linux/kernel
Qian Cai cda099b37d fork: Annotate a data race in vm_area_dup()
struct vm_area_struct could be accessed concurrently as noticed by
KCSAN,

 write to 0xffff9cf8bba08ad8 of 8 bytes by task 14263 on cpu 35:
  vma_interval_tree_insert+0x101/0x150:
  rb_insert_augmented_cached at include/linux/rbtree_augmented.h:58
  (inlined by) vma_interval_tree_insert at mm/interval_tree.c:23
  __vma_link_file+0x6e/0xe0
  __vma_link_file at mm/mmap.c:629
  vma_link+0xa2/0x120
  mmap_region+0x753/0xb90
  do_mmap+0x45c/0x710
  vm_mmap_pgoff+0xc0/0x130
  ksys_mmap_pgoff+0x1d1/0x300
  __x64_sys_mmap+0x33/0x40
  do_syscall_64+0x91/0xc44
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff9cf8bba08a80 of 200 bytes by task 14262 on cpu 122:
  vm_area_dup+0x6a/0xe0
  vm_area_dup at kernel/fork.c:362
  __split_vma+0x72/0x2a0
  __split_vma at mm/mmap.c:2661
  split_vma+0x5a/0x80
  mprotect_fixup+0x368/0x3f0
  do_mprotect_pkey+0x263/0x420
  __x64_sys_mprotect+0x51/0x70
  do_syscall_64+0x91/0xc44
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

vm_area_dup() blindly copies all fields of original VMA to the new one.
This includes coping vm_area_struct::shared.rb which is normally
protected by i_mmap_lock. But this is fine because the read value will
be overwritten on the following __vma_link_file() under proper
protection. Thus, mark it as an intentional data race and insert a few
assertions for the fields that should not be modified concurrently.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29 12:04:47 -07:00
..
bpf bpf: Don't return EINVAL from {get,set}sockopt when optlen > PAGE_SIZE 2020-06-17 10:54:05 -07:00
cgroup mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
configs
debug kgdb: Avoid suspicious RCU usage warning 2020-06-26 15:41:40 +01:00
dma dma-remap: align the size in dma_common_*_remap() 2020-06-23 14:14:41 +02:00
events Merge branch 'akpm' (patches from Andrew) 2020-06-09 09:54:46 -07:00
gcov treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
irq treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
kcsan kcsan: Support distinguishing volatile accesses 2020-06-11 20:04:01 +02:00
livepatch
locking The X86 entry, exception and interrupt code rework 2020-06-13 10:05:47 -07:00
power treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
printk Revert "kernel/printk: add kmsg SEEK_CUR handling" 2020-06-21 20:47:20 -07:00
rcu rcu: Fixup noinstr warnings 2020-06-25 08:24:32 -07:00
sched Peter Zijlstra says: 2020-06-28 10:37:39 -07:00
time The X86 entry, exception and interrupt code rework 2020-06-13 10:05:47 -07:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-25 18:27:40 -07:00
.gitignore
acct.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
async.c
audit.c audit/stable-5.8 PR 20200601 2020-06-02 17:13:37 -07:00
audit.h
audit_fsnotify.c
audit_tree.c
audit_watch.c
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c context_tracking: Ensure that the critical path cannot be instrumented 2020-06-11 15:14:36 +02:00
cpu.c The changes in this cycle are: 2020-06-03 13:06:42 -07:00
cpu_pm.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
extable.c
fail_function.c
fork.c fork: Annotate a data race in vm_area_dup() 2020-06-29 12:04:47 -07:00
freezer.c
futex.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
gen_kheaders.sh kbuild: add variables for compression tools 2020-06-06 23:42:01 +09:00
groups.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
hung_task.c kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected 2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c irq_work, smp: Allow irq_work on call_single_queue 2020-05-28 10:54:15 +02:00
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: check kcov_softirq in kcov_remote_stop() 2020-06-10 19:14:17 -07:00
kexec.c
kexec_core.c
kexec_elf.c
kexec_file.c kexec: do not verify the signature without the lockdown or mandatory signature 2020-06-26 00:27:36 -07:00
kexec_internal.h
kheaders.c
kmod.c
kprobes.c kretprobe: Prevent triggering kretprobe from within kprobe_flush_task 2020-06-16 21:21:01 -04:00
ksysfs.c
kthread.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
latencytop.c
Makefile Notifications over pipes + Keyring notifications 2020-06-13 09:56:21 -07:00
module-internal.h
module.c mm: remove vmalloc_exec 2020-06-26 00:27:38 -07:00
module_signature.c
module_signing.c
notifier.c mm: remove vmalloc_sync_(un)mappings() 2020-06-02 10:59:12 -07:00
nsproxy.c nsproxy: restore EINVAL for non-namespace file descriptor 2020-06-17 00:33:12 +02:00
padata.c padata: add basic support for multithreaded jobs 2020-06-03 20:09:45 -07:00
panic.c bug: Annotate WARN/BUG/stackfail as noinstr safe 2020-06-11 15:14:36 +02:00
params.c
pid.c
pid_namespace.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-06-03 16:27:18 -07:00
profile.c
ptrace.c
range.c
reboot.c printk: Collapse shutdown types into a single dump reason 2020-05-30 10:34:03 -07:00
relay.c mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
resource.c /dev/mem: Revoke mappings when a driver claims the region 2020-05-27 11:10:05 +02:00
rseq.c
scs.c scs: Report SCS usage in bytes rather than number of entries 2020-06-04 16:14:56 +01:00
seccomp.c
signal.c Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-06-01 16:21:46 -07:00
smp.c smp, irq_work: Continue smp_call_function*() and irq_work*() integration 2020-06-28 17:01:20 +02:00
smpboot.c
smpboot.h
softirq.c x86/entry: Clarify irq_{enter,exit}_rcu() 2020-06-11 15:15:24 +02:00
stackleak.c
stacktrace.c
stop_machine.c
sys.c Add additional LSM hooks for SafeSetID 2020-06-14 11:39:31 -07:00
sys_ni.c
sysctl-test.c
sysctl.c kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted 2020-06-08 11:05:56 -07:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c
up.c
user-return-notifier.c
user.c user.c: make uidhash_table static 2020-06-04 19:06:24 -07:00
user_namespace.c
utsname.c
utsname_sysctl.c
watch_queue.c Notifications over pipes + Keyring notifications 2020-06-13 09:56:21 -07:00
watchdog.c kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases 2020-06-08 11:05:56 -07:00
watchdog_hld.c
workqueue.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
workqueue_internal.h