_getxattr()
|> vfs_getxattr()
| |> __vfs_getxattr()
| | -> handler->get == ovl_posix_acl_xattr_get()
| | -> ovl_xattr_get()
| | -> vfs_getxattr()
| | |> __vfs_getxattr()
| | | -> handler->get() /* lower filesystem callback */
| | |> posix_acl_getxattr_idmapped_mnt()
| | {
| | 4 = make_kuid(&init_user_ns, 4);
| | 10000004 = mapped_kuid_fs(0:10000000:65536 /* lower idmapped mount */, 4);
| | 10000004 = from_kuid(&init_user_ns, 10000004);
| | |_______________________
| | } |
| | |
| |> posix_acl_getxattr_idmapped_mnt() |
| { V
| 10000004 = make_kuid(&init_user_ns, 10000004);
| 10000004 = mapped_kuid_fs(&init_user_ns /* no idmapped mount */, 10000004);
| 10000004 = from_kuid(0(&init_user_ns, 10000004);
| |_________________________________________________
| } |
| |
|> posix_acl_fix_xattr_to_user() |
{ V
10000004 = make_kuid(0:0:4k /* init_user_ns */, 10000004);
/* SUCCESS */
4 = from_kuid(0:10000000:65536 /* caller's idmappings */, 10000004);
}

The last remaining problem we need to fix here is ovl_get_acl(). During
ovl_permission() overlayfs will call:

ovl_permission()
-> generic_permission()
-> acl_permission_check()
-> check_acl()
-> get_acl()
-> inode->i_op->get_acl() == ovl_get_acl()
> get_acl() /* on the underlying filesystem)
->inode->i_op->get_acl() == /*lower filesystem callback */
-> posix_acl_permission()

passing through the get_acl request to the underlying filesystem. This will
retrieve the acls stored in the lower filesystem without taking the
idmapping of the underlying mount into account as this would mean altering
the cached values for the lower filesystem. The simple solution is to have
ovl_get_acl() simply duplicate the ACLs, update the values according to the
idmapped mount and return it to acl_permission_check() so it can be used in
posix_acl_permission(). Since overlayfs doesn't cache ACLs they'll be
released right after.

Link: https://github.com/brauner/mount-idmapped/issues/9
Cc: Seth Forshee <sforshee@digitalocean.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: linux-unionfs@vger.kernel.org
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Fixes: bc70682a497c ("ovl: support idmapped layers")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

show more ...


Revision tags: v5.15.52, v5.15.51, v5.15.50
# df672565 23-Jun-2022 Deming Wang <wangdeming@inspur.com>

docs: Remove duplicate word

Delete duplicate words of "the".

Signed-off-by: Deming Wang <wangdeming@inspur.com>
Link: https://lore.kernel.org/r/20220624014605.2007-1-wangdeming@inspur.com
Signed-of

docs: Remove duplicate word

Delete duplicate words of "the".

Signed-off-by: Deming Wang <wangdeming@inspur.com>
Link: https://lore.kernel.org/r/20220624014605.2007-1-wangdeming@inspur.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...


Revision tags: v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15
# 762f99f4 15-Jan-2022 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 5.17 merge window.


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