<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/drivers/base/firmware_loader, branch v5.13.18</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.13.18</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.13.18'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2021-09-15T08:00:38Z</updated>
<entry>
<title>firmware: fix theoretical UAF race with firmware cache and resume</title>
<updated>2021-09-15T08:00:38Z</updated>
<author>
<name>Zhen Lei</name>
<email>thunder.leizhen@huawei.com</email>
</author>
<published>2021-07-19T06:45:31Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=827979175c76b7faf58b7d0a192b647ba162515d'/>
<id>urn:sha1:827979175c76b7faf58b7d0a192b647ba162515d</id>
<content type='text'>
[ Upstream commit 3ecc8cb7c092b2f50e21d2aaaae35b8221ee7214 ]

This race was discovered when I carefully analyzed the code to locate
another firmware-related UAF issue. It can be triggered only when the
firmware load operation is executed during suspend. This possibility is
almost impossible because there are few firmware load and suspend actions
in the actual environment.

		CPU0			CPU1
__device_uncache_fw_images():		assign_fw():
					fw_cache_piggyback_on_request()
					&lt;----- P0
	spin_lock(&amp;fwc-&gt;name_lock);
	...
	list_del(&amp;fce-&gt;list);
	spin_unlock(&amp;fwc-&gt;name_lock);

	uncache_firmware(fce-&gt;name);
					&lt;----- P1
					kref_get(&amp;fw_priv-&gt;ref);

If CPU1 is interrupted at position P0, the new 'fce' has been added to the
list fwc-&gt;fw_names by the fw_cache_piggyback_on_request(). In this case,
CPU0 executes __device_uncache_fw_images() and will be able to see it when
it traverses list fwc-&gt;fw_names. Before CPU1 executes kref_get() at P1, if
CPU0 further executes uncache_firmware(), the count of fw_priv-&gt;ref may
decrease to 0, causing fw_priv to be released in advance.

Move kref_get() to the lock protection range of fwc-&gt;name_lock to fix it.

Fixes: ac39b3ea73aa ("firmware loader: let caching firmware piggyback on loading firmware")
Acked-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Link: https://lore.kernel.org/r/20210719064531.3733-2-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>firmware_loader: fix use-after-free in firmware_fallback_sysfs</title>
<updated>2021-08-12T11:32:13Z</updated>
<author>
<name>Anirudh Rayabharam</name>
<email>mail@anirudhrb.com</email>
</author>
<published>2021-07-28T08:51:07Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c14a54675db7131791402fa22fb0fa6da1f5fb66'/>
<id>urn:sha1:c14a54675db7131791402fa22fb0fa6da1f5fb66</id>
<content type='text'>
commit 75d95e2e39b27f733f21e6668af1c9893a97de5e upstream.

This use-after-free happens when a fw_priv object has been freed but
hasn't been removed from the pending list (pending_fw_head). The next
time fw_load_sysfs_fallback tries to insert into the list, it ends up
accessing the pending_list member of the previously freed fw_priv.

The root cause here is that all code paths that abort the fw load
don't delete it from the pending list. For example:

        _request_firmware()
          -&gt; fw_abort_batch_reqs()
              -&gt; fw_state_aborted()

To fix this, delete the fw_priv from the list in __fw_set_state() if
the new state is DONE or ABORTED. This way, all aborts will remove
the fw_priv from the list. Accordingly, remove calls to list_del_init
that were being made before calling fw_state_(aborted|done).

Also, in fw_load_sysfs_fallback, don't add the fw_priv to the pending
list if it is already aborted. Instead, just jump out and return early.

Fixes: bcfbd3523f3c ("firmware: fix a double abort case with fw_load_sysfs_fallback")
Cc: stable &lt;stable@vger.kernel.org&gt;
Reported-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com
Tested-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com
Reviewed-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Acked-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Signed-off-by: Anirudh Rayabharam &lt;mail@anirudhrb.com&gt;
Link: https://lore.kernel.org/r/20210728085107.4141-3-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>firmware_loader: use -ETIMEDOUT instead of -EAGAIN in fw_load_sysfs_fallback</title>
<updated>2021-08-12T11:32:13Z</updated>
<author>
<name>Anirudh Rayabharam</name>
<email>mail@anirudhrb.com</email>
</author>
<published>2021-07-28T08:51:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=34311eaec13bd68ce33e4fa12e036df0967c90f3'/>
<id>urn:sha1:34311eaec13bd68ce33e4fa12e036df0967c90f3</id>
<content type='text'>
commit 0d6434e10b5377a006f6dd995c8fc5e2d82acddc upstream.

The only motivation for using -EAGAIN in commit 0542ad88fbdd81bb
("firmware loader: Fix _request_firmware_load() return val for fw load
abort") was to distinguish the error from -ENOMEM, and so there is no
real reason in keeping it. -EAGAIN is typically used to tell the
userspace to try something again and in this case re-using the sysfs
loading interface cannot be retried when a timeout happens, so the
return value is also bogus.

-ETIMEDOUT is received when the wait times out and returning that
is much more telling of what the reason for the failure was. So, just
propagate that instead of returning -EAGAIN.

Suggested-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Reviewed-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Acked-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Signed-off-by: Anirudh Rayabharam &lt;mail@anirudhrb.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20210728085107.4141-2-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>init/initramfs.c: do unpacking asynchronously</title>
<updated>2021-05-07T07:26:33Z</updated>
<author>
<name>Rasmus Villemoes</name>
<email>linux@rasmusvillemoes.dk</email>
</author>
<published>2021-05-07T01:05:42Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e7cb072eb988e46295512617c39d004f9e1c26f8'/>
<id>urn:sha1:e7cb072eb988e46295512617c39d004f9e1c26f8</id>
<content type='text'>
Patch series "background initramfs unpacking, and CONFIG_MODPROBE_PATH", v3.

These two patches are independent, but better-together.

The second is a rather trivial patch that simply allows the developer to
change "/sbin/modprobe" to something else - e.g.  the empty string, so
that all request_module() during early boot return -ENOENT early, without
even spawning a usermode helper, needlessly synchronizing with the
initramfs unpacking.

The first patch delegates decompressing the initramfs to a worker thread,
allowing do_initcalls() in main.c to proceed to the device_ and late_
initcalls without waiting for that decompression (and populating of
rootfs) to finish.  Obviously, some of those later calls may rely on the
initramfs being available, so I've added synchronization points in the
firmware loader and usermodehelper paths - there might be other places
that would need this, but so far no one has been able to think of any
places I have missed.

There's not much to win if most of the functionality needed during boot is
only available as modules.  But systems with a custom-made .config and
initramfs can boot faster, partly due to utilizing more than one cpu
earlier, partly by avoiding known-futile modprobe calls (which would still
trigger synchronization with the initramfs unpacking, thus eliminating
most of the first benefit).

This patch (of 2):

Most of the boot process doesn't actually need anything from the
initramfs, until of course PID1 is to be executed.  So instead of doing
the decompressing and populating of the initramfs synchronously in
populate_rootfs() itself, push that off to a worker thread.

This is primarily motivated by an embedded ppc target, where unpacking
even the rather modest sized initramfs takes 0.6 seconds, which is long
enough that the external watchdog becomes unhappy that it doesn't get
attention soon enough.  By doing the initramfs decompression in a worker
thread, we get to do the device_initcalls and hence start petting the
watchdog much sooner.

Normal desktops might benefit as well.  On my mostly stock Ubuntu kernel,
my initramfs is a 26M xz-compressed blob, decompressing to around 126M.
That takes almost two seconds:

[    0.201454] Trying to unpack rootfs image as initramfs...
[    1.976633] Freeing initrd memory: 29416K

Before this patch, these lines occur consecutively in dmesg.  With this
patch, the timestamps on these two lines is roughly the same as above, but
with 172 lines inbetween - so more than one cpu has been kept busy doing
work that would otherwise only happen after the populate_rootfs()
finished.

Should one of the initcalls done after rootfs_initcall time (i.e., device_
and late_ initcalls) need something from the initramfs (say, a kernel
module or a firmware blob), it will simply wait for the initramfs
unpacking to be done before proceeding, which should in theory make this
completely safe.

But if some driver pokes around in the filesystem directly and not via one
of the official kernel interfaces (i.e.  request_firmware*(),
call_usermodehelper*) that theory may not hold - also, I certainly might
have missed a spot when sprinkling wait_for_initramfs().  So there is an
escape hatch in the form of an initramfs_async= command line parameter.

Link: https://lkml.kernel.org/r/20210313212528.2956377-1-linux@rasmusvillemoes.dk
Link: https://lkml.kernel.org/r/20210313212528.2956377-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Reviewed-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Cc: Jessica Yu &lt;jeyu@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>drivers: base: fix some kernel-doc markups</title>
<updated>2020-11-09T17:56:49Z</updated>
<author>
<name>Mauro Carvalho Chehab</name>
<email>mchehab+huawei@kernel.org</email>
</author>
<published>2020-10-23T16:32:56Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=33c0c9bdf7a59051a654cd98b7d2b48ce0080967'/>
<id>urn:sha1:33c0c9bdf7a59051a654cd98b7d2b48ce0080967</id>
<content type='text'>
class_create is actually defined at the header. Fix the
markup there and add a new one at the right place.

While here, also fix some markups for functions that have
different names between their prototypes and kernel-doc
comments.

Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
Link: https://lore.kernel.org/r/2fb6efd6a1f90d69ff73bf579566079cbb051e15.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc</title>
<updated>2020-10-15T17:01:51Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-10-15T17:01:51Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=726eb70e0d34dc4bc4dada71f52bba8ed638431e'/>
<id>urn:sha1:726eb70e0d34dc4bc4dada71f52bba8ed638431e</id>
<content type='text'>
Pull char/misc driver updates from Greg KH:
 "Here is the big set of char, misc, and other assorted driver subsystem
  patches for 5.10-rc1.

  There's a lot of different things in here, all over the drivers/
  directory. Some summaries:

   - soundwire driver updates

   - habanalabs driver updates

   - extcon driver updates

   - nitro_enclaves new driver

   - fsl-mc driver and core updates

   - mhi core and bus updates

   - nvmem driver updates

   - eeprom driver updates

   - binder driver updates and fixes

   - vbox minor bugfixes

   - fsi driver updates

   - w1 driver updates

   - coresight driver updates

   - interconnect driver updates

   - misc driver updates

   - other minor driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (396 commits)
  binder: fix UAF when releasing todo list
  docs: w1: w1_therm: Fix broken xref, mistakes, clarify text
  misc: Kconfig: fix a HISI_HIKEY_USB dependency
  LSM: Fix type of id parameter in kernel_post_load_data prototype
  misc: Kconfig: add a new dependency for HISI_HIKEY_USB
  firmware_loader: fix a kernel-doc markup
  w1: w1_therm: make w1_poll_completion static
  binder: simplify the return expression of binder_mmap
  test_firmware: Test partial read support
  firmware: Add request_partial_firmware_into_buf()
  firmware: Store opt_flags in fw_priv
  fs/kernel_file_read: Add "offset" arg for partial reads
  IMA: Add support for file reads without contents
  LSM: Add "contents" flag to kernel_read_file hook
  module: Call security_kernel_post_load_data()
  firmware_loader: Use security_post_load_data()
  LSM: Introduce kernel_post_load_data() hook
  fs/kernel_read_file: Add file_size output argument
  fs/kernel_read_file: Switch buffer size arg to size_t
  fs/kernel_read_file: Remove redundant size argument
  ...
</content>
</entry>
<entry>
<title>firmware_loader: fix a kernel-doc markup</title>
<updated>2020-10-06T16:54:54Z</updated>
<author>
<name>Mauro Carvalho Chehab</name>
<email>mchehab+huawei@kernel.org</email>
</author>
<published>2020-10-06T13:21:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=dba8648dcab90564b8a11c952c06a9e1153506fb'/>
<id>urn:sha1:dba8648dcab90564b8a11c952c06a9e1153506fb</id>
<content type='text'>
The firmware_fallback_sysfs had some changes at their
parameters. Those ended by dropping a documentation for
such parameter. Re-add it.

Fixes: 89287c169f8f ("firmware: Store opt_flags in fw_priv")
Fixes: c2c076166b58 ("firmware_loader: change enum fw_opt to u32")
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
Link: https://lore.kernel.org/r/23ec441bb9c206f5899b5d64d34e5c9f6add5fd9.1601990386.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>firmware: Add request_partial_firmware_into_buf()</title>
<updated>2020-10-05T11:37:04Z</updated>
<author>
<name>Scott Branden</name>
<email>scott.branden@broadcom.com</email>
</author>
<published>2020-10-02T17:38:27Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=59cdb23ca2dfef3b93411d1105409dfe9cd1f62f'/>
<id>urn:sha1:59cdb23ca2dfef3b93411d1105409dfe9cd1f62f</id>
<content type='text'>
Add request_partial_firmware_into_buf() to allow for portions of a
firmware file to be read into a buffer. This is needed when large firmware
must be loaded in portions from a file on memory constrained systems.

Signed-off-by: Scott Branden &lt;scott.branden@broadcom.com&gt;
Co-developed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20201002173828.2099543-16-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>firmware: Store opt_flags in fw_priv</title>
<updated>2020-10-05T11:37:04Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2020-10-02T17:38:26Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=89287c169f8ff79d466b274da1d5c862e8b29152'/>
<id>urn:sha1:89287c169f8ff79d466b274da1d5c862e8b29152</id>
<content type='text'>
Instead of passing opt_flags around so much, store it in the private
structure so it can be examined by internals without needing to add more
arguments to functions.

Co-developed-by: Scott Branden &lt;scott.branden@broadcom.com&gt;
Signed-off-by: Scott Branden &lt;scott.branden@broadcom.com&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20201002173828.2099543-15-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>fs/kernel_file_read: Add "offset" arg for partial reads</title>
<updated>2020-10-05T11:37:04Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2020-10-02T17:38:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=0fa8e084648779eeb8929ae004301b3acf3bad84'/>
<id>urn:sha1:0fa8e084648779eeb8929ae004301b3acf3bad84</id>
<content type='text'>
To perform partial reads, callers of kernel_read_file*() must have a
non-NULL file_size argument and a preallocated buffer. The new "offset"
argument can then be used to seek to specific locations in the file to
fill the buffer to, at most, "buf_size" per call.

Where possible, the LSM hooks can report whether a full file has been
read or not so that the contents can be reasoned about.

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Link: https://lore.kernel.org/r/20201002173828.2099543-14-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
