Daniel Borkmann
ca36960211
bpf: allow xadd only on aligned memory
...
The requirements around atomic_add() / atomic64_add() resp. their
JIT implementations differ across architectures. E.g. while x86_64
seems just fine with BPF's xadd on unaligned memory, on arm64 it
triggers via interpreter but also JIT the following crash:
[ 830.864985] Unable to handle kernel paging request at virtual address ffff8097d7ed6703
[...]
[ 830.916161] Internal error: Oops: 96000021 [#1 ] SMP
[ 830.984755] CPU: 37 PID: 2788 Comm: test_verifier Not tainted 4.16.0-rc2+ #8
[ 830.991790] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.29 07/17/2017
[ 830.998998] pstate: 80400005 (Nzcv daif +PAN -UAO)
[ 831.003793] pc : __ll_sc_atomic_add+0x4/0x18
[ 831.008055] lr : ___bpf_prog_run+0x1198/0x1588
[ 831.012485] sp : ffff00001ccabc20
[ 831.015786] x29: ffff00001ccabc20 x28: ffff8017d56a0f00
[ 831.021087] x27: 0000000000000001 x26: 0000000000000000
[ 831.026387] x25: 000000c168d9db98 x24: 0000000000000000
[ 831.031686] x23: ffff000008203878 x22: ffff000009488000
[ 831.036986] x21: ffff000008b14e28 x20: ffff00001ccabcb0
[ 831.042286] x19: ffff0000097b5080 x18: 0000000000000a03
[ 831.047585] x17: 0000000000000000 x16: 0000000000000000
[ 831.052885] x15: 0000ffffaeca8000 x14: 0000000000000000
[ 831.058184] x13: 0000000000000000 x12: 0000000000000000
[ 831.063484] x11: 0000000000000001 x10: 0000000000000000
[ 831.068783] x9 : 0000000000000000 x8 : 0000000000000000
[ 831.074083] x7 : 0000000000000000 x6 : 000580d428000000
[ 831.079383] x5 : 0000000000000018 x4 : 0000000000000000
[ 831.084682] x3 : ffff00001ccabcb0 x2 : 0000000000000001
[ 831.089982] x1 : ffff8097d7ed6703 x0 : 0000000000000001
[ 831.095282] Process test_verifier (pid: 2788, stack limit = 0x0000000018370044)
[ 831.102577] Call trace:
[ 831.105012] __ll_sc_atomic_add+0x4/0x18
[ 831.108923] __bpf_prog_run32+0x4c/0x70
[ 831.112748] bpf_test_run+0x78/0xf8
[ 831.116224] bpf_prog_test_run_xdp+0xb4/0x120
[ 831.120567] SyS_bpf+0x77c/0x1110
[ 831.123873] el0_svc_naked+0x30/0x34
[ 831.127437] Code: 97fffe97 17ffffec 00000000 f9800031 (885f7c31)
Reason for this is because memory is required to be aligned. In
case of BPF, we always enforce alignment in terms of stack access,
but not when accessing map values or packet data when the underlying
arch (e.g. arm64) has CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS set.
xadd on packet data that is local to us anyway is just wrong, so
forbid this case entirely. The only place where xadd makes sense in
fact are map values; xadd on stack is wrong as well, but it's been
around for much longer. Specifically enforce strict alignment in case
of xadd, so that we handle this case generically and avoid such crashes
in the first place.
Fixes: 17a5267067 ("bpf: verifier (add verifier core)")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-02-23 14:33:39 -08:00
..
bpf
bpf: allow xadd only on aligned memory
2018-02-23 14:33:39 -08:00
cgroup
kernel/cpuset: current_cpuset_is_being_rebound can be boolean
2018-02-06 18:32:47 -08:00
configs
KVM changes for 4.16
2018-02-10 13:16:35 -08:00
debug
signal: Simplify and fix kdb_send_sig
2018-01-03 18:01:08 -06:00
events
vfs: do bulk POLL* -> EPOLL* replacement
2018-02-11 14:34:03 -08:00
gcov
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
irq
irqdomain: Re-use DEFINE_SHOW_ATTRIBUTE() macro
2018-02-16 14:22:34 +00:00
livepatch
Merge branch 'for-4.16/remove-immediate' into for-linus
2018-01-31 16:36:38 +01:00
locking
locking/qspinlock: Ensure node->count is updated before initialising node
2018-02-13 14:50:14 +01:00
power
x86/power: Fix swsusp_arch_resume prototype
2018-02-02 23:33:50 +01:00
printk
vfs: do bulk POLL* -> EPOLL* replacement
2018-02-11 14:34:03 -08:00
rcu
SCSI misc on 20180131
2018-01-31 11:23:28 -08:00
sched
sched/cpufreq: Remove unused SUGOV_KTHREAD_PRIORITY macro
2018-02-13 13:04:03 +01:00
time
vfs: do bulk POLL* -> EPOLL* replacement
2018-02-11 14:34:03 -08:00
trace
bpf: fix bpf_prog_array_copy_to_user warning from perf event prog query
2018-02-14 08:59:37 -08:00
.gitignore
acct.c
kernel/acct.c: fix the acct->needcheck check in check_free_space()
2018-01-04 16:45:09 -08:00
async.c
kernel/async.c: revert "async: simplify lowest_in_progress()"
2018-02-06 18:32:44 -08:00
audit.c
Audit: remove unused audit_log_secctx function
2017-11-10 16:08:47 -05:00
audit.h
audit/stable-4.15 PR 20171113
2017-11-15 13:28:48 -08:00
audit_fsnotify.c
audit_tree.c
Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
2017-11-14 14:08:20 -08:00
audit_watch.c
audit/stable-4.13 PR 20170816
2017-08-16 16:48:34 -07:00
auditfilter.c
audit: filter PATH records keyed on filesystem magic
2017-11-10 16:08:56 -05:00
auditsc.c
audit/stable-4.15 PR 20171113
2017-11-15 13:28:48 -08:00
backtracetest.c
bounds.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
capability.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
compat.c
cpumask: make cpumask_size() return "unsigned int"
2018-02-06 18:32:45 -08:00
configs.c
context_tracking.c
cpu.c
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-12-31 12:30:34 -08:00
cpu_pm.c
PM / CPU: replace raw_notifier with atomic_notifier
2017-07-31 13:09:49 +02:00
crash_core.c
kdump: write correct address of mem_section into vmcoreinfo
2018-01-13 10:42:48 -08:00
crash_dump.c
cred.c
delayacct.c
delayacct: Account blkio completion on the correct task
2018-01-16 03:29:36 +01:00
dma.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
elfcore.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
exec_domain.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
exit.c
kernel/exit.c: export abort() to modules
2018-01-04 16:45:09 -08:00
extable.c
kprobes, x86/alternatives: Use text_mutex to protect smp_alt_modules
2017-11-07 12:20:09 +01:00
fail_function.c
error-injection: Support fault injection framework
2018-01-12 17:33:38 -08:00
fork.c
Merge branch 'akpm' (patches from Andrew)
2018-02-06 22:15:42 -08:00
freezer.c
futex.c
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
futex_compat.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
groups.c
kernel: make groups_sort calling a responsibility group_info allocators
2017-12-14 16:00:49 -08:00
hung_task.c
irq_work.c
irq/work: Improve the flag definitions
2018-01-08 19:43:15 +01:00
jump_label.c
sched/core: Fix cpu.max vs. cpuhotplug deadlock
2018-01-24 10:03:44 +01:00
kallsyms.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
2018-02-01 13:36:15 -08:00
kcmp.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kcov: detect double association with a single task
2018-02-06 18:32:46 -08:00
kexec.c
kdump: protect vmcoreinfo data under the crash memory
2017-07-12 16:26:00 -07:00
kexec_core.c
x86/mm, kexec: Allow kexec to be used with SME
2017-07-18 11:38:04 +02:00
kexec_file.c
resource: Provide resource struct in resource walk callback
2017-11-07 15:35:57 +01:00
kexec_internal.h
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
kmod.c
kmod: move #ifdef CONFIG_MODULES wrapper to Makefile
2017-09-08 18:26:51 -07:00
kprobes.c
kprobes: Propagate error from disarm_kprobe_ftrace()
2018-02-16 09:12:58 +01:00
ksysfs.c
kexec: move vmcoreinfo out of the kernel's .bss section
2017-07-12 16:25:59 -07:00
kthread.c
treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts
2017-11-21 16:35:54 -08:00
latencytop.c
Makefile
error-injection: Support fault injection framework
2018-01-12 17:33:38 -08:00
memremap.c
mm: Fix devm_memremap_pages() collision handling
2018-01-19 16:29:56 -08:00
module-internal.h
module.c
Modules updates for v4.16
2018-02-07 14:29:34 -08:00
module_signing.c
notifier.c
nsproxy.c
padata.c
padata: add SPDX identifier
2018-01-05 18:43:00 +11:00
panic.c
kernel/panic.c: add TAINT_AUX
2017-11-17 16:10:04 -08:00
params.c
kernel/params.c: improve STANDARD_PARAM_DEF readability
2017-10-03 17:54:26 -07:00
pid.c
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
pid_namespace.c
pid: remove pidhash
2017-11-17 16:10:04 -08:00
profile.c
ptrace.c
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
range.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
reboot.c
kernel/reboot.c: add devm_register_reboot_notifier()
2017-11-17 16:10:04 -08:00
relay.c
vfs: do bulk POLL* -> EPOLL* replacement
2018-02-11 14:34:03 -08:00
resource.c
Merge branch 'akpm' (patches from Andrew)
2018-02-06 22:15:42 -08:00
seccomp.c
Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2018-01-31 13:44:45 -08:00
signal.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
2018-01-31 13:02:18 -08:00
smp.c
smp/core: Use lockdep to assert IRQs are disabled/enabled
2017-11-08 11:13:50 +01:00
smpboot.c
watchdog/core, powerpc: Lock cpus across reconfiguration
2017-10-04 10:53:54 +02:00
smpboot.h
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
softirq.c
softirq: Eliminate cond_resched_rcu_qs() in favor of cond_resched()
2017-12-04 10:28:58 -08:00
stacktrace.c
stop_machine.c
sys.c
fix typo in assignment of fs default overflow gid
2017-12-14 16:01:45 -06:00
sys_ni.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
sysctl.c
pipe: reject F_SETPIPE_SZ with size over UINT_MAX
2018-02-06 18:32:47 -08:00
sysctl_binary.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
task_work.c
locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
2017-12-17 13:57:15 +01:00
taskstats.c
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
test_kprobes.c
kprobes: Disable the jprobes test code
2017-10-20 11:02:54 +02:00
torture.c
torture: Save a line in stutter_wait(): while -> for
2017-12-11 09:18:30 -08:00
tracepoint.c
tracepoint: Remove smp_read_barrier_depends() from comment
2017-12-04 10:52:56 -08:00
tsacct.c
ucount.c
uid16.c
kernel: make groups_sort calling a responsibility group_info allocators
2017-12-14 16:00:49 -08:00
umh.c
kernel/umh.c: optimize 'proc_cap_handler()'
2017-11-17 16:10:01 -08:00
up.c
smp: Avoid using two cache lines for struct call_single_data
2017-08-29 15:14:38 +02:00
user-return-notifier.c
user.c
userns: use union in {g,u}idmap struct
2017-10-31 17:22:58 -05:00
user_namespace.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2017-11-16 12:20:15 -08:00
utsname.c
utsname_sysctl.c
watchdog.c
Merge branch 'linus' into sched/core, to pick up fixes
2017-11-08 10:17:15 +01:00
watchdog_hld.c
Merge branch 'linus' into core/urgent, to pick up dependent commits
2017-11-04 08:53:04 +01:00
workqueue.c
Staging/IIO patches for 4.16-rc1
2018-02-01 09:51:57 -08:00
workqueue_internal.h
Merge branch 'for-4.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2017-11-06 12:26:49 -08:00