Commit 32a5ad9c2285 ("sysctl: handle overflow for file-max") hooked up
min/max values for the file-max sysctl parameter via the .extra1 and
.extra2 fields in the corresponding struct ctl_table entry.
Unfortunately, the minimum value points at the global 'zero' variable,
which is an int. This results in a KASAN splat when accessed as a long
by proc_doulongvec_minmax on 64-bit architectures:
| BUG: KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax+0x5d8/0x6a0
| Read of size 8 at addr ffff2000133d1c20 by task systemd/1
|
| CPU: 0 PID: 1 Comm: systemd Not tainted 5.1.0-rc3-00012-g40b114779944 #2
| Hardware name: linux,dummy-virt (DT)
| Call trace:
| dump_backtrace+0x0/0x228
| show_stack+0x14/0x20
| dump_stack+0xe8/0x124
| print_address_description+0x60/0x258
| kasan_report+0x140/0x1a0
| __asan_report_load8_noabort+0x18/0x20
| __do_proc_doulongvec_minmax+0x5d8/0x6a0
| proc_doulongvec_minmax+0x4c/0x78
| proc_sys_call_handler.isra.19+0x144/0x1d8
| proc_sys_write+0x34/0x58
| __vfs_write+0x54/0xe8
| vfs_write+0x124/0x3c0
| ksys_write+0xbc/0x168
| __arm64_sys_write+0x68/0x98
| el0_svc_common+0x100/0x258
| el0_svc_handler+0x48/0xc0
| el0_svc+0x8/0xc
|
| The buggy address belongs to the variable:
| zero+0x0/0x40
|
| Memory state around the buggy address:
| ffff2000133d1b00: 00 00 00 00 00 00 00 00 fa fa fa fa 04 fa fa fa
| ffff2000133d1b80: fa fa fa fa 04 fa fa fa fa fa fa fa 04 fa fa fa
| >ffff2000133d1c00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
| ^
| ffff2000133d1c80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
| ffff2000133d1d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Fix the splat by introducing a unsigned long 'zero_ul' and using that
instead.
This reverts commit 4aada79c6793c59e484b69fd4ed591396e2d4b39 which was
commit 71492580571467fb7177aade19c18ce7486267f5 upstream.
Tetsuo rightly points out that the backport here is incorrect, as it
touches the __lock_set_class function instead of the intended
__lock_downgrade function.
Reported-by: Tetsuo Handa <email address hidden>
Cc: Waiman Long <email address hidden>
Cc: Peter Zijlstra (Intel) <email address hidden>
Cc: Andrew Morton <email address hidden>
Cc: Linus Torvalds <email address hidden>
Cc: Paul E. McKenney <email address hidden>
Cc: Peter Zijlstra <email address hidden>
Cc: Thomas Gleixner <email address hidden>
Cc: Will Deacon <email address hidden>
Cc: Ingo Molnar <email address hidden>
Cc: Sasha Levin <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
Signed-off-by: Kleber Sacilotto de Souza <email address hidden>
The ALSA proc helper manages the child nodes in a linked list, but its
addition and deletion is done without any lock. This leads to a
corruption if they are operated concurrently. Usually this isn't a
problem because the proc entries are added sequentially in the driver
probe procedure itself. But the card registrations are done often
asynchronously, and the crash could be actually reproduced with
syzkaller.
This patch papers over it by protecting the link addition and deletion
with the parent's mutex. There is "access" mutex that is used for the
file access, and this can be reused for this purpose as well.
Commit 58bc4c34d249 ("mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly")
depends on skipping vmstat entries with empty name introduced in
7aaf77272358 ("mm: don't show nr_indirectly_reclaimable in
/proc/vmstat") but reverted in b29940c1abd7 ("mm: rename and change
semantics of nr_indirectly_reclaimable_bytes").
So skipping no longer works and /proc/vmstat has misformatted lines " 0".
This patch simply shows debug counters "nr_tlb_remote_*" for UP.
When dev_exception_add() returns an error (due to a failed memory
allocation), make sure that we move the RCU preemption count back to where
it was before we were called. We dropped the RCU read lock inside the loop
body, so we can't just "break".
sparse complains about this, too:
$ make -s C=2 security/device_cgroup.o
./include/linux/rcupdate.h:647:9: warning: context imbalance in
'propagate_exception' - unexpected unlock
Fixes: d591fb56618f ("device_cgroup: simplify cgroup tree walk in propagate_exception()")
Cc: <email address hidden>
Signed-off-by: Jann Horn <email address hidden>
Acked-by: Michal Hocko <email address hidden>
Signed-off-by: Tejun Heo <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
Signed-off-by: Kleber Sacilotto de Souza <email address hidden>
With extremely short cfs_period_us setting on a parent task group with a large
number of children the for loop in sched_cfs_period_timer() can run until the
watchdog fires. There is no guarantee that the call to hrtimer_forward_now()
will ever return 0. The large number of children can make
do_sched_cfs_period_timer() take longer than the period.
NMI watchdog: Watchdog detected hard LOCKUP on cpu 24
RIP: 0010:tg_nop+0x0/0x10
<IRQ>
walk_tg_tree_from+0x29/0xb0
unthrottle_cfs_rq+0xe0/0x1a0
distribute_cfs_runtime+0xd3/0xf0
sched_cfs_period_timer+0xcb/0x160
? sched_cfs_slack_timer+0xd0/0xd0
__hrtimer_run_queues+0xfb/0x270
hrtimer_interrupt+0x122/0x270
smp_apic_timer_interrupt+0x6a/0x140
apic_timer_interrupt+0xf/0x20
</IRQ>
To prevent this we add protection to the loop that detects when the loop has run
too many times and scales the period and quota up, proportionally, so that the timer
can complete before then next period expires. This preserves the relative runtime
quota while preventing the hard lockup.
A warning is issued reporting this state and the new values.
The clang option -Oz enables *aggressive* optimization for size,
which doesn't necessarily result in smaller images, but can have
negative impact on performance. Switch back to the less aggressive
-Os.
This reverts commit 6748cb3c299de1ffbe56733647b01dbcc398c419.
There are several scenarios in which mac80211 can call drv_wake_tx_queue
after ieee80211_restart_hw has been called and has not yet completed.
Driver private structs are considered uninitialized until mac80211 has
uploaded the vifs, stations and keys again, so using private tx queue
data during that time is not safe.
The driver can also not rely on drv_reconfig_complete to figure out when
it is safe to accept drv_wake_tx_queue calls again, because it is only
called after all tx queues are woken again.
To fix this, bail out early in drv_wake_tx_queue if local->in_reconfig
is set.
Cc: <email address hidden>
Signed-off-by: Felix Fietkau <email address hidden>
Signed-off-by: Johannes Berg <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
Signed-off-by: Kleber Sacilotto de Souza <email address hidden>
1e821a4...
by
Masami Hiramatsu <email address hidden>
kprobes: Fix error check when reusing optimized probes
The following commit introduced a bug in one of our error paths:
819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()")
it missed to handle the return value of kprobe_optready() as
error-value. In reality, the kprobe_optready() returns a bool
result, so "true" case must be passed instead of 0.
This causes some errors on kprobe boot-time selftests on ARM:
[ ] Beginning kprobe tests...
[ ] Probe ARM code
[ ] kprobe
[ ] kretprobe
[ ] ARM instruction simulation
[ ] Check decoding tables
[ ] Run test cases
[ ] FAIL: test_case_handler not run
[ ] FAIL: Test andge r10, r11, r14, asr r7
[ ] FAIL: Scenario 11
...
[ ] FAIL: Scenario 7
[ ] Total instruction simulation tests=1631, pass=1433 fail=198
[ ] kprobe tests failed
This can happen if an optimized probe is unregistered and next
kprobe is registered on same address until the previous probe
is not reclaimed.
If this happens, a hidden aggregated probe may be kept in memory,
and no new kprobe can probe same address. Also, in that case
register_kprobe() will return "1" instead of minus error value,
which can mislead caller logic.
Signed-off-by: Masami Hiramatsu <email address hidden>
Cc: Anil S Keshavamurthy <email address hidden>
Cc: David S . Miller <email address hidden>
Cc: Linus Torvalds <email address hidden>
Cc: Naveen N . Rao <email address hidden>
Cc: Peter Zijlstra <email address hidden>
Cc: Thomas Gleixner <email address hidden>
Cc: <email address hidden> # v5.0+
Fixes: 819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()")
Link: http://lkml.kernel.org/r/155530808559.32517.539898325433642204.stgit@devnote2
Signed-off-by: Ingo Molnar <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
Signed-off-by: Kleber Sacilotto de Souza <email address hidden>
