linux-stable.git/kernel/signal.c, branch v4.19.4

signal: Guard against negative signal numbers in copy_siginfo_from_user32

2018-11-13T19:08:45+00:00

commit a36700589b85443e28170be59fa11c8a104130a5 upstream.

While fixing an out of bounds array access in known_siginfo_layout
reported by the kernel test robot it became apparent that the same bug
exists in siginfo_layout and affects copy_siginfo_from_user32.

The straight forward fix that makes guards against making this mistake
in the future and should keep the code size small is to just take an
unsigned signal number instead of a signed signal number, as I did to
fix known_siginfo_layout.

Cc: stable@vger.kernel.org
Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init

2018-11-13T19:08:38+00:00

[ Upstream commit 3597dfe01d12f570bc739da67f857fd222a3ea66 ]

Instead of playing whack-a-mole and changing SEND_SIG_PRIV to
SEND_SIG_FORCED throughout the kernel to ensure a pid namespace init
gets signals sent by the kernel, stop allowing a pid namespace init to
ignore SIGKILL or SIGSTOP sent by the kernel.  A pid namespace init is
only supposed to be able to ignore signals sent from itself and
children with SIG_DFL.

Fixes: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals")
Reviewed-by: Thomas Gleixner 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

signal: Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack

2018-11-13T19:08:25+00:00

[ Upstream commit 22839869f21ab3850fbbac9b425ccc4c0023926f ]

The sigaltstack(2) system call fails with -ENOMEM if the new alternative
signal stack is found to be smaller than SIGMINSTKSZ. On architectures
such as arm64, where the native value for SIGMINSTKSZ is larger than
the compat value, this can result in an unexpected error being reported
to a compat task. See, for example:

  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904385

This patch fixes the problem by extending do_sigaltstack to take the
minimum signal stack size as an additional parameter, allowing the
native and compat system call entry code to pass in their respective
values. COMPAT_SIGMINSTKSZ is just defined as SIGMINSTKSZ if it has not
been defined by the architecture.

Cc: Arnd Bergmann 
Cc: Dominik Brodowski 
Cc: "Eric W. Biederman" 
Cc: Andrew Morton 
Cc: Al Viro 
Cc: Oleg Nesterov 
Reported-by: Steve McIntyre 
Tested-by: Steve McIntyre <93sam@debian.org>
Signed-off-by: Will Deacon 
Signed-off-by: Catalin Marinas 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'akpm' (patches from Andrew)

2018-08-22T19:34:08+00:00

Merge more updates from Andrew Morton:

 - the rest of MM

 - procfs updates

 - various misc things

 - more y2038 fixes

 - get_maintainer updates

 - lib/ updates

 - checkpatch updates

 - various epoll updates

 - autofs updates

 - hfsplus

 - some reiserfs work

 - fatfs updates

 - signal.c cleanups

 - ipc/ updates

* emailed patches from Andrew Morton : (166 commits)
  ipc/util.c: update return value of ipc_getref from int to bool
  ipc/util.c: further variable name cleanups
  ipc: simplify ipc initialization
  ipc: get rid of ids->tables_initialized hack
  lib/rhashtable: guarantee initial hashtable allocation
  lib/rhashtable: simplify bucket_table_alloc()
  ipc: drop ipc_lock()
  ipc/util.c: correct comment in ipc_obtain_object_check
  ipc: rename ipcctl_pre_down_nolock()
  ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()
  ipc: reorganize initialization of kern_ipc_perm.seq
  ipc: compute kern_ipc_perm.id under the ipc lock
  init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE
  fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp
  adfs: use timespec64 for time conversion
  kernel/sysctl.c: fix typos in comments
  drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md
  fork: don't copy inconsistent signal handler state to child
  signal: make get_signal() return bool
  signal: make sigkill_pending() return bool
  ...

signal: make get_signal() return bool

2018-08-22T17:52:51+00:00

make get_signal() already behaves like a boolean function.  Let's actually
declare it as such too.

Link: http://lkml.kernel.org/r/20180602103653.18181-18-christian@brauner.io
Signed-off-by: Christian Brauner 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal: make sigkill_pending() return bool

2018-08-22T17:52:51+00:00

sigkill_pending() already behaves like a boolean function.  Let's actually
declare it as such too.

Link: http://lkml.kernel.org/r/20180602103653.18181-17-christian@brauner.io
Signed-off-by: Christian Brauner 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal: make legacy_queue() return bool

2018-08-22T17:52:51+00:00

legacy_queue() already behaves like a boolean function.  Let's actually
declare it as such too.

Link: http://lkml.kernel.org/r/20180602103653.18181-16-christian@brauner.io
Signed-off-by: Christian Brauner 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal: make wants_signal() return bool

2018-08-22T17:52:51+00:00

wants_signal() already behaves like a boolean function.  Let's actually
declare it as such too.

Link: http://lkml.kernel.org/r/20180602103653.18181-15-christian@brauner.io
Signed-off-by: Christian Brauner 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal: make flush_sigqueue_mask() void

2018-08-22T17:52:51+00:00

The return value of flush_sigqueue_mask() is never checked anywhere.

Link: http://lkml.kernel.org/r/20180602103653.18181-14-christian@brauner.io
Signed-off-by: Christian Brauner 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signal: make unhandled_signal() return bool

2018-08-22T17:52:51+00:00

unhandled_signal() already behaves like a boolean function.  Let's
actually declare it as such too.  All callers treat it as such too.

Link: http://lkml.kernel.org/r/20180602103653.18181-13-christian@brauner.io
Signed-off-by: Christian Brauner 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Kees Cook 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds