Commit Graph

168 Commits

Author SHA1 Message Date
Rado Vrbovsky c1d10d813b Merge: Wireless core and drivers rebase to v6.11
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/5415

JIRA: https://issues.redhat.com/browse/RHEL-50013  

Tested: basic testing with several supported WiFi cards (Intel, Qualcomm, Mediatek and Realtek).

Wireless core and drivers update to v6.11.

Upstream status: linux.git

Later fixes to be included in next rebases:  
Omitted-fix: 0129e5ff2842 wifi: rtw88: 8703b: Fix reported RX band width  
Omitted-fix: 177b49dbf9c1 wifi: ath11k: use work queue to process beacon tx event  
Omitted-fix: 9b8d932053b8 wifi: mt76: mt7603: fix mixed declarations and code  
Omitted-fix: ded1a6d9e13a wifi: mt76: mt7996: fix handling mbss enable/disable  
Omitted-fix: 56310ddb50b1 wifi: rtw89: remove unused C2H event ID RTW89_MAC_C2H_FUNC_READ_WOW_CAM to prevent out-of-bounds reading  
Omitted-fix: d9dd3ac77cf7 wifi: rtw89: wow: fix wait condition for AOAC report request  
Omitted-fix: 76364f3edfde wifi: iwlwifi: mvm: allow ESR when we the ROC expires  
Omitted-fix: a949075d4bbf wifi: iwlwifi: mvm: set the cipher for secured NDP ranging  
Omitted-fix: a7bc66fe8093 bus: mhi: host: pci_generic: Update EDL firmware path for Foxconn modems  
Omitted-fix: bd9813d13be4 wifi: cfg80211: check radio iface combination for multi radio per wiphy  
Omitted-fix: 7c24c5bdf489 wifi: mac80211_hwsim: correct MODULE_PARM_DESC of multi_radio  
Omitted-fix: 45ae0e8cf8c7 wifi: rtw89: 8852c: support firmware format up to v1  
Omitted-fix: f403fed7f98e wifi: mac80211: remove label usage in ieee80211_start_radar_detection()  
Omitted-fix: f4bb650cfab4 wifi: trace: unlink rdev_end_cac trace event from wiphy_netdev_evt class  
Omitted-fix: 62c16f219a73 wifi: cfg80211: move DFS related members to links[] in wireless_dev  
Omitted-fix: 81f67d60ebf2 wifi: cfg80211: handle DFS per link  
Omitted-fix: d74380ee99b5 wifi: mac80211: handle DFS per link  
Omitted-fix: 0b7798232eee wifi: cfg80211/mac80211: use proper link ID for DFS  
Omitted-fix: bca8bc0399ac wifi: mac80211: handle ieee80211_radar_detected() for MLO  
Omitted-fix: 53d7c99719e2 wifi: ath11k: fix RCU documentation in ath11k_mac_op_ipv6_changed()  

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Approved-by: Herton R. Krzesinski <herton@redhat.com>
Approved-by: Desnes Nunes <desnesn@redhat.com>
Approved-by: Kamal Heib <kheib@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Rado Vrbovsky <rvrbovsk@redhat.com>
2024-11-15 13:27:52 +00:00
Jose Ignacio Tornos Martinez a49c33866c debugfs: fix wait/cancellation handling during remove
JIRA: https://issues.redhat.com/browse/RHEL-50013

commit 952c3fce297f12c7ff59380adb66b564e2bc9b64
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Thu Feb 29 15:36:20 2024 +0100

    debugfs: fix wait/cancellation handling during remove
    
    Ben Greear further reports deadlocks during concurrent debugfs
    remove while files are being accessed, even though the code in
    question now uses debugfs cancellations. Turns out that despite
    all the review on the locking, we missed completely that the
    logic is wrong: if the refcount hits zero we can finish (and
    need not wait for the completion), but if it doesn't we have
    to trigger all the cancellations. As written, we can _never_
    get into the loop triggering the cancellations. Fix this, and
    explain it better while at it.
    
    Cc: stable@vger.kernel.org
    Fixes: 8c88a474357e ("debugfs: add API to allow debugfs operations cancellation")
    Reported-by: Ben Greear <greearb@candelatech.com>
    Closes: https://lore.kernel.org/r/1c9fa9e5-09f1-0522-fdbc-dbcef4d255ca@candelatech.com
    Tested-by: Madhan Sai <madhan.singaraju@candelatech.com>
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>
    Link: https://lore.kernel.org/r/20240229153635.6bfab7eb34d3.I6c7aeff8c9d6628a8bc1ddcf332205a49d801f17@changeid
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
2024-10-29 08:16:29 +01:00
Jose Ignacio Tornos Martinez b96881051d Revert "debugfs: annotate debugfs handlers vs. removal with lockdep"
JIRA: https://issues.redhat.com/browse/RHEL-50013

commit 88ac06a9f938c158bbeafec16adb483b0c66142f
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Sat Dec 2 11:49:37 2023 +0100

    Revert "debugfs: annotate debugfs handlers vs. removal with lockdep"
    
    This reverts commit f4acfcd4deb1 ("debugfs: annotate debugfs handlers
    vs. removal with lockdep"), it appears to have false positives and
    really shouldn't have been in the -rc series with the fixes anyway.
    
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>
    Link: https://lore.kernel.org/r/20231202114936.fd55431ab160.I911aa53abeeca138126f690d383a89b13eb05667@changeid
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
2024-10-29 08:16:29 +01:00
Jose Ignacio Tornos Martinez e9ea4d1bb8 debugfs: add API to allow debugfs operations cancellation
JIRA: https://issues.redhat.com/browse/RHEL-50013

commit 8c88a474357ead632b07c70bf7f119ace8c3b39e
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Fri Nov 24 17:25:26 2023 +0100

    debugfs: add API to allow debugfs operations cancellation
    
    In some cases there might be longer-running hardware accesses
    in debugfs files, or attempts to acquire locks, and we want
    to still be able to quickly remove the files.
    
    Introduce a cancellations API to use inside the debugfs handler
    functions to be able to cancel such operations on a per-file
    basis.
    
    Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
2024-10-29 08:16:29 +01:00
Jose Ignacio Tornos Martinez 62473c92c1 debugfs: annotate debugfs handlers vs. removal with lockdep
JIRA: https://issues.redhat.com/browse/RHEL-50013

commit f4acfcd4deb158b96595250cc332901b282d15b0
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Fri Nov 24 17:25:25 2023 +0100

    debugfs: annotate debugfs handlers vs. removal with lockdep
    
    When you take a lock in a debugfs handler but also try
    to remove the debugfs file under that lock, things can
    deadlock since the removal has to wait for all users
    to finish.
    
    Add lockdep annotations in debugfs_file_get()/_put()
    to catch such issues.
    
    Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
2024-10-29 08:16:29 +01:00
Jose Ignacio Tornos Martinez a93f6ab7af debugfs: fix automount d_fsdata usage
JIRA: https://issues.redhat.com/browse/RHEL-50013

commit 0ed04a1847a10297595ac24dc7d46b35fb35f90a
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Fri Nov 24 17:25:24 2023 +0100

    debugfs: fix automount d_fsdata usage
    
    debugfs_create_automount() stores a function pointer in d_fsdata,
    but since commit 7c8d469877 ("debugfs: add support for more
    elaborate ->d_fsdata") debugfs_release_dentry() will free it, now
    conditionally on DEBUGFS_FSDATA_IS_REAL_FOPS_BIT, but that's not
    set for the function pointer in automount. As a result, removing
    an automount dentry would attempt to free the function pointer.
    Luckily, the only user of this (tracing) never removes it.
    
    Nevertheless, it's safer if we just handle the fsdata in one way,
    namely either DEBUGFS_FSDATA_IS_REAL_FOPS_BIT or allocated. Thus,
    change the automount to allocate it, and use the real_fops in the
    data to indicate whether or not automount is filled, rather than
    adding a type tag. At least for now this isn't actually needed,
    but the next changes will require it.
    
    Also check in debugfs_file_get() that it gets only called
    on regular files, just to make things clearer.
    
    Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
2024-10-29 08:16:29 +01:00
Ian Kent 19f3b4f1ba fs: port ->rename() to pass mnt_idmap
JIRA: https://issues.redhat.com/browse/RHEL-33888
Status: Linus

Conflicts: For consistency drop btrfs hunks because it isn't supported in
	CentOS Stream and other backports also drop such hunks.
	The cifs source has been moved in CentOS Stream so manually
	apply rejected hunks to fs/smb/client/cifsfs.h and
	fs/smb/client/inode.c.
	Dropped hunks for ntfs3 because the source is not present in the
	CentOS Stream source tree.
	Upstream commit cc14d24026704 ("hpfs: Convert symlinks to
	read_folio") is not present which causes fuzz 1 for hunk #1.
	CentOS Stream commit 892da692fa ("shmem: support idmapped
	mounts for tmpfs") is present, so a patch reorder was needed
	with appropriate adjustments.

commit e18275ae55e07a2937e48134589c2f4c1d99a369
Author: Christian Brauner <brauner@kernel.org>
Date:   Fri Jan 13 12:49:17 2023 +0100

    fs: port ->rename() to pass mnt_idmap

    Convert to struct mnt_idmap.

    Last cycle we merged the necessary infrastructure in
    256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
    This is just the conversion to struct mnt_idmap.

    Currently we still pass around the plain namespace that was attached to a
    mount. This is in general pretty convenient but it makes it easy to
    conflate namespaces that are relevant on the filesystem with namespaces
    that are relevent on the mount level. Especially for non-vfs developers
    without detailed knowledge in this area this can be a potential source for
    bugs.

    Once the conversion to struct mnt_idmap is done all helpers down to the
    really low-level helpers will take a struct mnt_idmap argument instead of
    two namespace arguments. This way it becomes impossible to conflate the two
    eliminating the possibility of any bugs. All of the vfs and all filesystems
    only operate on struct mnt_idmap.

    Acked-by: Dave Chinner <dchinner@redhat.com>
    Reviewed-by: Christoph Hellwig <hch@lst.de>
    Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

Signed-off-by: Ian Kent <ikent@redhat.com>
2024-10-16 10:45:07 +08:00
Ian Kent 43ca440cdf fs: port ->setattr() to pass mnt_idmap
JIRA: https://issues.redhat.com/browse/RHEL-33888
Status: Linus

Conflicts: CentOS Stream commit 3c29fadfb1 ("afs: split
	afs_pagecache_valid() out of afs_validate()") is present, manually
	adjust hunk #1 of fs/afs/internal.h.
	For consistency drop btrfs hunks because it isn't supported in
	CentOS Stream and other backports also drop such hunks.
	CentOS Stream commit 48fa94aacd ("ceph: fscrypt_auth handling
	for ceph") alters the definition of _ceph_setattr(), adjust
	manually.
	CentOS Stream commit 34b2a2b5a3 {"ceph: add some fscrypt
	guardrails") introduces a call to fscrypt_prepare_setattr() which
	causes fuzz when applying.
	The cifs source has been moved in CentOS Stream so manually
	apply rejected hunks to fs/smb/client/cifsfs.h and
	fs/smb/client/inode.c.
	Upstream commit 5a646fb3a3e2d ("coda: avoid doing bad things on
	inode type changes during revalidation") is not present which
	causes fuzz in fs/coda/coda_linux.h.
	Dropped hunks for ntfs3 because the source is not present in
	the CentOS Stream source tree.
	CentOS Stream commit 98ba731fc7 ("ovl: Move xattr support
	to new xattrs.c file") is presnt so manually apply hunk.
	CentOS Stream commit 892da692fa ("shmem: support idmapped
	mounts for tmpfs") is present so it's ok to pass idmap to
	setattr_prepare() and setattr_copy().
	Update to add incremental changes needed due to CentOS Stream
	commit 469e1d13f6 ("shmem: quota support").
	Allow for CentOS Stream commit 6c3396a0d8 ("kernfs: Introduce
	separate rwsem to protect inode attributes") which is already
	present.
	CentOS Stream commit f5219db0c0 ("KVM: fix Add KVM_CREATE_GUEST_MEMFD
	ioctl() for guest-specific backing memory") updated the upstream commit
	a7800aa80ea4d ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific
	backing memory") to account for missing idmapping commits. Now we have
	updated one of the two places these changes were made make one of the
	needed adjustments to match the original upstream patch.

commit c1632a0f11209338fc300c66252bcc4686e609e8
Author: Christian Brauner <brauner@kernel.org>
Date:   Fri Jan 13 12:49:11 2023 +0100

    fs: port ->setattr() to pass mnt_idmap

    Convert to struct mnt_idmap.

    Last cycle we merged the necessary infrastructure in
    256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
    This is just the conversion to struct mnt_idmap.

    Currently we still pass around the plain namespace that was attached to a
    mount. This is in general pretty convenient but it makes it easy to
    conflate namespaces that are relevant on the filesystem with namespaces
    that are relevent on the mount level. Especially for non-vfs developers
    without detailed knowledge in this area this can be a potential source for
    bugs.

    Once the conversion to struct mnt_idmap is done all helpers down to the
    really low-level helpers will take a struct mnt_idmap argument instead of
    two namespace arguments. This way it becomes impossible to conflate the two
    eliminating the possibility of any bugs. All of the vfs and all filesystems
    only operate on struct mnt_idmap.

    Acked-by: Dave Chinner <dchinner@redhat.com>
    Reviewed-by: Christoph Hellwig <hch@lst.de>
    Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

Signed-off-by: Ian Kent <ikent@redhat.com>
2024-10-16 09:07:05 +08:00
Phil Auld 4782b094b6 debugfs: add debugfs_lookup_and_remove()
Bugzilla: https://bugzilla.redhat.com/2115520

commit dec9b2f1e0455a151a7293c367da22ab973f713e
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date:   Fri Sep 2 16:59:15 2022 +0200

    debugfs: add debugfs_lookup_and_remove()

    There is a very common pattern of using
    debugfs_remove(debufs_lookup(..)) which results in a dentry leak of the
    dentry that was looked up.  Instead of having to open-code the correct
    pattern of calling dput() on the dentry, create
    debugfs_lookup_and_remove() to handle this pattern automatically and
    properly without any memory leaks.

    Cc: stable <stable@kernel.org>
    Reported-by: Kuyo Chang <kuyo.chang@mediatek.com>
    Tested-by: Kuyo Chang <kuyo.chang@mediatek.com>
    Link: https://lore.kernel.org/r/YxIaQ8cSinDR881k@kroah.com
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Phil Auld <pauld@redhat.com>
2022-11-04 13:14:41 -04:00
Ondrej Mosnacek 5881fa8dc2 debugfs: fix security_locked_down() call for SELinux
When (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) is zero, then
the SELinux implementation of the locked_down hook might report a denial
even though the operation would actually be allowed.

To fix this, make sure that security_locked_down() is called only when
the return value will be taken into account (i.e. when changing one of
the problematic attributes).

Note: this was introduced by commit 5496197f9b ("debugfs: Restrict
debugfs when the kernel is locked down"), but it didn't matter at that
time, as the SELinux support came in later.

Fixes: 59438b4647 ("security,lockdown,selinux: implement SELinux lockdown")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Link: https://lore.kernel.org/r/20210507125304.144394-1-omosnace@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-18 18:05:59 +02:00
Kees Cook 312723a0b3 debugfs: Make debugfs_allow RO after init
Since debugfs_allow is only set at boot time during __init, make it
read-only after being set.

Fixes: a24c6f7bc9 ("debugfs: Add access restriction option")
Cc: Peter Enderborg <peter.enderborg@sony.com>
Reviewed-by: Peter Enderborg <peter.enderborg@sony.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210405213959.3079432-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-09 16:58:15 +02:00
Linus Torvalds 7ac1161c27 Driver core / debugfs update for 5.12-rc1
Here is the "big" driver core and debugfs update for 5.12-rc1
 
 This set of driver core patches caused a bunch of problems in linux-next
 for the past few weeks, when Saravana tried to set fw_devlink=on as the
 default functionality.  This caused a number of systems to stop booting,
 and lots of bugs were fixed in this area for almost all of the reported
 systems, but this option is not ready to be turned on just yet for the
 default operation based on this testing, so I've reverted that change at
 the very end so we don't have to worry about regressions in 5.12.  We
 will try to turn this on for 5.13 if testing goes better over the next
 few months.
 
 Other than the fixes caused by the fw_devlink testing in here, there's
 not much more:
 	- debugfs fixes for invalid input into debugfs_lookup()
 	- kerneldoc cleanups
 	- warn message if platform drivers return an error on their
 	  remove callback (a futile effort, but good to catch).
 
 All of these have been in linux-next for a while now, and the
 regressions have gone away with the revert of the fw_devlink change.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / debugfs update from Greg KH:
 "Here is the "big" driver core and debugfs update for 5.12-rc1

  This set of driver core patches caused a bunch of problems in
  linux-next for the past few weeks, when Saravana tried to set
  fw_devlink=on as the default functionality. This caused a number of
  systems to stop booting, and lots of bugs were fixed in this area for
  almost all of the reported systems, but this option is not ready to be
  turned on just yet for the default operation based on this testing, so
  I've reverted that change at the very end so we don't have to worry
  about regressions in 5.12

  We will try to turn this on for 5.13 if testing goes better over the
  next few months.

  Other than the fixes caused by the fw_devlink testing in here, there's
  not much more:

   - debugfs fixes for invalid input into debugfs_lookup()

   - kerneldoc cleanups

   - warn message if platform drivers return an error on their remove
     callback (a futile effort, but good to catch).

  All of these have been in linux-next for a while now, and the
  regressions have gone away with the revert of the fw_devlink change"

* tag 'driver-core-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (35 commits)
  Revert "driver core: Set fw_devlink=on by default"
  of: property: fw_devlink: Ignore interrupts property for some configs
  debugfs: do not attempt to create a new file before the filesystem is initalized
  debugfs: be more robust at handling improper input in debugfs_lookup()
  driver core: auxiliary bus: Fix calling stage for auxiliary bus init
  of: irq: Fix the return value for of_irq_parse_one() stub
  of: irq: make a stub for of_irq_parse_one()
  clk: Mark fwnodes when their clock provider is added/removed
  PM: domains: Mark fwnodes when their powerdomain is added/removed
  irqdomain: Mark fwnodes when their irqdomain is added/removed
  driver core: fw_devlink: Handle suppliers that don't use driver core
  of: property: Add fw_devlink support for optional properties
  driver core: Add fw_devlink.strict kernel param
  of: property: Don't add links to absent suppliers
  driver core: fw_devlink: Detect supplier devices that will never be added
  driver core: platform: Emit a warning if a remove callback returned non-zero
  of: property: Fix fw_devlink handling of interrupts/interrupts-extended
  gpiolib: Don't probe gpio_device if it's not the primary device
  device.h: Remove bogus "the" in kerneldoc
  gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default
  ...
2021-02-24 10:13:55 -08:00
Greg Kroah-Hartman 56348560d4 debugfs: do not attempt to create a new file before the filesystem is initalized
Some subsystems want to add debugfs files at early boot, way before
debugfs is initialized.  This seems to work somehow as the vfs layer
will not allow it to happen, but let's be explicit and test to ensure we
are properly up and running before allowing files to be created.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Reported-by: Michael Walle <michael@walle.cc>
Reported-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210218100818.3622317-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-18 16:23:49 +01:00
Greg Kroah-Hartman bc6de804d3 debugfs: be more robust at handling improper input in debugfs_lookup()
debugfs_lookup() doesn't like it if it is passed an illegal name
pointer, or if the filesystem isn't even initialized yet.  If either of
these happen, it will crash the system, so fix it up by properly testing
for valid input and that we are up and running before trying to find a
file in the filesystem.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Reported-by: Michael Walle <michael@walle.cc>
Tested-by: Michael Walle <michael@walle.cc>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210218100818.3622317-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-18 16:23:46 +01:00
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00
Peter Enderborg a24c6f7bc9 debugfs: Add access restriction option
Since debugfs include sensitive information it need to be treated
carefully. But it also has many very useful debug functions for userspace.
With this option we can have same configuration for system with
need of debugfs and a way to turn it off. This gives a extra protection
for exposure on systems where user-space services with system
access are attacked.

It is controlled by a configurable default value that can be override
with a kernel command line parameter. (debugfs=)

It can be on or off, but also internally on but not seen from user-space.
This no-mount mode do not register a debugfs as filesystem, but client can
register their parts in the internal structures. This data can be readed
with a debugger or saved with a crashkernel. When it is off clients
get EPERM error when accessing the functions for registering their
components.

Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
Link: https://lore.kernel.org/r/20200716071511.26864-3-peter.enderborg@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23 17:10:25 +02:00
Greg Kroah-Hartman 526ee72dfd debugfs: remove return value of debugfs_create_file_size()
No one checks the return value of debugfs_create_file_size, as it's not
needed, so make the return value void, so that no one tries to do so in
the future.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200309163640.237984-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 13:35:29 +01:00
Linus Torvalds 72f582ff85 Merge branch 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs recursive removal updates from Al Viro:
 "We have quite a few places where synthetic filesystems do an
  equivalent of 'rm -rf', with varying amounts of code duplication,
  wrong locking, etc. That really ought to be a library helper.

  Only debugfs (and very similar tracefs) are converted here - I have
  more conversions, but they'd never been in -next, so they'll have to
  wait"

* 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems
2020-02-05 05:09:46 +00:00
Daniel W. S. Almeida adc92dd455 debugfs: Fix warnings when building documentation
Fix the following warnings:

fs/debugfs/inode.c:423: WARNING: Inline literal start-string without end-string.
fs/debugfs/inode.c:502: WARNING: Inline literal start-string without end-string.
fs/debugfs/inode.c:534: WARNING: Inline literal start-string without end-string.
fs/debugfs/inode.c:627: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:496: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:502: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:581: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:587: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:846: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:852: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:899: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:905: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:1091: WARNING: Inline literal start-string without end-string.
fs/debugfs/file.c:1097: WARNING: Inline literal start-string without end-string

By replacing %ERR_PTR with ERR_PTR.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20191227010035.854913-1-dwlsalmeida@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-06 20:35:37 +01:00
Al Viro a3d1e7eb5a simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems
two requirements: no file creations in IS_DEADDIR and no cross-directory
renames whatsoever.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-10 22:29:58 -05:00
Al Viro 6c2d4798a8 new helper: lookup_positive_unlocked()
Most of the callers of lookup_one_len_unlocked() treat negatives are
ERR_PTR(-ENOENT).  Provide a helper that would do just that.  Note
that a pinned positive dentry remains positive - it's ->d_inode is
stable, etc.; a pinned _negative_ dentry can become positive at any
point as long as you are not holding its parent at least shared.
So using lookup_one_len_unlocked() needs to be careful;
lookup_positive_unlocked() is safer and that's what the callers
end up open-coding anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-15 13:49:04 -05:00
Linus Torvalds aefcf2f4b5 Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...
2019-09-28 08:14:15 -07:00
David Howells 5496197f9b debugfs: Restrict debugfs when the kernel is locked down
Disallow opening of debugfs files that might be used to muck around when
the kernel is locked down as various drivers give raw access to hardware
through debugfs.  Given the effort of auditing all 2000 or so files and
manually fixing each one as necessary, I've chosen to apply a heuristic
instead.  The following changes are made:

 (1) chmod and chown are disallowed on debugfs objects (though the root dir
     can be modified by mount and remount, but I'm not worried about that).

 (2) When the kernel is locked down, only files with the following criteria
     are permitted to be opened:

	- The file must have mode 00444
	- The file must not have ioctl methods
	- The file must not have mmap

 (3) When the kernel is locked down, files may only be opened for reading.

Normal device interaction should be done through configfs, sysfs or a
miscdev, not debugfs.

Note that this makes it unnecessary to specifically lock down show_dsts(),
show_devs() and show_call() in the asus-wmi driver.

I would actually prefer to lock down all files by default and have the
the files unlocked by the creator.  This is tricky to manage correctly,
though, as there are 19 creation functions and ~1600 call sites (some of
them in loops scanning tables).

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Andy Shevchenko <andy.shevchenko@gmail.com>
cc: acpi4asus-user@lists.sourceforge.net
cc: platform-driver-x86@vger.kernel.org
cc: Matthew Garrett <mjg59@srcf.ucam.org>
cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Matthew Garrett <matthewgarrett@google.com>
Signed-off-by: James Morris <jmorris@namei.org>
2019-08-19 21:54:17 -07:00
Linus Torvalds f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00
Greg Kroah-Hartman c33d442328 debugfs: make error message a bit more verbose
When a file/directory is already present in debugfs, and it is attempted
to be created again, be more specific about what file/directory is being
created and where it is trying to be created to give a bit more help to
developers to figure out the problem.

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20190706154256.GA2683@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-08 10:44:57 +02:00
Greg Kroah-Hartman d03ae4778b debugfs: provide pr_fmt() macro
Use a common "debugfs: " prefix for all pr_* calls in a single place.

Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20190703071653.2799-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 16:55:52 +02:00
Greg Kroah-Hartman 43e23b6c0b debugfs: log errors when something goes wrong
As it is not recommended that debugfs calls be checked, it was pointed
out that major errors should still be logged somewhere so that
developers and users have a chance to figure out what went wrong.  To
help with this, error logging has been added to the debugfs core so that
it is not needed to be present in every individual file that calls
debugfs.

Reported-by: Mark Brown <broonie@kernel.org>
Reported-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20190703071653.2799-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 16:55:51 +02:00
Amir Goldstein 6679ea6dea debugfs: call fsnotify_{unlink,rmdir}() hooks
This will allow generating fsnotify delete events after the
fsnotify_nameremove() hook is removed from d_delete().

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-20 14:47:09 +02:00
Amir Goldstein 823e545c02 debugfs: simplify __debugfs_remove_file()
Move simple_unlink()+d_delete() from __debugfs_remove_file() into
caller __debugfs_remove() and rename helper for post remove file to
__debugfs_file_removed().

This will simplify adding fsnotify_unlink() hook.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-06-20 14:46:42 +02:00
Linus Torvalds d27fb65bc2 Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc dcache updates from Al Viro:
 "Most of this pile is putting name length into struct name_snapshot and
  making use of it.

  The beginning of this series ("ovl_lookup_real_one(): don't bother
  with strlen()") ought to have been split in two (separate switch of
  name_snapshot to struct qstr from overlayfs reaping the trivial
  benefits of that), but I wanted to avoid a rebase - by the time I'd
  spotted that it was (a) in -next and (b) close to 5.1-final ;-/"

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  audit_compare_dname_path(): switch to const struct qstr *
  audit_update_watch(): switch to const struct qstr *
  inotify_handle_event(): don't bother with strlen()
  fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
  fsnotify(): switch to passing const struct qstr * for file_name
  switch fsnotify_move() to passing const struct qstr * for old_name
  ovl_lookup_real_one(): don't bother with strlen()
  sysv: bury the broken "quietly truncate the long filenames" logics
  nsfs: unobfuscate
  unexport d_alloc_pseudo()
2019-05-07 20:03:32 -07:00
Al Viro 6234ddf429 debugfs: switch to ->free_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:24 -04:00
Al Viro f4ec3a3d43 switch fsnotify_move() to passing const struct qstr * for old_name
note that in the second (RENAME_EXCHANGE) call of fsnotify_move() in
vfs_rename() the old_dentry->d_name is guaranteed to be unchanged
throughout the evaluation of fsnotify_move() (by the fact that the
parent directory is locked exclusive), so we don't need to fetch
old_dentry->d_name.name in the caller.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26 13:22:05 -04:00
Al Viro 230c6402b1 ovl_lookup_real_one(): don't bother with strlen()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26 13:13:33 -04:00
Al Viro 93b919da64 debugfs: fix use-after-free on symlink traversal
symlink body shouldn't be freed without an RCU delay.  Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback.  Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-01 00:31:02 -04:00
Greg Kroah-Hartman 9481caf39b Merge 5.0-rc6 into driver-core-next
We need the debugfs fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-11 09:09:02 +01:00
Greg Kroah-Hartman 37ea7b630a debugfs: debugfs_lookup() should return NULL if not found
Lots of callers of debugfs_lookup() were just checking NULL to see if
the file/directory was found or not.  By changing this in ff9fb72bc0
("debugfs: return error values, not NULL") we caused some subsystems to
easily crash.

Fixes: ff9fb72bc0 ("debugfs: return error values, not NULL")
Reported-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-30 12:39:49 +01:00
Greg Kroah-Hartman ff9fb72bc0 debugfs: return error values, not NULL
When an error happens, debugfs should return an error pointer value, not
NULL.  This will prevent the totally theoretical error where a debugfs
call fails due to lack of memory, returning NULL, and that dentry value
is then passed to another debugfs call, which would end up succeeding,
creating a file at the root of the debugfs tree, but would then be
impossible to remove (because you can not remove the directory NULL).

So, to make everyone happy, always return errors, this makes the users
of debugfs much simpler (they do not have to ever check the return
value), and everyone can rest easy.

Reported-by: Gary R Hook <ghook@amd.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Michal Hocko <mhocko@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-29 21:28:35 +01:00
Greg Kroah-Hartman d88c93f090 debugfs: fix debugfs_rename parameter checking
debugfs_rename() needs to check that the dentries passed into it really
are valid, as sometimes they are not (i.e. if the return value of
another debugfs call is passed into this one.)  So fix this up by
properly checking if the two parent directories are errors (they are
allowed to be NULL), and if the dentry to rename is not NULL or an
error.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-25 12:56:32 +01:00
Sergey Senozhatsky 0eeb27311f debugfs: debugfs_use_start/finish do not exist anymore
debugfs_use_file_start() and debugfs_use_file_finish() do not exist
since commit c9afbec270 ("debugfs: purge obsolete SRCU based removal
protection"); tweak debugfs_create_file_unsafe() comment.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22 10:30:35 +01:00
Linus Torvalds f5b7769eb0 Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"
This reverts commit 95cde3c599.

The commit had good intentions, but it breaks kvm-tool and qemu-kvm.

With it in place, "lkvm run" just fails with

  Error: KVM_CREATE_VM ioctl
  Warning: Failed init: kvm__init

which isn't a wonderful error message, but bisection pinpointed the
problematic commit.

The problem is almost certainly due to the special kvm debugfs entries
created dynamically by kvm under /sys/kernel/debug/kvm/.  See
kvm_create_vm_debugfs()

Bisected-and-reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-12 20:52:16 -07:00
Thomas Richter 95cde3c599 debugfs: inode: debugfs_create_dir uses mode permission from parent
Currently function debugfs_create_dir() creates a new
directory in the debugfs (usually mounted /sys/kernel/debug)
with permission rwxr-xr-x. This is hard coded.

Change this to use the parent directory permission.

Output before the patch:
root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/
/sys/kernel/debug/
├── [drwxr-xr-x]  bdi
├── [drwxr-xr-x]  block
├── [drwxr-xr-x]  dasd
├── [drwxr-xr-x]  device_component
├── [drwxr-xr-x]  extfrag
├── [drwxr-xr-x]  hid
├── [drwxr-xr-x]  kprobes
├── [drwxr-xr-x]  kvm
├── [drwxr-xr-x]  memblock
├── [drwxr-xr-x]  pm_qos
├── [drwxr-xr-x]  qdio
├── [drwxr-xr-x]  s390
├── [drwxr-xr-x]  s390dbf
└── [drwx------]  tracing

14 directories
[root@s8360047 linux]#

Output after the patch:
[root@s8360047 ~]# tree -dp -L 1 /sys/kernel/debug/
sys/kernel/debug/
├── [drwx------]  bdi
├── [drwx------]  block
├── [drwx------]  dasd
├── [drwx------]  device_component
├── [drwx------]  extfrag
├── [drwx------]  hid
├── [drwx------]  kprobes
├── [drwx------]  kvm
├── [drwx------]  memblock
├── [drwx------]  pm_qos
├── [drwx------]  qdio
├── [drwx------]  s390
├── [drwx------]  s390dbf
└── [drwx------]  tracing

14 directories
[root@s8360047 linux]#

Here is the full diff output done with:
[root@s8360047 ~]# diff -u treefull.before treefull.after |
	sed 's-^- # -' > treefull.diff
 # --- treefull.before	2018-04-27 13:22:04.532824564 +0200
 # +++ treefull.after	2018-04-27 13:24:12.106182062 +0200
 # @@ -1,55 +1,55 @@
 #  /sys/kernel/debug/
 # -├── [drwxr-xr-x]  bdi
 # -│   ├── [drwxr-xr-x]  1:0
 # -│   ├── [drwxr-xr-x]  1:1
 # -│   ├── [drwxr-xr-x]  1:10
 # -│   ├── [drwxr-xr-x]  1:11
 # -│   ├── [drwxr-xr-x]  1:12
 # -│   ├── [drwxr-xr-x]  1:13
 # -│   ├── [drwxr-xr-x]  1:14
 # -│   ├── [drwxr-xr-x]  1:15
 # -│   ├── [drwxr-xr-x]  1:2
 # -│   ├── [drwxr-xr-x]  1:3
 # -│   ├── [drwxr-xr-x]  1:4
 # -│   ├── [drwxr-xr-x]  1:5
 # -│   ├── [drwxr-xr-x]  1:6
 # -│   ├── [drwxr-xr-x]  1:7
 # -│   ├── [drwxr-xr-x]  1:8
 # -│   ├── [drwxr-xr-x]  1:9
 # -│   └── [drwxr-xr-x]  94:0
 # -├── [drwxr-xr-x]  block
 # -├── [drwxr-xr-x]  dasd
 # -│   ├── [drwxr-xr-x]  0.0.e18a
 # -│   ├── [drwxr-xr-x]  dasda
 # -│   └── [drwxr-xr-x]  global
 # -├── [drwxr-xr-x]  device_component
 # -├── [drwxr-xr-x]  extfrag
 # -├── [drwxr-xr-x]  hid
 # -├── [drwxr-xr-x]  kprobes
 # -├── [drwxr-xr-x]  kvm
 # -├── [drwxr-xr-x]  memblock
 # -├── [drwxr-xr-x]  pm_qos
 # -├── [drwxr-xr-x]  qdio
 # -│   └── [drwxr-xr-x]  0.0.f5f2
 # -├── [drwxr-xr-x]  s390
 # -│   └── [drwxr-xr-x]  stsi
 # -├── [drwxr-xr-x]  s390dbf
 # -│   ├── [drwxr-xr-x]  0.0.e18a
 # -│   ├── [drwxr-xr-x]  cio_crw
 # -│   ├── [drwxr-xr-x]  cio_msg
 # -│   ├── [drwxr-xr-x]  cio_trace
 # -│   ├── [drwxr-xr-x]  dasd
 # -│   ├── [drwxr-xr-x]  kvm-trace
 # -│   ├── [drwxr-xr-x]  lgr
 # -│   ├── [drwxr-xr-x]  qdio_0.0.f5f2
 # -│   ├── [drwxr-xr-x]  qdio_error
 # -│   ├── [drwxr-xr-x]  qdio_setup
 # -│   ├── [drwxr-xr-x]  qeth_card_0.0.f5f0
 # -│   ├── [drwxr-xr-x]  qeth_control
 # -│   ├── [drwxr-xr-x]  qeth_msg
 # -│   ├── [drwxr-xr-x]  qeth_setup
 # -│   ├── [drwxr-xr-x]  vmcp
 # -│   └── [drwxr-xr-x]  vmur
 # +├── [drwx------]  bdi
 # +│   ├── [drwx------]  1:0
 # +│   ├── [drwx------]  1:1
 # +│   ├── [drwx------]  1:10
 # +│   ├── [drwx------]  1:11
 # +│   ├── [drwx------]  1:12
 # +│   ├── [drwx------]  1:13
 # +│   ├── [drwx------]  1:14
 # +│   ├── [drwx------]  1:15
 # +│   ├── [drwx------]  1:2
 # +│   ├── [drwx------]  1:3
 # +│   ├── [drwx------]  1:4
 # +│   ├── [drwx------]  1:5
 # +│   ├── [drwx------]  1:6
 # +│   ├── [drwx------]  1:7
 # +│   ├── [drwx------]  1:8
 # +│   ├── [drwx------]  1:9
 # +│   └── [drwx------]  94:0
 # +├── [drwx------]  block
 # +├── [drwx------]  dasd
 # +│   ├── [drwx------]  0.0.e18a
 # +│   ├── [drwx------]  dasda
 # +│   └── [drwx------]  global
 # +├── [drwx------]  device_component
 # +├── [drwx------]  extfrag
 # +├── [drwx------]  hid
 # +├── [drwx------]  kprobes
 # +├── [drwx------]  kvm
 # +├── [drwx------]  memblock
 # +├── [drwx------]  pm_qos
 # +├── [drwx------]  qdio
 # +│   └── [drwx------]  0.0.f5f2
 # +├── [drwx------]  s390
 # +│   └── [drwx------]  stsi
 # +├── [drwx------]  s390dbf
 # +│   ├── [drwx------]  0.0.e18a
 # +│   ├── [drwx------]  cio_crw
 # +│   ├── [drwx------]  cio_msg
 # +│   ├── [drwx------]  cio_trace
 # +│   ├── [drwx------]  dasd
 # +│   ├── [drwx------]  kvm-trace
 # +│   ├── [drwx------]  lgr
 # +│   ├── [drwx------]  qdio_0.0.f5f2
 # +│   ├── [drwx------]  qdio_error
 # +│   ├── [drwx------]  qdio_setup
 # +│   ├── [drwx------]  qeth_card_0.0.f5f0
 # +│   ├── [drwx------]  qeth_control
 # +│   ├── [drwx------]  qeth_msg
 # +│   ├── [drwx------]  qeth_setup
 # +│   ├── [drwx------]  vmcp
 # +│   └── [drwx------]  vmur
 #  └── [drwx------]  tracing
 #      ├── [drwxr-xr-x]  events
 #      │   ├── [drwxr-xr-x]  alarmtimer

Fixes: edac65eaf8 ("debugfs: take mode-dependent parts of debugfs_get_inode() into callers")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:48:18 +02:00
Al Viro cd1c0c9321 debugfs_lookup(): switch to lookup_one_len_unlocked()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-29 15:07:47 -04:00
Greg Kroah-Hartman 2b2d8788dd debugfs: Remove redundant license text
Now that the SPDX tag is in all debugfs files, that identifies the
license in a specific and legally-defined manner.  So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Greg Kroah-Hartman 3bce94fd5f debugfs: add SPDX identifiers to all debugfs files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the debugfs files files with the correct SPDX license identifier
based on the license text in the file itself.  The SPDX identifier is a
legally binding shorthand, which can be used instead of the full boiler
plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange 7d39bc50c4 debugfs: defer debugfs_fsdata allocation to first usage
Currently, __debugfs_create_file allocates one struct debugfs_fsdata
instance for every file created. However, there are potentially many
debugfs file around, most of which are never touched by userspace.

Thus, defer the allocations to the first usage, i.e. to the first
debugfs_file_get().

A dentry's ->d_fsdata starts out to point to the "real", user provided
fops. After a debugfs_fsdata instance has been allocated (and the real
fops pointer has been moved over into its ->real_fops member),
->d_fsdata is changed to point to it from then on. The two cases are
distinguished by setting BIT(0) for the real fops case.

struct debugfs_fsdata's foremost purpose is to track active users and to
make debugfs_remove() block until they are done. Since no debugfs_fsdata
instance means no active users, make debugfs_remove() return immediately
in this case.

Take care of possible races between debugfs_file_get() and
debugfs_remove(): either debugfs_remove() must see a debugfs_fsdata
instance and thus wait for possible active users or debugfs_file_get() must
see a dead dentry and return immediately.

Make a dentry's ->d_release(), i.e. debugfs_release_dentry(), check whether
->d_fsdata is actually a debugfs_fsdata instance before kfree()ing it.

Similarly, make debugfs_real_fops() check whether ->d_fsdata is actually
a debugfs_fsdata instance before returning it, otherwise emit a warning.

The set of possible error codes returned from debugfs_file_get() has grown
from -EIO to -EIO and -ENOMEM. Make open_proxy_open() and full_proxy_open()
pass the -ENOMEM onwards to their callers.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:03 +01:00
Nicolai Stange c9afbec270 debugfs: purge obsolete SRCU based removal protection
Purge the SRCU based file removal race protection in favour of the new,
refcount based debugfs_file_get()/debugfs_file_put() API.

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange e9117a5a4b debugfs: implement per-file removal protection
Since commit 49d200deaa ("debugfs: prevent access to removed files'
private data"), accesses to a file's private data are protected from
concurrent removal by covering all file_operations with a SRCU read section
and sychronizing with those before returning from debugfs_remove() by means
of synchronize_srcu().

As pointed out by Johannes Berg, there are debugfs files with forever
blocking file_operations. Their corresponding SRCU read side sections would
block any debugfs_remove() forever as well, even unrelated ones. This
results in a livelock. Because a remover can't cancel any indefinite
blocking within foreign files, this is a problem.

Resolve this by introducing support for more granular protection on a
per-file basis.

This is implemented by introducing an  'active_users' refcount_t to the
per-file struct debugfs_fsdata state. At file creation time, it is set to
one and a debugfs_remove() will drop that initial reference. The new
debugfs_file_get() and debugfs_file_put(), intended to be used in place of
former debugfs_use_file_start() and debugfs_use_file_finish(), increment
and decrement it respectively. Once the count drops to zero,
debugfs_file_put() will signal a completion which is possibly being waited
for from debugfs_remove().
Thus, as long as there is a debugfs_file_get() not yet matched by a
corresponding debugfs_file_put() around, debugfs_remove() will block.

Actual users of debugfs_use_file_start() and -finish() will get converted
to the new debugfs_file_get() and debugfs_file_put() by followup patches.

Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Nicolai Stange 7c8d469877 debugfs: add support for more elaborate ->d_fsdata
Currently, the user provided fops, "real_fops", are stored directly into
->d_fsdata.

In order to be able to store more per-file state and thus prepare for more
granular file removal protection, wrap the real_fops into a dynamically
allocated container struct, debugfs_fsdata.

A struct debugfs_fsdata gets allocated at file creation and freed from the
newly intoduced ->d_release().

Finally, move the implementation of debugfs_real_fops() out of the public
debugfs header such that struct debugfs_fsdata's declaration can be kept
private.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 20:25:02 +01:00
Linus Torvalds 78dcf73421 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ->s_options removal from Al Viro:
 "Preparations for fsmount/fsopen stuff (coming next cycle). Everything
  gets moved to explicit ->show_options(), killing ->s_options off +
  some cosmetic bits around fs/namespace.c and friends. Basically, the
  stuff needed to work with fsmount series with minimum of conflicts
  with other work.

  It's not strictly required for this merge window, but it would reduce
  the PITA during the coming cycle, so it would be nice to have those
  bits and pieces out of the way"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  isofs: Fix isofs_show_options()
  VFS: Kill off s_options and helpers
  orangefs: Implement show_options
  9p: Implement show_options
  isofs: Implement show_options
  afs: Implement show_options
  affs: Implement show_options
  befs: Implement show_options
  spufs: Implement show_options
  bpf: Implement show_options
  ramfs: Implement show_options
  pstore: Implement show_options
  omfs: Implement show_options
  hugetlbfs: Implement show_options
  VFS: Don't use save/replace_mount_options if not using generic_show_options
  VFS: Provide empty name qstr
  VFS: Make get_filesystem() return the affected filesystem
  VFS: Clean up whitespace in fs/namespace.c and fs/super.c
  Provide a function to create a NUL-terminated string from unterminated data
2017-07-15 12:00:42 -07:00
Linus Torvalds b8d4c1f9f4 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc filesystem updates from Al Viro:
 "Assorted normal VFS / filesystems stuff..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  dentry name snapshots
  Make statfs properly return read-only state after emergency remount
  fs/dcache: init in_lookup_hashtable
  minix: Deinline get_block, save 2691 bytes
  fs: Reorder inode_owner_or_capable() to avoid needless
  fs: warn in case userspace lied about modprobe return
2017-07-08 10:50:54 -07:00