The conversion of x86 VDSO to the generic clock mode storage broke the
paravirt and hyperv clocksource logic. These clock sources have their own
internal sequence counter to validate the clocksource at the point of
reading it. This is necessary because the hypervisor can invalidate the
clocksource asynchronously so a check during the VDSO data update is not
sufficient. If the internal check during read invalidates the clocksource
the read return U64_MAX. The original code checked this efficiently by
testing whether the result (casted to signed) is negative, i.e. bit 63 is
set. This was done that way because an extra indicator for the validity had
more overhead.

The conversion broke this check because the check was replaced by a check
for a valid VDSO clock mode.

The wreckage manifests itself when the paravirt clock is installed as a
valid VDSO clock and during runtime invalidated by the hypervisor,
e.g. after a host suspend/resume cycle. After the invalidation the read
function returns U64_MAX which is used as cycles and makes the clock jump
by ~2200 seconds, and become stale until the 2200 seconds have elapsed
where it starts to jump again. The period of this effect depends on the
shift/mult pair of the clocksource and the jumps and staleness are an
artifact of undefined but reproducible behaviour of math overflow.

Implement an x86 version of the new vdso_cycles_ok() inline which adds this
check back and a variant of vdso_clocksource_ok() which lets the compiler
optimize it out to avoid the extra conditional. That's suboptimal when the
system does not have a VDSO capable clocksource, but that's not the case
which is optimized for.

Fixes: 5d51bee7 ("clocksource: Add common vdso clock mode storage")
Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200606221532.080560273@linutronix.de

The original x86 VDSO implementation checked for the validity of the clock
source read by testing whether the returned signed cycles value is less
than zero. This check was also used by the vdso read function to signal
that the current selected clocksource is not VDSO capable.

During the rework of the VDSO code the check was removed and replaced with
a check for the clocksource mode being != NONE.

This turned out to be a mistake because the check is necessary for paravirt
and hyperv clock sources. The reason is that these clock sources have their
own internal sequence counter to validate the clocksource at the point of
reading it. This is necessary because the hypervisor can invalidate the
clocksource asynchronously so a check during the VDSO data update is not
sufficient. Having a separate indicator for the validity is slower than
just validating the cycles value. The check for it being negative turned
out to be the fastest implementation and safe as it would require an uptime
of ~73 years with a 4GHz counter frequency to result in a false positive.

Add an optional function to validate the cycles with a default
implementation which allows the compiler to optimize it out for
architectures which do not require it.

Fixes: 5d51bee7 ("clocksource: Add common vdso clock mode storage")
Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200606221531.963970768@linutronix.de

CONFIG_GENERIC_VDSO_CLOCK_MODE was a transitional config switch which got
removed after all architectures got converted to the new storage model.

But the removal forgot to remove the #ifdef which guards the
vdso_clock_mode sanity check, which effectively disables the sanity check.

Remove it now.

Fixes: f86fd32d ("lib/vdso: Cleanup clock mode storage leftovers")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200606221531.845475036@linutronix.de

'jiffies' and 'jiffies_64' are meant to alias (two different symbols that
share the same address).  Most architectures make the symbols alias to the
same address via a linker script assignment in their
arch/<arch>/kernel/vmlinux.lds.S:

jiffies = jiffies_64;

which is effectively a definition of jiffies.

jiffies and jiffies_64 are both forward declared for all architectures in
include/linux/jiffies.h. jiffies_64 is defined in kernel/time/timer.c.

x86_64 was peculiar in that it wasn't doing the above linker script
assignment, but rather was:
1. defining jiffies in arch/x86/kernel/time.c instead via the linker script.
2. overriding the symbol jiffies_64 from kernel/time/timer.c in
arch/x86/kernel/vmlinux.lds.s via 'jiffies_64 = jiffies;'.

As Fangrui notes:

  In LLD, symbol assignments in linker scripts override definitions in
  object files. GNU ld appears to have the same behavior. It would
  probably make sense for LLD to error "duplicate symbol" but GNU ld
  is unlikely to adopt for compatibility reasons.

This results in an ODR violation (UB), which seems to have survived
thus far. Where it becomes harmful is when;

1. -fno-semantic-interposition is used:

As Fangrui notes:

  Clang after LLVM commit 5b22bcc2b70d
  ("[X86][ELF] Prefer to lower MC_GlobalAddress operands to .Lfoo$local")
  defaults to -fno-semantic-interposition similar semantics which help
  -fpic/-fPIC code avoid GOT/PLT when the referenced symbol is defined
  within the same translation unit. Unlike GCC
  -fno-semantic-interposition, Clang emits such relocations referencing
  local symbols for non-pic code as well.

This causes references to jiffies to refer to '.Ljiffies$local' when
jiffies is defined in the same translation unit. Likewise, references to
jiffies_64 become references to '.Ljiffies_64$local' in translation units
that define jiffies_64.  Because these differ from the names used in the
linker script, they will not be rewritten to alias one another.

2. Full LTO

Full LTO effectively treats all source files as one translation
unit, causing these local references to be produced everywhere.  When
the linker processes the linker script, there are no longer any
references to jiffies_64' anywhere to replace with 'jiffies'.  And
thus '.Ljiffies$local' and '.Ljiffies_64$local' no longer alias
at all.

In the process of porting patches enabling Full LTO from arm64 to x86_64,
spooky bugs have been observed where the kernel appeared to boot, but init
doesn't get scheduled.

Avoid the ODR violation by matching other architectures and define jiffies
only by linker script.  For -fno-semantic-interposition + Full LTO, there
is no longer a global definition of jiffies for the compiler to produce a
local symbol which the linker script won't ensure aliases to jiffies_64.

Fixes: 40747ffa ("asmlinkage: Make jiffies visible")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reported-by: Alistair Delva <adelva@google.com>
Debugged-by: Nick Desaulniers <ndesaulniers@google.com>
Debugged-by: Sami Tolvanen <samitolvanen@google.com>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Bob Haarman <inglorion@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # build+boot on
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/852
Link: https://lkml.kernel.org/r/20200602193100.229287-1-inglorion@google.com

Currently, it is possible to enable indirect branch speculation even after
it was force-disabled using the PR_SPEC_FORCE_DISABLE option. Moreover, the
PR_GET_SPECULATION_CTRL command gives afterwards an incorrect result
(force-disabled when it is in fact enabled). This also is inconsistent
vs. STIBP and the documention which cleary states that
PR_SPEC_FORCE_DISABLE cannot be undone.

Fix this by actually enforcing force-disabled indirect branch
speculation. PR_SPEC_ENABLE called after PR_SPEC_FORCE_DISABLE now fails
with -EPERM as described in the documentation.

Fixes: 9137bb27 ("x86/speculation: Add prctl() control for indirect branch speculation")
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

On context switch the change of TIF_SSBD and TIF_SPEC_IB are evaluated
to adjust the mitigations accordingly. This is optimized to avoid the
expensive MSR write if not needed.

This optimization is buggy and allows an attacker to shutdown the SSBD
protection of a victim process.

The update logic reads the cached base value for the speculation control
MSR which has neither the SSBD nor the STIBP bit set. It then OR's the
SSBD bit only when TIF_SSBD is different and requests the MSR update.

That means if TIF_SSBD of the previous and next task are the same, then
the base value is not updated, even if TIF_SSBD is set. The MSR write is
not requested.

Subsequently if the TIF_STIBP bit differs then the STIBP bit is updated
in the base value and the MSR is written with a wrong SSBD value.

This was introduced when the per task/process conditional STIPB
switching was added on top of the existing SSBD switching.

It is exploitable if the attacker creates a process which enforces SSBD
and has the contrary value of STIBP than the victim process (i.e. if the
victim process enforces STIBP, the attacker process must not enforce it;
if the victim process does not enforce STIBP, the attacker process must
enforce it) and schedule it on the same core as the victim process. If
the victim runs after the attacker the victim becomes vulnerable to
Spectre V4.

To fix this, update the MSR value independent of the TIF_SSBD difference
and dependent on the SSBD mitigation method available. This ensures that
a subsequent STIPB initiated MSR write has the correct state of SSBD.

[ tglx: Handle X86_FEATURE_VIRT_SSBD & X86_FEATURE_VIRT_SSBD correctly
        and massaged changelog ]

Fixes: 5bfbe3ad ("x86/speculation: Prepare for per task indirect branch speculation control")
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

When STIBP is unavailable or enhanced IBRS is available, Linux
force-disables the IBPB mitigation of Spectre-BTB even when simultaneous
multithreading is disabled. While attempts to enable IBPB using
prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, ...) fail with
EPERM, the seccomp syscall (or its prctl(PR_SET_SECCOMP, ...) equivalent)
which are used e.g. by Chromium or OpenSSH succeed with no errors but the
application remains silently vulnerable to cross-process Spectre v2 attacks
(classical BTB poisoning). At the same time the SYSFS reporting
(/sys/devices/system/cpu/vulnerabilities/spectre_v2) displays that IBPB is
conditionally enabled when in fact it is unconditionally disabled.

STIBP is useful only when SMT is enabled. When SMT is disabled and STIBP is
unavailable, it makes no sense to force-disable also IBPB, because IBPB
protects against cross-process Spectre-BTB attacks regardless of the SMT
state. At the same time since missing STIBP was only observed on AMD CPUs,
AMD does not recommend using STIBP, but recommends using IBPB, so disabling
IBPB because of missing STIBP goes directly against AMD's advice:
https://developer.amd.com/wp-content/resources/Architecture_Guidelines_Update_Indirect_Branch_Control.pdf

Similarly, enhanced IBRS is designed to protect cross-core BTB poisoning
and BTB-poisoning attacks from user space against kernel (and
BTB-poisoning attacks from guest against hypervisor), it is not designed
to prevent cross-process (or cross-VM) BTB poisoning between processes (or
VMs) running on the same core. Therefore, even with enhanced IBRS it is
necessary to flush the BTB during context-switches, so there is no reason
to force disable IBPB when enhanced IBRS is available.

Enable the prctl control of IBPB even when STIBP is unavailable or enhanced
IBRS is available.

Fixes: 7cc765a6 ("x86/speculation: Enable prctl mode for spectre_v2_user")
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

Latest edition (039) of "Intel Architecture Instruction Set Extensions
and Future Features Programming Reference" includes three new CPU model
numbers. Linux already has the two Ice Lake server ones. Add the new
model number for Sapphire Rapids.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200603173352.15506-1-tony.luck@intel.com

Pick up these single-commit branches.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Yes, staying withing 80 columns is certainly still _preferred_.  But
it's not the hard limit that the checkpatch warnings imply, and other
concerns can most certainly dominate.

Increase the default limit to 100 characters.  Not because 100
characters is some hard limit either, but that's certainly a "what are
you doing" kind of value and less likely to be about the occasional
slightly longer lines.

Miscellanea:

 - to avoid unnecessary whitespace changes in files, checkpatch will no
   longer emit a warning about line length when scanning files unless
   --strict is also used

 - Add a bit to coding-style about alignment to open parenthesis
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A pile of x86 fixes:

   - Prevent a memory leak in ioperm which was caused by the stupid
     assumption that the exit cleanup is always called for current,
     which is not the case when fork fails after taking a reference on
     the ioperm bitmap.

   - Fix an arithmething overflow in the DMA code on 32bit systems

   - Fill gaps in the xstate copy with defaults instead of leaving them
     uninitialized

   - Revert: "Make __X32_SYSCALL_BIT be unsigned long" as it turned out
     that existing user space fails to build"

* tag 'x86-urgent-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioperm: Prevent a memory leak when fork fails
  x86/dma: Fix max PFN arithmetic overflow on 32 bit systems
  copy_xstate_to_kernel(): don't leave parts of destination uninitialized
  x86/syscalls: Revert "x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long"

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix preventing a crash in NUMA balancing.

  The current->mm check is not reliable as the mm might be temporary due
  to use_mm() in a kthread. Check for PF_KTHREAD explictly"

* tag 'sched-urgent-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Don't NUMA balance for kthreads

Pull networking fixes from David Miller:
 "Another week, another set of bug fixes:

   1) Fix pskb_pull length in __xfrm_transport_prep(), from Xin Long.

   2) Fix double xfrm_state put in esp{4,6}_gro_receive(), also from Xin
      Long.

   3) Re-arm discovery timer properly in mac80211 mesh code, from Linus
      Lüssing.

   4) Prevent buffer overflows in nf_conntrack_pptp debug code, from
      Pablo Neira Ayuso.

   5) Fix race in ktls code between tls_sw_recvmsg() and
      tls_decrypt_done(), from Vinay Kumar Yadav.

   6) Fix crashes on TCP fallback in MPTCP code, from Paolo Abeni.

   7) More validation is necessary of untrusted GSO packets coming from
      virtualization devices, from Willem de Bruijn.

   8) Fix endianness of bnxt_en firmware message length accesses, from
      Edwin Peer.

   9) Fix infinite loop in sch_fq_pie, from Davide Caratti.

  10) Fix lockdep splat in DSA by setting lockless TX in netdev features
      for slave ports, from Vladimir Oltean.

  11) Fix suspend/resume crashes in mlx5, from Mark Bloch.

  12) Fix use after free in bpf fmod_ret, from Alexei Starovoitov.

  13) ARP retransmit timer guard uses wrong offset, from Hongbin Liu.

  14) Fix leak in inetdev_init(), from Yang Yingliang.

  15) Don't try to use inet hash and unhash in l2tp code, results in
      crashes. From Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits)
  l2tp: add sk_family checks to l2tp_validate_socket
  l2tp: do not use inet_hash()/inet_unhash()
  net: qrtr: Allocate workqueue before kernel_bind
  mptcp: remove msk from the token container at destruction time.
  mptcp: fix race between MP_JOIN and close
  mptcp: fix unblocking connect()
  net/sched: act_ct: add nat mangle action only for NAT-conntrack
  devinet: fix memleak in inetdev_init()
  virtio_vsock: Fix race condition in virtio_transport_recv_pkt
  drivers/net/ibmvnic: Update VNIC protocol version reporting
  NFC: st21nfca: add missed kfree_skb() in an error path
  neigh: fix ARP retransmit timer guard
  bpf, selftests: Add a verifier test for assigning 32bit reg states to 64bit ones
  bpf, selftests: Verifier bounds tests need to be updated
  bpf: Fix a verifier issue when assigning 32bit reg states to 64bit ones
  bpf: Fix use-after-free in fmod_ret check
  net/mlx5e: replace EINVAL in mlx5e_flower_parse_meta()
  net/mlx5e: Fix MLX5_TC_CT dependencies
  net/mlx5e: Properly set default values when disabling adaptive moderation
  net/mlx5e: Fix arch depending casting issue in FEC
  ...

syzbot was able to trigger a crash after using an ISDN socket
and fool l2tp.

Fix this by making sure the UDP socket is of the proper family.

BUG: KASAN: slab-out-of-bounds in setup_udp_tunnel_sock+0x465/0x540 net/ipv4/udp_tunnel.c:78
Write of size 1 at addr ffff88808ed0c590 by task syz-executor.5/3018

CPU: 0 PID: 3018 Comm: syz-executor.5 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382
 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 setup_udp_tunnel_sock+0x465/0x540 net/ipv4/udp_tunnel.c:78
 l2tp_tunnel_register+0xb15/0xdd0 net/l2tp/l2tp_core.c:1523
 l2tp_nl_cmd_tunnel_create+0x4b2/0xa60 net/l2tp/l2tp_netlink.c:249
 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:718 [inline]
 genl_rcv_msg+0x627/0xdf0 net/netlink/genetlink.c:735
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:746
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e6/0x810 net/socket.c:2352
 ___sys_sendmsg+0x100/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007effe76edc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004fe1c0 RCX: 000000000045ca29
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000094e R14: 00000000004d5d00 R15: 00007effe76ee6d4

Allocated by task 3018:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x161/0x7a0 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 sk_prot_alloc+0x223/0x2f0 net/core/sock.c:1612
 sk_alloc+0x36/0x1100 net/core/sock.c:1666
 data_sock_create drivers/isdn/mISDN/socket.c:600 [inline]
 mISDN_sock_create+0x272/0x400 drivers/isdn/mISDN/socket.c:796
 __sock_create+0x3cb/0x730 net/socket.c:1428
 sock_create net/socket.c:1479 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1521
 __do_sys_socket net/socket.c:1530 [inline]
 __se_sys_socket net/socket.c:1528 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1528
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 2484:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 mm/slab.c:3757
 kvfree+0x42/0x50 mm/util.c:603
 __free_fdtable+0x2d/0x70 fs/file.c:31
 put_files_struct fs/file.c:420 [inline]
 put_files_struct+0x248/0x2e0 fs/file.c:413
 exit_files+0x7e/0xa0 fs/file.c:445
 do_exit+0xb04/0x2dd0 kernel/exit.c:791
 do_group_exit+0x125/0x340 kernel/exit.c:894
 get_signal+0x47b/0x24e0 kernel/signal.c:2739
 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784
 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff88808ed0c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1424 bytes inside of
 2048-byte region [ffff88808ed0c000, ffff88808ed0c800)
The buggy address belongs to the page:
page:ffffea00023b4300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002838208 ffffea00015ba288 ffff8880aa000e00
raw: 0000000000000000 ffff88808ed0c000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808ed0c480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808ed0c500: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808ed0c580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88808ed0c600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808ed0c680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 6b9f3423 ("l2tp: fix races in tunnel creation")
Fixes: fd558d18 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Guillaume Nault <gnault@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

syzbot recently found a way to crash the kernel [1]

Issue here is that inet_hash() & inet_unhash() are currently
only meant to be used by TCP & DCCP, since only these protocols
provide the needed hashinfo pointer.

L2TP uses a single list (instead of a hash table)

This old bug became an issue after commit 61023658
("bpf: Add new cgroup attach type to enable sock modifications")
since after this commit, sk_common_release() can be called
while the L2TP socket is still considered 'hashed'.

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05 00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:ffffc90001777d30 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809a6df940 RCX: ffffffff8697c242
RDX: 0000000000000001 RSI: ffffffff8697c251 RDI: 0000000000000008
RBP: 0000000000000000 R08: ffff88809f3ae1c0 R09: fffffbfff1514cc1
R10: ffffffff8a8a6607 R11: fffffbfff1514cc0 R12: ffff88809a6df9b0
R13: 0000000000000007 R14: 0000000000000000 R15: ffffffff873a4d00
FS:  0000000001d2b880(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006cd090 CR3: 000000009403a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sk_common_release+0xba/0x370 net/core/sock.c:3210
 inet_create net/ipv4/af_inet.c:390 [inline]
 inet_create+0x966/0xe00 net/ipv4/af_inet.c:248
 __sock_create+0x3cb/0x730 net/socket.c:1428
 sock_create net/socket.c:1479 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1521
 __do_sys_socket net/socket.c:1530 [inline]
 __se_sys_socket net/socket.c:1528 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1528
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x441e29
Code: e8 fc b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdce184148 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441e29
RDX: 0000000000000073 RSI: 0000000000000002 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000402c30 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 23b6578228ce553e ]---
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05 00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:ffffc90001777d30 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809a6df940 RCX: ffffffff8697c242
RDX: 0000000000000001 RSI: ffffffff8697c251 RDI: 0000000000000008
RBP: 0000000000000000 R08: ffff88809f3ae1c0 R09: fffffbfff1514cc1
R10: ffffffff8a8a6607 R11: fffffbfff1514cc0 R12: ffff88809a6df9b0
R13: 0000000000000007 R14: 0000000000000000 R15: ffffffff873a4d00
FS:  0000000001d2b880(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006cd090 CR3: 000000009403a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: 0d76751f ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Reported-by: syzbot+3610d489778b57cc8031@syzkaller.appspotmail.com

A null pointer dereference in qrtr_ns_data_ready() is seen if a client
opens a qrtr socket before qrtr_ns_init() can bind to the control port.
When the control port is bound, the ENETRESET error will be broadcasted
and clients will close their sockets. This results in DEL_CLIENT
packets being sent to the ns and qrtr_ns_data_ready() being called
without the workqueue being allocated.

Allocate the workqueue before setting sk_data_ready and binding to the
control port. This ensures that the work and workqueue structs are
allocated and initialized before qrtr_ns_data_ready can be called.

Fixes: 0c2204a4 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Chris Lew <clew@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Paolo Abeni says:

====================
mptcp: a bunch of fixes

This patch series pulls together a few bugfixes for MPTCP bug observed while
doing stress-test with apache bench - forced to use MPTCP and multiple
subflows.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently we remote the msk from the token container only
via mptcp_close(). The MPTCP master socket can be destroyed
also via other paths (e.g. if not yet accepted, when shutting
down the listener socket). When we hit the latter scenario,
dangling msk references are left into the token container,
leading to memory corruption and/or UaF.

This change addresses the issue by moving the token removal
into the msk destructor.

Fixes: 79c0949e ("mptcp: Add key generation and token tree")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If a MP_JOIN subflow completes the 3whs while another
CPU is closing the master msk, we can hit the
following race:

CPU1                                    CPU2

close()
 mptcp_close
                                        subflow_syn_recv_sock
                                         mptcp_token_get_sock
                                         mptcp_finish_join
                                          inet_sk_state_load
  mptcp_token_destroy
  inet_sk_state_store(TCP_CLOSE)
  __mptcp_flush_join_list()
                                          mptcp_sock_graft
                                          list_add_tail
  sk_common_release
   sock_orphan()
 <socket free>

The MP_JOIN socket will be leaked. Additionally we can hit
UaF for the msk 'struct socket' referenced via the 'conn'
field.

This change try to address the issue introducing some
synchronization between the MP_JOIN 3whs and mptcp_close
via the join_list spinlock. If we detect the msk is closing
the MP_JOIN socket is closed, too.

Fixes: f296234c ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently unblocking connect() on MPTCP sockets fails frequently.
If mptcp_stream_connect() is invoked to complete a previously
attempted unblocking connection, it will still try to create
the first subflow via __mptcp_socket_create(). If the 3whs is
completed and the 'can_ack' flag is already set, the latter
will fail with -EINVAL.

This change addresses the issue checking for pending connect and
delegating the completion to the first subflow. Additionally
do msk addresses and sk_state changes only when needed.

Fixes: 2303f994 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently add nat mangle action with comparing invert and orig tuple.
It is better to check IPS_NAT_MASK flags first to avoid non necessary
memcmp for non-NAT conntrack.
Signed-off-by: wenxu <wenxu@ucloud.cn>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When devinet_sysctl_register() failed, the memory allocated
in neigh_parms_alloc() should be freed.

Fixes: 20e61da7 ("ipv4: fail early when creating netdev named all or default")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When client on the host tries to connect(SOCK_STREAM, O_NONBLOCK) to the
server on the guest, there will be a panic on a ThunderX2 (armv8a server):

[  463.718844] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  463.718848] Mem abort info:
[  463.718849]   ESR = 0x96000044
[  463.718852]   EC = 0x25: DABT (current EL), IL = 32 bits
[  463.718853]   SET = 0, FnV = 0
[  463.718854]   EA = 0, S1PTW = 0
[  463.718855] Data abort info:
[  463.718856]   ISV = 0, ISS = 0x00000044
[  463.718857]   CM = 0, WnR = 1
[  463.718859] user pgtable: 4k pages, 48-bit VAs, pgdp=0000008f6f6e9000
[  463.718861] [0000000000000000] pgd=0000000000000000
[  463.718866] Internal error: Oops: 96000044 [#1] SMP
[...]
[  463.718977] CPU: 213 PID: 5040 Comm: vhost-5032 Tainted: G           O      5.7.0-rc7+ #139
[  463.718980] Hardware name: GIGABYTE R281-T91-00/MT91-FS1-00, BIOS F06 09/25/2018
[  463.718982] pstate: 60400009 (nZCv daif +PAN -UAO)
[  463.718995] pc : virtio_transport_recv_pkt+0x4c8/0xd40 [vmw_vsock_virtio_transport_common]
[  463.718999] lr : virtio_transport_recv_pkt+0x1fc/0xd40 [vmw_vsock_virtio_transport_common]
[  463.719000] sp : ffff80002dbe3c40
[...]
[  463.719025] Call trace:
[  463.719030]  virtio_transport_recv_pkt+0x4c8/0xd40 [vmw_vsock_virtio_transport_common]
[  463.719034]  vhost_vsock_handle_tx_kick+0x360/0x408 [vhost_vsock]
[  463.719041]  vhost_worker+0x100/0x1a0 [vhost]
[  463.719048]  kthread+0x128/0x130
[  463.719052]  ret_from_fork+0x10/0x18

The race condition is as follows:
Task1                                Task2
=====                                =====
__sock_release                       virtio_transport_recv_pkt
  __vsock_release                      vsock_find_bound_socket (found sk)
    lock_sock_nested
    vsock_remove_sock
    sock_orphan
      sk_set_socket(sk, NULL)
    sk->sk_shutdown = SHUTDOWN_MASK
    ...
    release_sock
                                    lock_sock
                                       virtio_transport_recv_connecting
                                         sk->sk_socket->state (panic!)

The root cause is that vsock_find_bound_socket can't hold the lock_sock,
so there is a small race window between vsock_find_bound_socket() and
lock_sock(). If __vsock_release() is running in another task,
sk->sk_socket will be set to NULL inadvertently.

This fixes it by checking sk->sk_shutdown(suggested by Stefano) after
lock_sock since sk->sk_shutdown is set to SHUTDOWN_MASK under the
protection of lock_sock_nested.
Signed-off-by: Jia He <justin.he@arm.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull powerpc fixes from Michael Ellerman:

 - a fix for the recent change to how we restore non-volatile GPRs,
   which broke our emulation of reading from the DSCR (Data Stream
   Control Register).

 - a fix for the recent rewrite of interrupt/syscall exit in C, we need
   to exclude KCOV from that code, otherwise it can lead to
   unrecoverable faults.

Thanks to Daniel Axtens.

* tag 'powerpc-5.7-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Disable sanitisers for C syscall/interrupt entry/exit code
  powerpc/64s: Fix restore of NV GPRs after facility unavailable exception

Pull GPIO fixes from Linus Walleij:
 "Here are some (very) late fixes for GPIO, none of them very serious
  except the one tagged for stable for enabling IRQ on open drain lines:

   - Fix probing of mvebu chips without PWM

   - Fix error path on ida_get_simple() on the exar driver

   - Notify userspace properly about line status changes when flags are
     changed on lines.

   - Fix a sleeping while holding spinlock in the mellanox driver.

   - Fix return value of the PXA and Kona probe calls.

   - Fix IRQ locking of open drain lines, it is fine to have IRQs on
     open drain lines flagged for output"

* tag 'gpio-v5.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: fix locking open drain IRQ lines
  gpio: bcm-kona: Fix return value of bcm_kona_gpio_probe()
  gpio: pxa: Fix return value of pxa_gpio_probe()
  gpio: mlxbf2: Fix sleeping while holding spinlock
  gpiolib: notify user-space about line status changes after flags are set
  gpio: exar: Fix bad handling for ida_simple_get error path
  gpio: mvebu: Fix probing for chips without PWM

VNIC protocol version is reported in big-endian format, but it
is not byteswapped before logging. Fix that, and remove version
comparison as only one protocol version exists at this time.
Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

st21nfca_tm_send_atr_res() misses to call kfree_skb() in an error path.
Add the missed function call to fix it.

Fixes: 1892bf84 ("NFC: st21nfca: Adding P2P support to st21nfca in Initiator & Target mode")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In commit 19e16d22 ("neigh: support smaller retrans_time settting")
we add more accurate control for ARP and NS. But for ARP I forgot to
update the latest guard in neigh_timer_handler(), then the next
retransmit would be reset to jiffies + HZ/2 if we set the retrans_time
less than 500ms. Fix it by setting the time_before() check to HZ/100.

IPv6 does not have this issue.
Reported-by: Jianwen Ji <jiji@redhat.com>
Fixes: 19e16d22 ("neigh: support smaller retrans_time settting")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5 fixes 2020-05-28

This series introduces some fixes to mlx5 driver.

v1->v2:
 - Fix bad sha1, Jakub.
 - Added one more patch by Pablo.
   net/mlx5e: replace EINVAL in mlx5e_flower_parse_meta()

Nothing major, the only patch worth mentioning is the suspend/resume crash
fix by adding the missing pci device handlers, the fix is very straight
forward and as Dexuan already expressed, the patch is important for Azure
users to avoid crash on VM hibernation, patch is marked for -stable v4.6
below.

Conflict note:
('net/mlx5e: Fix MLX5_TC_CT dependencies') has a trivial one line conflict
with current net-next, which can be resolved by simply using the line from
net-next.

Please pull and let me know if there is any problem.

For -stable v4.6
 ('net/mlx5: Fix crash upon suspend/resume')

For -stable v5.6
 ('net/mlx5e: replace EINVAL in mlx5e_flower_parse_meta()')
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull ARM SoC fixes from Arnd Bergmann:
 "This time there is one fix for the error path in the mediatek cmdq
  driver (used by their video driver) and a couple of devicetree fixes,
  mostly for 32-bit ARM, and fairly harmless:

   - On OMAP2 there were a few regressions in the ethernet drivers, one
     of them leading to an external abort trap

   - One Raspberry Pi version had a misconfigured LED

   - Interrupts on Broadcom NSP were slightly misconfigured

   - One i.MX6q board had issues with graphics mode setting

   - On mmp3 there are some minor fixes that were submitted for v5.8
     with a cc:stable tag, so I ended up picking them up here as well

   - The Mediatek Video Codec needs to run at a higher frequency than
     configured originally"

* tag 'armsoc-fixes-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: dts: mmp3: Drop usb-nop-xceiv from HSIC phy
  ARM: dts: mmp3-dell-ariel: Fix the SPI devices
  ARM: dts: mmp3: Use the MMP3 compatible string for /clocks
  ARM: dts: bcm: HR2: Fix PPI interrupt types
  ARM: dts: bcm2835-rpi-zero-w: Fix led polarity
  ARM: dts/imx6q-bx50v3: Set display interface clock parents
  soc: mediatek: cmdq: return send msg error code
  arm64: dts: mt8173: fix vcodec-enc clock
  ARM: dts: Fix wrong mdio clock for dm814x
  ARM: dts: am437x: fix networking on boards with ksz9031 phy
  ARM: dts: am57xx: fix networking on boards with ksz9031 phy

Alexei Starovoitov says:

====================
pull-request: bpf 2020-05-29

The following pull-request contains BPF updates for your *net* tree.

We've added 6 non-merge commits during the last 7 day(s) which contain
a total of 4 files changed, 55 insertions(+), 34 deletions(-).

The main changes are:

1) minor verifier fix for fmod_ret progs, from Alexei.

2) af_xdp overflow check, from Bjorn.

3) minor verifier fix for 32bit assignment, from John.

4) powerpc has non-overlapping addr space, from Petr.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull ceph fixes from Ilya Dryomov:
 "Cache tiering and cap handling fixups, both marked for stable"

* tag 'ceph-for-5.7-rc8' of git://github.com/ceph/ceph-client:
  ceph: flush release queue when handling caps for unknown inode
  libceph: ignore pool overlay and cache logic on redirects

Pull gfs2 fix from Andreas Gruenbacher:
 "Fix the previous, flawed gfs2_find_jhead commit"

* tag 'gfs2-v5.7-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Even more gfs2_find_jhead fixes

Pull arm64 fix from Catalin Marinas:
 "Ensure __cpu_up() returns an error if cpu_online() is false after
  waiting for completion on cpu_running"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/kernel: Fix return value when cpu_online() fails in __cpu_up()

Pull parisc fix from Helge Deller:
 "Fix a kernel panic at boot time for some HP-PARISC machines"

* 'parisc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix kernel panic in mem_init()

Pull iommu fixes from Joerg Roedel:

 - Two build fixes for issues introduced during the merge window

 - A fix for a reference count leak in an error path of
   iommu_group_alloc()

* tag 'iommu-fixes-v5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu: Fix reference count leak in iommu_group_alloc.
  x86: Hide the archdata.iommu field behind generic IOMMU_API
  ia64: Hide the archdata.iommu field behind generic IOMMU_API

Pull block fixes from Jens Axboe:
 "Two small fixes:

   - Revert a block change that mixed up the return values for non-mq
     devices

   - NVMe poll race fix"

* tag 'block-5.7-2020-05-29' of git://git.kernel.dk/linux-block:
  Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"
  nvme-pci: avoid race between nvme_reap_pending_cqes() and nvme_poll()

Pull rdma fixes from Jason Gunthorpe:
 "Nothing profound here, just a last set of long standing bug fixes:

   - Incorrect error unwind in qib and pvrdma

   - User triggerable NULL pointer crash in mlx5 with ODP prefetch

   - syzkaller RCU race in uverbs

   - Rare double free crash in ipoib"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  IB/ipoib: Fix double free of skb in case of multicast traffic in CM mode
  RDMA/core: Fix double destruction of uobject
  RDMA/pvrdma: Fix missing pci disable in pvrdma_pci_probe()
  RDMA/mlx5: Fix NULL pointer dereference in destroy_prefetch_work
  IB/qib: Call kobject_put() when kobject_init_and_add() fails

Added a verifier test for assigning 32bit reg states to
64bit where 32bit reg holds a constant value of 0.

Without previous kernel verifier.c fix, the test in
this patch will fail.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/159077335867.6014.2075350327073125374.stgit@john-Precision-5820-Tower