Eric W. Biederman
35634ffa17
signal: Always notice exiting tasks ...
Recently syzkaller was able to create unkillablle processes by
creating a timer that is delivered as a thread local signal on SIGHUP,
and receiving SIGHUP SA_NODEFERER. Ultimately causing a loop
failing to deliver SIGHUP but always trying.
Upon examination it turns out part of the problem is actually most of
the solution. Since 2.5 signal delivery has found all fatal signals,
marked the signal group for death, and queued SIGKILL in every threads
thread queue relying on signal->group_exit_code to preserve the
information of which was the actual fatal signal.
The conversion of all fatal signals to SIGKILL results in the
synchronous signal heuristic in next_signal kicking in and preferring
SIGHUP to SIGKILL. Which is especially problematic as all
fatal signals have already been transformed into SIGKILL.
Instead of dequeueing signals and depending upon SIGKILL to
be the first signal dequeued, first test if the signal group
has already been marked for death. This guarantees that
nothing in the signal queue can prevent a process that needs
to exit from exiting.
Cc: stable@vger.kernel.org
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Ref: ebf5ebe31d2c ("[PATCH] signal-fixes-2.5.59-A4")
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-02-07 08:59:50 -06:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
Merge branch 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2018-12-29 10:57:20 -08:00
kvm_config: add CONFIG_VIRTIO_MENU
2018-10-24 20:55:56 -04:00
kdb: use bool for binary state indicators
2018-12-30 08:31:52 +00:00
dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
2019-01-05 08:28:29 +01:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
genirq/affinity: Add is_managed to struct irq_affinity_desc
2018-12-19 11:32:08 +01:00
livepatch: Replace synchronize_sched() with synchronize_rcu()
2018-12-01 12:38:50 -08:00
kernel/locking/mutex.c: remove caller signal_pending branch predictions
2019-01-04 13:13:48 -08:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
rcutorture: Don't do busted forward-progress testing
2018-12-01 12:45:42 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
y2038: more syscalls and cleanups
2018-12-28 12:45:04 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
audit: remove duplicated include from audit.c
2018-12-14 12:09:30 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
kbuild: fix kernel/bounds.c 'W=1' warning
2018-10-31 08:54:14 -07:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
x86/speculation: Rework SMT state change
2018-11-28 11:57:07 +01:00
kernel/crash_core.c: print timestamp using time64_t
2018-08-22 10:52:47 -07:00
cred: export get_task_cred().
2018-12-19 13:52:44 -05:00
delayacct: track delays from thrashing cache pages
2018-10-26 16:26:32 -07:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
kernel/fail_function.c: remove meaningless null pointer check before debugfs_remove_recursive
2018-10-31 08:54:12 -07:00
fork: fix some -Wmissing-prototypes warnings
2019-01-04 13:13:47 -08:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
kernel/hung_task.c: break RCU locks based on jiffies
2019-01-04 13:13:45 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
kallsyms: reduce size a little on 64-bit
2018-09-10 22:54:33 +09:00
kconfig: warn no new line at end of file
2018-12-15 17:44:35 +09:00
kernel/kcov.c: mark write_comp_data() as notrace
2019-01-04 13:13:47 -08:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
kexec_file: kexec_walk_memblock() only walks a dedicated region at kdump
2018-12-06 14:38:50 +00:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 14:45:18 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
kbuild: change filechk to surround the given command with { }
2019-01-06 09:46:51 +09:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
jump_label: move 'asm goto' support test to Kconfig
2019-01-06 09:46:51 +09:00
modsign: use all trusted keys to verify module signature
2018-11-07 14:41:41 +01:00
padata: clean an indentation issue, remove extraneous space
2018-11-16 14:11:04 +08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
Fix failure path in alloc_pid()
2018-12-28 12:42:30 -08:00
signal: Use group_send_sig_info to kill all processes in a pid namespace
2018-09-16 16:08:25 +02:00
mm: remove include/linux/bootmem.h
2018-10-31 08:54:16 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
kernel/reboot.c: export pm_power_off_prepare
2018-09-11 16:13:24 +01:00
kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable
2018-12-28 12:11:49 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
seccomp: fix poor type promotion
2018-12-13 16:49:01 -08:00
signal: Always notice exiting tasks
2019-02-07 08:59:50 -06:00
smp,cpumask: introduce on_each_cpu_cond_mask
2018-10-09 16:51:11 +02:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-10-25 11:43:47 -07:00
stackleak: Mark stackleak_track_stack() as notrace
2018-12-05 19:31:44 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
y2038: socket: Add compat_sys_recvmmsg_time64
2018-12-18 16:13:04 +01:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
torture: Remove unnecessary "ret" variables
2018-12-01 12:45:35 -08:00
tracing: Replace synchronize_sched() and call_rcu_sched()
2018-11-27 09:21:41 -08:00
umh: Add command line to user mode helpers
2018-10-22 19:37:36 -07:00
smp,cpumask: introduce on_each_cpu_cond_mask
2018-10-09 16:51:11 +02:00
userns: use irqsave variant of refcount_dec_and_lock()
2018-08-22 10:52:47 -07:00
userns: also map extents in the reverse map to kernel IDs
2018-11-07 23:51:16 -06:00
sys: don't hold uts_sem while accessing userspace memory
2018-08-11 02:05:53 -05:00
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
workqueue: Replace call_rcu_sched() with call_rcu()
2018-11-27 09:21:44 -08:00
35634ffa17