Jann reported that the original commit back in b2157399cc
("bpf: prevent out-of-bounds speculation") was not sufficient
to stop CPU from speculating out of bounds memory access:
While b2157399cc 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 ...
PTR += 0x1000 (e.g. K-based imm)
PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON
PTR += 0x1000
PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON
[...]
... which under speculation could end up as ...
PTR += 0x1000
PTR -= 0 [ truncated by mitigation ]
PTR += 0x1000
PTR -= 0 [ truncated by mitigation ]
[...]
... 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:
# bpftool prog dump xlated id 282
[...]
28: (79) r1 = *(u64 *)(r7 +0)
29: (79) r2 = *(u64 *)(r7 +8)
30: (57) r1 &= 15
31: (79) r3 = *(u64 *)(r0 +4608)
32: (57) r3 &= 1
33: (47) r3 |= 1
34: (2d) if r2 > r3 goto pc+19
35: (b4) (u32) r11 = (u32) 20479 |
36: (1f) r11 -= r2 | Dynamic sanitation for pointer
37: (4f) r11 |= r2 | arithmetic with registers
38: (87) r11 = -r11 | containing bounded or known
39: (c7) r11 s>>= 63 | scalars in order to prevent
40: (5f) r11 &= r2 | out of bounds speculation.
41: (0f) r4 += r11 |
42: (71) r4 = *(u8 *)(r4 +0)
43: (6f) r4 <<= r1
[...]
For the case where the scalar sits in the destination register
as opposed to the source register, the following code is emitted
for the above example:
[...]
16: (b4) (u32) r11 = (u32) 20479
17: (1f) r11 -= r2
18: (4f) r11 |= r2
19: (87) r11 = -r11
20: (c7) r11 s>>= 63
21: (5f) r2 &= r11
22: (0f) r2 += r0
23: (61) r0 = *(u32 *)(r2 +0)
[...]
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
Fixes: b2157399cc ("bpf: prevent out-of-bounds speculation")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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].
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As a simple fix, just print the correct map type.
Signed-off-by: Xiaozhou Liu <liuxiaozhou@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Commit 33a48ab105 ("ibmveth: Fix DMA unmap error") fixed an issue in the
normal code path of ibmveth_xmit_start() that was originally introduced by
Commit 6e8ab30ec6 ("ibmveth: Add scatter-gather support"). This original
fix missed the error path where dma_unmap_page is wrongly called on the
header portion in descs[0] which was mapped with dma_map_single. As a
result a failure to DMA map any of the frags results in a dmesg warning
when CONFIG_DMA_API_DEBUG is enabled.
------------[ cut here ]------------
DMA-API: ibmveth 30000002: device driver frees DMA memory with wrong function
[device address=0x000000000a430000] [size=172 bytes] [mapped as page] [unmapped as single]
WARNING: CPU: 1 PID: 8426 at kernel/dma/debug.c:1085 check_unmap+0x4fc/0xe10
...
<snip>
...
DMA-API: Mapped at:
ibmveth_start_xmit+0x30c/0xb60
dev_hard_start_xmit+0x100/0x450
sch_direct_xmit+0x224/0x490
__qdisc_run+0x20c/0x980
__dev_queue_xmit+0x1bc/0xf20
This fixes the API misuse by unampping descs[0] with dma_unmap_single.
Fixes: 6e8ab30ec6 ("ibmveth: Add scatter-gather support")
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In rtl8169_runtime_resume() we configure WoL but don't set the device
to wakeup-enabled. This prevents PME generation once the cable is
re-plugged. Fix this by moving the call to device_set_wakeup_enable()
to __rtl8169_set_wol().
Fixes: 433f9d0ddc ("r8169: improve saved_wolopts handling")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
nr_find_socket(), nr_find_peer() and nr_find_listener() lock the
sock after finding it in the global list. However, the call path
requires BH disabled for the sock lock consistently.
Actually the locking is unnecessary at this point, we can just hold
the sock refcnt to make sure it is not gone after we unlock the global
list, and lock it later only when needed.
Reported-and-tested-by: syzbot+f621cda8b7e598908efa@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When x25_asy_open() fails, it already cleans up by itself,
so its caller doesn't need to free the memory again.
It seems we still have to call x25_asy_free() to clear the SLF_INUSE
bit, so just set these pointers to NULL after kfree().
Reported-and-tested-by: syzbot+5e5e969e525129229052@syzkaller.appspotmail.com
Fixes: 3b780bed31 ("x25_asy: Free x25_asy on x25_asy_open() failure.")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are multiple issues here:
1. After freeing dev->ax25_ptr, we need to set it to NULL otherwise
we may use a dangling pointer.
2. There is a race between ax25_setsockopt() and device notifier as
reported by syzbot. Close it by holding RTNL lock.
3. We need to test if dev->ax25_ptr is NULL before using it.
Reported-and-tested-by: syzbot+ae6bb869cbed29b29040@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
gcc warn this:
net/ipv4/fib_rules.c:203 fib_empty_table() warn:
always true condition '(id <= 4294967295) => (0-u32max <= u32max)'
'id' is u32, which always not greater than RT_TABLE_MAX
(0xFFFFFFFF), So add a check to break while wrap around.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'ipv6_find_idev()' returns NULL on error, not an error pointer.
Update the test accordingly and return -ENOBUFS, as already done in
'addrconf_add_dev()', if NULL is returned.
Fixes: ("ipv6: allow userspace to add IFA_F_OPTIMISTIC addresses")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
We must have an address to lookup otherwise we'll derefence a null
pointer in the ndo_fdb_get callbacks.
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: David Ahern <dsa@cumulusnetworks.com>
Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
Fixes: 5b2f94b276 ("net: rtnetlink: support for fdb get")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net, specifically
fixes for the nf_conncount infrastructure which is causing troubles
since 5c789e131c ("netfilter: nf_conncount: Add list lock and gc
worker, and RCU for init tree search"). Patches aim to simplify this
infrastructure while fixing up the problems:
1) Use fixed size CONNCOUNT_SLOTS in nf_conncount, from Shawn Bohrer.
2) Incorrect signedness in age calculation from find_or_evict(),
from Florian Westphal.
3) Proper locking for the garbage collector workqueue callback,
first make a patch to count how many nodes can be collected
without holding locks, then grab lock and release them. Also
from Florian.
4) Restart node lookup from the insertion path, after releasing nodes
via packet path garbage collection. Shawn Bohrer described a scenario
that may result in inserting a connection in an already dead list
node. Patch from Florian.
5) Merge lookup and add function to avoid a hold release and re-grab.
From Florian.
6) Be safe and iterate over the node lists under the spinlock.
7) Speculative list nodes removal via garbage collection, check if
list node got a connection while it was scheduled for deletion
via gc.
8) Accidental argument swap in find_next_bit() that leads to more
frequent scheduling of the workqueue. From Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In drivers/isdn/hisax/hfc_pci.c, the functions hfcpci_interrupt() and
HFCPCI_l1hw() may be concurrently executed.
HFCPCI_l1hw()
line 1173: if (!cs->tx_skb)
hfcpci_interrupt()
line 942: spin_lock_irqsave();
line 1066: dev_kfree_skb_irq(cs->tx_skb);
Thus, a possible concurrency use-after-free bug may occur
in HFCPCI_l1hw().
To fix these bugs, the calls to spin_lock_irqsave() and
spin_unlock_irqrestore() are added in HFCPCI_l1hw(), to protect the
access to cs->tx_skb.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The return type for get_regs_len in struct ethtool_ops is int,
the hns3 driver may return error when failing to get the regs
len by sending cmd to firmware.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Size and 'next bit' were swapped, this bug could cause worker to
reschedule itself even if system was idle.
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of removing a empty list node that might be reintroduced soon
thereafter, tentatively place the empty list node on the list passed to
tree_nodes_free(), then re-check if the list is empty again before erasing
it from the tree.
[ Florian: rebase on top of pending nf_conncount fixes ]
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Two CPUs may race to remove a connection from the list, the existing
conn->dead will result in a use-after-free. Use the per-list spinlock to
protect list iterations.
As all accesses to the list now happen while holding the per-list lock,
we no longer need to delay free operations with rcu.
Joint work with Florian.
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
'lookup' is always followed by 'add'.
Merge both and make the list-walk part of nf_conncount_add().
This also avoids one unneeded unlock/re-lock pair.
Extra care needs to be taken in count_tree, as we only hold rcu
read lock, i.e. we can only insert to an existing tree node after
acquiring its lock and making sure it has a nonzero count.
As a zero count should be rare, just fall back to insert_tree()
(which acquires tree lock).
This issue and its solution were pointed out by Shawn Bohrer
during patch review.
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Shawn Bohrer reported a following crash:
|RIP: 0010:rb_erase+0xae/0x360
[..]
Call Trace:
nf_conncount_destroy+0x59/0xc0 [nf_conncount]
cleanup_match+0x45/0x70 [ip_tables]
...
Shawn tracked this down to bogus 'parent' pointer:
Problem is that when we insert a new node, then there is a chance that
the 'parent' that we found was also passed to tree_nodes_free() (because
that node was empty) for erase+free.
Instead of trying to be clever and detect when this happens, restart
the search if we have evicted one or more nodes. To prevent frequent
restarts, do not perform gc on the second round.
Also, unconditionally schedule the gc worker.
The condition
gc_count > ARRAY_SIZE(gc_nodes))
cannot be true unless tree grows very large, as the height of the tree
will be low even with hundreds of nodes present.
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reported-by: Shawn Bohrer <sbohrer@cloudflare.com>
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The lockless workqueue garbage collector can race with packet path
garbage collector to delete list nodes, as it calls tree_nodes_free()
with the addresses of nodes that might have been free'd already from
another cpu.
To fix this, split gc into two phases.
One phase to perform gc on the connections: From a locking perspective,
this is the same as count_tree(): we hold rcu lock, but we do not
change the tree, we only change the nodes' contents.
The second phase acquires the tree lock and reaps empty nodes.
This avoids a race condition of the garbage collection vs. packet path:
If a node has been free'd already, the second phase won't find it anymore.
This second phase is, from locking perspective, same as insert_tree().
The former only modifies nodes (list content, count), latter modifies
the tree itself (rb_erase or rb_insert).
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
age is signed integer, so result can be negative when the timestamps
have a large delta. In this case we want to discard the entry.
Instead of using age >= 2 || age < 0, just make it unsigned.
Fixes: b36e4523d4 ("netfilter: nf_conncount: fix garbage collection confirm race")
Reviewed-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Most of the time these were the same value anyway, but when
CONFIG_LOCKDEP was enabled we would use a smaller number of locks to
reduce overhead. Unfortunately having two values is confusing and not
worth the complexity.
This fixes a bug where tree_gc_worker() would only GC up to
CONNCOUNT_LOCK_SLOTS trees which meant when CONFIG_LOCKDEP was enabled
not all trees would be GCed by tree_gc_worker().
Fixes: 5c789e131c ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Shawn Bohrer <sbohrer@cloudflare.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If nla_nest_start() may fail. The fix checks its return value and goes
to nla_put_failure if it fails.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Correct two minor kerneldoc errors:
1) missing reference to @mode in struct phy_ops
2) obsolete reference to @init_data in struct_phy_attrs,
removed in dbc98635e0
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
1) note that gianfar_phy.c was removed years ago
2) fix obvious copy and paste error in regular doc
3) change regular doc into kerneldoc for phy_modes()
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
When acpi_match_device fails, its return value is NULL. Directly using
the return value without a check may result in a NULL-pointer
dereference. The fix checks if acpi_match_device fails, and if so,
returns -EINVAL.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
genlmsg_put could fail. The fix inserts a check of its return value, and
if it fails, returns -EMSGSIZE.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
atl1e_write_phy_reg() could fail. The fix issues an error message when
it fails.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both bcm_sf2_sw_indir_rw and mdiobus_write_nested could fail, so let's
return their error codes upstream.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
clk_prepare() could fail, so let's check its status, and if it fails,
return its error code upstream.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
clk_prepare() could fail, so let's check its status, and if it fails,
return its error code upstream.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
niu_pci_eeprom_read() may fail, so we should check its return value
before using the read data.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Acked-by: Shannon Nelson <shannon.lee.nelson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cudbg_collect_hw_sched() could fail when the function cudg_get_buffer()
returns an error. The fix adds a check to the latter function returning
error on failure
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
While flushing the cache via ipv6_sysctl_rtcache_flush(), the call
to proc_dointvec() may fail. The fix adds a check that returns the
error, on failure.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
bearer_disable() already calls kfree_rcu() to free struct tipc_bearer,
we don't need to call kfree() again.
Fixes: cb30a63384 ("tipc: refactor function tipc_enable_bearer()")
Reported-by: syzbot+b981acf1fb240c0c128b@syzkaller.appspotmail.com
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull crypto updates from Herbert Xu:
"API:
- Add 1472-byte test to tcrypt for IPsec
- Reintroduced crypto stats interface with numerous changes
- Support incremental algorithm dumps
Algorithms:
- Add xchacha12/20
- Add nhpoly1305
- Add adiantum
- Add streebog hash
- Mark cts(cbc(aes)) as FIPS allowed
Drivers:
- Improve performance of arm64/chacha20
- Improve performance of x86/chacha20
- Add NEON-accelerated nhpoly1305
- Add SSE2 accelerated nhpoly1305
- Add AVX2 accelerated nhpoly1305
- Add support for 192/256-bit keys in gcmaes AVX
- Add SG support in gcmaes AVX
- ESN for inline IPsec tx in chcr
- Add support for CryptoCell 703 in ccree
- Add support for CryptoCell 713 in ccree
- Add SM4 support in ccree
- Add SM3 support in ccree
- Add support for chacha20 in caam/qi2
- Add support for chacha20 + poly1305 in caam/jr
- Add support for chacha20 + poly1305 in caam/qi2
- Add AEAD cipher support in cavium/nitrox"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (130 commits)
crypto: skcipher - remove remnants of internal IV generators
crypto: cavium/nitrox - Fix build with !CONFIG_DEBUG_FS
crypto: salsa20-generic - don't unnecessarily use atomic walk
crypto: skcipher - add might_sleep() to skcipher_walk_virt()
crypto: x86/chacha - avoid sleeping under kernel_fpu_begin()
crypto: cavium/nitrox - Added AEAD cipher support
crypto: mxc-scc - fix build warnings on ARM64
crypto: api - document missing stats member
crypto: user - remove unused dump functions
crypto: chelsio - Fix wrong error counter increments
crypto: chelsio - Reset counters on cxgb4 Detach
crypto: chelsio - Handle PCI shutdown event
crypto: chelsio - cleanup:send addr as value in function argument
crypto: chelsio - Use same value for both channel in single WR
crypto: chelsio - Swap location of AAD and IV sent in WR
crypto: chelsio - remove set but not used variable 'kctx_len'
crypto: ux500 - Use proper enum in hash_set_dma_transfer
crypto: ux500 - Use proper enum in cryp_set_dma_transfer
crypto: aesni - Add scatter/gather avx stubs, and use them in C
crypto: aesni - Introduce partial block macro
..
Pull networking updates from David Miller:
1) New ipset extensions for matching on destination MAC addresses, from
Stefano Brivio.
2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
nfp driver. From Stefano Brivio.
3) Implement GRO for plain UDP sockets, from Paolo Abeni.
4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
bit so that we could support the entire vlan_tci value.
5) Rework the IPSEC policy lookups to better optimize more usecases,
from Florian Westphal.
6) Infrastructure changes eliminating direct manipulation of SKB lists
wherever possible, and to always use the appropriate SKB list
helpers. This work is still ongoing...
7) Lots of PHY driver and state machine improvements and
simplifications, from Heiner Kallweit.
8) Various TSO deferral refinements, from Eric Dumazet.
9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.
10) Batch dropping of XDP packets in tuntap, from Jason Wang.
11) Lots of cleanups and improvements to the r8169 driver from Heiner
Kallweit, including support for ->xmit_more. This driver has been
getting some much needed love since he started working on it.
12) Lots of new forwarding selftests from Petr Machata.
13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.
14) Packed ring support for virtio, from Tiwei Bie.
15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.
16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.
17) Implement coalescing on TCP backlog queue, from Eric Dumazet.
18) Implement carrier change in tun driver, from Nicolas Dichtel.
19) Support msg_zerocopy in UDP, from Willem de Bruijn.
20) Significantly improve garbage collection of neighbor objects when
the table has many PERMANENT entries, from David Ahern.
21) Remove egdev usage from nfp and mlx5, and remove the facility
completely from the tree as it no longer has any users. From Oz
Shlomo and others.
22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
therefore abort the operation before the commit phase (which is the
NETDEV_CHANGEADDR event). From Petr Machata.
23) Add indirect call wrappers to avoid retpoline overhead, and use them
in the GRO code paths. From Paolo Abeni.
24) Add support for netlink FDB get operations, from Roopa Prabhu.
25) Support bloom filter in mlxsw driver, from Nir Dotan.
26) Add SKB extension infrastructure. This consolidates the handling of
the auxiliary SKB data used by IPSEC and bridge netfilter, and is
designed to support the needs to MPTCP which could be integrated in
the future.
27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
net: dccp: fix kernel crash on module load
drivers/net: appletalk/cops: remove redundant if statement and mask
bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
net/net_namespace: Check the return value of register_pernet_subsys()
net/netlink_compat: Fix a missing check of nla_parse_nested
ieee802154: lowpan_header_create check must check daddr
net/mlx4_core: drop useless LIST_HEAD
mlxsw: spectrum: drop useless LIST_HEAD
net/mlx5e: drop useless LIST_HEAD
iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
net/mlx5e: fix semicolon.cocci warnings
staging: octeon: fix build failure with XFRM enabled
net: Revert recent Spectre-v1 patches.
can: af_can: Fix Spectre v1 vulnerability
packet: validate address length if non-zero
nfc: af_nfc: Fix Spectre v1 vulnerability
phonet: af_phonet: Fix Spectre v1 vulnerability
net: core: Fix Spectre v1 vulnerability
net: minor cleanup in skb_ext_add()
net: drop the unused helper skb_ext_get()
...
Summary of modules changes for the 4.21 merge window:
- Some modules-related kallsyms cleanups and a kallsyms fix for ARM.
- Include keys from the secondary keyring in module signature
verification.
Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
- Some modules-related kallsyms cleanups and a kallsyms fix for ARM.
- Include keys from the secondary keyring in module signature
verification.
* tag 'modules-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
ARM: module: Fix function kallsyms on Thumb-2
module: Overwrite st_size instead of st_info
module: make it clearer when we're handling kallsyms symbols vs exported symbols
modsign: use all trusted keys to verify module signature
Pull general security subsystem updates from James Morris:
"The main changes here are Paul Gortmaker's removal of unneccesary
module.h infrastructure"
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
security: integrity: partial revert of make ima_main explicitly non-modular
security: fs: make inode explicitly non-modular
security: audit and remove any unnecessary uses of module.h
security: integrity: make evm_main explicitly non-modular
keys: remove needless modular infrastructure from ecryptfs_format
security: integrity: make ima_main explicitly non-modular
tomoyo: fix small typo
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Merge tag 'selinux-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux patches from Paul Moore:
"I already used my best holiday pull request lines in the audit pull
request, so this one is going to be a bit more boring, sorry about
that. To make up for this, we do have a birthday of sorts to
celebrate: SELinux turns 18 years old this December. Perhaps not the
most exciting thing in the world for most people, but I think it's
safe to say that anyone reading this email doesn't exactly fall into
the "most people" category.
Back to business and the pull request itself:
Ondrej has five patches in this pull request and I lump them into
three categories: one patch to always allow submounts (using similar
logic to elsewhere in the kernel), one to fix some issues with the
SELinux policydb, and the others to cleanup and improve the SELinux
sidtab.
The other patches from Alexey and Petr and trivial fixes that are
adequately described in their respective subject lines.
With this last pull request of the year, I want to thank everyone who
has contributed patches, testing, and reviews to the SELinux project
this year, and the past 18 years. Like any good open source effort,
SELinux is only as good as the community which supports it, and I'm
very happy that we have the community we do - thank you all!"
* tag 'selinux-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: overhaul sidtab to fix bug and improve performance
selinux: use separate table for initial SID lookup
selinux: make "selinux_policycap_names[]" const char *
selinux: always allow mounting submounts
selinux: refactor sidtab conversion
Documentation: Update SELinux reference policy URL
selinux: policydb - fix byte order and alignment issues
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Merge tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
"In the finest of holiday of traditions, I have a number of gifts to
share today. While most of them are re-gifts from others, unlike the
typical re-gift, these are things you will want in and around your
tree; I promise.
This pull request is perhaps a bit larger than our typical PR, but
most of it comes from Jan's rework of audit's fanotify code; a very
welcome improvement. We ran this through our normal regression tests,
as well as some newly created stress tests and everything looks good.
Richard added a few patches, mostly cleaning up a few things and and
shortening some of the audit records that we send to userspace; a
change the userspace folks are quite happy about.
Finally YueHaibing and I kick in a few patches to simplify things a
bit and make the code less prone to errors.
Lastly, I want to say thanks one more time to everyone who has
contributed patches, testing, and code reviews for the audit subsystem
over the past year. The project is what it is due to your help and
contributions - thank you"
* tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: (22 commits)
audit: remove duplicated include from audit.c
audit: shorten PATH cap values when zero
audit: use current whenever possible
audit: minimize our use of audit_log_format()
audit: remove WATCH and TREE config options
audit: use session_info helper
audit: localize audit_log_session_info prototype
audit: Use 'mark' name for fsnotify_mark variables
audit: Replace chunk attached to mark instead of replacing mark
audit: Simplify locking around untag_chunk()
audit: Drop all unused chunk nodes during deletion
audit: Guarantee forward progress of chunk untagging
audit: Allocate fsnotify mark independently of chunk
audit: Provide helper for dropping mark's chunk reference
audit: Remove pointless check in insert_hash()
audit: Factor out chunk replacement code
audit: Make hash table insertion safe against concurrent lookups
audit: Embed key into chunk
audit: Fix possible tagging failures
audit: Fix possible spurious -ENOSPC error
...
