linux_dsm_epyc7002/kernel
Eric W. Biederman d1e7fd6462 signal: Extend exec_id to 64bits
Replace the 32bit exec_id with a 64bit exec_id to make it impossible
to wrap the exec_id counter.  With care an attacker can cause exec_id
wrap and send arbitrary signals to a newly exec'd parent.  This
bypasses the signal sending checks if the parent changes their
credentials during exec.

The severity of this problem can been seen that in my limited testing
of a 32bit exec_id it can take as little as 19s to exec 65536 times.
Which means that it can take as little as 14 days to wrap a 32bit
exec_id.  Adam Zabrocki has succeeded wrapping the self_exe_id in 7
days.  Even my slower timing is in the uptime of a typical server.
Which means self_exec_id is simply a speed bump today, and if exec
gets noticably faster self_exec_id won't even be a speed bump.

Extending self_exec_id to 64bits introduces a problem on 32bit
architectures where reading self_exec_id is no longer atomic and can
take two read instructions.  Which means that is is possible to hit
a window where the read value of exec_id does not match the written
value.  So with very lucky timing after this change this still
remains expoiltable.

I have updated the update of exec_id on exec to use WRITE_ONCE
and the read of exec_id in do_notify_parent to use READ_ONCE
to make it clear that there is no locking between these two
locations.

Link: https://lore.kernel.org/kernel-hardening/20200324215049.GA3710@pi3.com.pl
Fixes: 2.3.23pre2
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-04-01 12:04:24 -05:00
..
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-08 17:15:08 -08:00
cgroup Merge branch 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2020-02-10 17:07:05 -08:00
configs
debug Revert "kdb: Get rid of confusing diag msg from "rd" if current task has no regs" 2020-02-06 11:40:09 +00:00
dma lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr 2019-12-04 19:44:13 -08:00
events perf: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
gcov Revert "um: Enable CONFIG_CONSTRUCTORS" 2020-01-19 22:42:06 +01:00
irq A set of fixes for X86: 2020-02-09 12:11:12 -08:00
livepatch New tracing features: 2019-11-27 11:42:01 -08:00
locking proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
power ACPI: PM: s2idle: Avoid possible race related to the EC GPE 2020-02-11 10:11:02 +01:00
printk printk: fix exclusive_console replaying 2020-01-02 16:15:04 +01:00
rcu rcu: Forgive slow expedited grace periods at boot time 2020-01-25 12:00:40 -08:00
sched Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-02-15 12:51:22 -08:00
time Two small fixes for the time(r) subsystem: 2020-02-09 12:00:12 -08:00
trace Various fixes: 2020-02-11 16:39:18 -08:00
.gitignore
acct.c acct: stop using get_seconds() 2019-12-18 18:07:31 +01:00
async.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
audit_fsnotify.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
audit_tree.c
audit_watch.c audit_get_nd(): don't unlock parent too early 2019-11-10 11:56:55 -05:00
audit.c audit: Add __rcu annotation to RCU pointer 2019-12-09 15:19:03 -05:00
audit.h audit/stable-5.3 PR 20190702 2019-07-08 18:55:42 -07:00
auditfilter.c audit/stable-5.3 PR 20190702 2019-07-08 18:55:42 -07:00
auditsc.c Revert "bpf: Emit audit messages upon successful prog load and unload" 2019-11-23 09:56:02 -08:00
backtracetest.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
bounds.c
capability.c
compat.c y2038: itimer: compat handling to itimer.c 2019-11-15 14:38:30 +01:00
configs.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
context_tracking.c context_tracking: Rename context_tracking_is_enabled() => context_tracking_enabled() 2019-10-29 10:01:12 +01:00
cpu_pm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
cpu.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
crash_core.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
crash_dump.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
cred.c kernel: doc: remove outdated comment cred.c 2020-03-25 10:04:01 -05:00
delayacct.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25 2019-05-21 11:52:39 +02:00
dma.c
elfcore.c kernel/elfcore.c: include proper prototypes 2019-09-25 17:51:39 -07:00
exec_domain.c
exit.c proc: Use a list of inodes to flush from proc 2020-02-24 10:14:44 -06:00
extable.c bpf: Allow to resolve bpf trampoline and dispatcher in unwind 2020-01-25 07:12:40 -08:00
fail_function.c fail_function: no need to check return value of debugfs_create functions 2019-06-03 15:49:06 +02:00
fork.c exec: Fix a deadlock in strace 2020-03-25 10:04:00 -05:00
freezer.c Revert "libata, freezer: avoid block device removal while system is frozen" 2019-10-06 09:11:37 -06:00
futex.c futex: Fix kernel-doc notation warning 2020-01-09 13:23:40 +01:00
gen_kheaders.sh kheaders: explain why include/config/autoconf.h is excluded from md5sum 2019-11-11 20:10:01 +09:00
groups.c
hung_task.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
iomem.c mm/nvdimm: add is_ioremap_addr and use that to check ioremap address 2019-07-12 11:05:40 -07:00
irq_work.c irq_work: Fix IRQ_WORK_BUSY bit clearing 2019-11-15 10:48:37 +01:00
jump_label.c jump_label: Don't warn on __exit jump entries 2019-08-29 15:10:10 +01:00
kallsyms.c Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
kcmp.c kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
Kconfig.freezer treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.hz treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.locks sched/rt, locking: Use CONFIG_PREEMPTION 2019-12-08 14:37:36 +01:00
Kconfig.preempt sched/Kconfig: Fix spelling mistake in user-visible help text 2019-11-12 11:35:32 +01:00
kcov.c kcov: remote coverage support 2019-12-04 19:44:14 -08:00
kexec_core.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_elf.c kexec_elf: support 32 bit ELF files 2019-09-06 23:58:44 +02:00
kexec_file.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_internal.h kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kheaders.c kheaders: Move from proc to sysfs 2019-05-24 20:16:01 +02:00
kmod.c
kprobes.c kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic 2020-01-09 12:40:13 +01:00
ksysfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 170 2019-05-30 11:26:39 -07:00
kthread.c kthread: make __kthread_queue_delayed_work static 2019-10-16 09:20:58 -07:00
latencytop.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
Makefile kcov: ignore fault-inject and stacktrace 2020-01-31 10:30:41 -08:00
module_signature.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module_signing.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module-internal.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
module.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
notifier.c kernel/notifier.c: remove blocking_notifier_chain_cond_register() 2019-12-04 19:44:12 -08:00
nsproxy.c ns: Introduce Time Namespace 2020-01-14 12:20:48 +01:00
padata.c padata: update documentation 2019-12-11 16:37:02 +08:00
panic.c locking/refcount: Remove unused 'refcount_error_report()' function 2019-11-25 09:15:42 +01:00
params.c lockdown: Lock down module params that specify hardware parameters (eg. ioport) 2019-08-19 21:54:16 -07:00
pid_namespace.c pid: Improve the comment about waiting in zap_pid_ns_processes 2020-02-28 16:29:12 -06:00
pid.c pidfd: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
profile.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ptrace.c ptrace: reintroduce usage of subjective credentials in ptrace_has_cap() 2020-01-18 13:51:39 +01:00
range.c
reboot.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
relay.c
resource.c mm/memory_hotplug.c: use PFN_UP / PFN_DOWN in walk_system_ram_range() 2019-09-24 15:54:09 -07:00
rseq.c rseq: Reject unknown flags on rseq unregister 2019-12-25 10:41:20 +01:00
seccomp.c seccomp: Check that seccomp_notif is zeroed out by the user 2020-01-02 13:03:45 -08:00
signal.c signal: Extend exec_id to 64bits 2020-04-01 12:04:24 -05:00
smp.c smp: Remove superfluous cond_func check in smp_call_function_many_cond() 2020-01-28 15:43:00 +01:00
smpboot.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
smpboot.h
softirq.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 11:01:13 -07:00
stackleak.c
stacktrace.c stacktrace: Get rid of unneeded '!!' pattern 2019-11-11 10:30:59 +01:00
stop_machine.c stop_machine: Make stop_cpus() static 2020-01-17 10:19:21 +01:00
sys_ni.c y2038: allow disabling time32 system calls 2019-11-15 14:38:30 +01:00
sys.c prctl: PR_{G,S}ET_IO_FLUSHER to support controlling memory reclaim 2020-01-28 10:09:51 +01:00
sysctl_binary.c sysctl: Remove the sysctl system call 2019-11-26 13:03:56 -06:00
sysctl-test.c kunit: allow kunit tests to be loaded as a module 2020-01-09 16:42:29 -07:00
sysctl.c rcu: Make PREEMPT_RCU be a modifier to TREE_RCU 2019-12-09 12:37:51 -08:00
task_work.c
taskstats.c taskstats: fix data-race 2019-12-04 15:18:39 +01:00
test_kprobes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25 2019-05-21 11:52:39 +02:00
torture.c torture: Remove exporting of internal functions 2019-08-01 14:30:22 -07:00
tracepoint.c The main changes in this release include: 2019-07-18 11:51:00 -07:00
tsacct.c tsacct: add 64-bit btime field 2019-12-18 18:07:31 +01:00
ucount.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
uid16.c
uid16.h
umh.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
up.c smp/up: Make smp_call_function_single() match SMP semantics 2020-02-07 15:34:12 +01:00
user_namespace.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
user-return-notifier.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
user.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
utsname_sysctl.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
utsname.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
watchdog_hld.c
watchdog.c watchdog/softlockup: Enforce that timestamp is valid on boot 2020-01-17 11:19:22 +01:00
workqueue_internal.h
workqueue.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00