linux.git/init, branch v5.15.185

sched/isolation: Make CONFIG_CPU_ISOLATION depend on CONFIG_SMP

2025-05-02T05:44:36+00:00

[ Upstream commit 975776841e689dd8ba36df9fa72ac3eca3c2957a ]

kernel/sched/isolation.c obviously makes no sense without CONFIG_SMP, but
the Kconfig entry we have right now:

	config CPU_ISOLATION
		bool "CPU isolation"
		depends on SMP || COMPILE_TEST

allows the creation of pointless .config's which cause
build failures.

Reported-by: kernel test robot 
Signed-off-by: Oleg Nesterov 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20250330134955.GA7910@redhat.com

Closes: https://lore.kernel.org/oe-kbuild-all/202503260646.lrUqD3j5-lkp@intel.com/
Signed-off-by: Sasha Levin

module: sign with sha512 instead of sha1 by default

2025-05-02T05:44:25+00:00

commit f3b93547b91ad849b58eb5ab2dd070950ad7beb3 upstream.

Switch away from using sha1 for module signing by default and use the
more modern sha512 instead, which is what among others Arch, Fedora,
RHEL, and Ubuntu are currently using for their kernels.

Sha1 has not been considered secure against well-funded opponents since
2005[1]; since 2011 the NIST and other organizations furthermore
recommended its replacement[2]. This is why OpenSSL on RHEL9, Fedora
Linux 41+[3], and likely some other current and future distributions
reject the creation of sha1 signatures, which leads to a build error of
allmodconfig configurations:

  80A20474797F0000:error:03000098:digital envelope routines:do_sigver_init:invalid digest:crypto/evp/m_sigver.c:342:
  make[4]: *** [.../certs/Makefile:53: certs/signing_key.pem] Error 1
  make[4]: *** Deleting file 'certs/signing_key.pem'
  make[4]: *** Waiting for unfinished jobs....
  make[3]: *** [.../scripts/Makefile.build:478: certs] Error 2
  make[2]: *** [.../Makefile:1936: .] Error 2
  make[1]: *** [.../Makefile:224: __sub-make] Error 2
  make[1]: Leaving directory '...'
  make: *** [Makefile:224: __sub-make] Error 2

This change makes allmodconfig work again and sets a default that is
more appropriate for current and future users, too.

Link: https://www.schneier.com/blog/archives/2005/02/cryptanalysis_o.html [1]
Link: https://csrc.nist.gov/projects/hash-functions [2]
Link: https://fedoraproject.org/wiki/Changes/OpenSSLDistrustsha1SigVer [3]
Signed-off-by: Thorsten Leemhuis 
Reviewed-by: Sami Tolvanen 
Tested-by: kdevops  [0]
Link: https://github.com/linux-kdevops/linux-modules-kpd/actions/runs/11420092929/job/31775404330 [0]
Link: https://lore.kernel.org/r/52ee32c0c92afc4d3263cea1f8a1cdc809728aff.1729088288.git.linux@leemhuis.info
Signed-off-by: Petr Pavlu 
Signed-off-by: Greg Kroah-Hartman

initramfs: avoid filename buffer overrun

2024-12-14T18:50:42+00:00

[ Upstream commit e017671f534dd3f568db9e47b0583e853d2da9b5 ]

The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:

 37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
...
 55 ============= ================== =========================
 56 Field name    Field size         Meaning
 57 ============= ================== =========================
...
 70 c_namesize    8 bytes            Length of filename, including final \0

When extracting an initramfs cpio archive, the kernel's do_name() path
handler assumes a zero-terminated path at @collected, passing it
directly to filp_open() / init_mkdir() / init_mknod().

If a specially crafted cpio entry carries a non-zero-terminated filename
and is followed by uninitialized memory, then a file may be created with
trailing characters that represent the uninitialized memory. The ability
to create an initramfs entry would imply already having full control of
the system, so the buffer overrun shouldn't be considered a security
vulnerability.

Append the output of the following bash script to an existing initramfs
and observe any created /initramfs_test_fname_overrunAA* path. E.g.
  ./reproducer.sh | gzip >> /myinitramfs

It's easiest to observe non-zero uninitialized memory when the output is
gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(),
rather than the initrd_start+initrd_size block.

---- reproducer.sh ----
nilchar="A"	# change to "\0" to properly zero terminate / pad
magic="070701"
ino=1
mode=$(( 0100777 ))
uid=0
gid=0
nlink=1
mtime=1
filesize=0
devmajor=0
devminor=1
rdevmajor=0
rdevminor=0
csum=0
fname="initramfs_test_fname_overrun"
namelen=$(( ${#fname} + 1 ))	# plus one to account for terminator

printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \
	$magic $ino $mode $uid $gid $nlink $mtime $filesize \
	$devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname

termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) ))
printf "%.s${nilchar}" $(seq 1 $termpadlen)
---- reproducer.sh ----

Symlink filename fields handled in do_symlink() won't overrun past the
data segment, due to the explicit zero-termination of the symlink
target.

Fix filename buffer overrun by aborting the initramfs FSM if any cpio
entry doesn't carry a zero-terminator at the expected (name_len - 1)
offset.

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: David Disseldorp 
Link: https://lore.kernel.org/r/20241030035509.20194-2-ddiss@suse.de
Signed-off-by: Christian Brauner 
Signed-off-by: Sasha Levin

init/main.c: Fix potential static_command_line memory overflow

2024-04-27T15:05:28+00:00

commit 46dad3c1e57897ab9228332f03e1c14798d2d3b9 upstream.

We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for
static_command_line, but the strings copied into static_command_line are
extra_command_line and command_line, rather than extra_command_line and
boot_command_line.

When strlen(command_line) > strlen(boot_command_line), static_command_line
will overflow.

This patch just recovers strlen(command_line) which was miss-consolidated
with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add
checks for the return value of memblock_alloc*()")

Link: https://lore.kernel.org/all/20240412081733.35925-2-ytcoode@gmail.com/

Fixes: f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()")
Cc: stable@vger.kernel.org
Signed-off-by: Yuntao Wang 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Greg Kroah-Hartman

init: open /initrd.image with O_LARGEFILE

2024-04-10T14:19:31+00:00

commit 4624b346cf67400ef46a31771011fb798dd2f999 upstream.

If initrd data is larger than 2Gb, we'll eventually fail to write to the
/initrd.image file when we hit that limit, unless O_LARGEFILE is set.

Link: https://lkml.kernel.org/r/20240317221522.896040-1-jsperbeck@google.com
Signed-off-by: John Sperbeck 
Cc: Jens Axboe 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

modules: wait do_free_init correctly

2024-03-26T22:21:31+00:00

[ Upstream commit 8f8cd6c0a43ed637e620bbe45a8d0e0c2f4d5130 ]

The synchronization here is to ensure the ordering of freeing of a module
init so that it happens before W+X checking.  It is worth noting it is not
that the freeing was not happening, it is just that our sanity checkers
raced against the permission checkers which assume init memory is already
gone.

Commit 1a7b7d922081 ("modules: Use vmalloc special flag") moved calling
do_free_init() into a global workqueue instead of relying on it being
called through call_rcu(..., do_free_init), which used to allowed us call
do_free_init() asynchronously after the end of a subsequent grace period.
The move to a global workqueue broke the gaurantees for code which needed
to be sure the do_free_init() would complete with rcu_barrier().  To fix
this callers which used to rely on rcu_barrier() must now instead use
flush_work(&init_free_wq).

Without this fix, we still could encounter false positive reports in W+X
checking since the rcu_barrier() here can not ensure the ordering now.

Even worse, the rcu_barrier() can introduce significant delay.  Eric
Chanudet reported that the rcu_barrier introduces ~0.1s delay on a
PREEMPT_RT kernel.

  [    0.291444] Freeing unused kernel memory: 5568K
  [    0.402442] Run /sbin/init as init process

With this fix, the above delay can be eliminated.

Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com
Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag")
Signed-off-by: Changbin Du 
Tested-by: Eric Chanudet 
Acked-by: Luis Chamberlain 
Cc: Xiaoyi Su 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

rootfs: Fix support for rootfstype= when root= is given

2024-01-25T22:52:48+00:00

commit 21528c69a0d8483f7c6345b1a0bc8d8975e9a172 upstream.

Documentation/filesystems/ramfs-rootfs-initramfs.rst states:

  If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by
  default.  To force ramfs, add "rootfstype=ramfs" to the kernel command
  line.

This currently does not work when root= is provided since then
saved_root_name contains a string and rootfstype= is ignored. Therefore,
ramfs is currently always chosen when root= is provided.

The current behavior for rootfs's filesystem is:

   root=       | rootfstype= | chosen rootfs filesystem
   ------------+-------------+--------------------------
   unspecified | unspecified | tmpfs
   unspecified | tmpfs       | tmpfs
   unspecified | ramfs       | ramfs
    provided   | ignored     | ramfs

rootfstype= should be respected regardless whether root= is given,
as shown below:

   root=       | rootfstype= | chosen rootfs filesystem
   ------------+-------------+--------------------------
   unspecified | unspecified | tmpfs  (as before)
   unspecified | tmpfs       | tmpfs  (as before)
   unspecified | ramfs       | ramfs  (as before)
    provided   | unspecified | ramfs  (compatibility with before)
    provided   | tmpfs       | tmpfs  (new)
    provided   | ramfs       | ramfs  (new)

This table represents the new behavior.

Fixes: 6e19eded3684 ("initmpfs: use initramfs if rootfstype= or root= specified")
Cc: 
Signed-off-by: Rob Landley 
Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/
Reviewed-and-Tested-by: Mimi Zohar 
Signed-off-by: Stefan Berger 
Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman

proc: sysctl: prevent aliased sysctls from getting passed to init

2023-12-03T06:31:24+00:00

commit 8001f49394e353f035306a45bcf504f06fca6355 upstream.

The code that checks for unknown boot options is unaware of the sysctl
alias facility, which maps bootparams to sysctl values.  If a user sets
an old value that has a valid alias, a message about an invalid
parameter will be printed during boot, and the parameter will get passed
to init.  Fix by checking for the existence of aliased parameters in the
unknown boot parameter code.  If an alias exists, don't return an error
or pass the value to init.

Signed-off-by: Krister Johansen 
Cc: stable@vger.kernel.org
Fixes: 0a477e1ae21b ("kernel/sysctl: support handling command line aliases")
Signed-off-by: Luis Chamberlain 
Signed-off-by: Krister Johansen 
Signed-off-by: Greg Kroah-Hartman

x86/mm: Initialize text poking earlier

2023-08-08T17:58:33+00:00

commit 5b93a83649c7cba3a15eb7e8959b250841acb1b1 upstream.

Move poking_init() up a bunch; specifically move it right after
mm_init() which is right before ftrace_init().

This will allow simplifying ftrace text poking which currently has
a bunch of exceptions for early boot.

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20221025201057.881703081@infradead.org
Signed-off-by: Greg Kroah-Hartman

mm: Move mm_cachep initialization to mm_init()

2023-08-08T17:58:33+00:00

commit af80602799681c78f14fbe20b6185a56020dedee upstream.

In order to allow using mm_alloc() much earlier, move initializing
mm_cachep into mm_init().

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20221025201057.751153381@infradead.org
Signed-off-by: Greg Kroah-Hartman