====================
This set fixes an out of bounds case under speculative execution
by implementing masking of pointer alu into the verifier. For
details please see the individual patches.
Thanks!
v2 -> v3:
- 8/9: change states_equal condition into old->speculative &&
!cur->speculative, thanks Jakub!
- 8/9: remove incorrect speculative state test in
propagate_liveness(), thanks Jakub!
v1 -> v2:
- Typo fixes in commit msg and a comment, thanks David!
====================
Daniel Borkmann [Wed, 2 Jan 2019 23:58:35 +0000 (00:58 +0100)]
bpf: add various test cases to selftests
Add various map value pointer related test cases to test_verifier
kselftest to reflect recent changes and improve test coverage. The
tests include basic masking functionality, unprivileged behavior
on pointer arithmetic which goes oob, mixed bounds tests, negative
unknown scalar but resulting positive offset for access and helper
range, handling of arithmetic from multiple maps, various masking
scenarios with subsequent map value access and others including two
test cases from Jann Horn for prior fixes.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:34 +0000 (00:58 +0100)]
bpf: prevent out of bounds speculation on pointer arithmetic
Jann reported that the original commit back in b2157399cc98
("bpf: prevent out-of-bounds speculation") was not sufficient
to stop CPU from speculating out of bounds memory access:
While b2157399cc98 only focussed on masking array map access
for unprivileged users for tail calls and data access such
that the user provided index gets sanitized from BPF program
and syscall side, there is still a more generic form affected
from BPF programs that applies to most maps that hold user
data in relation to dynamic map access when dealing with
unknown scalars or "slow" known scalars as access offset, for
example:
- Load a map value pointer into R6
- Load an index into R7
- Do a slow computation (e.g. with a memory dependency) that
loads a limit into R8 (e.g. load the limit from a map for
high latency, then mask it to make the verifier happy)
- Exit if R7 >= R8 (mispredicted branch)
- Load R0 = R6[R7]
- Load R0 = R6[R0]
For unknown scalars there are two options in the BPF verifier
where we could derive knowledge from in order to guarantee
safe access to the memory: i) While </>/<=/>= variants won't
allow to derive any lower or upper bounds from the unknown
scalar where it would be safe to add it to the map value
pointer, it is possible through ==/!= test however. ii) another
option is to transform the unknown scalar into a known scalar,
for example, through ALU ops combination such as R &= <imm>
followed by R |= <imm> or any similar combination where the
original information from the unknown scalar would be destroyed
entirely leaving R with a constant. The initial slow load still
precedes the latter ALU ops on that register, so the CPU
executes speculatively from that point. Once we have the known
scalar, any compare operation would work then. A third option
only involving registers with known scalars could be crafted
as described in [0] where a CPU port (e.g. Slow Int unit)
would be filled with many dependent computations such that
the subsequent condition depending on its outcome has to wait
for evaluation on its execution port and thereby executing
speculatively if the speculated code can be scheduled on a
different execution port, or any other form of mistraining
as described in [1], for example. Given this is not limited
to only unknown scalars, not only map but also stack access
is affected since both is accessible for unprivileged users
and could potentially be used for out of bounds access under
speculation.
In order to prevent any of these cases, the verifier is now
sanitizing pointer arithmetic on the offset such that any
out of bounds speculation would be masked in a way where the
pointer arithmetic result in the destination register will
stay unchanged, meaning offset masked into zero similar as
in array_index_nospec() case. With regards to implementation,
there are three options that were considered: i) new insn
for sanitation, ii) push/pop insn and sanitation as inlined
BPF, iii) reuse of ax register and sanitation as inlined BPF.
Option i) has the downside that we end up using from reserved
bits in the opcode space, but also that we would require
each JIT to emit masking as native arch opcodes meaning
mitigation would have slow adoption till everyone implements
it eventually which is counter-productive. Option ii) and iii)
have both in common that a temporary register is needed in
order to implement the sanitation as inlined BPF since we
are not allowed to modify the source register. While a push /
pop insn in ii) would be useful to have in any case, it
requires once again that every JIT needs to implement it
first. While possible, amount of changes needed would also
be unsuitable for a -stable patch. Therefore, the path which
has fewer changes, less BPF instructions for the mitigation
and does not require anything to be changed in the JITs is
option iii) which this work is pursuing. The ax register is
already mapped to a register in all JITs (modulo arm32 where
it's mapped to stack as various other BPF registers there)
and used in constant blinding for JITs-only so far. It can
be reused for verifier rewrites under certain constraints.
The interpreter's tmp "register" has therefore been remapped
into extending the register set with hidden ax register and
reusing that for a number of instructions that needed the
prior temporary variable internally (e.g. div, mod). This
allows for zero increase in stack space usage in the interpreter,
and enables (restricted) generic use in rewrites otherwise as
long as such a patchlet does not make use of these instructions.
The sanitation mask is dynamic and relative to the offset the
map value or stack pointer currently holds.
There are various cases that need to be taken under consideration
for the masking, e.g. such operation could look as follows:
ptr += val or val += ptr or ptr -= val. Thus, the value to be
sanitized could reside either in source or in destination
register, and the limit is different depending on whether
the ALU op is addition or subtraction and depending on the
current known and bounded offset. The limit is derived as
follows: limit := max_value_size - (smin_value + off). For
subtraction: limit := umax_value + off. This holds because
we do not allow any pointer arithmetic that would
temporarily go out of bounds or would have an unknown
value with mixed signed bounds where it is unclear at
verification time whether the actual runtime value would
be either negative or positive. For example, we have a
derived map pointer value with constant offset and bounded
one, so limit based on smin_value works because the verifier
requires that statically analyzed arithmetic on the pointer
must be in bounds, and thus it checks if resulting
smin_value + off and umax_value + off is still within map
value bounds at time of arithmetic in addition to time of
access. Similarly, for the case of stack access we derive
the limit as follows: MAX_BPF_STACK + off for subtraction
and -off for the case of addition where off := ptr_reg->off +
ptr_reg->var_off.value. Subtraction is a special case for
the masking which can be in form of ptr += -val, ptr -= -val,
or ptr -= val. In the first two cases where we know that
the value is negative, we need to temporarily negate the
value in order to do the sanitation on a positive value
where we later swap the ALU op, and restore original source
register if the value was in source.
The sanitation of pointer arithmetic alone is still not fully
sufficient as is, since a scenario like the following could
happen ...
... and therefore still access out of bounds. To prevent such
case, the verifier is also analyzing safety for potential out
of bounds access under speculative execution. Meaning, it is
also simulating pointer access under truncation. We therefore
"branch off" and push the current verification state after the
ALU operation with known 0 to the verification stack for later
analysis. Given the current path analysis succeeded it is
likely that the one under speculation can be pruned. In any
case, it is also subject to existing complexity limits and
therefore anything beyond this point will be rejected. In
terms of pruning, it needs to be ensured that the verification
state from speculative execution simulation must never prune
a non-speculative execution path, therefore, we mark verifier
state accordingly at the time of push_stack(). If verifier
detects out of bounds access under speculative execution from
one of the possible paths that includes a truncation, it will
reject such program.
Given we mask every reg-based pointer arithmetic for
unprivileged programs, we've been looking into how it could
affect real-world programs in terms of size increase. As the
majority of programs are targeted for privileged-only use
case, we've unconditionally enabled masking (with its alu
restrictions on top of it) for privileged programs for the
sake of testing in order to check i) whether they get rejected
in its current form, and ii) by how much the number of
instructions and size will increase. We've tested this by
using Katran, Cilium and test_l4lb from the kernel selftests.
For Katran we've evaluated balancer_kern.o, Cilium bpf_lxc.o
and an older test object bpf_lxc_opt_-DUNKNOWN.o and l4lb
we've used test_l4lb.o as well as test_l4lb_noinline.o. We
found that none of the programs got rejected by the verifier
with this change, and that impact is rather minimal to none.
balancer_kern.o had 13,904 bytes (1,738 insns) xlated and
7,797 bytes JITed before and after the change. Most complex
program in bpf_lxc.o had 30,544 bytes (3,817 insns) xlated
and 18,538 bytes JITed before and after and none of the other
tail call programs in bpf_lxc.o had any changes either. For
the older bpf_lxc_opt_-DUNKNOWN.o object we found a small
increase from 20,616 bytes (2,576 insns) and 12,536 bytes JITed
before to 20,664 bytes (2,582 insns) and 12,558 bytes JITed
after the change. Other programs from that object file had
similar small increase. Both test_l4lb.o had no change and
remained at 6,544 bytes (817 insns) xlated and 3,401 bytes
JITed and for test_l4lb_noinline.o constant at 5,080 bytes
(634 insns) xlated and 3,313 bytes JITed. This can be explained
in that LLVM typically optimizes stack based pointer arithmetic
by using K-based operations and that use of dynamic map access
is not overly frequent. However, in future we may decide to
optimize the algorithm further under known guarantees from
branch and value speculation. Latter seems also unclear in
terms of prediction heuristics that today's CPUs apply as well
as whether there could be collisions in e.g. the predictor's
Value History/Pattern Table for triggering out of bounds access,
thus masking is performed unconditionally at this point but could
be subject to relaxation later on. We were generally also
brainstorming various other approaches for mitigation, but the
blocker was always lack of available registers at runtime and/or
overhead for runtime tracking of limits belonging to a specific
pointer. Thus, we found this to be minimally intrusive under
given constraints.
With that in place, a simple example with sanitized access on
unprivileged load at post-verification time looks as follows:
JIT blinding example with non-conflicting use of r10:
[...]
d5: je 0x0000000000000106 _
d7: mov 0x0(%rax),%edi |
da: mov $0xf153246,%r10d | Index load from map value and
e0: xor $0xf153259,%r10 | (const blinded) mask with 0x1f.
e7: and %r10,%rdi |_
ea: mov $0x2f,%r10d |
f0: sub %rdi,%r10 | Sanitized addition. Both use r10
f3: or %rdi,%r10 | but do not interfere with each
f6: neg %r10 | other. (Neither do these instructions
f9: sar $0x3f,%r10 | interfere with the use of ax as temp
fd: and %r10,%rdi | in interpreter.)
100: add %rax,%rdi |_
103: mov 0x0(%rdi),%eax
[...]
Tested that it fixes Jann's reproducer, and also checked that test_verifier
and test_progs suite with interpreter, JIT and JIT with hardening enabled
on x86-64 and arm64 runs successfully.
[0] Speculose: Analyzing the Security Implications of Speculative
Execution in CPUs, Giorgi Maisuradze and Christian Rossow,
https://arxiv.org/pdf/1801.04084.pdf
[1] A Systematic Evaluation of Transient Execution Attacks and
Defenses, Claudio Canella, Jo Van Bulck, Michael Schwarz,
Moritz Lipp, Benjamin von Berg, Philipp Ortner, Frank Piessens,
Dmitry Evtyushkin, Daniel Gruss,
https://arxiv.org/pdf/1811.05441.pdf
Daniel Borkmann [Wed, 2 Jan 2019 23:58:33 +0000 (00:58 +0100)]
bpf: fix check_map_access smin_value test when pointer contains offset
In check_map_access() we probe actual bounds through __check_map_access()
with offset of reg->smin_value + off for lower bound and offset of
reg->umax_value + off for the upper bound. However, even though the
reg->smin_value could have a negative value, the final result of the
sum with off could be positive when pointer arithmetic with known and
unknown scalars is combined. In this case we reject the program with
an error such as "R<x> min value is negative, either use unsigned index
or do a if (index >=0) check." even though the access itself would be
fine. Therefore extend the check to probe whether the actual resulting
reg->smin_value + off is less than zero.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:32 +0000 (00:58 +0100)]
bpf: restrict unknown scalars of mixed signed bounds for unprivileged
For unknown scalars of mixed signed bounds, meaning their smin_value is
negative and their smax_value is positive, we need to reject arithmetic
with pointer to map value. For unprivileged the goal is to mask every
map pointer arithmetic and this cannot reliably be done when it is
unknown at verification time whether the scalar value is negative or
positive. Given this is a corner case, the likelihood of breaking should
be very small.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:31 +0000 (00:58 +0100)]
bpf: restrict stack pointer arithmetic for unprivileged
Restrict stack pointer arithmetic for unprivileged users in that
arithmetic itself must not go out of bounds as opposed to the actual
access later on. Therefore after each adjust_ptr_min_max_vals() with
a stack pointer as a destination we simulate a check_stack_access()
of 1 byte on the destination and once that fails the program is
rejected for unprivileged program loads. This is analog to map
value pointer arithmetic and needed for masking later on.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:30 +0000 (00:58 +0100)]
bpf: restrict map value pointer arithmetic for unprivileged
Restrict map value pointer arithmetic for unprivileged users in that
arithmetic itself must not go out of bounds as opposed to the actual
access later on. Therefore after each adjust_ptr_min_max_vals() with a
map value pointer as a destination it will simulate a check_map_access()
of 1 byte on the destination and once that fails the program is rejected
for unprivileged program loads. We use this later on for masking any
pointer arithmetic with the remainder of the map value space. The
likelihood of breaking any existing real-world unprivileged eBPF
program is very small for this corner case.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:29 +0000 (00:58 +0100)]
bpf: enable access to ax register also from verifier rewrite
Right now we are using BPF ax register in JIT for constant blinding as
well as in interpreter as temporary variable. Verifier will not be able
to use it simply because its use will get overridden from the former in
bpf_jit_blind_insn(). However, it can be made to work in that blinding
will be skipped if there is prior use in either source or destination
register on the instruction. Taking constraints of ax into account, the
verifier is then open to use it in rewrites under some constraints. Note,
ax register already has mappings in every eBPF JIT.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:28 +0000 (00:58 +0100)]
bpf: move tmp variable into ax register in interpreter
This change moves the on-stack 64 bit tmp variable in ___bpf_prog_run()
into the hidden ax register. The latter is currently only used in JITs
for constant blinding as a temporary scratch register, meaning the BPF
interpreter will never see the use of ax. Therefore it is safe to use
it for the cases where tmp has been used earlier. This is needed to later
on allow restricted hidden use of ax in both interpreter and JITs.
Daniel Borkmann [Wed, 2 Jan 2019 23:58:27 +0000 (00:58 +0100)]
bpf: move {prev_,}insn_idx into verifier env
Move prev_insn_idx and insn_idx from the do_check() function into
the verifier environment, so they can be read inside the various
helper functions for handling the instructions. It's easier to put
this into the environment rather than changing all call-sites only
to pass it along. insn_idx is useful in particular since this later
on allows to hold state in env->insn_aux_data[env->insn_idx].
Julia Lawall [Sun, 23 Dec 2018 08:57:01 +0000 (09:57 +0100)]
IB/ipoib: drop useless LIST_HEAD
Drop LIST_HEAD where the variable it declares is never used.
Commit 31c02e215700 ("IPoIB: Avoid using stale last_send counter
when reaping AHs") removed the uses, but not the declaration.
The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
@@
- LIST_HEAD(x);
... when != x
// </smpl>
Fixes: 31c02e215700 ("IPoIB: Avoid using stale last_send counter when reaping AHs") Signed-off-by: Julia Lawall <[email protected]> Reviewed-by: Leon Romanovsky <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]>
Aaro Koskinen [Wed, 2 Jan 2019 18:43:01 +0000 (20:43 +0200)]
MIPS: OCTEON: mark RGMII interface disabled on OCTEON III
Commit 885872b722b7 ("MIPS: Octeon: Add Octeon III CN7xxx
interface detection") added RGMII interface detection for OCTEON III,
but it results in the following logs:
[ 7.165984] ERROR: Unsupported Octeon model in __cvmx_helper_rgmii_probe
[ 7.173017] ERROR: Unsupported Octeon model in __cvmx_helper_rgmii_probe
The current RGMII routines are valid only for older OCTEONS that
use GMX/ASX hardware blocks. On later chips AGL should be used,
but support for that is missing in the mainline. Until that is added,
mark the interface as disabled.
Bjorn Helgaas [Wed, 2 Jan 2019 21:31:09 +0000 (15:31 -0600)]
Merge branch 'remotes/lorenzo/pci/dwc-msi'
- Mask DesignWare interrupts instead of disabling them to avoid lost
interrupts (Marc Zyngier)
- Add locking when acking DesignWare interrupts (Marc Zyngier)
- Ack DesignWare interrupts in the proper callbacks (Marc Zyngier)
* remotes/lorenzo/pci/dwc-msi:
PCI: dwc: Move interrupt acking into the proper callback
PCI: dwc: Take lock when ACKing an interrupt
PCI: dwc: Use interrupt masking instead of disabling
Bjorn Helgaas [Wed, 2 Jan 2019 21:31:03 +0000 (15:31 -0600)]
Merge branch 'pci/misc'
- Expand Kconfig "PF" acronyms (Randy Dunlap)
- Update MAINTAINERS for arch/x86/kernel/early-quirks.c (Bjorn Helgaas)
- Add missing include to drivers/pci.h (Alexandru Gagniuc)
- Override Synopsys USB 3.x HAPS device class so dwc3-haps can claim it
instead of xhci (Thinh Nguyen)
* pci/misc:
PCI: Override Synopsys USB 3.x HAPS device class
PCI: Move Synopsys HAPS platform device IDs
PCI: Add missing include to drivers/pci.h
PCI: Remove unnecessary space before function pointer arguments
MAINTAINERS: Add x86 early-quirks.c file pattern to PCI subsystem
PCI: Expand the "PF" acronym in Kconfig help text
Linus Torvalds [Wed, 2 Jan 2019 20:11:01 +0000 (12:11 -0800)]
Merge tag '9p-for-4.21' of git://github.com/martinetd/linux
Pull 9p updates from Dominique Martinet:
"Missing prototype warning fix and a syzkaller fix when a 9p server
advertises a too small msize"
* tag '9p-for-4.21' of git://github.com/martinetd/linux:
9p/net: put a lower bound on msize
net/9p: include trans_common.h to fix missing prototype warning.
Linus Torvalds [Wed, 2 Jan 2019 20:08:29 +0000 (12:08 -0800)]
Merge tag '4.21-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs updates from Steve French:
- four fixes for stable
- improvements to DFS including allowing failover to alternate targets
- some small performance improvements
* tag '4.21-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: (39 commits)
cifs: update internal module version number
cifs: we can not use small padding iovs together with encryption
cifs: Minor Kconfig clarification
cifs: Always resolve hostname before reconnecting
cifs: Add support for failover in cifs_reconnect_tcon()
cifs: Add support for failover in smb2_reconnect()
cifs: Only free DFS target list if we actually got one
cifs: start DFS cache refresher in cifs_mount()
cifs: Use GFP_ATOMIC when a lock is held in cifs_mount()
cifs: Add support for failover in cifs_reconnect()
cifs: Add support for failover in cifs_mount()
cifs: remove set but not used variable 'sep'
cifs: Make use of DFS cache to get new DFS referrals
cifs: minor updates to documentation
cifs: check kzalloc return
cifs: remove set but not used variable 'server'
cifs: Use kzfree() to free password
cifs: Fix to use kmem_cache_free() instead of kfree()
cifs: update for current_kernel_time64() removal
cifs: Add DFS cache routines
...
Linus Torvalds [Wed, 2 Jan 2019 19:05:43 +0000 (11:05 -0800)]
Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull TPM updates from James Morris:
- Support for partial reads of /dev/tpm0.
- Clean up for TPM 1.x code: move the commands to tpm1-cmd.c and make
everything to use the same data structure for building TPM commands
i.e. struct tpm_buf.
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (25 commits)
tpm: add support for partial reads
tpm: tpm_ibmvtpm: fix kdoc warnings
tpm: fix kdoc for tpm2_flush_context_cmd()
tpm: tpm_try_transmit() refactor error flow.
tpm: use u32 instead of int for PCR index
tpm1: reimplement tpm1_continue_selftest() using tpm_buf
tpm1: reimplement SAVESTATE using tpm_buf
tpm1: rename tpm1_pcr_read_dev to tpm1_pcr_read()
tpm1: implement tpm1_pcr_read_dev() using tpm_buf structure
tpm: tpm1: rewrite tpm1_get_random() using tpm_buf structure
tpm: tpm-space.c remove unneeded semicolon
tpm: tpm-interface.c drop unused macros
tpm: add tpm_auto_startup() into tpm-interface.c
tpm: factor out tpm_startup function
tpm: factor out tpm 1.x pm suspend flow into tpm1-cmd.c
tpm: move tpm 1.x selftest code from tpm-interface.c tpm1-cmd.c
tpm: factor out tpm1_get_random into tpm1-cmd.c
tpm: move tpm_getcap to tpm1-cmd.c
tpm: move tpm1_pcr_extend to tpm1-cmd.c
tpm: factor out tpm_get_timeouts()
...
Linus Torvalds [Wed, 2 Jan 2019 18:46:03 +0000 (10:46 -0800)]
block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE)
This mostly reverts commit 849a370016a5 ("block: avoid ordered task
state change for polled IO"). It was wrongly claiming that the ordering
wasn't necessary. The memory barrier _is_ necessary.
If something is truly polling and not going to sleep, it's the whole
state setting that is unnecessary, not the memory barrier. Whenever you
set your state to a sleeping state, you absolutely need the memory
barrier.
Note that sometimes the memory barrier can be elsewhere. For example,
the ordering might be provided by an external lock, or by setting the
process state to sleeping before adding yourself to the wait queue list
that is used for waking up (where the wait queue lock itself will
guarantee that any wakeup will correctly see the sleeping state).
But none of those cases were true here.
NOTE! Some of the polling paths may indeed be able to drop the state
setting entirely, at which point the memory barrier also goes away.
(Also note that this doesn't revert the TASK_RUNNING cases: there is no
race between a wakeup and setting the process state to TASK_RUNNING,
since the end result doesn't depend on ordering).
Local variable description: ----data.i@capi_unlocked_ioctl
Variable was created at:
capi_ioctl drivers/isdn/capi/capi.c:747 [inline]
capi_unlocked_ioctl+0x82/0x1bf0 drivers/isdn/capi/capi.c:939
do_vfs_ioctl+0xebd/0x2bf0 fs/ioctl.c:46
Bytes 12-63 of 64 are uninitialized
Memory access of size 64 starts at ffff88807ac5fce8
Data copied to user address 0000000020000080
Stefano Brivio [Wed, 2 Jan 2019 12:29:27 +0000 (13:29 +0100)]
ipv6: route: Fix return value of ip6_neigh_lookup() on neigh_create() error
In ip6_neigh_lookup(), we must not return errors coming from
neigh_create(): if creation of a neighbour entry fails, the lookup should
return NULL, in the same way as it's done in __neigh_lookup().
Otherwise, callers legitimately checking for a non-NULL return value of
the lookup function might dereference an invalid pointer.
For instance, on neighbour table overflow, ndisc_router_discovery()
crashes ndisc_update() by passing ERR_PTR(-ENOBUFS) as 'neigh' argument.
Linus Torvalds [Wed, 2 Jan 2019 17:48:13 +0000 (09:48 -0800)]
Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull seccomp updates from James Morris:
- Add SECCOMP_RET_USER_NOTIF
- seccomp fixes for sparse warnings and s390 build (Tycho)
* 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
seccomp, s390: fix build for syscall type change
seccomp: fix poor type promotion
samples: add an example of seccomp user trap
seccomp: add a return code to trap to userspace
seccomp: switch system call argument type to void *
seccomp: hoist struct seccomp_data recalculation higher
Linus Torvalds [Wed, 2 Jan 2019 17:43:14 +0000 (09:43 -0800)]
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
"In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load syscall.
Different signature verification methods exist for verifying the
kexec'ed kernel image. This adds additional support in IMA to prevent
loading unsigned kernel images via the kexec_load syscall,
independently of the IMA policy rules, based on the runtime "secure
boot" flag. An initial IMA kselftest is included.
In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.
(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here)"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
integrity: Remove references to module keyring
ima: Use inode_is_open_for_write
ima: Support platform keyring for kernel appraisal
efi: Allow the "db" UEFI variable to be suppressed
efi: Import certificates from UEFI Secure Boot
efi: Add an EFI signature blob parser
efi: Add EFI signature data types
integrity: Load certs to the platform keyring
integrity: Define a trusted platform keyring
selftests/ima: kexec_load syscall test
ima: don't measure/appraise files on efivarfs
x86/ima: retry detecting secure boot mode
docs: Extend trusted keys documentation for TPM 2.0
x86/ima: define arch_get_ima_policy() for x86
ima: add support for arch specific policies
ima: refactor ima_init_policy()
ima: prevent kexec_load syscall based on runtime secureboot flag
x86/ima: define arch_ima_get_secureboot
integrity: support new struct public_key_signature encoding field
Multipathing: In case of NFSv3, rpc_clnt_test_and_add_xprt() adds
the xprt to xprt switch (i.e. xps) if rpc_call_null_helper() returns
success. But in case of NFSv4.1, it needs to do EXCHANGEID to verify
the path along with check for session trunking.
Add the xprt in nfs4_test_session_trunk() only when
nfs4_detect_session_trunking() returns success. Also release refcount
hold by rpc_clnt_setup_test_and_add_xprt().
J. Bruce Fields [Thu, 20 Dec 2018 15:42:36 +0000 (10:42 -0500)]
sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS
It's OK to sleep here, we just don't want to recurse into the filesystem
as a writeout could be waiting on this.
Future work: the documentation for GFP_NOFS says "Please try to avoid
using this flag directly and instead use memalloc_nofs_{save,restore} to
mark the whole scope which cannot/shouldn't recurse into the FS layer
with a short explanation why. All allocation requests will inherit
GFP_NOFS implicitly."
But I'm not sure where to do this. Should the workqueue be arranging
that for us in the case of workqueues created with WQ_MEM_RECLAIM?
Chuck Lever [Fri, 7 Dec 2018 16:11:44 +0000 (11:11 -0500)]
xprtrdma: Prevent leak of rpcrdma_rep objects
If a reply has been processed but the RPC is later retransmitted
anyway, the req->rl_reply field still contains the only pointer to
the old rpcrdma rep. When the next reply comes in, the reply handler
will stomp on the rl_reply field, leaking the old rep.
A trace event is added to capture such leaks.
This problem seems to be worsened by the restructuring of the RPC
Call path in v4.20. Fully addressing this issue will require at
least a re-architecture of the disconnect logic, which is not
appropriate during -rc.
Original commit (e4648aa4f98a "NFS recover from destination server
reboot for copies") used memcmp() and then it was changed to use
nfs4_stateid_match_other() but that function returns opposite of
memcmp. As the result, recovery can't find the copy leading
to copy hanging.
Fixes: 80f42368868e ("NFSv4: Split out NFS v4.2 copy completion functions") Fixes: cb7a8384dc02 ("NFS: Split out the body of nfs4_reclaim_open_state") Signed-of-by: Olga Kornievskaia <[email protected]> Signed-off-by: Anna Schumaker <[email protected]>
Chuck Lever [Wed, 19 Dec 2018 16:00:32 +0000 (11:00 -0500)]
xprtrdma: Replace outdated comment for rpcrdma_ep_post
Since commit 7c8d9e7c8863 ("xprtrdma: Move Receive posting to
Receive handler"), rpcrdma_ep_post is no longer responsible for
posting Receive buffers. Update the documenting comment to reflect
this change.
Chuck Lever [Wed, 19 Dec 2018 16:00:27 +0000 (11:00 -0500)]
xprtrdma: Update comments in frwr_op_send
Commit f2877623082b ("xprtrdma: Chain Send to FastReg WRs") was
written before commit ce5b37178283 ("xprtrdma: Replace all usage of
"frmr" with "frwr""), but was merged afterwards. Thus it still
refers to FRMR and MWs.
Chuck Lever [Wed, 19 Dec 2018 16:00:11 +0000 (11:00 -0500)]
NFS: Fix NFSv4 symbolic trace point output
These symbolic values were not being displayed in string form.
TRACE_DEFINE_ENUM was missing in many cases. It also turns out that
__print_symbolic wants an unsigned long in the first field...
Chuck Lever [Wed, 19 Dec 2018 15:59:33 +0000 (10:59 -0500)]
xprtrdma: Simplify locking that protects the rl_allreqs list
Clean up: There's little chance of contention between the use of
rb_lock and rb_reqslock, so merge the two. This avoids having to
take both in some (possibly future) cases.
Transport tear-down is already serialized, thus there is no need for
locking at all when destroying rpcrdma_reqs.
Chuck Lever [Wed, 19 Dec 2018 15:59:23 +0000 (10:59 -0500)]
xprtrdma: Remove request_module from backchannel
Since commit ffe1f0df5862 ("rpcrdma: Merge svcrdma and xprtrdma
modules into one"), the forward and backchannel components are part
of the same kernel module. A separate request_module() call in the
backchannel code is no longer necessary.
Chuck Lever [Wed, 19 Dec 2018 15:59:17 +0000 (10:59 -0500)]
xprtrdma: Recognize XDRBUF_SPARSE_PAGES
Commit 431f6eb3570f ("SUNRPC: Add a label for RPC calls that require
allocation on receive") didn't update similar logic in rpc_rdma.c.
I don't think this is a bug, per-se; the commit just adds more
careful checking for broken upper layer behavior.
Chuck Lever [Wed, 19 Dec 2018 15:59:12 +0000 (10:59 -0500)]
NFS: Make "port=" mount option optional for RDMA mounts
Having to specify "proto=rdma,port=20049" is cumbersome.
RFC 8267 Section 6.3 requires NFSv4 clients to use "the alternative
well-known port number", which is 20049. Make the use of the well-
known port number automatic, just as it is for NFS/TCP and port
2049.
For NFSv2/3, Section 4.2 allows clients to simply choose 20049 as
the default or use rpcbind. I don't know of an NFS/RDMA server
implementation that registers it's NFS/RDMA service with rpcbind,
so automatically choosing 20049 seems like the better choice. The
other widely-deployed NFS/RDMA client, Solaris, also uses 20049
as the default port.
Chuck Lever [Wed, 19 Dec 2018 15:59:07 +0000 (10:59 -0500)]
xprtrdma: Plant XID in on-the-wire RDMA offset (FRWR)
Place the associated RPC transaction's XID in the upper 32 bits of
each RDMA segment's rdma_offset field. There are two reasons to do
this:
- The R_key only has 8 bits that are different from registration to
registration. The XID adds more uniqueness to each RDMA segment to
reduce the likelihood of a software bug on the server reading from
or writing into memory it's not supposed to.
- On-the-wire RDMA Read and Write requests do not otherwise carry
any identifier that matches them up to an RPC. The XID in the
upper 32 bits will act as an eye-catcher in network captures.
Chuck Lever [Wed, 19 Dec 2018 15:59:01 +0000 (10:59 -0500)]
xprtrdma: Remove rpcrdma_memreg_ops
Clean up: Now that there is only FRWR, there is no need for a memory
registration switch. The indirect calls to the memreg operations can
be replaced with faster direct calls.
Chuck Lever [Wed, 19 Dec 2018 15:58:56 +0000 (10:58 -0500)]
xprtrdma: Remove support for FMR memory registration
FMR is not supported on most recent RDMA devices. It is also less
secure than FRWR because an FMR memory registration can expose
adjacent bytes to remote reading or writing. As discussed during the
RDMA BoF at LPC 2018, it is time to remove support for FMR in the
NFS/RDMA client stack.
Note that NFS/RDMA server-side uses either local memory registration
or FRWR. FMR is not used.
There are a few Infiniband/RoCE devices in the kernel tree that do
not appear to support MEM_MGT_EXTENSIONS (FRWR), and therefore will
not support client-side NFS/RDMA after this patch. These are:
- mthca
- qib
- hns (RoCE)
Users of these devices can use NFS/TCP on IPoIB instead.
Chuck Lever [Wed, 19 Dec 2018 15:58:51 +0000 (10:58 -0500)]
xprtrdma: Reduce max_frwr_depth
Some devices advertise a large max_fast_reg_page_list_len
capability, but perform optimally when MRs are significantly smaller
than that depth -- probably when the MR itself is no larger than a
page.
By default, the RDMA R/W core API uses max_sge_rd as the maximum
page depth for MRs. For some devices, the value of max_sge_rd is
1, which is also not optimal. Thus, when max_sge_rd is larger than
1, use that value. Otherwise use the value of the
max_fast_reg_page_list_len attribute.
I've tested this with CX-3 Pro, FastLinq, and CX-5 devices. It
reproducibly improves the throughput of large I/Os by several
percent.
Chuck Lever [Wed, 19 Dec 2018 15:58:45 +0000 (10:58 -0500)]
xprtrdma: Fix ri_max_segs and the result of ro_maxpages
With certain combinations of krb5i/p, MR size, and r/wsize, I/O can
fail with EMSGSIZE. This is because the calculated value of
ri_max_segs (the max number of MRs per RPC) exceeded
RPCRDMA_MAX_HDR_SEGS, which caused Read or Write list encoding to
walk off the end of the transport header.
Once that was addressed, the ro_maxpages result has to be corrected
to account for the number of MRs needed for Reply chunks, which is
2 MRs smaller than a normal Read or Write chunk.
Chuck Lever [Wed, 19 Dec 2018 15:58:40 +0000 (10:58 -0500)]
xprtrdma: Don't wake pending tasks until disconnect is done
Transport disconnect processing does a "wake pending tasks" at
various points.
Suppose an RPC Reply is being processed. The RPC task that Reply
goes with is waiting on the pending queue. If a disconnect wake-up
happens before reply processing is done, that reply, even if it is
good, is thrown away, and the RPC has to be sent again.
This window apparently does not exist for socket transports because
there is a lock held while a reply is being received which prevents
the wake-up call until after reply processing is done.
To resolve this, all RPC replies being processed on an RPC-over-RDMA
transport have to complete before pending tasks are awoken due to a
transport disconnect.
Callers that already hold the transport write lock may invoke
->ops->close directly. Others use a generic helper that schedules
a close when the write lock can be taken safely.
Chuck Lever [Wed, 19 Dec 2018 15:58:35 +0000 (10:58 -0500)]
xprtrdma: No qp_event disconnect
After thinking about this more, and auditing other kernel ULP imple-
mentations, I believe that a DISCONNECT cm_event will occur after a
fatal QP event. If that's the case, there's no need for an explicit
disconnect in the QP event handler.
Chuck Lever [Wed, 19 Dec 2018 15:58:29 +0000 (10:58 -0500)]
xprtrdma: Replace rpcrdma_receive_wq with a per-xprt workqueue
To address a connection-close ordering problem, we need the ability
to drain the RPC completions running on rpcrdma_receive_wq for just
one transport. Give each transport its own RPC completion workqueue,
and drain that workqueue when disconnecting the transport.
Chuck Lever [Wed, 19 Dec 2018 15:58:24 +0000 (10:58 -0500)]
xprtrdma: Refactor Receive accounting
Clean up: Divide the work cleanly:
- rpcrdma_wc_receive is responsible only for RDMA Receives
- rpcrdma_reply_handler is responsible only for RPC Replies
- the posted send and receive counts both belong in rpcrdma_ep
Chuck Lever [Wed, 19 Dec 2018 15:58:13 +0000 (10:58 -0500)]
xprtrdma: Yet another double DMA-unmap
While chasing yet another set of DMAR fault reports, I noticed that
the frwr recycler conflates whether or not an MR has been DMA
unmapped with frwr->fr_state. Actually the two have only an indirect
relationship. It's in fact impossible to guess reliably whether the
MR has been DMA unmapped based on its fr_state field, especially as
the surrounding code and its assumptions have changed over time.
A better approach is to track the DMA mapping status explicitly so
that the recycler is less brittle to unexpected situations, and
attempts to DMA-unmap a second time are prevented.
Moni Shoua [Wed, 26 Dec 2018 19:42:12 +0000 (21:42 +0200)]
IB/core: Add advise_mr to the list of known ops
We need to add advise_mr to the list of operation setters on the ib_device
or otherwise callers to ib_set_device_ops() for advise_mr operation will
not have their callback registered.
When the advise_mr series was merged with the device ops series the
SET_DEVICE_OPS() was missed.
Adrian Hunter [Fri, 21 Dec 2018 12:06:20 +0000 (14:06 +0200)]
perf session: Add comment for perf_session__register_idle_thread()
Add a comment to perf_session__register_idle_thread() to bring attention to
a pitfall with the idle task thread structure. The pitfall is that there
should really be a 'struct thread' for the idle task of each cpu, but there
is only one that can have pid == tid == 0.
Adrian Hunter [Fri, 21 Dec 2018 12:06:19 +0000 (14:06 +0200)]
perf thread-stack: Fix thread stack processing for the idle task
perf creates a single 'struct thread' to represent the idle task. That
is because threads are identified by PID and TID, and the idle task
always has PID == TID == 0.
However, there are actually separate idle tasks for each CPU. That
creates a problem for thread stack processing which assumes that each
thread has a single stack, not one stack per CPU.
Fix that by passing through the CPU number, and in the case of the idle
"thread", pick the thread stack from an array based on the CPU number.
Adrian Hunter [Fri, 21 Dec 2018 12:06:15 +0000 (14:06 +0200)]
perf thread-stack: Avoid direct reference to the thread's stack
In preparation for fixing thread stack processing for the idle task,
avoid direct reference to the thread's stack. The thread stack will
change to an array of thread stacks, at which point the meaning of the
direct reference will change.
In preparation for fixing thread stack processing for the idle task,
tidy thread_stack__bottom() usage. Specifically, the parameter 'thread'
is not needed.
Bjorn Andersson [Mon, 24 Dec 2018 07:26:44 +0000 (23:26 -0800)]
thermal: generic-adc: Fix adc to temp interpolation
First correct the edge case to return the last element if we're
outside the range, rather than at the last element, so that
interpolation is not omitted for points between the two last entries in
the table.
Then correct the formula to perform linear interpolation based the two
points surrounding the read ADC value. The indices for temp are kept as
"hi" and "lo" to pair with the adc indices, but there's no requirement
that the temperature is provided in descendent order. mult_frac() is
used to prevent issues with overflowing the int.
Miquel Raynal [Wed, 12 Dec 2018 09:36:40 +0000 (10:36 +0100)]
thermal: armada: add overheat interrupt support
The IP can manage to trigger interrupts on overheat situation from all
the sensors.
However, the interrupt source changes along with the last selected
source (ie. the last read sensor), which is an inconsistent behavior.
Avoid possible glitches by always selecting back only one channel which
will then be referenced as the "overheat_sensor" (arbitrarily: the first
in the DT which has a critical trip point filled in).
It is possible that the scan of all thermal zone nodes did not bring a
critical trip point from which the overheat interrupt could be
configured. In this case just complain but do not fail the probe.
Also disable sensor switch during overheat situations because changing
the channel while the system is too hot could clear the overheat state
by changing the source while the temperature is still very high.
Even if the overheat state is not declared, overheat interrupt must be
cleared by reading the DFX interrupt cause _after_ the temperature has
fallen down to the low threshold, otherwise future possible interrupts
would not be served. A work polls the corresponding register until the
overheat flag gets cleared in this case.