linux-stable.git/drivers/base/firmware_loader, branch v4.19.232

firmware_loader: fix pre-allocated buf built-in firmware use

2021-11-26T10:36:20+00:00

[ Upstream commit f7a07f7b96033df7709042ff38e998720a3f7119 ]

The firmware_loader can be used with a pre-allocated buffer
through the use of the API calls:

  o request_firmware_into_buf()
  o request_partial_firmware_into_buf()

If the firmware was built-in and present, our current check
for if the built-in firmware fits into the pre-allocated buffer
does not return any errors, and we proceed to tell the caller
that everything worked fine. It's a lie and no firmware would
end up being copied into the pre-allocated buffer. So if the
caller trust the result it may end up writing a bunch of 0's
to a device!

Fix this by making the function that checks for the pre-allocated
buffer return non-void. Since the typical use case is when no
pre-allocated buffer is provided make this return successfully
for that case. If the built-in firmware does *not* fit into the
pre-allocated buffer size return a failure as we should have
been doing before.

I'm not aware of users of the built-in firmware using the API
calls with a pre-allocated buffer, as such I doubt this fixes
any real life issue. But you never know... perhaps some oddball
private tree might use it.

In so far as upstream is concerned this just fixes our code for
correctness.

Signed-off-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20210917182226.3532898-2-mcgrof@kernel.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

firmware_loader: fix use-after-free in firmware_fallback_sysfs

2021-08-12T11:19:41+00:00

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()
          -> fw_abort_batch_reqs()
              -> 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 
Reported-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com
Tested-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com
Reviewed-by: Shuah Khan 
Acked-by: Luis Chamberlain 
Signed-off-by: Anirudh Rayabharam 
Link: https://lore.kernel.org/r/20210728085107.4141-3-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman

firmware_loader: use -ETIMEDOUT instead of -EAGAIN in fw_load_sysfs_fallback

2021-08-12T11:19:41+00:00

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 
Reviewed-by: Shuah Khan 
Acked-by: Luis Chamberlain 
Signed-off-by: Anirudh Rayabharam 
Cc: stable 
Link: https://lore.kernel.org/r/20210728085107.4141-2-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman

firmware: fix a double abort case with fw_load_sysfs_fallback

2020-04-17T08:48:42+00:00

[ Upstream commit bcfbd3523f3c6eea51a74d217a8ebc5463bcb7f4 ]

fw_sysfs_wait_timeout may return err with -ENOENT
at fw_load_sysfs_fallback and firmware is already
in abort status, no need to abort again, so skip it.

This issue is caused by concurrent situation like below:
when thread 1# wait firmware loading, thread 2# may write
-1 to abort loading and wakeup thread 1# before it timeout.
so wait_for_completion_killable_timeout of thread 1# would
return remaining time which is != 0 with fw_st->status
FW_STATUS_ABORTED.And the results would be converted into
err -ENOENT in __fw_state_wait_common and transfered to
fw_load_sysfs_fallback in thread 1#.
The -ENOENT means firmware status is already at ABORTED,
so fw_load_sysfs_fallback no need to get mutex to abort again.
-----------------------------
thread 1#,wait for loading
fw_load_sysfs_fallback
 ->fw_sysfs_wait_timeout
    ->__fw_state_wait_common
       ->wait_for_completion_killable_timeout

in __fw_state_wait_common,
...
93    ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
94    if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
95       return -ENOENT;
96    if (!ret)
97	 return -ETIMEDOUT;
98
99    return ret < 0 ? ret : 0;
-----------------------------
thread 2#, write -1 to abort loading
firmware_loading_store
 ->fw_load_abort
   ->__fw_load_abort
     ->fw_state_aborted
       ->__fw_state_set
         ->complete_all

in __fw_state_set,
...
111    if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
112       complete_all(&fw_st->completion);
-------------------------------------------
BTW,the double abort issue would not cause kernel panic or create an issue,
but slow down it sometimes.The change is just a minor optimization.

Signed-off-by: Junyong Sun 
Acked-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/1583202968-28792-1-git-send-email-sunjunyong@xiaomi.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

firmware: improve LSM/IMA security behaviour

2019-07-21T07:03:03+00:00

commit 2472d64af2d3561954e2f05365a67692bb852f2a upstream.

The firmware loader queries if LSM/IMA permits it to load firmware
via the sysfs fallback. Unfortunately, the code does the opposite:
it expressly permits sysfs fw loading if security_kernel_load_data(
LOADING_FIRMWARE) returns -EACCES. This happens because a
zero-on-success return value is cast to a bool that's true on success.

Fix the return value handling so we get the correct behaviour.

Fixes: 6e852651f28e ("firmware: add call to LSM hook before firmware sysfs fallback")
Cc: Stable 
Cc: Mimi Zohar 
Cc: Kees Cook 
To: Luis Chamberlain 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sven Van Asbroeck 
Reviewed-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

firmware: Always initialize the fw_priv list object

2018-09-30T15:49:55+00:00

When freeing the fw_priv the item is taken off the list. This causes an
oops in the FW_OPT_NOCACHE case as the list object is not initialized.

Make sure to initialize the list object regardless of this flag.

Fixes: 422b3db2a503 ("firmware: Fix security issue with request_firmware_into_buf()")
Cc: stable@vger.kernel.org
Cc: Rishabh Bhatnagar 
Signed-off-by: Bjorn Andersson 
Reviewed-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

firmware: Fix security issue with request_firmware_into_buf()

2018-09-12T07:31:00+00:00

When calling request_firmware_into_buf() with the FW_OPT_NOCACHE flag
it is expected that firmware is loaded into buffer from memory.
But inside alloc_lookup_fw_priv every new firmware that is loaded is
added to the firmware cache (fwc) list head. So if any driver requests
a firmware that is already loaded the code iterates over the above
mentioned list and it can end up giving a pointer to other device driver's
firmware buffer.
Also the existing copy may either be modified by drivers, remote processors
or even freed. This causes a potential security issue with batched requests
when using request_firmware_into_buf.

Fix alloc_lookup_fw_priv to not add to the fwc head list if FW_OPT_NOCACHE
is set, and also don't do the lookup in the list.

Fixes: 0e742e9275 ("firmware: provide infrastructure to make fw caching optional")
[mcgrof: broken since feature introduction on v4.8]

Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Vikram Mulukutla 
Signed-off-by: Rishabh Bhatnagar 
Signed-off-by: Luis Chamberlain 
Signed-off-by: Greg Kroah-Hartman

mm: provide a fallback for PAGE_KERNEL_RO for architectures

2018-08-17T23:20:29+00:00

Some architectures do not define certain PAGE_KERNEL_* flags, this is
either because:

 a) The way to implement some of these flags is *not yet ported*, or
 b) The architecture *has no way* to describe them

Over time we have accumulated a few PAGE_KERNEL_* fallback workarounds
for architectures in the kernel which do not define them using
*relatively safe* equivalents.  Move these scattered fallback hacks into
asm-generic.

We start off with PAGE_KERNEL_RO using PAGE_KERNEL as a fallback.  This
has been in place on the firmware loader for years.  Move the fallback
into the respective asm-generic header.

Link: http://lkml.kernel.org/r/20180510185507.2439-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez 
Reviewed-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Greg Kroah-Hartman 
Cc: Matthew Wilcox 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

firmware: add call to LSM hook before firmware sysfs fallback

2018-07-16T19:31:57+00:00

Add an LSM hook prior to allowing firmware sysfs fallback loading.

Signed-off-by: Mimi Zohar 
Acked-by: Luis R. Rodriguez 
Reviewed-by: Kees Cook 
Signed-off-by: James Morris

treewide: Use array_size() in vmalloc()

2018-06-12T23:19:22+00:00

The vmalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

        vmalloc(a * b)

with:
        vmalloc(array_size(a, b))

as well as handling cases of:

        vmalloc(a * b * c)

with:

        vmalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

        vmalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  vmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  vmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  vmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

  vmalloc(
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  vmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  vmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  vmalloc(C1 * C2 * C3, ...)
|
  vmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
  vmalloc(C1 * C2, ...)
|
  vmalloc(
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook