linux-stable.git/include/linux, branch v5.4.3

rfkill: allocate static minor

2019-12-13T07:43:18+00:00

commit 8670b2b8b029a6650d133486be9d2ace146fd29a upstream.

udev has a feature of creating /dev/ device-nodes if it finds
a devnode: modalias. This allows for auto-loading of modules that
provide the node. This requires to use a statically allocated minor
number for misc character devices.

However, rfkill uses dynamic minor numbers and prevents auto-loading
of the module. So allocate the next static misc minor number and use
it for rfkill.

Signed-off-by: Marcel Holtmann 
Link: https://lore.kernel.org/r/20191024174042.19851-1-marcel@holtmann.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

jbd2: Fix possible overflow in jbd2_log_space_left()

2019-12-13T07:42:53+00:00

commit add3efdd78b8a0478ce423bb9d4df6bd95e8b335 upstream.

When number of free space in the journal is very low, the arithmetic in
jbd2_log_space_left() could underflow resulting in very high number of
free blocks and thus triggering assertion failure in transaction commit
code complaining there's not enough space in the journal:

J_ASSERT(journal->j_free > 1);

Properly check for the low number of free blocks.

CC: stable@vger.kernel.org
Reviewed-by: Theodore Ts'o 
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20191105164437.32602-1-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

kernfs: fix ino wrap-around detection

2019-12-13T07:42:53+00:00

commit e23f568aa63f64cd6b355094224cc9356c0f696b upstream.

When the 32bit ino wraps around, kernfs increments the generation
number to distinguish reused ino instances.  The wrap-around detection
tests whether the allocated ino is lower than what the cursor but the
cursor is pointing to the next ino to allocate so the condition never
triggers.

Fix it by remembering the last ino and comparing against that.

Signed-off-by: Tejun Heo 
Reviewed-by: Greg Kroah-Hartman 
Fixes: 4a3ef68acacf ("kernfs: implement i_generation")
Cc: Namhyung Kim 
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Greg Kroah-Hartman

net: skmsg: fix TLS 1.3 crash with full sk_msg

2019-12-04T21:31:01+00:00

[ Upstream commit 031097d9e079e40dce401031d1012e83d80eaf01 ]

TLS 1.3 started using the entry at the end of the SG array
for chaining-in the single byte content type entry. This mostly
works:

[ E E E E E E . . ]
  ^           ^
   start       end

                 E < content type
               /
[ E E E E E E C . ]
  ^           ^
   start       end

(Where E denotes a populated SG entry; C denotes a chaining entry.)

If the array is full, however, the end will point to the start:

[ E E E E E E E E ]
  ^
   start
   end

And we end up overwriting the start:

    E < content type
   /
[ C E E E E E E E ]
  ^
   start
   end

The sg array is supposed to be a circular buffer with start and
end markers pointing anywhere. In case where start > end
(i.e. the circular buffer has "wrapped") there is an extra entry
reserved at the end to chain the two halves together.

[ E E E E E E . . l ]

(Where l is the reserved entry for "looping" back to front.

As suggested by John, let's reserve another entry for chaining
SG entries after the main circular buffer. Note that this entry
has to be pointed to by the end entry so its position is not fixed.

Examples of full messages:

[ E E E E E E E E . l ]
  ^               ^
   start           end

   <---------------.
[ E E . E E E E E E l ]
      ^ ^
   end   start

Now the end will always point to an unused entry, so TLS 1.3
can always use it.

Fixes: 130b392c6cd6 ("net: tls: Add tls 1.3 support")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

futex: Add mutex around futex exit

2019-11-29T09:10:13+00:00

commit 3f186d974826847a07bc7964d79ec4eded475ad9 upstream.

The mutex will be used in subsequent changes to replace the busy looping of
a waiter when the futex owner is currently executing the exit cleanup to
prevent a potential live lock.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20191106224556.845798895@linutronix.de
Signed-off-by: Greg Kroah-Hartman

futex: Mark the begin of futex exit explicitly

2019-11-29T09:10:11+00:00

commit 18f694385c4fd77a09851fd301236746ca83f3cb upstream.

Instead of relying on PF_EXITING use an explicit state for the futex exit
and set it in the futex exit function. This moves the smp barrier and the
lock/unlock serialization into the futex code.

As with the DEAD state this is restricted to the exit path as exec
continues to use the same task struct.

This allows to simplify that logic in a next step.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20191106224556.539409004@linutronix.de
Signed-off-by: Greg Kroah-Hartman

futex: Split futex_mm_release() for exit/exec

2019-11-29T09:10:10+00:00

commit 150d71584b12809144b8145b817e83b81158ae5f upstream.

To allow separate handling of the futex exit state in the futex exit code
for exit and exec, split futex_mm_release() into two functions and invoke
them from the corresponding exit/exec_mm_release() callsites.

Preparatory only, no functional change.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20191106224556.332094221@linutronix.de
Signed-off-by: Greg Kroah-Hartman

exit/exec: Seperate mm_release()

2019-11-29T09:10:10+00:00

commit 4610ba7ad877fafc0a25a30c6c82015304120426 upstream.

mm_release() contains the futex exit handling. mm_release() is called from
do_exit()->exit_mm() and from exec()->exec_mm().

In the exit_mm() case PF_EXITING and the futex state is updated. In the
exec_mm() case these states are not touched.

As the futex exit code needs further protections against exit races, this
needs to be split into two functions.

Preparatory only, no functional change.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20191106224556.240518241@linutronix.de
Signed-off-by: Greg Kroah-Hartman

futex: Replace PF_EXITPIDONE with a state

2019-11-29T09:10:09+00:00

commit 3d4775df0a89240f671861c6ab6e8d59af8e9e41 upstream.

The futex exit handling relies on PF_ flags. That's suboptimal as it
requires a smp_mb() and an ugly lock/unlock of the exiting tasks pi_lock in
the middle of do_exit() to enforce the observability of PF_EXITING in the
futex code.

Add a futex_state member to task_struct and convert the PF_EXITPIDONE logic
over to the new state. The PF_EXITING dependency will be cleaned up in a
later step.

This prepares for handling various futex exit issues later.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20191106224556.149449274@linutronix.de
Signed-off-by: Greg Kroah-Hartman

futex: Move futex exit handling into futex code

2019-11-29T09:10:08+00:00

commit ba31c1a48538992316cc71ce94fa9cd3e7b427c0 upstream.

The futex exit handling is #ifdeffed into mm_release() which is not pretty
to begin with. But upcoming changes to address futex exit races need to add
more functionality to this exit code.

Split it out into a function, move it into futex code and make the various
futex exit functions static.

Preparatory only and no functional change.

Folded build fix from Borislav.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20191106224556.049705556@linutronix.de
Signed-off-by: Greg Kroah-Hartman