Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
code
Clone this repository
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Pull selinux fix from Paul Moore:
"A single SELinux patch to address a problem with a single domain using
multiple xperm classes"
* tag 'selinux-pr-20250107' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: match extended permissions to their base permissions
Pull vfs fixes from Christian Brauner:
- Relax assertions on failure to encode file handles
The ->encode_fh() method can fail for various reasons. None of them
warrant a WARN_ON().
- Fix overlayfs file handle encoding by allowing encoding an fid from
an inode without an alias
- Make sure fuse_dir_open() handles FOPEN_KEEP_CACHE. If it's not
specified fuse needs to invaludate the directory inode page cache
- Fix qnx6 so it builds with gcc-15
- Various fixes for netfslib and ceph and nfs filesystems:
- Ignore silly rename files from afs and nfs when building header
archives
- Fix read result collection in netfslib with multiple subrequests
- Handle ENOMEM for netfslib buffered reads
- Fix oops in nfs_netfs_init_request()
- Parse the secctx command immediately in cachefiles
- Remove a redundant smp_rmb() in netfslib
- Handle recursion in read retry in netfslib
- Fix clearing of folio_queue
- Fix missing cancellation of copy-to_cache when the cache for a
file is temporarly disabled in netfslib
- Sanity check the hfs root record
- Fix zero padding data issues in concurrent write scenarios
- Fix is_mnt_ns_file() after converting nsfs to path_from_stashed()
- Fix missing declaration of init_files
- Increase I/O priority when writing revoke records in jbd2
- Flush filesystem device before updating tail sequence in jbd2
* tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits)
ovl: support encoding fid from inode with no alias
ovl: pass realinode to ovl_encode_real_fh() instead of realdentry
fuse: respect FOPEN_KEEP_CACHE on opendir
netfs: Fix is-caching check in read-retry
netfs: Fix the (non-)cancellation of copy when cache is temporarily disabled
netfs: Fix ceph copy to cache on write-begin
netfs: Work around recursion by abandoning retry if nothing read
netfs: Fix missing barriers by using clear_and_wake_up_bit()
netfs: Remove redundant use of smp_rmb()
cachefiles: Parse the "secctx" immediately
nfs: Fix oops in nfs_netfs_init_request() when copying to cache
netfs: Fix enomem handling in buffered reads
netfs: Fix non-contiguous donation between completed reads
kheaders: Ignore silly-rename files
fs: relax assertions on failure to encode file handles
fs: fix missing declaration of init_files
fs: fix is_mnt_ns_file()
iomap: fix zero padding data issue in concurrent append writes
iomap: pass byte granular end position to iomap_add_to_ioend
jbd2: flush filesystem device before updating tail sequence
...
In commit d1d991efaf34 ("selinux: Add netlink xperm support") a new
extended permission was added ("nlmsg"). This was the second extended
permission implemented in selinux ("ioctl" being the first one).
Extended permissions are associated with a base permission. It was found
that, in the access vector cache (avc), the extended permission did not
keep track of its base permission. This is an issue for a domain that is
using both extended permissions (i.e., a domain calling ioctl() on a
netlink socket). In this case, the extended permissions were
overlapping.
Keep track of the base permission in the cache. A new field "base_perm"
is added to struct extended_perms_decision to make sure that the
extended permission refers to the correct policy permission. A new field
"base_perms" is added to struct extended_perms to quickly decide if
extended permissions apply.
While it is in theory possible to retrieve the base permission from the
access vector, the same base permission may not be mapped to the same
bit for each class (e.g., "nlmsg" is mapped to a different bit for
"netlink_route_socket" and "netlink_audit_socket"). Instead, use a
constant (AVC_EXT_IOCTL or AVC_EXT_NLMSG) provided by the caller.
Fixes: d1d991efaf34 ("selinux: Add netlink xperm support")
Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull vfio fix from Alex Williamson:
- Fix a missed order alignment requirement of the pfn when inserting
mappings through the new huge fault handler introduced in v6.12 (Alex
Williamson)
* tag 'vfio-v6.13-rc7' of https://github.com/awilliam/linux-vfio:
vfio/pci: Fallback huge faults for unaligned pfn
Amir Goldstein <amir73il@gmail.com> says:
This is a followup fix to the reported regression [1] that was
introduced by overlayfs non-decodable file handles support in v6.6.
The first fix posted two weeks ago [2] was a quick band aid which is
justified on its own and is still queued on your vfs.fixes branch.
This followup fix fixes the root cause of overlayfs file handle encoding
failure and it also solves a bug with fanotify FAN_DELETE_SELF events on
overlayfs, that was discovered from analysis of the first report.
The fix to fanotify delete events was verified with a new LTP test [3].
[1] https://lore.kernel.org/linux-fsdevel/CAOQ4uxiie81voLZZi2zXS1BziXZCM24nXqPAxbu8kxXCUWdwOg@mail.gmail.com/
[2] https://lore.kernel.org/linux-fsdevel/20241219115301.465396-1-amir73il@gmail.com/
[3] https://github.com/amir73il/ltp/commits/ovl_encode_fid/
* patches from https://lore.kernel.org/r/20250105162404.357058-1-amir73il@gmail.com:
ovl: support encoding fid from inode with no alias
ovl: pass realinode to ovl_encode_real_fh() instead of realdentry
Link: https://lore.kernel.org/r/20250105162404.357058-1-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
When evaluating extended permissions, ignore unknown permissions instead
of calling BUG(). This commit ensures that future permissions can be
added without interfering with older kernels.
Cc: stable@vger.kernel.org
Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls")
Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull exfat fixes from Namjae Jeon:
"All fixes are for issues reported by syzbot:
- Fix wrong error return in exfat_find_empty_entry()
- Fix a endless loop by self-linked chain
- fix a KMSAN uninit-value issue in exfat_extend_valid_size()"
* tag 'exfat-for-6.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
exfat: fix the infinite loop in __exfat_free_cluster()
exfat: fix the new buffer was not zeroed before writing
exfat: fix the infinite loop in exfat_readdir()
exfat: fix exfat_find_empty_entry() not returning error on failure
The PFN must also be aligned to the fault order to insert a huge
pfnmap. Test the alignment and fallback when unaligned.
Fixes: f9e54c3a2f5b ("vfio/pci: implement huge_fault support")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219619
Reported-by: Athul Krishna <athul.krishna.kr@protonmail.com>
Reported-by: Precific <precification@posteo.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Precific <precification@posteo.de>
Link: https://lore.kernel.org/r/20250102183416.1841878-1-alex.williamson@redhat.com
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The re-factoring of fuse_dir_open() missed the need to invalidate
directory inode page cache with open flag FOPEN_KEEP_CACHE.
Fixes: 7de64d521bf92 ("fuse: break up fuse_open_common()")
Reported-by: Prince Kumar <princer@google.com>
Closes: https://lore.kernel.org/linux-fsdevel/CAEW=TRr7CYb4LtsvQPLj-zx5Y+EYBmGfM24SuzwyDoGVNoKm7w@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250101130037.96680-1-amir73il@gmail.com
Reviewed-by: Bernd Schubert <bernd.schubert@fastmail.fm>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Dmitry Safonov reported that a WARN_ON() assertion can be trigered by
userspace when calling inotify_show_fdinfo() for an overlayfs watched
inode, whose dentry aliases were discarded with drop_caches.
The WARN_ON() assertion in inotify_show_fdinfo() was removed, because
it is possible for encoding file handle to fail for other reason, but
the impact of failing to encode an overlayfs file handle goes beyond
this assertion.
As shown in the LTP test case mentioned in the link below, failure to
encode an overlayfs file handle from a non-aliased inode also leads to
failure to report an fid with FAN_DELETE_SELF fanotify events.
As Dmitry notes in his analyzis of the problem, ovl_encode_fh() fails
if it cannot find an alias for the inode, but this failure can be fixed.
ovl_encode_fh() seldom uses the alias and in the case of non-decodable
file handles, as is often the case with fanotify fid info,
ovl_encode_fh() never needs to use the alias to encode a file handle.
Defer finding an alias until it is actually needed so ovl_encode_fh()
will not fail in the common case of FAN_DELETE_SELF fanotify events.
Fixes: 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles")
Reported-by: Dmitry Safonov <dima@arista.com>
Closes: https://lore.kernel.org/linux-fsdevel/CAOQ4uxiie81voLZZi2zXS1BziXZCM24nXqPAxbu8kxXCUWdwOg@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250105162404.357058-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This reverts commit adcfb264c3ed51fbbf5068ddf10d309a63683868.
It turns out this just causes a different warning splat instead that
seems to be much easier to trigger, so let's revert ASAP.
Reported-and-bisected-by: Borislav Petkov <bp@alien8.de>
Tested-by: Breno Leitao <leitao@debian.org>
Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/all/20250106131817.GAZ3vYGVr3-hWFFPLj@fat_crate.local/
Cc: Koichiro Den <koichiro.den@canonical.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In __exfat_free_cluster(), the cluster chain is traversed until the
EOF cluster. If the cluster chain includes a loop due to file system
corruption, the EOF cluster cannot be traversed, resulting in an
infinite loop.
This commit uses the total number of clusters to prevent this infinite
loop.
Reported-by: syzbot+1de5a37cb85a2d536330@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1de5a37cb85a2d536330
Tested-by: syzbot+1de5a37cb85a2d536330@syzkaller.appspotmail.com
Fixes: 31023864e67a ("exfat: add fat entry operations")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
David Howells <dhowells@redhat.com> says:
Here are some miscellaneous fixes and changes for netfslib and the ceph and
nfs filesystems:
(1) Ignore silly-rename files from afs and nfs when building the header
archive in a kernel build.
(2) netfs: Fix the way read result collection applies results to folios
when each folio is being read by multiple subrequests and the results
come out of order.
(3) netfs: Fix ENOMEM handling in buffered reads.
(4) nfs: Fix an oops in nfs_netfs_init_request() when copying to the cache.
(5) cachefiles: Parse the "secctx" command immediately to get the correct
error rather than leaving it to the "bind" command.
(6) netfs: Remove a redundant smp_rmb(). This isn't a bug per se and
could be deferred.
(7) netfs: Fix missing barriers by using clear_and_wake_up_bit().
(8) netfs: Work around recursion in read retry by failing and abandoning
the retried subrequest if no I/O is performed.
[!] NOTE: This only works around the recursion problem if the
recursion keeps returning no data. If the server manages, say, to
repeatedly return a single byte of data faster than the retry
algorithm can complete, it will still recurse and the stack
overrun may still occur. Actually fixing this requires quite an
intrusive change which will hopefully make the next merge window.
(9) netfs: Fix the clearance of a folio_queue when unlocking the page if
we're going to want to subsequently send the queue for copying to the
cache (if, for example, we're using ceph).
(10) netfs: Fix the lack of cancellation of copy-to-cache when the cache
for a file is temporarily disabled (for example when a DIO write is
done to the file). This patch and (9) fix hangs with ceph.
With these patches, I can run xfstest -g quick to completion on ceph with a
local cache.
The patches can also be found here with a bonus cifs patch:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=netfs-fixes
* patches from https://lore.kernel.org/r/20241213135013.2964079-1-dhowells@redhat.com:
netfs: Fix is-caching check in read-retry
netfs: Fix the (non-)cancellation of copy when cache is temporarily disabled
netfs: Fix ceph copy to cache on write-begin
netfs: Work around recursion by abandoning retry if nothing read
netfs: Fix missing barriers by using clear_and_wake_up_bit()
netfs: Remove redundant use of smp_rmb()
cachefiles: Parse the "secctx" immediately
nfs: Fix oops in nfs_netfs_init_request() when copying to cache
netfs: Fix enomem handling in buffered reads
netfs: Fix non-contiguous donation between completed reads
kheaders: Ignore silly-rename files
Link: https://lore.kernel.org/r/20241213135013.2964079-1-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
We want to be able to encode an fid from an inode with no alias.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250105162404.357058-2-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull i2c component probing support from Wolfram Sang:
"Add OF component probing.
Some devices are designed and manufactured with some components having
multiple drop-in replacement options. These components are often
connected to the mainboard via ribbon cables, having the same signals
and pin assignments across all options. These may include the display
panel and touchscreen on laptops and tablets, and the trackpad on
laptops. Sometimes which component option is used in a particular
device can be detected by some firmware provided identifier, other
times that information is not available, and the kernel has to try to
probe each device.
Instead of a delicate dance between drivers and device tree quirks,
this change introduces a simple I2C component probe function. For a
given class of devices on the same I2C bus, it will go through all of
them, doing a simple I2C read transfer and see which one of them
responds. It will then enable the device that responds"
* tag 'i2c-for-6.13-rc1-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
MAINTAINERS: fix typo in I2C OF COMPONENT PROBER
of: base: Document prefix argument for of_get_next_child_with_prefix()
i2c: Fix whitespace style issue
arm64: dts: mediatek: mt8173-elm-hana: Mark touchscreens and trackpads as fail
platform/chrome: Introduce device tree hardware prober
i2c: of-prober: Add GPIO support to simple helpers
i2c: of-prober: Add simple helpers for regulator support
i2c: Introduce OF component probe function
of: base: Add for_each_child_of_node_with_prefix()
of: dynamic: Add of_changeset_update_prop_string