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9f255b632bf12c4dd7fc31caee89aa991ef75176
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Josh Poimboeuf 9f255b632b module: Fix livepatch/ftrace module text permissions race 
It's possible for livepatch and ftrace to be toggling a module's text
permissions at the same time, resulting in the following panic:

  BUG: unable to handle page fault for address: ffffffffc005b1d9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 3ea0c067 P4D 3ea0c067 PUD 3ea0e067 PMD 3cc13067 PTE 3b8a1061
  Oops: 0003 [#1] PREEMPT SMP PTI
  CPU: 1 PID: 453 Comm: insmod Tainted: G           O  K   5.2.0-rc1-a188339ca5 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
  RIP: 0010:apply_relocate_add+0xbe/0x14c
  Code: fa 0b 74 21 48 83 fa 18 74 38 48 83 fa 0a 75 40 eb 08 48 83 38 00 74 33 eb 53 83 38 00 75 4e 89 08 89 c8 eb 0a 83 38 00 75 43 <89> 08 48 63 c1 48 39 c8 74 2e eb 48 83 38 00 75 32 48 29 c1 89 08
  RSP: 0018:ffffb223c00dbb10 EFLAGS: 00010246
  RAX: ffffffffc005b1d9 RBX: 0000000000000000 RCX: ffffffff8b200060
  RDX: 000000000000000b RSI: 0000004b0000000b RDI: ffff96bdfcd33000
  RBP: ffffb223c00dbb38 R08: ffffffffc005d040 R09: ffffffffc005c1f0
  R10: ffff96bdfcd33c40 R11: ffff96bdfcd33b80 R12: 0000000000000018
  R13: ffffffffc005c1f0 R14: ffffffffc005e708 R15: ffffffff8b2fbc74
  FS:  00007f5f447beba8(0000) GS:ffff96bdff900000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffffffc005b1d9 CR3: 000000003cedc002 CR4: 0000000000360ea0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   klp_init_object_loaded+0x10f/0x219
   ? preempt_latency_start+0x21/0x57
   klp_enable_patch+0x662/0x809
   ? virt_to_head_page+0x3a/0x3c
   ? kfree+0x8c/0x126
   patch_init+0x2ed/0x1000 [livepatch_test02]
   ? 0xffffffffc0060000
   do_one_initcall+0x9f/0x1c5
   ? kmem_cache_alloc_trace+0xc4/0xd4
   ? do_init_module+0x27/0x210
   do_init_module+0x5f/0x210
   load_module+0x1c41/0x2290
   ? fsnotify_path+0x3b/0x42
   ? strstarts+0x2b/0x2b
   ? kernel_read+0x58/0x65
   __do_sys_finit_module+0x9f/0xc3
   ? __do_sys_finit_module+0x9f/0xc3
   __x64_sys_finit_module+0x1a/0x1c
   do_syscall_64+0x52/0x61
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The above panic occurs when loading two modules at the same time with
ftrace enabled, where at least one of the modules is a livepatch module:

CPU0					CPU1
klp_enable_patch()
  klp_init_object_loaded()
    module_disable_ro()
    					ftrace_module_enable()
					  ftrace_arch_code_modify_post_process()
				    	    set_all_modules_text_ro()
      klp_write_object_relocations()
        apply_relocate_add()
	  *patches read-only code* - BOOM

A similar race exists when toggling ftrace while loading a livepatch
module.

Fix it by ensuring that the livepatch and ftrace code patching
operations -- and their respective permissions changes -- are protected
by the text_mutex.

Link: http://lkml.kernel.org/r/ab43d56ab909469ac5d2520c5d944ad6d4abd476.1560474114.git.jpoimboe@redhat.com

Reported-by: Johannes Erdfelt <johannes@erdfelt.com>
Fixes: 444d13ff10 ("modules: add ro_after_init support")
Acked-by: Jessica Yu <jeyu@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 17:01:50 -04:00
..
bpf
bpf: fix undefined behavior in narrow load handling
2019-05-13 02:05:50 +02:00
cgroup
kernel/sched/psi.c: expose pressure metrics on root cgroup
2019-05-14 19:52:48 -07:00
configs
…
debug
kdb: Fix bound check compiler warning
2019-05-14 13:44:24 +01:00
dma
Merge tag 'dma-mapping-5.2' of git://git.infradead.org/users/hch/dma-mapping
2019-05-09 08:40:55 -07:00
events
mm/mmu_notifier: use correct mmu_notifier events for each invalidation
2019-05-14 09:47:49 -07:00
gcov
gcov: clang support
2019-05-14 19:52:51 -07:00
irq
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-19 10:58:45 -07:00
livepatch
module: Fix livepatch/ftrace module text permissions race
2019-06-14 17:01:50 -04:00
locking
locking/rwsem: Prevent decrement of reader count before increment
2019-05-07 08:46:46 +02:00
power
Merge tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
2019-05-06 19:40:31 -07:00
printk
panic: add an option to replay all the printk message in buffer
2019-05-18 15:52:26 -07:00
rcu
Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
2019-05-15 16:05:47 -07:00
sched
kernel/sched/psi.c: expose pressure metrics on root cgroup
2019-05-14 19:52:48 -07:00
time
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-16 11:00:20 -07:00
trace
module: Fix livepatch/ftrace module text permissions race
2019-06-14 17:01:50 -04:00
.gitignore
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
acct.c
acct_on(): don't mess with freeze protection
2019-04-04 21:04:13 -04:00
async.c
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
audit_fsnotify.c
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
audit_tree.c
fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
2019-04-26 13:51:03 -04:00
audit_watch.c
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
audit.c
audit: connect LOGIN record to its syscall record
2019-03-20 20:57:48 -04:00
audit.h
audit_compare_dname_path(): switch to const struct qstr *
2019-04-28 20:33:43 -04:00
auditfilter.c
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-05-07 20:03:32 -07:00
auditsc.c
Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-05-07 20:03:32 -07:00
backtracetest.c
backtrace-test: Simplify stack trace handling
2019-04-29 12:37:47 +02:00
bounds.c
…
capability.c
LSM: add SafeSetID module that gates setid calls
2019-01-25 11:22:43 -08:00
compat.c
kernel/compat.c: mark expected switch fall-throughs
2019-05-15 08:16:14 -07:00
configs.c
kernel/configs: use .incbin directive to embed config_data.gz
2019-03-07 18:32:02 -08:00
context_tracking.c
…
cpu_pm.c
…
cpu.c
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2019-05-06 14:50:46 -07:00
crash_core.c
kexec: export PG_offline to VMCOREINFO
2019-03-05 21:07:14 -08:00
crash_dump.c
…
cred.c
SELinux: Remove cred security blob poisoning
2019-01-08 13:18:44 -08:00
delayacct.c
…
dma.c
…
elfcore.c
…
exec_domain.c
…
exit.c
mm: change mm_update_next_owner() to update mm->owner with WRITE_ONCE
2019-05-14 19:52:47 -07:00
extable.c
…
fail_function.c
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
fork.c
kernel/latencytop.c: rename clear_all_latency_tracing to clear_tsk_latency_tracing
2019-05-14 19:52:49 -07:00
freezer.c
…
futex.c
mm/gup: change GUP fast to use flags rather than a write 'bool'
2019-05-14 09:47:46 -07:00
gen_ikh_data.sh
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
groups.c
…
hung_task.c
kernel/hung_task.c: Use continuously blocked time when reporting.
2019-03-07 18:31:59 -08:00
iomem.c
mm/resource: Use resource_overlaps() to simplify region_intersects()
2019-04-19 12:59:36 +02:00
irq_work.c
irq_work: Do not raise an IPI when queueing work on the local CPU
2019-04-18 14:07:52 +02:00
jump_label.c
locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred()
2019-04-29 08:29:21 +02:00
kallsyms.c
bpf: Add module name [bpf] to ksymbols for bpf programs
2019-01-21 17:38:56 -03:00
kcmp.c
…
Kconfig.freezer
…
Kconfig.hz
…
Kconfig.locks
Merge tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
2019-05-06 16:57:52 -07:00
Kconfig.preempt
kconfig: warn no new line at end of file
2018-12-15 17:44:35 +09:00
kcov.c
kcov: convert kcov.refcount to refcount_t
2019-03-07 18:32:02 -08:00
kexec_core.c
power/suspend: Add function to disable secondaries for suspend
2019-05-03 19:42:41 +02:00
kexec_file.c
mm: memblock: make keeping memblock memory opt-in rather than opt-out
2019-05-14 09:47:50 -07:00
kexec_internal.h
…
kexec.c
…
kheaders.c
Provide in-kernel headers to make extending kernel easier
2019-04-29 16:48:03 +02:00
kmod.c
…
kprobes.c
kprobes: Fix error check when reusing optimized probes
2019-04-16 09:38:16 +02:00
ksysfs.c
…
kthread.c
include/: refactor headers to allow kthread.h inclusion in psi_types.h
2019-05-14 19:52:48 -07:00
latencytop.c
kernel/latencytop.c: rename clear_all_latency_tracing to clear_tsk_latency_tracing
2019-05-14 19:52:49 -07:00
Makefile
kernel/Makefile: don't assume that kernel/gen_ikh_data.sh is executable
2019-05-14 19:52:47 -07:00
memremap.c
kernel/memremap.c: remove the unused device_private_entry_fault() export
2019-05-14 09:47:51 -07:00
module_signing.c
…
module-internal.h
kallsyms: store type information in its own array
2019-03-28 15:00:37 +01:00
module.c
Merge tag 'modules-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
2019-05-14 10:55:54 -07:00
notifier.c
kernel/notifier.c: double register detection
2019-05-14 19:52:49 -07:00
nsproxy.c
…
padata.c
padata: Replace padata_attr_type default_attrs field with groups
2019-04-25 22:06:11 +02:00
panic.c
panic: add an option to replay all the printk message in buffer
2019-05-18 15:52:26 -07:00
params.c
…
pid_namespace.c
…
pid.c
kernel/pid.c: remove unneeded hash header file
2019-05-14 19:52:51 -07:00
profile.c
…
ptrace.c
ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK
2019-03-29 10:01:37 -07:00
range.c
…
reboot.c
panic/reboot: allow specifying reboot_mode for panic only
2019-05-14 19:52:51 -07:00
relay.c
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-03-12 13:27:20 -07:00
resource.c
mm/resource: Use resource_overlaps() to simplify region_intersects()
2019-04-19 12:59:36 +02:00
rseq.c
rseq: Remove superfluous rseq_len from task_struct
2019-04-19 12:39:32 +02:00
seccomp.c
Merge tag 'audit-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
2019-05-07 19:06:04 -07:00
signal.c
signal: unconditionally leave the frozen state in ptrace_stop()
2019-05-16 10:43:58 -07:00
smp.c
cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM
2019-01-30 19:27:00 +01:00
smpboot.c
…
smpboot.h
…
softirq.c
softirq: Remove tasklet_hrtimer
2019-03-22 14:36:02 +01:00
stackleak.c
stackleak: Mark stackleak_track_stack() as notrace
2018-12-05 19:31:44 -08:00
stacktrace.c
stacktrace: Provide common infrastructure
2019-04-29 12:37:57 +02:00
stop_machine.c
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
2019-04-09 14:19:06 +02:00
sys_ni.c
signal: support CLONE_PIDFD with pidfd_send_signal
2019-05-07 14:31:03 +02:00
sys.c
kernel/sys.c: prctl: fix false positive in validate_prctl_map()
2019-05-14 09:47:44 -07:00
sysctl_binary.c
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
sysctl.c
kernel/sysctl.c: fix proc_do_large_bitmap for large input buffers
2019-05-14 19:52:51 -07:00
task_work.c
…
taskstats.c
genetlink: optionally validate strictly/dumps
2019-04-27 17:07:22 -04:00
test_kprobes.c
…
torture.c
torture: Don't try to offline the last CPU
2019-03-26 14:42:53 -07:00
tracepoint.c
tracing: Replace synchronize_sched() and call_rcu_sched()
2018-11-27 09:21:41 -08:00
tsacct.c
…
ucount.c
…
uid16.c
…
uid16.h
…
umh.c
umh: add exit routine for UMH process
2019-01-11 18:05:40 -08:00
up.c
…
user_namespace.c
…
user-return-notifier.c
…
user.c
kernel/user.c: clean up some leftover code
2019-05-14 19:52:49 -07:00
utsname_sysctl.c
…
utsname.c
…
watchdog_hld.c
kernel/watchdog_hld.c: hard lockup message should end with a newline
2019-04-19 09:46:05 -07:00
watchdog.c
watchdog: Fix typo in comment
2019-04-18 14:05:51 +02:00
workqueue_internal.h
sched/core, workqueues: Distangle worker accounting from rq lock
2019-04-16 16:55:15 +02:00
workqueue.c
Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2019-05-09 13:48:52 -07:00