Currently, for bpf_trace_printk helper, fake ip address 0x1
is used with comments saying that fake ip will not be printed.
This is indeed true for 4.12 and earlier version, but for
4.13 and later version, the ip address will be printed if
it cannot be resolved with kallsym. Running samples/bpf/tracex5
program and you will have the following in the debugfs
trace_pipe output:
...
<...>-1819 [003] .... 443.497877: 0x00000001: mmap
<...>-1819 [003] .... 443.498289: 0x00000001: syscall=102 (one of get/set uid/pid/gid)
...
The kernel commit changed this behavior is:
commit feaf1283d1
Author: Steven Rostedt (VMware) <rostedt@goodmis.org>
Date: Thu Jun 22 17:04:55 2017 -0400
tracing: Show address when function names are not found
...
This patch changed the comment and also altered the fake ip
address to 0x0 as users may think 0x1 has some special meaning
while it doesn't. The new output:
...
<...>-1799 [002] .... 25.953576: 0: mmap
<...>-1799 [002] .... 25.953865: 0: read(fd=0, buf=00000000053936b5, size=512)
...
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
For host JIT, there are "jited_len"/"bpf_func" fields in struct bpf_prog
used by all host JIT targets to get jited image and it's length. While for
offload, targets are likely to have different offload mechanisms that these
info are kept in device private data fields.
Therefore, BPF_OBJ_GET_INFO_BY_FD syscall needs an unified way to get JIT
length and contents info for offload targets.
One way is to introduce new callback to parse device private data then fill
those fields in bpf_prog_info. This might be a little heavy, the other way
is to add generic fields which will be initialized by all offload targets.
This patch follow the second approach to introduce two new fields in
struct bpf_dev_offload and teach bpf_prog_get_info_by_fd about them to fill
correct jited_prog_len and jited_prog_insns in bpf_prog_info.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Functions of type bpf_insn_print_t take printf-like format
string, mark the type accordingly.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Daniel suggests it would be more logical for bpf_offload_dev_match()
to return false is either the program or the map are not offloaded,
rather than treating the both not offloaded case as a "matching
CPU/host device".
This makes no functional difference today, since verifier only calls
bpf_offload_dev_match() when one of the objects is offloaded.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Fixes the following sparse warnings:
kernel/bpf/cpumap.c:146:6: warning:
symbol '__cpu_map_queue_destructor' was not declared. Should it be static?
kernel/bpf/cpumap.c:225:16: warning:
symbol 'cpu_map_build_skb' was not declared. Should it be static?
kernel/bpf/cpumap.c:340:26: warning:
symbol '__cpu_map_entry_alloc' was not declared. Should it be static?
kernel/bpf/cpumap.c:398:6: warning:
symbol '__cpu_map_entry_free' was not declared. Should it be static?
kernel/bpf/cpumap.c:441:6: warning:
symbol '__cpu_map_entry_replace' was not declared. Should it be static?
kernel/bpf/cpumap.c:454:5: warning:
symbol 'cpu_map_delete_elem' was not declared. Should it be static?
kernel/bpf/cpumap.c:467:5: warning:
symbol 'cpu_map_update_elem' was not declared. Should it be static?
kernel/bpf/cpumap.c:505:6: warning:
symbol 'cpu_map_free' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull networking fixes from David Miller:
1) Two read past end of buffer fixes in AF_KEY, from Eric Biggers.
2) Memory leak in key_notify_policy(), from Steffen Klassert.
3) Fix overflow with bpf arrays, from Daniel Borkmann.
4) Fix RDMA regression with mlx5 due to mlx5 no longer using
pci_irq_get_affinity(), from Saeed Mahameed.
5) Missing RCU read locking in nl80211_send_iface() when it calls
ieee80211_bss_get_ie(), from Dominik Brodowski.
6) cfg80211 should check dev_set_name()'s return value, from Johannes
Berg.
7) Missing module license tag in 9p protocol, from Stephen Hemminger.
8) Fix crash due to too small MTU in udp ipv6 sendmsg, from Mike
Maloney.
9) Fix endless loop in netlink extack code, from David Ahern.
10) TLS socket layer sets inverted error codes, resulting in an endless
loop. From Robert Hering.
11) Revert openvswitch erspan tunnel support, it's mis-designed and we
need to kill it before it goes into a real release. From William Tu.
12) Fix lan78xx failures in full speed USB mode, from Yuiko Oshino.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (54 commits)
net, sched: fix panic when updating miniq {b,q}stats
qed: Fix potential use-after-free in qed_spq_post()
nfp: use the correct index for link speed table
lan78xx: Fix failure in USB Full Speed
sctp: do not allow the v4 socket to bind a v4mapped v6 address
sctp: return error if the asoc has been peeled off in sctp_wait_for_sndbuf
sctp: reinit stream if stream outcnt has been change by sinit in sendmsg
ibmvnic: Fix pending MAC address changes
netlink: extack: avoid parenthesized string constant warning
ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY
net: Allow neigh contructor functions ability to modify the primary_key
sh_eth: fix dumping ARSTR
Revert "openvswitch: Add erspan tunnel support."
net/tls: Fix inverted error codes to avoid endless loop
ipv6: ip6_make_skb() needs to clear cork.base.dst
sctp: avoid compiler warning on implicit fallthru
net: ipv4: Make "ip route get" match iif lo rules again.
netlink: extack needs to be reset each time through loop
tipc: fix a memory leak in tipc_nl_node_get_link()
ipv6: fix udpv6 sendmsg crash caused by too small MTU
...
- Bring back context level recursive protection in ring buffer.
The simpler counter protection failed, due to a path when
tracing with trace_clock_global() as it could not be reentrant
and depended on the ring buffer recursive protection to keep that
from happening.
- Prevent branch profiling when FORTIFY_SOURCE is enabled. It causes
50 - 60 MB in warning messages. Branch profiling should never be
run on production systems, so there's no reason that it needs to
be enabled with FORTIFY_SOURCE.
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Merge tag 'trace-v4.15-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Bring back context level recursive protection in ring buffer.
The simpler counter protection failed, due to a path when tracing
with trace_clock_global() as it could not be reentrant and depended
on the ring buffer recursive protection to keep that from happening.
- Prevent branch profiling when FORTIFY_SOURCE is enabled.
It causes 50 - 60 MB in warning messages. Branch profiling should
never be run on production systems, so there's no reason that it
needs to be enabled with FORTIFY_SOURCE.
* tag 'trace-v4.15-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y
ring-buffer: Bring back context level recursive checks
I regularly get 50 MB - 60 MB files during kernel randconfig builds.
These large files mostly contain (many repeats of; e.g., 124,594):
In file included from ../include/linux/string.h:6:0,
from ../include/linux/uuid.h:20,
from ../include/linux/mod_devicetable.h:13,
from ../scripts/mod/devicetable-offsets.c:3:
../include/linux/compiler.h:64:4: warning: '______f' is static but declared in inline function 'strcpy' which is not static [enabled by default]
______f = { \
^
../include/linux/compiler.h:56:23: note: in expansion of macro '__trace_if'
^
../include/linux/string.h:425:2: note: in expansion of macro 'if'
if (p_size == (size_t)-1 && q_size == (size_t)-1)
^
This only happens when CONFIG_FORTIFY_SOURCE=y and
CONFIG_PROFILE_ALL_BRANCHES=y, so prevent PROFILE_ALL_BRANCHES if
FORTIFY_SOURCE=y.
Link: http://lkml.kernel.org/r/9199446b-a141-c0c3-9678-a3f9107f2750@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Commit 1a149d7d3f ("ring-buffer: Rewrite trace_recursive_(un)lock() to be
simpler") replaced the context level recursion checks with a simple counter.
This would prevent the ring buffer code from recursively calling itself more
than the max number of contexts that exist (Normal, softirq, irq, nmi). But
this change caused a lockup in a specific case, which was during suspend and
resume using a global clock. Adding a stack dump to see where this occurred,
the issue was in the trace global clock itself:
trace_buffer_lock_reserve+0x1c/0x50
__trace_graph_entry+0x2d/0x90
trace_graph_entry+0xe8/0x200
prepare_ftrace_return+0x69/0xc0
ftrace_graph_caller+0x78/0xa8
queued_spin_lock_slowpath+0x5/0x1d0
trace_clock_global+0xb0/0xc0
ring_buffer_lock_reserve+0xf9/0x390
The function graph tracer traced queued_spin_lock_slowpath that was called
by trace_clock_global. This pointed out that the trace_clock_global() is not
reentrant, as it takes a spin lock. It depended on the ring buffer recursive
lock from letting that happen.
By removing the context detection and adding just a max number of allowable
recursions, it allowed the trace_clock_global() to be entered again and try
to retake the spinlock it already held, causing a deadlock.
Fixes: 1a149d7d3f ("ring-buffer: Rewrite trace_recursive_(un)lock() to be simpler")
Reported-by: David Weinehall <david.weinehall@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
BPF map offload follow similar path to program offload. At creation
time users may specify ifindex of the device on which they want to
create the map. Map will be validated by the kernel's
.map_alloc_check callback and device driver will be called for the
actual allocation. Map will have an empty set of operations
associated with it (save for alloc and free callbacks). The real
device callbacks are kept in map->offload->dev_ops because they
have slightly different signatures. Map operations are called in
process context so the driver may communicate with HW freely,
msleep(), wait() etc.
Map alloc and free callbacks are muxed via existing .ndo_bpf, and
are always called with rtnl lock held. Maps and programs are
guaranteed to be destroyed before .ndo_uninit (i.e. before
unregister_netdev() returns). Map callbacks are invoked with
bpf_devs_lock *read* locked, drivers must take care of exclusive
locking if necessary.
All offload-specific branches are marked with unlikely() (through
bpf_map_is_dev_bound()), given that branch penalty will be
negligible compared to IO anyway, and we don't want to penalize
SW path unnecessarily.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add a helper to check if netdev could be found and whether it
has .ndo_bpf callback. There is no need to check the callback
every time it's invoked, ndos can't reasonably be swapped for
a set without .ndp_bpf while program is loaded.
bpf_dev_offload_check() will also be used by map offload.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
With map offload coming, we need to call program offload structure
something less ambiguous. Pure rename, no functional changes.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
All map types reimplement the field-by-field copy of union bpf_attr
members into struct bpf_map. Add a helper to perform this operation.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Use the new callback to perform allocation checks for hash maps.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Number of attribute checks are currently performed after hashtab
is already allocated. Move them to be able to split them out to
the check function later on. Checks have to now be performed on
the attr union directly instead of the members of bpf_map, since
bpf_map will be allocated later. No functional changes.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
.map_alloc callbacks contain a number of checks validating user-
-provided map attributes against constraints of a particular map
type. For offloaded maps we will need to check map attributes
without actually allocating any memory on the host. Add a new
callback for validating attributes before any memory is allocated.
This callback can be selectively implemented by map types for
sharing code with offloads, or simply to separate the logical
steps of validation and allocation.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Merge misc fixlets from Andrew Morton:
"4 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
tools/objtool/Makefile: don't assume sync-check.sh is executable
kdump: write correct address of mem_section into vmcoreinfo
kmemleak: allow to coexist with fault injection
MAINTAINERS, nilfs2: change project home URLs
Depending on configuration mem_section can now be an array or a pointer
to an array allocated dynamically. In most cases, we can continue to
refer to it as 'mem_section' regardless of what it is.
But there's one exception: '&mem_section' means "address of the array"
if mem_section is an array, but if mem_section is a pointer, it would
mean "address of the pointer".
We've stepped onto this in kdump code. VMCOREINFO_SYMBOL(mem_section)
writes down address of pointer into vmcoreinfo, not array as we wanted.
Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the
situation correctly for both cases.
Link: http://lkml.kernel.org/r/20180112162532.35896-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes: 83e3c48729 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y")
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Support in-kernel fault-injection framework via debugfs.
This allows you to inject a conditional error to specified
function using debugfs interfaces.
Here is the result of test script described in
Documentation/fault-injection/fault-injection.txt
===========
# ./test_fail_function.sh
1+0 records in
1+0 records out
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0227404 s, 46.1 MB/s
btrfs-progs v4.4
See http://btrfs.wiki.kernel.org for more information.
Label: (null)
UUID: bfa96010-12e9-4360-aed0-42eec7af5798
Node size: 16384
Sector size: 4096
Filesystem size: 1001.00MiB
Block group profiles:
Data: single 8.00MiB
Metadata: DUP 58.00MiB
System: DUP 12.00MiB
SSD detected: no
Incompat features: extref, skinny-metadata
Number of devices: 1
Devices:
ID SIZE PATH
1 1001.00MiB /dev/loop2
mount: mount /dev/loop2 on /opt/tmpmnt failed: Cannot allocate memory
SUCCESS!
===========
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.
Some differences has been made:
- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
feature. It is automatically enabled if the arch supports
error injection feature for kprobe or ftrace etc.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Compare instruction pointer with original one on the
stack instead using per-cpu bpf_kprobe_override flag.
This patch also consolidates reset_current_kprobe() and
preempt_enable_no_resched() blocks. Those can be done
in one place.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Check whether error injectable event is on function entry or not.
Currently it checks the event is ftrace-based kprobes or not,
but that is wrong. It should check if the event is on the entry
of target function. Since error injection will override a function
to just return with modified return value, that operation must
be done before the target function starts making stackframe.
As a side effect, bpf error injection is no need to depend on
function-tracer. It can work with sw-breakpoint based kprobe
events too.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull scheduler fixes from Ingo Molnar:
"A Kconfig fix, a build fix and a membarrier bug fix"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
membarrier: Disable preemption when calling smp_call_function_many()
sched/isolation: Make CONFIG_CPU_ISOLATION=y depend on SMP or COMPILE_TEST
ia64, sched/cputime: Fix build error if CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y
Pull locking fixes from Ingo Molnar:
"No functional effects intended: removes leftovers from recent lockdep
and refcounts work"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/refcounts: Remove stale comment from the ARCH_HAS_REFCOUNT Kconfig entry
locking/lockdep: Remove cross-release leftovers
locking/Documentation: Remove stale crossrelease_fullstack parameter
BPF alignment tests got a conflict because the registers
are output as Rn_w instead of just Rn in net-next, and
in net a fixup for a testcase prohibits logical operations
on pointers before using them.
Also, we should attempt to patch BPF call args if JIT always on is
enabled. Instead, if we fail to JIT the subprogs we should pass
an error back up and fail immediately.
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-01-11
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Various BPF related improvements and fixes to nfp driver: i) do
not register XDP RXQ structure to control queues, ii) round up
program stack size to word size for nfp, iii) restrict MTU changes
when BPF offload is active, iv) add more fully featured relocation
support to JIT, v) add support for signed compare instructions to
the nfp JIT, vi) export and reuse verfier log routine for nfp, and
many more, from Jakub, Quentin and Nic.
2) Fix a syzkaller reported GPF in BPF's copy_verifier_state() when
we hit kmalloc failure path, from Alexei.
3) Add two follow-up fixes for the recent XDP RXQ series: i) kvzalloc()
allocated memory was only kfree()'ed, and ii) fix a memory leak where
RX queue was not freed in netif_free_rx_queues(), from Jakub.
4) Add a sample for transferring XDP meta data into the skb, here it
is used for setting skb->mark with the buffer from XDP, from Jesper.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
syzkaller tried to alloc a map with 0xfffffffd entries out of a userns,
and thus unprivileged. With the recently added logic in b2157399cc
("bpf: prevent out-of-bounds speculation") we round this up to the next
power of two value for max_entries for unprivileged such that we can
apply proper masking into potentially zeroed out map slots.
However, this will generate an index_mask of 0xffffffff, and therefore
a + 1 will let this overflow into new max_entries of 0. This will pass
allocation, etc, and later on map access we still enforce on the original
attr->max_entries value which was 0xfffffffd, therefore triggering GPF
all over the place. Thus bail out on overflow in such case.
Moreover, on 32 bit archs roundup_pow_of_two() can also not be used,
since fls_long(max_entries - 1) can result in 32 and 1UL << 32 in 32 bit
space is undefined. Therefore, do this by hand in a 64 bit variable.
This fixes all the issues triggered by syzkaller's reproducers.
Fixes: b2157399cc ("bpf: prevent out-of-bounds speculation")
Reported-by: syzbot+b0efb8e572d01bce1ae0@syzkaller.appspotmail.com
Reported-by: syzbot+6c15e9744f75f2364773@syzkaller.appspotmail.com
Reported-by: syzbot+d2f5524fb46fd3b312ee@syzkaller.appspotmail.com
Reported-by: syzbot+61d23c95395cc90dbc2b@syzkaller.appspotmail.com
Reported-by: syzbot+0d363c942452cca68c01@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The following snippet was throwing an 'unknown opcode cc' warning
in BPF interpreter:
0: (18) r0 = 0x0
2: (7b) *(u64 *)(r10 -16) = r0
3: (cc) (u32) r0 s>>= (u32) r0
4: (95) exit
Although a number of JITs do support BPF_ALU | BPF_ARSH | BPF_{K,X}
generation, not all of them do and interpreter does neither. We can
leave existing ones and implement it later in bpf-next for the
remaining ones, but reject this properly in verifier for the time
being.
Fixes: 17a5267067 ("bpf: verifier (add verifier core)")
Reported-by: syzbot+93c4904c5c70348a6890@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Trivial fix to spelling mistake in error message text.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf 2018-01-09
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Prevent out-of-bounds speculation in BPF maps by masking the
index after bounds checks in order to fix spectre v1, and
add an option BPF_JIT_ALWAYS_ON into Kconfig that allows for
removing the BPF interpreter from the kernel in favor of
JIT-only mode to make spectre v2 harder, from Alexei.
2) Remove false sharing of map refcount with max_entries which
was used in spectre v1, from Daniel.
3) Add a missing NULL psock check in sockmap in order to fix
a race, from John.
4) Fix test_align BPF selftest case since a recent change in
verifier rejects the bit-wise arithmetic on pointers
earlier but test_align update was missing, from Alexei.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename the BPF verifier `verbose()` to `bpf_verifier_log_write()` and
export it, so that other components (in particular, drivers for BPF
offload) can reuse the user buffer log to dump error messages at
verification time.
Renaming `verbose()` was necessary in order to avoid a name so generic
to be exported to the global namespace. However to prevent too much pain
for backports, the calls to `verbose()` in the kernel BPF verifier were
not changed. Instead, use function aliasing to make `verbose` point to
`bpf_verifier_log_write`. Another solution could consist in making a
wrapper around `verbose()`, but since it is a variadic function, I don't
see a clean way without creating two identical wrappers, one for the
verifier and one to export.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
smp_call_function_many() requires disabling preemption around the call.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <stable@vger.kernel.org> # v4.14+
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171215192310.25293-1-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715.
A quote from goolge project zero blog:
"At this point, it would normally be necessary to locate gadgets in
the host kernel code that can be used to actually leak data by reading
from an attacker-controlled location, shifting and masking the result
appropriately and then using the result of that as offset to an
attacker-controlled address for a load. But piecing gadgets together
and figuring out which ones work in a speculation context seems annoying.
So instead, we decided to use the eBPF interpreter, which is built into
the host kernel - while there is no legitimate way to invoke it from inside
a VM, the presence of the code in the host kernel's text section is sufficient
to make it usable for the attack, just like with ordinary ROP gadgets."
To make attacker job harder introduce BPF_JIT_ALWAYS_ON config
option that removes interpreter from the kernel in favor of JIT-only mode.
So far eBPF JIT is supported by:
x64, arm64, arm32, sparc64, s390, powerpc64, mips64
The start of JITed program is randomized and code page is marked as read-only.
In addition "constant blinding" can be turned on with net.core.bpf_jit_harden
v2->v3:
- move __bpf_prog_ret0 under ifdef (Daniel)
v1->v2:
- fix init order, test_bpf and cBPF (Daniel's feedback)
- fix offloaded bpf (Jakub's feedback)
- add 'return 0' dummy in case something can invoke prog->bpf_func
- retarget bpf tree. For bpf-next the patch would need one extra hunk.
It will be sent when the trees are merged back to net-next
Considered doing:
int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT;
but it seems better to land the patch as-is and in bpf-next remove
bpf_jit_enable global variable from all JITs, consolidate in one place
and remove this jit_init() function.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Under speculation, CPUs may mis-predict branches in bounds checks. Thus,
memory accesses under a bounds check may be speculated even if the
bounds check fails, providing a primitive for building a side channel.
To avoid leaking kernel data round up array-based maps and mask the index
after bounds check, so speculated load with out of bounds index will load
either valid value from the array or zero from the padded area.
Unconditionally mask index for all array types even when max_entries
are not rounded to power of 2 for root user.
When map is created by unpriv user generate a sequence of bpf insns
that includes AND operation to make sure that JITed code includes
the same 'index & index_mask' operation.
If prog_array map is created by unpriv user replace
bpf_tail_call(ctx, map, index);
with
if (index >= max_entries) {
index &= map->index_mask;
bpf_tail_call(ctx, map, index);
}
(along with roundup to power 2) to prevent out-of-bounds speculation.
There is secondary redundant 'if (index >= max_entries)' in the interpreter
and in all JITs, but they can be optimized later if necessary.
Other array-like maps (cpumap, devmap, sockmap, perf_event_array, cgroup_array)
cannot be used by unpriv, so no changes there.
That fixes bpf side of "Variant 1: bounds check bypass (CVE-2017-5753)" on
all architectures with and without JIT.
v2->v3:
Daniel noticed that attack potentially can be crafted via syscall commands
without loading the program, so add masking to those paths as well.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull cgroup fixes from Tejun Heo:
"This contains fixes for the following two non-trivial issues:
- The task iterator got broken while adding thread mode support for
v4.14. It was less visible because it only triggers when both
cgroup1 and cgroup2 hierarchies are in use. The recent versions of
systemd uses cgroup2 for process management even when cgroup1 is
used for resource control exposing this issue.
- cpuset CPU hotplug path could deadlock when racing against exits.
There also are two patches to replace unlimited strcpy() usages with
strlcpy()"
* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix css_task_iter crash on CSS_TASK_ITER_PROC
cgroup: Fix deadlock in cpu hotplug path
cgroup: use strlcpy() instead of strscpy() to avoid spurious warning
cgroup: avoid copying strings longer than the buffers
syzbot reported the following panic in the verifier triggered
by kmalloc error injection:
kasan: GPF could be caused by NULL-ptr deref or user memory access
RIP: 0010:copy_func_state kernel/bpf/verifier.c:403 [inline]
RIP: 0010:copy_verifier_state+0x364/0x590 kernel/bpf/verifier.c:431
Call Trace:
pop_stack+0x8c/0x270 kernel/bpf/verifier.c:449
push_stack kernel/bpf/verifier.c:491 [inline]
check_cond_jmp_op kernel/bpf/verifier.c:3598 [inline]
do_check+0x4b60/0xa050 kernel/bpf/verifier.c:4731
bpf_check+0x3296/0x58c0 kernel/bpf/verifier.c:5489
bpf_prog_load+0xa2a/0x1b00 kernel/bpf/syscall.c:1198
SYSC_bpf kernel/bpf/syscall.c:1807 [inline]
SyS_bpf+0x1044/0x4420 kernel/bpf/syscall.c:1769
when copy_verifier_state() aborts in the middle due to kmalloc failure
some of the frames could have been partially copied while
current free_verifier_state() loop
for (i = 0; i <= state->curframe; i++)
assumed that all frames are non-null.
Simply fix it by adding 'if (!state)' to free_func_state().
Also avoid stressing copy frame logic more if kzalloc fails
in push_stack() free env->cur_state right away.
Fixes: f4d7e40a5b ("bpf: introduce function calls (verification)")
Reported-by: syzbot+32ac5a3e473f2e01cfc7@syzkaller.appspotmail.com
Reported-by: syzbot+fa99e24f3c29d269a7d5@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull vfs fixes from Al Viro:
- untangle sys_close() abuses in xt_bpf
- deal with register_shrinker() failures in sget()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"
sget(): handle failures of register_shrinker()
mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.
Add psock NULL check to handle a racing sock event that can get the
sk_callback_lock before this case but after xchg happens causing the
refcnt to hit zero and sock user data (psock) to be null and queued
for garbage collection.
Also add a comment in the code because this is a bit subtle and
not obvious in my opinion.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Currently, bpf syscall command BPF_MAP_GET_NEXT_KEY is not
supported for stacktrace map. However, there are use cases where
user space wants to enumerate all stacktrace map entries where
BPF_MAP_GET_NEXT_KEY command will be really helpful.
In addition, if user space wants to delete all map entries
in order to save memory and does not want to close the
map file descriptor, BPF_MAP_GET_NEXT_KEY may help improve
performance if map entries are sparsely populated.
The implementation has similar behavior for
BPF_MAP_GET_NEXT_KEY implementation in hashtab. If user provides
a NULL key pointer or an invalid key, the first key is returned.
Otherwise, the first valid key after the input parameter "key"
is returned, or -ENOENT if no valid key can be found.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Descriptor table is a shared object; it's not a place where you can
stick temporary references to files, especially when we don't need
an opened file at all.
Cc: stable@vger.kernel.org # v4.14
Fixes: 98589a0998 ("netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check
is very wrong, we need time_is_after_jiffies() to make sys_acct() work.
Ignoring the overflows, the code should "goto out" if needcheck >
jiffies, while currently it checks "needcheck < jiffies" and thus in the
likely case check_free_space() does nothing until jiffies overflow.
In particular this means that sys_acct() is simply broken, acct_on()
sets acct->needcheck = jiffies and expects that check_free_space()
should set acct->active = 1 after the free-space check, but this won't
happen if jiffies increments in between.
This was broken by commit 32dc730860 ("get rid of timer in
kern/acct.c") in 2011, then another (correct) commit 795a2f22a8
("acct() should honour the limits from the very beginning") made the
problem more visible.
Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com
Fixes: 32dc730860 ("get rid of timer in kern/acct.c")
Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The sockmap infrastructure is only aware of TCP sockets at the
moment. In the future we plan to add UDP. In both cases CONFIG_NET
should be built-in.
So lets only build sockmap if CONFIG_INET is enabled.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This was added for some work that was eventually factored out but the
helper call was missed. Remove it now and add it back later if needed.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull pid allocation bug fix from Eric Biederman:
"The replacement of the pid hash table and the pid bitmap with an idr
resulted in an implementation that now fails more often in low memory
situations. Allowing fuzzers to observe bad behavior from a memory
allocation failure during pid allocation.
This is a small change to fix this by making the kernel more robust in
the case of error. The non-error paths are left alone so the only
danger is to the already broken error path. I have manually injected
errors and verified that this new error handling works"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
pid: Handle failure to allocate the first pid in a pid namespace
Pull timer fixes from Thomas Gleixner:
"A pile of fixes for long standing issues with the timer wheel and the
NOHZ code:
- Prevent timer base confusion accross the nohz switch, which can
cause unlocked access and data corruption
- Reinitialize the stale base clock on cpu hotplug to prevent subtle
side effects including rollovers on 32bit
- Prevent an interrupt storm when the timer softirq is already
pending caused by tick_nohz_stop_sched_tick()
- Move the timer start tracepoint to a place where it actually makes
sense
- Add documentation to timerqueue functions as they caused confusion
several times now"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timerqueue: Document return values of timerqueue_add/del()
timers: Invoke timer_start_debug() where it makes sense
nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
timers: Reinitialize per cpu bases on hotplug
timers: Use deferrable base independent of base::nohz_active
Pull smp fixlet from Thomas Gleixner:
"A trivial build warning fix for newer compilers"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Move inline keyword at the beginning of declaration
