linux-stable.git/include, branch v5.4.136

drm: Return -ENOTTY for non-drm ioctls

2021-07-28T11:31:01+00:00

commit 3abab27c322e0f2acf981595aa8040c9164dc9fb upstream.

drm: Return -ENOTTY for non-drm ioctls

Return -ENOTTY from drm_ioctl() when userspace passes in a cmd number
which doesn't relate to the drm subsystem.

Glibc uses the TCGETS ioctl to implement isatty(), and without this
change isatty() returns it incorrectly returns true for drm devices.

To test run this command:
$ if [ -t 0 ]; then echo is a tty; fi < /dev/dri/card0
which shows "is a tty" without this patch.

This may also modify memory which the userspace application is not
expecting.

Signed-off-by: Charles Baylis 
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/YPG3IBlzaMhfPqCr@stando.fishzet.co.uk
Signed-off-by: Greg Kroah-Hartman

afs: Fix tracepoint string placement with built-in AFS

2021-07-28T11:30:58+00:00

[ Upstream commit 6c881ca0b3040f3e724eae513117ba4ddef86057 ]

To quote Alexey[1]:

    I was adding custom tracepoint to the kernel, grabbed full F34 kernel
    .config, disabled modules and booted whole shebang as VM kernel.

    Then did

	perf record -a -e ...

    It crashed:

	general protection fault, probably for non-canonical address 0x435f5346592e4243: 0000 [#1] SMP PTI
	CPU: 1 PID: 842 Comm: cat Not tainted 5.12.6+ #26
	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
	RIP: 0010:t_show+0x22/0xd0

    Then reproducer was narrowed to

	# cat /sys/kernel/tracing/printk_formats

    Original F34 kernel with modules didn't crash.

    So I started to disable options and after disabling AFS everything
    started working again.

    The root cause is that AFS was placing char arrays content into a
    section full of _pointers_ to strings with predictable consequences.

    Non canonical address 435f5346592e4243 is "CB.YFS_" which came from
    CM_NAME macro.

    Steps to reproduce:

	CONFIG_AFS=y
	CONFIG_TRACING=y

	# cat /sys/kernel/tracing/printk_formats

Fix this by the following means:

 (1) Add enum->string translation tables in the event header with the AFS
     and YFS cache/callback manager operations listed by RPC operation ID.

 (2) Modify the afs_cb_call tracepoint to print the string from the
     translation table rather than using the string at the afs_call name
     pointer.

 (3) Switch translation table depending on the service we're being accessed
     as (AFS or YFS) in the tracepoint print clause.  Will this cause
     problems to userspace utilities?

     Note that the symbolic representation of the YFS service ID isn't
     available to this header, so I've put it in as a number.  I'm not sure
     if this is the best way to do this.

 (4) Remove the name wrangling (CM_NAME) macro and put the names directly
     into the afs_call_type structs in cmservice.c.

Fixes: 8e8d7f13b6d5a9 ("afs: Add some tracepoints")
Reported-by: Alexey Dobriyan (SK hynix) 
Signed-off-by: David Howells 
Reviewed-by: Steven Rostedt (VMware) 
Reviewed-by: Marc Dionne 
cc: Andrew Morton 
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/YLAXfvZ+rObEOdc%2F@localhost.localdomain/ [1]
Link: https://lore.kernel.org/r/643721.1623754699@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/162430903582.2896199.6098150063997983353.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162609463957.3133237.15916579353149746363.stgit@warthog.procyon.org.uk/ # v1 (repost)
Link: https://lore.kernel.org/r/162610726860.3408253.445207609466288531.stgit@warthog.procyon.org.uk/ # v2
Signed-off-by: Sasha Levin

net: validate lwtstate->data before returning from skb_tunnel_info()

2021-07-25T12:35:15+00:00

commit 67a9c94317402b826fc3db32afc8f39336803d97 upstream.

skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.

Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811

CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
 dump_stack_lvl+0x56/0x7b
 print_address_description.constprop.8.cold.13+0x13/0x2ee
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 kasan_report.cold.14+0x83/0xdf
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 vxlan_get_route+0x418/0x4b0 [vxlan]
 [ ... ]
 vxlan_xmit_one+0x148b/0x32b0 [vxlan]
 [ ... ]
 vxlan_xmit+0x25c5/0x4780 [vxlan]
 [ ... ]
 dev_hard_start_xmit+0x1ae/0x6e0
 __dev_queue_xmit+0x1f39/0x31a0
 [ ... ]
 neigh_xmit+0x2f9/0x940
 mpls_xmit+0x911/0x1600 [mpls_iptunnel]
 lwtunnel_xmit+0x18f/0x450
 ip_finish_output2+0x867/0x2040
 [ ... ]

Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv6: fix return value of ip6_skb_dst_mtu

2021-07-25T12:35:14+00:00

commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream.

Commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.

Fixes: 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern 
Signed-off-by: Vadim Fedorenko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

x86/signal: Detect and prevent an alternate signal stack overflow

2021-07-20T14:10:49+00:00

[ Upstream commit 2beb4a53fc3f1081cedc1c1a198c7f56cc4fc60c ]

The kernel pushes context on to the userspace stack to prepare for the
user's signal handler. When the user has supplied an alternate signal
stack, via sigaltstack(2), it is easy for the kernel to verify that the
stack size is sufficient for the current hardware context.

Check if writing the hardware context to the alternate stack will exceed
it's size. If yes, then instead of corrupting user-data and proceeding with
the original signal handler, an immediate SIGSEGV signal is delivered.

Refactor the stack pointer check code from on_sig_stack() and use the new
helper.

While the kernel allows new source code to discover and use a sufficient
alternate signal stack size, this check is still necessary to protect
binaries with insufficient alternate signal stack size from data
corruption.

Fixes: c2bc11f10a39 ("x86, AVX-512: Enable AVX-512 States Context Switch")
Reported-by: Florian Weimer 
Suggested-by: Jann Horn 
Suggested-by: Andy Lutomirski 
Signed-off-by: Chang S. Bae 
Signed-off-by: Borislav Petkov 
Reviewed-by: Len Brown 
Acked-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20210518200320.17239-6-chang.seok.bae@intel.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=153531
Signed-off-by: Sasha Levin

NFS: nfs_find_open_context() may only select open files

2021-07-20T14:10:48+00:00

[ Upstream commit e97bc66377bca097e1f3349ca18ca17f202ff659 ]

If a file has already been closed, then it should not be selected to
support further I/O.

Signed-off-by: Trond Myklebust 
[Trond: Fix an invalid pointer deref reported by Colin Ian King]
Signed-off-by: Sasha Levin

scsi: iscsi: Fix conn use after free during resets

2021-07-20T14:10:43+00:00

[ Upstream commit ec29d0ac29be366450a7faffbcf8cba3a6a3b506 ]

If we haven't done a unbind target call we can race where
iscsi_conn_teardown wakes up the EH thread and then frees the conn while
those threads are still accessing the conn ehwait.

We can only do one TMF per session so this just moves the TMF fields from
the conn to the session. We can then rely on the
iscsi_session_teardown->iscsi_remove_session->__iscsi_unbind_session call
to remove the target and it's devices, and know after that point there is
no device or scsi-ml callout trying to access the session.

Link: https://lore.kernel.org/r/20210525181821.7617-14-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: iscsi: Add iscsi_cls_conn refcount helpers

2021-07-20T14:10:43+00:00

[ Upstream commit b1d19e8c92cfb0ded180ef3376c20e130414e067 ]

There are a couple places where we could free the iscsi_cls_conn while it's
still in use. This adds some helpers to get/put a refcount on the struct
and converts an exiting user. Subsequent commits will then use the helpers
to fix 2 bugs in the eh code.

Link: https://lore.kernel.org/r/20210525181821.7617-11-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

media: subdev: disallow ioctl for saa6588/davinci

2021-07-19T06:53:17+00:00

commit 0a7790be182d32b9b332a37cb4206e24fe94b728 upstream.

The saa6588_ioctl() function expects to get called from other kernel
functions with a 'saa6588_command' pointer, but I found nothing stops it
from getting called from user space instead, which seems rather dangerous.

The same thing happens in the davinci vpbe driver with its VENC_GET_FLD
command.

As a quick fix, add a separate .command() callback pointer for this
driver and change the two callers over to that.  This change can easily
get backported to stable kernels if necessary, but since there are only
two drivers, we may want to eventually replace this with a set of more
specialized callbacks in the long run.

Fixes: c3fda7f835b0 ("V4L/DVB (10537): saa6588: convert to v4l2_subdev.")
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

rq-qos: fix missed wake-ups in rq_qos_throttle try two

2021-07-19T06:53:16+00:00

commit 11c7aa0ddea8611007768d3e6b58d45dc60a19e1 upstream.

Commit 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle")
tried to fix a problem that a process could be sleeping in rq_qos_wait()
without anyone to wake it up. However the fix is not complete and the
following can still happen:

CPU1 (waiter1)		CPU2 (waiter2)		CPU3 (waker)
rq_qos_wait()		rq_qos_wait()
  acquire_inflight_cb() -> fails
			  acquire_inflight_cb() -> fails

						completes IOs, inflight
						  decreased
  prepare_to_wait_exclusive()
			  prepare_to_wait_exclusive()
  has_sleeper = !wq_has_single_sleeper() -> true as there are two sleepers
			  has_sleeper = !wq_has_single_sleeper() -> true
  io_schedule()		  io_schedule()

Deadlock as now there's nobody to wakeup the two waiters. The logic
automatically blocking when there are already sleepers is really subtle
and the only way to make it work reliably is that we check whether there
are some waiters in the queue when adding ourselves there. That way, we
are guaranteed that at least the first process to enter the wait queue
will recheck the waiting condition before going to sleep and thus
guarantee forward progress.

Fixes: 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20210607112613.25344-1-jack@suse.cz
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman