This is a simple mechanical transformation done by:
@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
When a link is enslave to bond, it need to set the interface down first.
This makes the slave remove mac multicast address 33:33:00:00:00:01(The
IPv6 multicast address ff02::1 is kept even when the interface down). When
bond set the slave up, ipv6_mc_up() was not called due to commit c2edacf80e
("bonding / ipv6: no addrconf for slaves separately from master").
This is not an issue before we adding the lladdr target feature for bonding,
as the mac multicast address will be added back when bond interface up and
join group ff02::1.
But after adding lladdr target feature for bonding. When user set a lladdr
target, the unsolicited NA message with all-nodes multicast dest will be
dropped as the slave interface never add 33:33:00:00:00:01 back.
Fix this by calling ipv6_mc_up() to add 33:33:00:00:00:01 back when
the slave interface up.
Reported-by: LiLiang <liali@redhat.com>
Fixes: 5e1eeef69c ("bonding: NS target should accept link local address")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_devconf_inherit_init_net, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 856c395cfa ("net: introduce a knob to control whether to inherit devconf config")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The accept_untracked_na sysctl changed from a boolean to an integer
when a new knob '2' was added. This patch provides a safeguard to avoid
accepting values that are not defined in the sysctl. When setting a
value greater than 2, the user will get an 'invalid argument' warning.
Fixes: aaa5f515b1 ("net: ipv6: new accept_untracked_na option to accept na only if in-network")
Signed-off-by: Jaehee Park <jhpark1013@gmail.com>
Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Suggested-by: Roopa Prabhu <roopa@nvidia.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20220720183632.376138-1-jhpark1013@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds a third knob, '2', which extends the
accept_untracked_na option to learn a neighbor only if the src ip is
in the same subnet as an address configured on the interface that
received the neighbor advertisement. This is similar to the arp_accept
configuration for ipv4.
Signed-off-by: Jaehee Park <jhpark1013@gmail.com>
Suggested-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/ethernet/microchip/sparx5/sparx5_switchdev.c
9c5de246c1 ("net: sparx5: mdb add/del handle non-sparx5 devices")
fbb89d02e3 ("net: sparx5: Allow mdb entries to both CPU and ports")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The addrconf_verify_rtnl() function uses a big if/elseif/elseif/... block
to categorize each address by what type of attention it needs. An
about-to-expire (RFC 4941) temporary address is one such category, but the
previous elseif branch catches addresses that have already run out their
prefered_lft. This means that if addrconf_verify_rtnl() fails to run in
the necessary time window (i.e. REGEN_ADVANCE time units before the end of
the prefered_lft), the temporary address will never be regenerated, and no
temporary addresses will be available until each one's valid_lft runs out
and manage_tempaddrs() begins anew.
Fix this by moving the entire temporary address regeneration case out of
that block. That block is supposed to implement the "destructive" part of
an address's lifecycle, and regenerating a fresh temporary address is not,
semantically speaking, actually tied to any particular lifecycle stage.
The age test is also changed from `age >= prefered_lft - regen_advance`
to `age + regen_advance >= prefered_lft` instead, to ensure no underflow
occurs if the system administrator increases the regen_advance to a value
greater than the already-set prefered_lft.
Note that this does not fix the problem of addrconf_verify_rtnl() sometimes
not running in time, resulting in the race condition described in RFC 4941
section 3.4 - it only ensures that the address is regenerated. Fixing THAT
problem may require either using jiffies instead of seconds for all time
arithmetic here, or always rounding up when regen_advance is converted to
seconds.
Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Link: https://lore.kernel.org/r/20220623181103.7033-1-CFSworks@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When routes corresponding to addresses are restored by
fixup_permanent_addr(), the dst_nopolicy parameter was not set.
The typical use case is a user that configures an address on a down
interface and then put this interface up.
Let's take care of this flag in addrconf_f6i_alloc(), so that every callers
benefit ont it.
CC: stable@kernel.org
CC: David Forster <dforster@brocade.com>
Fixes: df789fe752 ("ipv6: Provide ipv6 version of "disable_policy" sysctl")
Reported-by: Siwar Zitouni <siwar.zitouni@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220623120015.32640-1-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
RFC 9131 changes default behaviour of handling RX of NA messages when the
corresponding entry is absent in the neighbour cache. The current
implementation is limited to accept just unsolicited NAs. However, the
RFC is more generic where it also accepts solicited NAs. Both types
should result in adding a STALE entry for this case.
Expand accept_untracked_na behaviour to also accept solicited NAs to
be compliant with the RFC and rename the sysctl knob to
accept_untracked_na.
Fixes: f9a2fb7331 ("net/ipv6: Introduce accept_unsolicited_na knob to implement router-side changes for RFC9131")
Signed-off-by: Arun Ajith S <aajith@arista.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220530101414.65439-1-aajith@arista.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Core
----
- Support TCPv6 segmentation offload with super-segments larger than
64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).
- Generalize skb freeing deferral to per-cpu lists, instead of
per-socket lists.
- Add a netdev statistic for packets dropped due to L2 address
mismatch (rx_otherhost_dropped).
- Continue work annotating skb drop reasons.
- Accept alternative netdev names (ALT_IFNAME) in more netlink
requests.
- Add VLAN support for AF_PACKET SOCK_RAW GSO.
- Allow receiving skb mark from the socket as a cmsg.
- Enable memcg accounting for veth queues, sysctl tables and IPv6.
BPF
---
- Add libbpf support for User Statically-Defined Tracing (USDTs).
- Speed up symbol resolution for kprobes multi-link attachments.
- Support storing typed pointers to referenced and unreferenced
objects in BPF maps.
- Add support for BPF link iterator.
- Introduce access to remote CPU map elements in BPF per-cpu map.
- Allow middle-of-the-road settings for the
kernel.unprivileged_bpf_disabled sysctl.
- Implement basic types of dynamic pointers e.g. to allow for
dynamically sized ringbuf reservations without extra memory copies.
Protocols
---------
- Retire port only listening_hash table, add a second bind table
hashed by port and address. Avoid linear list walk when binding
to very popular ports (e.g. 443).
- Add bridge FDB bulk flush filtering support allowing user space
to remove all FDB entries matching a condition.
- Introduce accept_unsolicited_na sysctl for IPv6 to implement
router-side changes for RFC9131.
- Support for MPTCP path manager in user space.
- Add MPTCP support for fallback to regular TCP for connections
that have never connected additional subflows or transmitted
out-of-sequence data (partial support for RFC8684 fallback).
- Avoid races in MPTCP-level window tracking, stabilize and improve
throughput.
- Support lockless operation of GRE tunnels with seq numbers enabled.
- WiFi support for host based BSS color collision detection.
- Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.
- Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).
- Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).
- Allow matching on the number of VLAN tags via tc-flower.
- Add tracepoint for tcp_set_ca_state().
Driver API
----------
- Improve error reporting from classifier and action offload.
- Add support for listing line cards in switches (devlink).
- Add helpers for reporting page pool statistics with ethtool -S.
- Add support for reading clock cycles when using PTP virtual clocks,
instead of having the driver convert to time before reporting.
This makes it possible to report time from different vclocks.
- Support configuring low-latency Tx descriptor push via ethtool.
- Separate Clause 22 and Clause 45 MDIO accesses more explicitly.
New hardware / drivers
----------------------
- Ethernet:
- Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
- Sunplus SP7021 SoC (sp7021_emac)
- Add support for Renesas RZ/V2M (in ravb)
- Add support for MediaTek mt7986 switches (in mtk_eth_soc)
- Ethernet PHYs:
- ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
- TI DP83TD510 PHY
- Microchip LAN8742/LAN88xx PHYs
- WiFi:
- Driver for pureLiFi X, XL, XC devices (plfxlc)
- Driver for Silicon Labs devices (wfx)
- Support for WCN6750 (in ath11k)
- Support Realtek 8852ce devices (in rtw89)
- Mobile:
- MediaTek T700 modems (Intel 5G 5000 M.2 cards)
- CAN:
- ctucanfd: add support for CTU CAN FD open-source IP core
from Czech Technical University in Prague
Drivers
-------
- Delete a number of old drivers still using virt_to_bus().
- Ethernet NICs:
- intel: support TSO on tunnels MPLS
- broadcom: support multi-buffer XDP
- nfp: support VF rate limiting
- sfc: use hardware tx timestamps for more than PTP
- mlx5: multi-port eswitch support
- hyper-v: add support for XDP_REDIRECT
- atlantic: XDP support (including multi-buffer)
- macb: improve real-time perf by deferring Tx processing to NAPI
- High-speed Ethernet switches:
- mlxsw: implement basic line card information querying
- prestera: add support for traffic policing on ingress and egress
- Embedded Ethernet switches:
- lan966x: add support for packet DMA (FDMA)
- lan966x: add support for PTP programmable pins
- ti: cpsw_new: enable bc/mc storm prevention
- Qualcomm 802.11ax WiFi (ath11k):
- Wake-on-WLAN support for QCA6390 and WCN6855
- device recovery (firmware restart) support
- support setting Specific Absorption Rate (SAR) for WCN6855
- read country code from SMBIOS for WCN6855/QCA6390
- enable keep-alive during WoWLAN suspend
- implement remain-on-channel support
- MediaTek WiFi (mt76):
- support Wireless Ethernet Dispatch offloading packet movement
between the Ethernet switch and WiFi interfaces
- non-standard VHT MCS10-11 support
- mt7921 AP mode support
- mt7921 IPv6 NS offload support
- Ethernet PHYs:
- micrel: ksz9031/ksz9131: cabletest support
- lan87xx: SQI support for T1 PHYs
- lan937x: add interrupt support for link detection
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core
----
- Support TCPv6 segmentation offload with super-segments larger than
64k bytes using the IPv6 Jumbogram extension header (AKA BIG TCP).
- Generalize skb freeing deferral to per-cpu lists, instead of
per-socket lists.
- Add a netdev statistic for packets dropped due to L2 address
mismatch (rx_otherhost_dropped).
- Continue work annotating skb drop reasons.
- Accept alternative netdev names (ALT_IFNAME) in more netlink
requests.
- Add VLAN support for AF_PACKET SOCK_RAW GSO.
- Allow receiving skb mark from the socket as a cmsg.
- Enable memcg accounting for veth queues, sysctl tables and IPv6.
BPF
---
- Add libbpf support for User Statically-Defined Tracing (USDTs).
- Speed up symbol resolution for kprobes multi-link attachments.
- Support storing typed pointers to referenced and unreferenced
objects in BPF maps.
- Add support for BPF link iterator.
- Introduce access to remote CPU map elements in BPF per-cpu map.
- Allow middle-of-the-road settings for the
kernel.unprivileged_bpf_disabled sysctl.
- Implement basic types of dynamic pointers e.g. to allow for
dynamically sized ringbuf reservations without extra memory copies.
Protocols
---------
- Retire port only listening_hash table, add a second bind table
hashed by port and address. Avoid linear list walk when binding to
very popular ports (e.g. 443).
- Add bridge FDB bulk flush filtering support allowing user space to
remove all FDB entries matching a condition.
- Introduce accept_unsolicited_na sysctl for IPv6 to implement
router-side changes for RFC9131.
- Support for MPTCP path manager in user space.
- Add MPTCP support for fallback to regular TCP for connections that
have never connected additional subflows or transmitted
out-of-sequence data (partial support for RFC8684 fallback).
- Avoid races in MPTCP-level window tracking, stabilize and improve
throughput.
- Support lockless operation of GRE tunnels with seq numbers enabled.
- WiFi support for host based BSS color collision detection.
- Add support for SO_TXTIME/SCM_TXTIME on CAN sockets.
- Support transmission w/o flow control in CAN ISOTP (ISO 15765-2).
- Support zero-copy Tx with TLS 1.2 crypto offload (sendfile).
- Allow matching on the number of VLAN tags via tc-flower.
- Add tracepoint for tcp_set_ca_state().
Driver API
----------
- Improve error reporting from classifier and action offload.
- Add support for listing line cards in switches (devlink).
- Add helpers for reporting page pool statistics with ethtool -S.
- Add support for reading clock cycles when using PTP virtual clocks,
instead of having the driver convert to time before reporting. This
makes it possible to report time from different vclocks.
- Support configuring low-latency Tx descriptor push via ethtool.
- Separate Clause 22 and Clause 45 MDIO accesses more explicitly.
New hardware / drivers
----------------------
- Ethernet:
- Marvell's Octeon NIC PCI Endpoint support (octeon_ep)
- Sunplus SP7021 SoC (sp7021_emac)
- Add support for Renesas RZ/V2M (in ravb)
- Add support for MediaTek mt7986 switches (in mtk_eth_soc)
- Ethernet PHYs:
- ADIN1100 industrial PHYs (w/ 10BASE-T1L and SQI reporting)
- TI DP83TD510 PHY
- Microchip LAN8742/LAN88xx PHYs
- WiFi:
- Driver for pureLiFi X, XL, XC devices (plfxlc)
- Driver for Silicon Labs devices (wfx)
- Support for WCN6750 (in ath11k)
- Support Realtek 8852ce devices (in rtw89)
- Mobile:
- MediaTek T700 modems (Intel 5G 5000 M.2 cards)
- CAN:
- ctucanfd: add support for CTU CAN FD open-source IP core from
Czech Technical University in Prague
Drivers
-------
- Delete a number of old drivers still using virt_to_bus().
- Ethernet NICs:
- intel: support TSO on tunnels MPLS
- broadcom: support multi-buffer XDP
- nfp: support VF rate limiting
- sfc: use hardware tx timestamps for more than PTP
- mlx5: multi-port eswitch support
- hyper-v: add support for XDP_REDIRECT
- atlantic: XDP support (including multi-buffer)
- macb: improve real-time perf by deferring Tx processing to NAPI
- High-speed Ethernet switches:
- mlxsw: implement basic line card information querying
- prestera: add support for traffic policing on ingress and egress
- Embedded Ethernet switches:
- lan966x: add support for packet DMA (FDMA)
- lan966x: add support for PTP programmable pins
- ti: cpsw_new: enable bc/mc storm prevention
- Qualcomm 802.11ax WiFi (ath11k):
- Wake-on-WLAN support for QCA6390 and WCN6855
- device recovery (firmware restart) support
- support setting Specific Absorption Rate (SAR) for WCN6855
- read country code from SMBIOS for WCN6855/QCA6390
- enable keep-alive during WoWLAN suspend
- implement remain-on-channel support
- MediaTek WiFi (mt76):
- support Wireless Ethernet Dispatch offloading packet movement
between the Ethernet switch and WiFi interfaces
- non-standard VHT MCS10-11 support
- mt7921 AP mode support
- mt7921 IPv6 NS offload support
- Ethernet PHYs:
- micrel: ksz9031/ksz9131: cabletest support
- lan87xx: SQI support for T1 PHYs
- lan937x: add interrupt support for link detection"
* tag 'net-next-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1809 commits)
ptp: ocp: Add firmware header checks
ptp: ocp: fix PPS source selector debugfs reporting
ptp: ocp: add .init function for sma_op vector
ptp: ocp: vectorize the sma accessor functions
ptp: ocp: constify selectors
ptp: ocp: parameterize input/output sma selectors
ptp: ocp: revise firmware display
ptp: ocp: add Celestica timecard PCI ids
ptp: ocp: Remove #ifdefs around PCI IDs
ptp: ocp: 32-bit fixups for pci start address
Revert "net/smc: fix listen processing for SMC-Rv2"
ath6kl: Use cc-disable-warning to disable -Wdangling-pointer
selftests/bpf: Dynptr tests
bpf: Add dynptr data slices
bpf: Add bpf_dynptr_read and bpf_dynptr_write
bpf: Dynptr support for ring buffers
bpf: Add bpf_dynptr_from_mem for local dynptrs
bpf: Add verifier support for dynptrs
bpf: Suppress 'passing zero to PTR_ERR' warning
bpf: Introduce bpf_arch_text_invalidate for bpf_prog_pack
...
random32.c has two random number generators in it: one that is meant to
be used deterministically, with some predefined seed, and one that does
the same exact thing as random.c, except does it poorly. The first one
has some use cases. The second one no longer does and can be replaced
with calls to random.c's proper random number generator.
The relatively recent siphash-based bad random32.c code was added in
response to concerns that the prior random32.c was too deterministic.
Out of fears that random.c was (at the time) too slow, this code was
anonymously contributed. Then out of that emerged a kind of shadow
entropy gathering system, with its own tentacles throughout various net
code, added willy nilly.
Stop👏making👏bespoke👏random👏number👏generators👏.
Fortunately, recent advances in random.c mean that we can stop playing
with this sketchiness, and just use get_random_u32(), which is now fast
enough. In micro benchmarks using RDPMC, I'm seeing the same median
cycle count between the two functions, with the mean being _slightly_
higher due to batches refilling (which we can optimize further need be).
However, when doing *real* benchmarks of the net functions that actually
use these random numbers, the mean cycles actually *decreased* slightly
(with the median still staying the same), likely because the additional
prandom code means icache misses and complexity, whereas random.c is
generally already being used by something else nearby.
The biggest benefit of this is that there are many users of prandom who
probably should be using cryptographically secure random numbers. This
makes all of those accidental cases become secure by just flipping a
switch. Later on, we can do a tree-wide cleanup to remove the static
inline wrapper functions that this commit adds.
There are also some low-ish hanging fruits for making this even faster
in the future: a get_random_u16() function for use in the networking
stack will give a 2x performance boost there, using SIMD for ChaCha20
will let us compute 4 or 8 or 16 blocks of output in parallel, instead
of just one, giving us large buffers for cheap, and introducing a
get_random_*_bh() function that assumes irqs are already disabled will
shave off a few cycles for ordinary calls. These are things we can chip
away at down the road.
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Creating a new netdevice allocates at least ~50Kb of memory for various
kernel objects, but only ~5Kb of them are accounted to memcg. As a result,
creating an unlimited number of netdevice inside a memcg-limited container
does not fall within memcg restrictions, consumes a significant part
of the host's memory, can cause global OOM and lead to random kills of
host processes.
The main consumers of non-accounted memory are:
~10Kb 80+ kernfs nodes
~6Kb ipv6_add_dev() allocations
6Kb __register_sysctl_table() allocations
4Kb neigh_sysctl_register() allocations
4Kb __devinet_sysctl_register() allocations
4Kb __addrconf_sysctl_register() allocations
Accounting of these objects allows to increase the share of memcg-related
memory up to 60-70% (~38Kb accounted vs ~54Kb total for dummy netdevice
on typical VM with default Fedora 35 kernel) and this should be enough
to somehow protect the host from misuse inside container.
Other related objects are quite small and may not be taken into account
to minimize the expected performance degradation.
It should be separately mentonied ~300 bytes of percpu allocation
of struct ipstats_mib in snmp6_alloc_dev(), on huge multi-cpu nodes
it can become the main consumer of memory.
This patch does not enables kernfs accounting as it affects
other parts of the kernel and should be discussed separately.
However, even without kernfs, this patch significantly improves the
current situation and allows to take into account more than half
of all netdevice allocations.
Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/354a0a5f-9ec3-a25c-3215-304eab2157bc@openvz.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix mistake in the original patch where limits were specified but the
handler didn't take care of the limits.
Signed-off-by: Arun Ajith S <aajith@arista.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new neighbour cache entry in STALE state for routers on receiving
an unsolicited (gratuitous) neighbour advertisement with
target link-layer-address option specified.
This is similar to the arp_accept configuration for IPv4.
A new sysctl endpoint is created to turn on this behaviour:
/proc/sys/net/ipv6/conf/interface/accept_unsolicited_na.
Signed-off-by: Arun Ajith S <aajith@arista.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
idev->addr_list needs to be protected by idev->lock. However, it is not
always possible to do so while iterating and performing actions on
inet6_ifaddr instances. For example, multiple functions (like
addrconf_{join,leave}_anycast) eventually call down to other functions
that acquire the idev->lock. The current code temporarily unlocked the
idev->lock during the loops, which can cause race conditions. Moving the
locks up is also not an appropriate solution as the ordering of lock
acquisition will be inconsistent with for example mc_lock.
This solution adds an additional field to inet6_ifaddr that is used
to temporarily add the instances to a temporary list while holding
idev->lock. The temporary list can then be traversed without holding
idev->lock. This change was done in two places. In addrconf_ifdown, the
list_for_each_entry_safe variant of the list loop is also no longer
necessary as there is no deletion within that specific loop.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20220403231523.45843-1-dossche.niels@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There are two reasons for addrconf_notify() to be called with NETDEV_DOWN:
either the network device is actually going down, or IPv6 was disabled
on the interface.
If either of them stays down while the other is toggled, we repeatedly
call the code for NETDEV_DOWN, including ipv6_mc_down(), while never
calling the corresponding ipv6_mc_up() in between. This will cause a
new entry in idev->mc_tomb to be allocated for each multicast group
the interface is subscribed to, which in turn leaks one struct ifmcaddr6
per nontrivial multicast group the interface is subscribed to.
The following reproducer will leak at least $n objects:
ip addr add ff2e::4242/32 dev eth0 autojoin
sysctl -w net.ipv6.conf.eth0.disable_ipv6=1
for i in $(seq 1 $n); do
ip link set up eth0; ip link set down eth0
done
Joining groups with IPV6_ADD_MEMBERSHIP (unprivileged) or setting the
sysctl net.ipv6.conf.eth0.forwarding to 1 (=> subscribing to ff02::2)
can also be used to create a nontrivial idev->mc_list, which will the
leak objects with the right up-down-sequence.
Based on both sources for NETDEV_DOWN events the interface IPv6 state
should be considered:
- not ready if the network interface is not ready OR IPv6 is disabled
for it
- ready if the network interface is ready AND IPv6 is enabled for it
The functions ipv6_mc_up() and ipv6_down() should only be run when this
state changes.
Implement this by remembering when the IPv6 state is ready, and only
run ipv6_mc_down() if it actually changed from ready to not ready.
The other direction (not ready -> ready) already works correctly, as:
- the interface notification triggered codepath for NETDEV_UP /
NETDEV_CHANGE returns early if ipv6 is disabled, and
- the disable_ipv6=0 triggered codepath skips fully initializing the
interface as long as addrconf_link_ready(dev) returns false
- calling ipv6_mc_up() repeatedly does not leak anything
Fixes: 3ce62a84d5 ("ipv6: exit early in addrconf_notify() if IPv6 is disabled")
Signed-off-by: Johannes Nixdorf <j.nixdorf@avm.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
valid_lft, prefered_lft and tstamp are always accessed under the lock
"lock" in other places. Reading these without taking the lock may result
in inconsistencies regarding the calculation of the valid and preferred
variables since decisions are taken on these fields for those variables.
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Niels Dossche <niels.dossche@ugent.be>
Link: https://lore.kernel.org/r/20220223131954.6570-1-niels.dossche@ugent.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds a new protocol attribute to IPv4 and IPv6 addresses.
Inspiration was taken from the protocol attribute of routes. User space
applications like iproute2 can set/get the protocol with the Netlink API.
The attribute is stored as an 8-bit unsigned integer.
The protocol attribute is set by kernel for these categories:
- IPv4 and IPv6 loopback addresses
- IPv6 addresses generated from router announcements
- IPv6 link local addresses
User space may pass custom protocols, not defined by the kernel.
Grouping addresses on their origin is useful in scenarios where you want
to distinguish between addresses based on who added them, e.g. kernel
vs. user space.
Tagging addresses with a string label is an existing feature that could be
used as a solution. Unfortunately the max length of a label is
15 characters, and for compatibility reasons the label must be prefixed
with the name of the device followed by a colon. Since device names also
have a max length of 15 characters, only -1 characters is guaranteed to be
available for any origin tag, which is not that much.
A reference implementation of user space setting and getting protocols
is available for iproute2:
9a6ea18bd7
Signed-off-by: Jacques de Laval <Jacques.De.Laval@westermo.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220217150202.80802-1-Jacques.De.Laval@westermo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Before freeing the hash table in addrconf_exit_net(),
we need to make sure the work queue has completed,
or risk NULL dereference or UAF.
Thus, use cancel_delayed_work_sync() to enforce this.
We do not hold RTNL in addrconf_exit_net(), making this safe.
Fixes: 8805d13ff1 ("ipv6/addrconf: use one delayed work per netns")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220216182037.3742-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Whenever rt6_uncached_list_flush_dev() swaps rt->rt6_idev
to the blackhole device, parts of IPv6 stack might still need
to increment one SNMP counter.
Root cause, patch from Ido, changelog from Eric :)
This bug suggests that we need to audit rt->rt6_idev usages
and make sure they are properly using RCU protection.
Fixes: e5f80fcf86 ("ipv6: give an IPv6 dev to blackhole_netdev")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv6 addrconf notifiers wants the loopback device to
be the last device being dismantled at netns deletion.
This caused many limitations and work arounds.
Back in linux-5.3, Mahesh added a per host blackhole_netdev
that can be used whenever we need to make sure objects no longer
refer to a disappearing device.
If we attach to blackhole_netdev an ip6_ptr (allocate an idev),
then we can use this special device (which is never freed)
in place of the loopback_dev (which can be freed).
This will permit improvements in netdev_run_todo() and other parts
of the stack where had steps to make sure loopback_dev was
the last device to disappear.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv6 does not scale very well with the number of IPv6 addresses.
It uses a global (shared by all netns) hash table with 256 buckets.
Some functions like addrconf_verify_rtnl() and addrconf_ifdown()
have to iterate all addresses in the hash table.
I have seen addrconf_verify_rtnl() holding the cpu for 10ms or more.
Switch to the per netns hashtable (and spinlock) added
in prior patches.
This considerably speeds up netns dismantle times on hosts
with thousands of netns. This also has an impact
on regular (fast path) IPv6 processing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Next step for using per netns inet6_addr_lst
is to have per netns work item to ultimately
call addrconf_verify_rtnl() and addrconf_verify()
with a new 'struct net*' argument.
Everything is still using the global inet6_addr_lst[] table.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a per netns hash table and a dedicated spinlock,
first step to get rid of the global inet6_addr_lst[] one.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This fixes minor data-races in ip6_mc_input() and
batadv_mcast_mla_rtr_flags_softif_get_ipv6()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit b75326c201.
This commit breaks Linux compatibility with USGv6 tests. The RFC this
commit was based on is actually an expired draft: no published RFC
currently allows the new behaviour it introduced.
Without full IETF endorsement, the flash renumbering scenario this
patch was supposed to enable is never going to work, as other IPv6
equipements on the same LAN will keep the 2 hours limit.
Fixes: b75326c201 ("ipv6: Honor all IPv6 PIO Valid Lifetime values")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In most situations the neighbor discovery cache should be cleared on a
NOCARRIER event which is currently done unconditionally. But for wireless
roams the neighbor discovery cache can and should remain intact since
the underlying network has not changed.
This patch introduces a sysctl option ndisc_evict_nocarrier which can
be disabled by a wireless supplicant during a roam. This allows packets
to be sent after a roam immediately without having to wait for
neighbor discovery.
A user reported roughly a 1 second delay after a roam before packets
could be sent out (note, on IPv4). This delay was due to the ARP
cache being cleared. During testing of this same scenario using IPv6
no delay was noticed, but regardless there is no reason to clear
the ndisc cache for wireless roams.
Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When addr_gen_mode is set to IN6_ADDR_GEN_MODE_NONE, the link-local addr
should not be generated. But it isn't the case for GRE (as well as GRE6)
and SIT tunnels. Make it so that tunnels consider the addr_gen_mode,
especially for IN6_ADDR_GEN_MODE_NONE.
Do this in add_v4_addrs() to cover both GRE and SIT only if the addr
scope is link.
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Acked-by: Antonio Quartulli <a@unstable.cc>
Link: https://lore.kernel.org/r/20211020200618.467342-1-ssuryaextr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
GRE interfaces are not Ether-like and therefore it is not
possible to generate the v6LL address the same way as (for example)
GRETAP devices.
With default settings, a GRE interface will attempt generating its v6LL
address using the EUI64 approach, but this will fail when the local
endpoint of the GRE tunnel is set to "any". In this case the GRE
interface will end up with no v6LL address, thus violating RFC4291.
SIT interfaces already implement a different logic to ensure that a v6LL
address is always computed.
Change the GRE v6LL generation logic to follow the same approach as SIT.
This way GRE interfaces will always have a v6LL address as well.
Behaviour of GRETAP interfaces has not been changed as they behave like
classic Ether-like interfaces.
To avoid code duplication sit_add_v4_addrs() has been renamed to
add_v4_addrs() and adapted to handle also the IP6GRE/GRE cases.
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
The kernel provides a "/proc/sys/net/ipv6/conf/<iface>/mtu"
file, which can temporarily record the mtu value of the last
received RA message when the RA mtu value is lower than the
interface mtu, but this proc has following limitations:
(1) when the interface mtu (/sys/class/net/<iface>/mtu) is
updeated, mtu6 (/proc/sys/net/ipv6/conf/<iface>/mtu) will
be updated to the value of interface mtu;
(2) mtu6 (/proc/sys/net/ipv6/conf/<iface>/mtu) only affect
ipv6 connection, and not affect ipv4.
Therefore, when the mtu option is carried in the RA message,
there will be a problem that the user sometimes cannot obtain
RA mtu value correctly by reading mtu6.
After this patch set, if a RA message carries the mtu option,
you can send a netlink msg which nlmsg_type is RTM_GETLINK,
and then by parsing the attribute of IFLA_INET6_RA_MTU to
get the mtu value carried in the RA message received on the
inet6 device. In addition, you can also get a link notification
when ra_mtu is updated so it doesn't have to poll.
In this way, if the MTU values that the device receives from
the network in the PCO IPv4 and the RA IPv6 procedures are
different, the user can obtain the correct ipv6 ra_mtu value
and compare the value of ra_mtu and ipv4 mtu, then the device
can use the lower MTU value for both IPv4 and IPv6.
Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210827150412.9267-1-rocco.yue@mediatek.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass extack arg to validate_linkmsg and validate_link_af callbacks.
If a netlink attribute has a reject_message, use the extended ack
mechanism to carry the message back to user space.
Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When compiling without CONFIG_SYSCTL, this warning appears:
net/ipv6/addrconf.c:99:12: error: 'ioam6_if_id_max' defined but not used [-Werror=unused-variable]
99 | static u32 ioam6_if_id_max = U16_MAX;
| ^~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Simply moving the declaration of this variable under ...
#ifdef CONFIG_SYSCTL
... with other similar variables fixes the issue.
Fixes: 9ee11f0fff ("ipv6: ioam: Data plane support for Pre-allocated Trace")
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement support for processing the IOAM Pre-allocated Trace with IPv6,
see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option, see IANA [3].
A new per-interface sysctl is introduced. The value is a boolean to accept (=1)
or ignore (=0, by default) IPv6 IOAM options on ingress for an interface:
- net.ipv6.conf.XXX.ioam6_enabled
Two other sysctls are introduced to define IOAM IDs, represented by an integer.
They are respectively per-namespace and per-interface:
- net.ipv6.ioam6_id
- net.ipv6.conf.XXX.ioam6_id
The value of the first one represents the IOAM ID of the node itself (u32; max
and default value = U32_MAX>>8, due to hop limit concatenation) while the other
represents the IOAM ID of an interface (u16; max and default value = U16_MAX).
Each "ioam6_id" sysctl has a "_wide" equivalent:
- net.ipv6.ioam6_id_wide
- net.ipv6.conf.XXX.ioam6_id_wide
The value of the first one represents the wide IOAM ID of the node itself (u64;
max and default value = U64_MAX>>8, due to hop limit concatenation) while the
other represents the wide IOAM ID of an interface (u32; max and default value
= U32_MAX).
The use of short and wide equivalents is not exclusive, a deployment could
choose to leverage both. For example, net.ipv6.conf.XXX.ioam6_id (short format)
could be an identifier for a physical interface, whereas
net.ipv6.conf.XXX.ioam6_id_wide (wide format) could be an identifier for a
logical sub-interface. Documentation about new sysctls is provided at the end
of this patchset.
Two relativistic hash tables are used: one for IOAM namespaces, the other for
IOAM schemas. A namespace can only have a single active schema and a schema
can only be attached to a single namespace (1:1 relationship).
[1] https://tools.ietf.org/html/draft-ietf-ippm-ioam-ipv6-options
[2] https://tools.ietf.org/html/draft-ietf-ippm-ioam-data
[3] https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
An netadmin inside container can use 'ip a a' and 'ip r a'
to assign a large number of ipv4/ipv6 addresses and routing entries
and force kernel to allocate megabytes of unaccounted memory
for long-lived per-netdevice related kernel objects:
'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node',
'struct rt6_info', 'struct fib_rules' and ip_fib caches.
These objects can be manually removed, though usually they lives
in memory till destroy of its net namespace.
It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.
One of such objects is the 'struct fib6_node' mostly allocated in
net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section:
write_lock_bh(&table->tb6_lock);
err = fib6_add(&table->tb6_root, rt, info, mxc);
write_unlock_bh(&table->tb6_lock);
In this case it is not enough to simply add SLAB_ACCOUNT to corresponding
kmem cache. The proper memory cgroup still cannot be found due to the
incorrect 'in_interrupt()' check used in memcg_kmem_bypass().
Obsoleted in_interrupt() does not describe real execution context properly.
>From include/linux/preempt.h:
The following macros are deprecated and should not be used in new code:
in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled
To verify the current execution context new macro should be used instead:
in_task() - We're in task context
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The local variable "struct net *net" in the two functions of
inet6_rtm_getaddr() and inet6_dump_addr() are actually useless,
so remove them.
Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh
scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
