Syzkaller with KASAN has reported a use-after-free of vma->vm_flags in
__do_page_fault() with the following reproducer:
mmap(&(0x7f0000000000/0xfff000)=nil, 0xfff000, 0x3, 0x32, 0xffffffffffffffff, 0x0)
mmap(&(0x7f0000011000/0x3000)=nil, 0x3000, 0x1, 0x32, 0xffffffffffffffff, 0x0)
r0 = userfaultfd(0x0)
ioctl$UFFDIO_API(r0, 0xc018aa3f, &(0x7f0000002000-0x18)={0xaa, 0x0, 0x0})
ioctl$UFFDIO_REGISTER(r0, 0xc020aa00, &(0x7f0000019000)={{&(0x7f0000012000/0x2000)=nil, 0x2000}, 0x1, 0x0})
r1 = gettid()
syz_open_dev$evdev(&(0x7f0000013000-0x12)="2f6465762f696e7075742f6576656e742300", 0x0, 0x0)
tkill(r1, 0x7)
The vma should be pinned by mmap_sem, but handle_userfault() might (in a
return to userspace scenario) release it and then acquire again, so when
we return to __do_page_fault() (with other result than VM_FAULT_RETRY),
the vma might be gone.
Specifically, per Andrea the scenario is
"A return to userland to repeat the page fault later with a
VM_FAULT_NOPAGE retval (potentially after handling any pending signal
during the return to userland). The return to userland is identified
whenever FAULT_FLAG_USER|FAULT_FLAG_KILLABLE are both set in
vmf->flags"
However, since commit a3c4fb7c9c ("x86/mm: Fix fault error path using
unsafe vma pointer") there is a vma_pkey() read of vma->vm_flags after
that point, which can thus become use-after-free. Fix this by moving
the read before calling handle_mm_fault().
Reported-by: syzbot <bot+6a5269ce759a7bb12754ed9622076dc93f65a1f6@syzkaller.appspotmail.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Fixes: 3c4fb7c9c2e ("x86/mm: Fix fault error path using unsafe vma pointer")
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cifs fix from Steve French:
"smb3 file name too long fix"
* tag 'smb3-file-name-too-long-fix' of git://git.samba.org/sfrench/cifs-2.6:
cifs: check MaxPathNameComponentLength != 0 before using it
Pull power management commit reverts from Rafael Wysocki:
"Since Geert reports additional problems with my PM QoS fix from the
last week that have not been addressed by the most recent fixup on top
of it, they both should better be reverted now and let's fix the
original issue properly in 4.15.
This reverts two recent PM QoS commits one of which introduced
multiple problems and the other one fixed some, but not all of them
(Rafael Wysocki)"
* tag 'pm-reverts-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
Revert "PM / QoS: Fix device resume latency PM QoS"
Revert "PM / QoS: Fix default runtime_pm device resume latency"
IB device index is nldev's handler and it should be checked always.
Fixes: c3f66f7b00 ("RDMA/netlink: Implement nldev port doit callback")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Doug Ledford <dledford@redhat.com>
[ Applying directly, since Doug fried his SSD's and is rebuilding - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 0cc2b4e5a0 (PM / QoS: Fix device resume latency PM
QoS) as it introduced regressions on multiple systems and the fix-up
in commit 2a9a86d5c8 (PM / QoS: Fix default runtime_pm device resume
latency) does not address all of them.
The original problem that commit 0cc2b4e5a0 was attempting to fix
will be addressed later.
Fixes: 0cc2b4e5a0 (PM / QoS: Fix device resume latency PM QoS)
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This reverts commit 2a9a86d5c8 (PM / QoS: Fix default runtime_pm
device resume latency) as the commit it depends on is going to be
reverted.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull power management fix from Rafael Wysocki:
"This fixes new breakage introduced by the most recent PM QoS fix in
which, embarrassingly enough, I forgot to update
dev_pm_qos_raw_read_value() to return the right default for devices
with no PM QoS constraints at all which prevents runtime PM from
suspending those devices (fix from Tero Kristo)"
* tag 'pm-urgent-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / QoS: Fix default runtime_pm device resume latency
It turns out that some drivers seem to think it's ok to remap page
ranges from within interrupts and even NMI's. That is definitely not
the case, since the page table build-up is simply not interrupt-safe.
This showed up in the zero-day robot that reported it for the ACPI APEI
GHES ("Generic Hardware Error Source") driver. Normally it had been
hidden by the fact that no page table operations had been needed because
the vmalloc area had been set up by other things.
Apparently due to a recent change to the GHEI driver: commit
77b246b32b ("acpi: apei: check for pending errors when probing GHES
entries") 0day actually caught a case during bootup whenthe ioremap
called down to page allocation. But that recent change only showed the
symptom, it wasn't the root cause of the problem.
Hopefully it is limited to just that one driver.
If you need to access random physical memory, you either need to ioremap
in process context, or you need to use the FIXMAP facility to set one
particular fixmap entry to the required mapping - that can be done safely.
Cc: Borislav Petkov <bp@suse.de>
Cc: Len Brown <lenb@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Tyler Baicar <tbaicar@codeaurora.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull MMC fixes from Ulf Hansson:
"A couple of MMC host fixes intended for v4.14-rc8:
- renesas_sdhi: fix kernel panic
- tmio: fix swiotlb buffer is full"
* tag 'mmc-v4.14-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
mmc: renesas_sdhi: fix kernel panic in _internal_dmac.c
mmc: tmio: fix swiotlb buffer is full
The recent change to the PM QoS framework to introduce a proper
no constraint value overlooked to handle the devices which don't
implement PM QoS OPS. Runtime PM is one of the more severely
impacted subsystems, failing every attempt to runtime suspend
a device. This leads into some nasty second level issues like
probe failures and increased power consumption among other
things.
Fix this by adding a proper return value for devices that don't
implement PM QoS.
Fixes: 0cc2b4e5a0 (PM / QoS: Fix device resume latency PM QoS)
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull networking fixes from David Miller:
1) Fix route leak in xfrm_bundle_create().
2) In mac80211, validate user rate mask before configuring it. From
Johannes Berg.
3) Properly enforce memory limits in fair queueing code, from Toke
Hoiland-Jorgensen.
4) Fix lockdep splat in inet_csk_route_req(), from Eric Dumazet.
5) Fix TSO header allocation and management in mvpp2 driver, from Yan
Markman.
6) Don't take socket lock in BH handler in strparser code, from Tom
Herbert.
7) Don't show sockets from other namespaces in AF_UNIX code, from
Andrei Vagin.
8) Fix double free in error path of tap_open(), from Girish Moodalbail.
9) Fix TX map failure path in igb and ixgbe, from Jean-Philippe Brucker
and Alexander Duyck.
10) Fix DCB mode programming in stmmac driver, from Jose Abreu.
11) Fix err_count handling in various tunnels (ipip, ip6_gre). From Xin
Long.
12) Properly align SKB head before building SKB in tuntap, from Jason
Wang.
13) Avoid matching qdiscs with a zero handle during lookups, from Cong
Wang.
14) Fix various endianness bugs in sctp, from Xin Long.
15) Fix tc filter callback races and add selftests which trigger the
problem, from Cong Wang.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (73 commits)
selftests: Introduce a new test case to tc testsuite
selftests: Introduce a new script to generate tc batch file
net_sched: fix call_rcu() race on act_sample module removal
net_sched: add rtnl assertion to tcf_exts_destroy()
net_sched: use tcf_queue_work() in tcindex filter
net_sched: use tcf_queue_work() in rsvp filter
net_sched: use tcf_queue_work() in route filter
net_sched: use tcf_queue_work() in u32 filter
net_sched: use tcf_queue_work() in matchall filter
net_sched: use tcf_queue_work() in fw filter
net_sched: use tcf_queue_work() in flower filter
net_sched: use tcf_queue_work() in flow filter
net_sched: use tcf_queue_work() in cgroup filter
net_sched: use tcf_queue_work() in bpf filter
net_sched: use tcf_queue_work() in basic filter
net_sched: introduce a workqueue for RCU callbacks of tc filter
sctp: fix some type cast warnings introduced since very beginning
sctp: fix a type cast warnings that causes a_rwnd gets the wrong value
sctp: fix some type cast warnings introduced by transport rhashtable
sctp: fix some type cast warnings introduced by stream reconf
...
Cong Wang says:
====================
net_sched: fix races with RCU callbacks
Recently, the RCU callbacks used in TC filters and TC actions keep
drawing my attention, they introduce at least 4 race condition bugs:
1. A simple one fixed by Daniel:
commit c78e1746d3
Author: Daniel Borkmann <daniel@iogearbox.net>
Date: Wed May 20 17:13:33 2015 +0200
net: sched: fix call_rcu() race on classifier module unloads
2. A very nasty one fixed by me:
commit 1697c4bb52
Author: Cong Wang <xiyou.wangcong@gmail.com>
Date: Mon Sep 11 16:33:32 2017 -0700
net_sched: carefully handle tcf_block_put()
3. Two more bugs found by Chris:
https://patchwork.ozlabs.org/patch/826696/https://patchwork.ozlabs.org/patch/826695/
Usually RCU callbacks are simple, however for TC filters and actions,
they are complex because at least TC actions could be destroyed
together with the TC filter in one callback. And RCU callbacks are
invoked in BH context, without locking they are parallel too. All of
these contribute to the cause of these nasty bugs.
Alternatively, we could also:
a) Introduce a spinlock to serialize these RCU callbacks. But as I
said in commit 1697c4bb52 ("net_sched: carefully handle
tcf_block_put()"), it is very hard to do because of tcf_chain_dump().
Potentially we need to do a lot of work to make it possible (if not
impossible).
b) Just get rid of these RCU callbacks, because they are not
necessary at all, callers of these call_rcu() are all on slow paths
and holding RTNL lock, so blocking is allowed in their contexts.
However, David and Eric dislike adding synchronize_rcu() here.
As suggested by Paul, we could defer the work to a workqueue and
gain the permission of holding RTNL again without any performance
impact, however, in tcf_block_put() we could have a deadlock when
flushing workqueue while hodling RTNL lock, the trick here is to
defer the work itself in workqueue and make it queued after all
other works so that we keep the same ordering to avoid any
use-after-free. Please see the first patch for details.
Patch 1 introduces the infrastructure, patch 2~12 move each
tc filter to the new tc filter workqueue, patch 13 adds
an assertion to catch potential bugs like this, patch 14
closes another rcu callback race, patch 15 and patch 16 add
new test cases.
====================
Reported-by: Chris Mi <chrism@mellanox.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In this patchset, we fixed a tc bug. This patch adds the test case
that reproduces the bug. To run this test case, user should specify
an existing NIC device:
# sudo ./tdc.py -d enp4s0f0
This test case belongs to category "flower". If user doesn't specify
a NIC device, the test cases belong to "flower" will not be run.
In this test case, we create 1M filters and all filters share the same
action. When destroying all filters, kernel should not panic. It takes
about 18s to run it.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Lucas Bates <lucasb@mojatatu.com>
Signed-off-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
# ./tdc_batch.py -h
usage: tdc_batch.py [-h] [-n NUMBER] [-o] [-s] [-p] device file
TC batch file generator
positional arguments:
device device name
file batch file name
optional arguments:
-h, --help show this help message and exit
-n NUMBER, --number NUMBER
how many lines in batch file
-o, --skip_sw skip_sw (offload), by default skip_hw
-s, --share_action all filters share the same action
-p, --prio all filters have different prio
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Lucas Bates <lucasb@mojatatu.com>
Signed-off-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vlastimil Babka
Linus Torvalds
Leon Romanovsky
Rafael J. Wysocki
Tero Kristo
Ronnie Sahlberg
David S. Miller
Chris Mi
Cong Wang