linux-stable.git/include, branch v5.4.86

xen/xenbus: Count pending messages for each watch

2020-12-30T10:51:47+00:00

commit 3dc86ca6b4c8cfcba9da7996189d1b5a358a94fc upstream.

This commit adds a counter of pending messages for each watch in the
struct.  It is used to skip unnecessary pending messages lookup in
'unregister_xenbus_watch()'.  It could also be used in 'will_handle'
callback.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park 
Reported-by: Michael Kurth 
Reported-by: Pawel Wieczorkiewicz 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()

2020-12-30T10:51:46+00:00

commit 2e85d32b1c865bec703ce0c962221a5e955c52c2 upstream.

Some code does not directly make 'xenbus_watch' object and call
'register_xenbus_watch()' but use 'xenbus_watch_path()' instead.  This
commit adds support of 'will_handle' callback in the
'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park 
Reported-by: Michael Kurth 
Reported-by: Pawel Wieczorkiewicz 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/xenbus: Allow watches discard events before queueing

2020-12-30T10:51:46+00:00

commit fed1755b118147721f2c87b37b9d66e62c39b668 upstream.

If handling logics of watch events are slower than the events enqueue
logic and the events can be created from the guests, the guests could
trigger memory pressure by intensively inducing the events, because it
will create a huge number of pending events that exhausting the memory.

Fortunately, some watch events could be ignored, depending on its
handler callback.  For example, if the callback has interest in only one
single path, the watch wouldn't want multiple pending events.  Or, some
watches could ignore events to same path.

To let such watches to volutarily help avoiding the memory pressure
situation, this commit introduces new watch callback, 'will_handle'.  If
it is not NULL, it will be called for each new event just before
enqueuing it.  Then, if the callback returns false, the event will be
discarded.  No watch is using the callback for now, though.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park 
Reported-by: Michael Kurth 
Reported-by: Pawel Wieczorkiewicz 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

binder: add flag to clear buffer on txn complete

2020-12-30T10:51:35+00:00

commit 0f966cba95c78029f491b433ea95ff38f414a761 upstream.

Add a per-transaction flag to indicate that the buffer
must be cleared when the transaction is complete to
prevent copies of sensitive data from being preserved
in memory.

Signed-off-by: Todd Kjos 
Link: https://lore.kernel.org/r/20201120233743.3617529-1-tkjos@google.com
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup()

2020-12-30T10:51:32+00:00

commit 7482c5cb90e5a7f9e9e12dd154d405e0219656e3 upstream.

The idea behind acpi_pm_set_bridge_wakeup() was to allow bridges to
be reference counted for wakeup enabling, because they may be enabled
to signal wakeup on behalf of their subordinate devices and that
may happen for multiple times in a row, whereas for the other devices
it only makes sense to enable wakeup signaling once.

However, this becomes problematic if the bridge itself is suspended,
because it is treated as a "regular" device in that case and the
reference counting doesn't work.

For instance, suppose that there are two devices below a bridge and
they both can signal wakeup.  Every time one of them is suspended,
wakeup signaling is enabled for the bridge, so when they both have
been suspended, the bridge's wakeup reference counter value is 2.

Say that the bridge is suspended subsequently and acpi_pci_wakeup()
is called for it.  Because the bridge can signal wakeup, that
function will invoke acpi_pm_set_device_wakeup() to configure it
and __acpi_pm_set_device_wakeup() will be called with the last
argument equal to 1.  This causes __acpi_device_wakeup_enable()
invoked by it to omit the reference counting, because the reference
counter of the target device (the bridge) is 2 at that time.

Now say that the bridge resumes and one of the device below it
resumes too, so the bridge's reference counter becomes 0 and
wakeup signaling is disabled for it, but there is still the other
suspended device which may need the bridge to signal wakeup on its
behalf and that is not going to work.

To address this scenario, use wakeup enable reference counting for
all devices, not just for bridges, so drop the last argument from
__acpi_device_wakeup_enable() and __acpi_pm_set_device_wakeup(),
which causes acpi_pm_set_device_wakeup() and
acpi_pm_set_bridge_wakeup() to become identical, so drop the latter
and use the former instead of it everywhere.

Fixes: 1ba51a7c1496 ("ACPI / PCI / PM: Rework acpi_pci_propagate_wakeup()")
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg 
Acked-by: Bjorn Helgaas 
Cc: 4.14+  # 4.14+
Signed-off-by: Greg Kroah-Hartman

fix namespaced fscaps when !CONFIG_SECURITY

2020-12-30T10:51:30+00:00

[ Upstream commit ed9b25d1970a4787ac6a39c2091e63b127ecbfc1 ]

Namespaced file capabilities were introduced in 8db6c34f1dbc .
When userspace reads an xattr for a namespaced capability, a
virtualized representation of it is returned if the caller is
in a user namespace owned by the capability's owning rootid.
The function which performs this virtualization was not hooked
up if CONFIG_SECURITY=n.  Therefore in that case the original
xattr was shown instead of the virtualized one.

To test this using libcap-bin (*1),

$ v=$(mktemp)
$ unshare -Ur setcap cap_sys_admin-eip $v
$ unshare -Ur setcap -v cap_sys_admin-eip $v
/tmp/tmp.lSiIFRvt8Y: OK

"setcap -v" verifies the values instead of setting them, and
will check whether the rootid value is set.  Therefore, with
this bug un-fixed, and with CONFIG_SECURITY=n, setcap -v will
fail:

$ v=$(mktemp)
$ unshare -Ur setcap cap_sys_admin=eip $v
$ unshare -Ur setcap -v cap_sys_admin=eip $v
nsowner[got=1000, want=0],/tmp/tmp.HHDiOOl9fY differs in []

Fix this bug by calling cap_inode_getsecurity() in
security_inode_getsecurity() instead of returning
-EOPNOTSUPP, when CONFIG_SECURITY=n.

*1 - note, if libcap is too old for getcap to have the '-n'
option, then use verify-caps instead.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209689
Cc: Hervé Guillemet 
Acked-by: Casey Schaufler 
Signed-off-by: Serge Hallyn 
Signed-off-by: Andrew G. Morgan 
Signed-off-by: James Morris 
Signed-off-by: Sasha Levin

seq_buf: Avoid type mismatch for seq_buf_init

2020-12-30T10:51:21+00:00

[ Upstream commit d9a9280a0d0ae51dc1d4142138b99242b7ec8ac6 ]

Building with W=2 prints a number of warnings for one function that
has a pointer type mismatch:

linux/seq_buf.h: In function 'seq_buf_init':
linux/seq_buf.h:35:12: warning: pointer targets in assignment from 'unsigned char *' to 'char *' differ in signedness [-Wpointer-sign]

Change the type in the function prototype according to the type in
the structure.

Link: https://lkml.kernel.org/r/20201026161108.3707783-1-arnd@kernel.org

Fixes: 9a7777935c34 ("tracing: Convert seq_buf fields to be like seq_file fields")
Reviewed-by: Cezary Rojewski 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Sasha Levin

SUNRPC: xprt_load_transport() needs to support the netid "rdma6"

2020-12-30T10:51:16+00:00

[ Upstream commit d5aa6b22e2258f05317313ecc02efbb988ed6d38 ]

According to RFC5666, the correct netid for an IPv6 addressed RDMA
transport is "rdma6", which we've supported as a mount option since
Linux-4.7. The problem is when we try to load the module "xprtrdma6",
that will fail, since there is no modulealias of that name.

Fixes: 181342c5ebe8 ("xprtrdma: Add rdma6 option to support NFS/RDMA IPv6")
Signed-off-by: Trond Myklebust 
Signed-off-by: Sasha Levin

media: v4l2-fwnode: Return -EINVAL for invalid bus-type

2020-12-30T10:51:08+00:00

[ Upstream commit 69baf338fc16a4d55c78da8874ce3f06feb38c78 ]

Return -EINVAL if invalid bus-type is detected while parsing endpoints.

Fixes: 26c1126c9b56 ("media: v4l: fwnode: Use media bus type for bus parser selection")
Signed-off-by: Lad Prabhakar 
Signed-off-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin

crypto: af_alg - avoid undefined behavior accessing salg_name

2020-12-30T10:51:00+00:00

commit 92eb6c3060ebe3adf381fd9899451c5b047bb14d upstream.

Commit 3f69cc60768b ("crypto: af_alg - Allow arbitrarily long algorithm
names") made the kernel start accepting arbitrarily long algorithm names
in sockaddr_alg.  However, the actual length of the salg_name field
stayed at the original 64 bytes.

This is broken because the kernel can access indices >= 64 in salg_name,
which is undefined behavior -- even though the memory that is accessed
is still located within the sockaddr structure.  It would only be
defined behavior if the array were properly marked as arbitrary-length
(either by making it a flexible array, which is the recommended way
these days, or by making it an array of length 0 or 1).

We can't simply change salg_name into a flexible array, since that would
break source compatibility with userspace programs that embed
sockaddr_alg into another struct, or (more commonly) declare a
sockaddr_alg like 'struct sockaddr_alg sa = { .salg_name = "foo" };'.

One solution would be to change salg_name into a flexible array only
when '#ifdef __KERNEL__'.  However, that would keep userspace without an
easy way to actually use the longer algorithm names.

Instead, add a new structure 'sockaddr_alg_new' that has the flexible
array field, and expose it to both userspace and the kernel.
Make the kernel use it correctly in alg_bind().

This addresses the syzbot report
"UBSAN: array-index-out-of-bounds in alg_bind"
(https://syzkaller.appspot.com/bug?extid=92ead4eb8e26a26d465e).

Reported-by: syzbot+92ead4eb8e26a26d465e@syzkaller.appspotmail.com
Fixes: 3f69cc60768b ("crypto: af_alg - Allow arbitrarily long algorithm names")
Cc:  # v4.12+
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman