linux-stable.git/include/linux/signal.h, 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

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 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

signal: Pass pid type into do_send_sig_info

2018-07-21T17:57:35+00:00

This passes the information we already have at the call sight into
do_send_sig_info.  Ultimately allowing for better handling of signals
sent to a group of processes during fork.

Signed-off-by: "Eric W. Biederman"

signal: Pass pid type into group_send_sig_info

2018-07-21T17:57:35+00:00

This passes the information we already have at the call sight
into group_send_sig_info.  Ultimatelly allowing for to better handle
signals sent to a group of processes.

Signed-off-by: "Eric W. Biederman"

signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}

2018-04-27T00:51:14+00:00

Update the siginfo_layout function and enum siginfo_layout to represent
all of the possible field layouts of struct siginfo.

This allows the uses of siginfo_layout in um and arm64 where they are testing
for SIL_FAULT to be more accurate as this rules out the other cases.

Further this allows the switch statements on siginfo_layout to be simpler
if perhaps a little more wordy.  Making it easier to understand what is
actually going on.

As SIL_FAULT_BNDERR and SIL_FAULT_PKUERR are never expected to appear
in signalfd just treat them as SIL_FAULT.  To include them would take
20 extra bytes an pretty much fill up what is left of
signalfd_siginfo.

Signed-off-by: "Eric W. Biederman"

signal: Remove unnecessary ifdefs now that there is only one struct siginfo

2018-01-12T20:34:49+00:00

Remove HAVE_ARCH_SIGINFO_T
Remove __ARCH_SIGSYS

Signed-off-by: "Eric W. Biederman"

signal: Introduce clear_siginfo

2018-01-12T20:21:06+00:00

Unfortunately struct siginfo has holes both in the common part of the
structure, in the union members, and in the lack of padding of the
union members.  The result of those wholes is that the C standard does
not guarantee those bits will be initialized.  As struct siginfo is
for communication between the kernel and userspace that is a problem.

Add the helper function clear_siginfo that is guaranteed to clear all of
the bits in struct siginfo so when the structure is copied there is no danger
of copying old kernel data and causing a leak of information from kernel
space to userspace.

Signed-off-by: "Eric W. Biederman"

signal: Reduce copy_siginfo to just a memcpy

2018-01-12T20:21:06+00:00

The savings for copying just part of struct siginfo appears to be in the
noise on modern machines.  So remove this ``optimization'' and simplify the code.

At the same time mark the second parameter as constant so there is no confusion
as to which direction the copy will go.

This ensures that a fully initialized siginfo that is sent ends up as
a fully initialized siginfo on the signal queue.  This full initialization
ensures even confused code won't copy unitialized data to userspace, and
it prepares for turning copy_siginfo_to_user into a simple copy_to_user.

Signed-off-by: "Eric W. Biederman"