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2023-04-21net: dst: fix missing initialization of rt_uncachedMaxime Bizon
xfrm_alloc_dst() followed by xfrm4_dst_destroy(), without a xfrm4_fill_dst() call in between, causes the following BUG: BUG: spinlock bad magic on CPU#0, fbxhostapd/732 lock: 0x890b7668, .magic: 890b7668, .owner: <none>/-1, .owner_cpu: 0 CPU: 0 PID: 732 Comm: fbxhostapd Not tainted 6.3.0-rc6-next-20230414-00613-ge8de66369925-dirty #9 Hardware name: Marvell Kirkwood (Flattened Device Tree) unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x28/0x30 dump_stack_lvl from do_raw_spin_lock+0x20/0x80 do_raw_spin_lock from rt_del_uncached_list+0x30/0x64 rt_del_uncached_list from xfrm4_dst_destroy+0x3c/0xbc xfrm4_dst_destroy from dst_destroy+0x5c/0xb0 dst_destroy from rcu_process_callbacks+0xc4/0xec rcu_process_callbacks from __do_softirq+0xb4/0x22c __do_softirq from call_with_stack+0x1c/0x24 call_with_stack from do_softirq+0x60/0x6c do_softirq from __local_bh_enable_ip+0xa0/0xcc Patch "net: dst: Prevent false sharing vs. dst_entry:: __refcnt" moved rt_uncached and rt_uncached_list fields from rtable struct to dst struct, so they are more zeroed by memset_after(xdst, 0, u.dst) in xfrm_alloc_dst(). Note that rt_uncached (list_head) was never properly initialized at alloc time, but xfrm[46]_dst_destroy() is written in such a way that it was not an issue thanks to the memset: if (xdst->u.rt.dst.rt_uncached_list) rt_del_uncached_list(&xdst->u.rt); The route code does it the other way around: rt_uncached_list is assumed to be valid IIF rt_uncached list_head is not empty: void rt_del_uncached_list(struct rtable *rt) { if (!list_empty(&rt->dst.rt_uncached)) { struct uncached_list *ul = rt->dst.rt_uncached_list; spin_lock_bh(&ul->lock); list_del_init(&rt->dst.rt_uncached); spin_unlock_bh(&ul->lock); } } This patch adds mandatory rt_uncached list_head initialization in generic dst_init(), and adapt xfrm[46]_dst_destroy logic to match the rest of the code. Fixes: d288a162dd1c ("net: dst: Prevent false sharing vs. dst_entry:: __refcnt") Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/oe-lkp/202304162125.18b7bcdd-oliver.sang@intel.com Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> CC: Leon Romanovsky <leon@kernel.org> Signed-off-by: Maxime Bizon <mbizon@freebox.fr> Link: https://lore.kernel.org/r/20230420182508.2417582-1-mbizon@freebox.fr Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-28net: dst: Prevent false sharing vs. dst_entry:: __refcntWangyang Guo
dst_entry::__refcnt is highly contended in scenarios where many connections happen from and to the same IP. The reference count is an atomic_t, so the reference count operations have to take the cache-line exclusive. Aside of the unavoidable reference count contention there is another significant problem which is caused by that: False sharing. perf top identified two affected read accesses. dst_entry::lwtstate and rtable::rt_genid. dst_entry:__refcnt is located at offset 64 of dst_entry, which puts it into a seperate cacheline vs. the read mostly members located at the beginning of the struct. That prevents false sharing vs. the struct members in the first 64 bytes of the structure, but there is also dst_entry::lwtstate which is located after the reference count and in the same cache line. This member is read after a reference count has been acquired. struct rtable embeds a struct dst_entry at offset 0. struct dst_entry has a size of 112 bytes, which means that the struct members of rtable which follow the dst member share the same cache line as dst_entry::__refcnt. Especially rtable::rt_genid is also read by the contexts which have a reference count acquired already. When dst_entry:__refcnt is incremented or decremented via an atomic operation these read accesses stall. This was found when analysing the memtier benchmark in 1:100 mode, which amplifies the problem extremly. Move the rt[6i]_uncached[_list] members out of struct rtable and struct rt6_info into struct dst_entry to provide padding and move the lwtstate member after that so it ends up in the same cache line. The resulting improvement depends on the micro-architecture and the number of CPUs. It ranges from +20% to +120% with a localhost memtier/memcached benchmark. [ tglx: Rearrange struct ] Signed-off-by: Wangyang Guo <wangyang.guo@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230323102800.042297517@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-21neighbour: switch to standard rcu, instead of rcu_bhEric Dumazet
rcu_bh is no longer a win, especially for objects freed with standard call_rcu(). Switch neighbour code to no longer disable BH when not necessary. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-15neighbour: annotate lockless accesses to n->nud_stateEric Dumazet
We have many lockless accesses to n->nud_state. Before adding another one in the following patch, add annotations to readers and writers. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-18treewide: use get_random_u32_below() instead of deprecated functionJason A. Donenfeld
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>
2022-10-11treewide: use get_random_bytes() when possibleJason A. Donenfeld
The prandom_bytes() function has been a deprecated inline wrapper around get_random_bytes() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. This was done as a basic find and replace. 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: Christophe Leroy <christophe.leroy@csgroup.eu> # powerpc Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11treewide: use get_random_u32() when possibleJason A. Donenfeld
The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. 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: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-07-25Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2022-07-20 1) Don't set DST_NOPOLICY in IPv4, a recent patch made this superfluous. From Eyal Birger. 2) Convert alg_key to flexible array member to avoid an iproute2 compile warning when built with gcc-12. From Stephen Hemminger. 3) xfrm_register_km and xfrm_unregister_km do always return 0 so change the type to void. From Zhengchao Shao. 4) Fix spelling mistake in esp6.c From Zhang Jiaming. 5) Improve the wording of comment above XFRM_OFFLOAD flags. From Petr Vaněk. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-20ipv4: Fix data-races around sysctl_fib_multipath_hash_fields.Kuniyuki Iwashima
While reading sysctl_fib_multipath_hash_fields, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: ce5c9c20d364 ("ipv4: Add a sysctl to control multipath hash fields") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-20ipv4: Fix data-races around sysctl_fib_multipath_hash_policy.Kuniyuki Iwashima
While reading sysctl_fib_multipath_hash_policy, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: bf4e0a3db97e ("net: ipv4: add support for ECMP hash policy choice") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-15ip: Fix data-races around sysctl_ip_fwd_use_pmtu.Kuniyuki Iwashima
While reading sysctl_ip_fwd_use_pmtu, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: f87c10a8aa1e ("ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-12net: change the type of ip_route_input_rcu to staticZhengchao Shao
The type of ip_route_input_rcu should be static. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Link: https://lore.kernel.org/r/20220711073549.8947-1-shaozhengchao@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-06-10xfrm: no need to set DST_NOPOLICY in IPv4Eyal Birger
This is a cleanup patch following commit e6175a2ed1f1 ("xfrm: fix "disable_policy" flag use when arriving from different devices") which made DST_NOPOLICY no longer be used for inbound policy checks. On outbound the flag was set, but never used. As such, avoid setting it altogether and remove the nopolicy argument from rt_dst_alloc(). Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2022-06-09net: rename reference+tracking helpersJakub Kicinski
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>
2022-05-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/ethernet/mellanox/mlx5/core/main.c b33886971dbc ("net/mlx5: Initialize flow steering during driver probe") 40379a0084c2 ("net/mlx5_fpga: Drop INNOVA TLS support") f2b41b32cde8 ("net/mlx5: Remove ipsec_ops function table") https://lore.kernel.org/all/20220519040345.6yrjromcdistu7vh@sx1/ 16d42d313350 ("net/mlx5: Drain fw_reset when removing device") 8324a02c342a ("net/mlx5: Add exit route when waiting for FW") https://lore.kernel.org/all/20220519114119.060ce014@canb.auug.org.au/ tools/testing/selftests/net/mptcp/mptcp_join.sh e274f7154008 ("selftests: mptcp: add subflow limits test-cases") b6e074e171bc ("selftests: mptcp: add infinite map testcase") 5ac1d2d63451 ("selftests: mptcp: Add tests for userspace PM type") https://lore.kernel.org/all/20220516111918.366d747f@canb.auug.org.au/ net/mptcp/options.c ba2c89e0ea74 ("mptcp: fix checksum byte order") 1e39e5a32ad7 ("mptcp: infinite mapping sending") ea66758c1795 ("tcp: allow MPTCP to update the announced window") https://lore.kernel.org/all/20220519115146.751c3a37@canb.auug.org.au/ net/mptcp/pm.c 95d686517884 ("mptcp: fix subflow accounting on close") 4d25247d3ae4 ("mptcp: bypass in-kernel PM restrictions for non-kernel PMs") https://lore.kernel.org/all/20220516111435.72f35dca@canb.auug.org.au/ net/mptcp/subflow.c ae66fb2ba6c3 ("mptcp: Do TCP fallback on early DSS checksum failure") 0348c690ed37 ("mptcp: add the fallback check") f8d4bcacff3b ("mptcp: infinite mapping receiving") https://lore.kernel.org/all/20220519115837.380bb8d4@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-18Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2022-05-18 1) Fix "disable_policy" flag use when arriving from different devices. From Eyal Birger. 2) Fix error handling of pfkey_broadcast in function pfkey_process. From Jiasheng Jiang. 3) Check the encryption module availability consistency in pfkey. From Thomas Bartschies. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-16xfrm: fix "disable_policy" flag use when arriving from different devicesEyal Birger
In IPv4 setting the "disable_policy" flag on a device means no policy should be enforced for traffic originating from the device. This was implemented by seting the DST_NOPOLICY flag in the dst based on the originating device. However, dsts are cached in nexthops regardless of the originating devices, in which case, the DST_NOPOLICY flag value may be incorrect. Consider the following setup: +------------------------------+ | ROUTER | +-------------+ | +-----------------+ | | ipsec src |----|-|ipsec0 | | +-------------+ | |disable_policy=0 | +----+ | | +-----------------+ |eth1|-|----- +-------------+ | +-----------------+ +----+ | | noipsec src |----|-|eth0 | | +-------------+ | |disable_policy=1 | | | +-----------------+ | +------------------------------+ Where ROUTER has a default route towards eth1. dst entries for traffic arriving from eth0 would have DST_NOPOLICY and would be cached and therefore can be reused by traffic originating from ipsec0, skipping policy check. Fix by setting a IPSKB_NOPOLICY flag in IPCB and observing it instead of the DST in IN/FWD IPv4 policy checks. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2022-05-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Build issue in drivers/net/ethernet/sfc/ptp.c 54fccfdd7c66 ("sfc: efx_default_channel_type APIs can be static") 49e6123c65da ("net: sfc: fix memory leak due to ptp channel") https://lore.kernel.org/all/20220510130556.52598fe2@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-06ipv4: drop dst in multicast routing pathLokesh Dhoundiyal
kmemleak reports the following when routing multicast traffic over an ipsec tunnel. Kmemleak output: unreferenced object 0x8000000044bebb00 (size 256): comm "softirq", pid 0, jiffies 4294985356 (age 126.810s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 80 00 00 00 05 13 74 80 ..............t. 80 00 00 00 04 9b bf f9 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000f83947e0>] __kmalloc+0x1e8/0x300 [<00000000b7ed8dca>] metadata_dst_alloc+0x24/0x58 [<0000000081d32c20>] __ipgre_rcv+0x100/0x2b8 [<00000000824f6cf1>] gre_rcv+0x178/0x540 [<00000000ccd4e162>] gre_rcv+0x7c/0xd8 [<00000000c024b148>] ip_protocol_deliver_rcu+0x124/0x350 [<000000006a483377>] ip_local_deliver_finish+0x54/0x68 [<00000000d9271b3a>] ip_local_deliver+0x128/0x168 [<00000000bd4968ae>] xfrm_trans_reinject+0xb8/0xf8 [<0000000071672a19>] tasklet_action_common.isra.16+0xc4/0x1b0 [<0000000062e9c336>] __do_softirq+0x1fc/0x3e0 [<00000000013d7914>] irq_exit+0xc4/0xe0 [<00000000a4d73e90>] plat_irq_dispatch+0x7c/0x108 [<000000000751eb8e>] handle_int+0x16c/0x178 [<000000001668023b>] _raw_spin_unlock_irqrestore+0x1c/0x28 The metadata dst is leaked when ip_route_input_mc() updates the dst for the skb. Commit f38a9eb1f77b ("dst: Metadata destinations") correctly handled dropping the dst in ip_route_input_slow() but missed the multicast case which is handled by ip_route_input_mc(). Drop the dst in ip_route_input_mc() avoiding the leak. Fixes: f38a9eb1f77b ("dst: Metadata destinations") Signed-off-by: Lokesh Dhoundiyal <lokesh.dhoundiyal@alliedtelesis.co.nz> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220505020017.3111846-1-chris.packham@alliedtelesis.co.nz Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-22ipv4: Initialise ->flowi4_scope properly in ICMP handlers.Guillaume Nault
All the *_redirect() and *_update_pmtu() functions initialise their struct flowi4 variable with either __build_flow_key() or build_sk_flow_key(). When sk is provided, these functions use RT_CONN_FLAGS() to set ->flowi4_tos and always use RT_SCOPE_UNIVERSE for ->flowi4_scope. Then they rely on ip_rt_fix_tos() to adjust the scope based on the RTO_ONLINK bit and to mask the tos with IPTOS_RT_MASK. This patch modifies __build_flow_key() and build_sk_flow_key() to properly initialise ->flowi4_tos and ->flowi4_scope, so that the ICMP redirects and PMTU handlers don't need an extra call to ip_rt_fix_tos() before doing a fib lookup. That is, we: * Drop RT_CONN_FLAGS(): use ip_sock_rt_tos() and ip_sock_rt_scope() instead, so that we don't have to rely on ip_rt_fix_tos() to adjust the scope anymore. * Apply IPTOS_RT_MASK to the tos, so that we don't need ip_rt_fix_tos() to do it for us. * Drop the ip_rt_fix_tos() calls that now become useless. The only remaining ip_rt_fix_tos() caller is ip_route_output_key_hash() which needs it as long as external callers still use the RTO_ONLINK flag. Note: This patch also drops some useless RT_TOS() calls as IPTOS_RT_MASK is a stronger mask. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-22ipv4: Don't reset ->flowi4_scope in ip_rt_fix_tos().Guillaume Nault
All callers already initialise ->flowi4_scope with RT_SCOPE_UNIVERSE, either by manual field assignment, memset(0) of the whole structure or implicit structure initialisation of on-stack variables (RT_SCOPE_UNIVERSE actually equals 0). Therefore, we don't need to always initialise ->flowi4_scope in ip_rt_fix_tos(). We only need to reduce the scope to RT_SCOPE_LINK when the special RTO_ONLINK flag is present in the tos. This will allow some code simplification, like removing ip_rt_fix_tos(). Also, the long term idea is to remove RTO_ONLINK entirely by properly initialising ->flowi4_scope, instead of overloading ->flowi4_tos with a special flag. Eventually, this will allow to convert ->flowi4_tos to dscp_t. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-13net: ipv4: add skb drop reasons to ip_error()Menglong Dong
Eventually, I find out the handler function for inputting route lookup fail: ip_error(). The drop reasons we used in ip_error() are almost corresponding to IPSTATS_MIB_*, and following new reasons are introduced: SKB_DROP_REASON_IP_INADDRERRORS SKB_DROP_REASON_IP_INNOROUTES Isn't the name SKB_DROP_REASON_IP_HOSTUNREACH and SKB_DROP_REASON_IP_NETUNREACH more accurate? To make them corresponding to IPSTATS_MIB_*, we keep their name still. Signed-off-by: Menglong Dong <imagedong@tencent.com> Reviewed-by: Jiang Biao <benbjiang@tencent.com> Reviewed-by: Hao Peng <flyingpeng@tencent.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-11ipv4: Use dscp_t in struct fib_rt_infoGuillaume Nault
Use the new dscp_t type to replace the tos field of struct fib_rt_info. This ensures ECN bits are ignored and makes it compatible with the fa_dscp field of struct fib_alias. This also allows sparse to flag potential incorrect uses of DSCP and ECN bits. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in overtime fixes, no conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-18ipv4: Fix route lookups when handling ICMP redirects and PMTU updatesGuillaume Nault
The PMTU update and ICMP redirect helper functions initialise their fl4 variable with either __build_flow_key() or build_sk_flow_key(). These initialisation functions always set ->flowi4_scope with RT_SCOPE_UNIVERSE and might set the ECN bits of ->flowi4_tos. This is not a problem when the route lookup is later done via ip_route_output_key_hash(), which properly clears the ECN bits from ->flowi4_tos and initialises ->flowi4_scope based on the RTO_ONLINK flag. However, some helpers call fib_lookup() directly, without sanitising the tos and scope fields, so the route lookup can fail and, as a result, the ICMP redirect or PMTU update aren't taken into account. Fix this by extracting the ->flowi4_tos and ->flowi4_scope sanitisation code into ip_rt_fix_tos(), then use this function in handlers that call fib_lookup() directly. Note 1: We can't sanitise ->flowi4_tos and ->flowi4_scope in a central place (like __build_flow_key() or flowi4_init_output()), because ip_route_output_key_hash() expects non-sanitised values. When called with sanitised values, it can erroneously overwrite RT_SCOPE_LINK with RT_SCOPE_UNIVERSE in ->flowi4_scope. Therefore we have to be careful to sanitise the values only for those paths that don't call ip_route_output_key_hash(). Note 2: The problem is mostly about sanitising ->flowi4_tos. Having ->flowi4_scope initialised with RT_SCOPE_UNIVERSE instead of RT_SCOPE_LINK probably wasn't really a problem: sockets with the SOCK_LOCALROUTE flag set (those that'd result in RTO_ONLINK being set) normally shouldn't receive ICMP redirects or PMTU updates. Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-15net: Add l3mdev index to flow struct and avoid oif reset for port devicesDavid Ahern
The fundamental premise of VRF and l3mdev core code is binding a socket to a device (l3mdev or netdev with an L3 domain) to indicate L3 scope. Legacy code resets flowi_oif to the l3mdev losing any original port device binding. Ben (among others) has demonstrated use cases where the original port device binding is important and needs to be retained. This patch handles that by adding a new entry to the common flow struct that can indicate the l3mdev index for later rule and table matching avoiding the need to reset flowi_oif. In addition to allowing more use cases that require port device binds, this patch brings a few datapath simplications: 1. l3mdev_fib_rule_match is only called when walking fib rules and always after l3mdev_update_flow. That allows an optimization to bail early for non-VRF type uses cases when flowi_l3mdev is not set. Also, only that index needs to be checked for the FIB table id. 2. l3mdev_update_flow can be called with flowi_oif set to a l3mdev (e.g., VRF) device. By resetting flowi_oif only for this case the FLOWI_FLAG_SKIP_NH_OIF flag is not longer needed and can be removed, removing several checks in the datapath. The flowi_iif path can be simplified to only be called if the it is not loopback (loopback can not be assigned to an L3 domain) and the l3mdev index is not already set. 3. Avoid another device lookup in the output path when the fib lookup returns a reject failure. Note: 2 functional tests for local traffic with reject fib rules are updated to reflect the new direct failure at FIB lookup time for ping rather than the failure on packet path. The current code fails like this: HINT: Fails since address on vrf device is out of device scope COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1 ping: Warning: source address might be selected on device other than: eth1 PING 172.16.3.1 (172.16.3.1) from 172.16.3.1 eth1: 56(84) bytes of data. --- 172.16.3.1 ping statistics --- 1 packets transmitted, 0 received, 100% packet loss, time 0ms where the test now directly fails: HINT: Fails since address on vrf device is out of device scope COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1 ping: connect: No route to host Signed-off-by: David Ahern <dsahern@kernel.org> Tested-by: Ben Greear <greearb@candelatech.com> Link: https://lore.kernel.org/r/20220314204551.16369-1-dsahern@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17ipv4: fix data races in fib_alias_hw_flags_setEric Dumazet
fib_alias_hw_flags_set() can be used by concurrent threads, and is only RCU protected. We need to annotate accesses to following fields of struct fib_alias: offload, trap, offload_failed Because of READ_ONCE()WRITE_ONCE() limitations, make these field u8. BUG: KCSAN: data-race in fib_alias_hw_flags_set / fib_alias_hw_flags_set read to 0xffff888134224a6a of 1 bytes by task 2013 on cpu 1: fib_alias_hw_flags_set+0x28a/0x470 net/ipv4/fib_trie.c:1050 nsim_fib4_rt_hw_flags_set drivers/net/netdevsim/fib.c:350 [inline] nsim_fib4_rt_add drivers/net/netdevsim/fib.c:367 [inline] nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:429 [inline] nsim_fib4_event drivers/net/netdevsim/fib.c:461 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:881 [inline] nsim_fib_event_work+0x1852/0x2cf0 drivers/net/netdevsim/fib.c:1477 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307 process_scheduled_works kernel/workqueue.c:2370 [inline] worker_thread+0x7df/0xa70 kernel/workqueue.c:2456 kthread+0x1bf/0x1e0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 write to 0xffff888134224a6a of 1 bytes by task 4872 on cpu 0: fib_alias_hw_flags_set+0x2d5/0x470 net/ipv4/fib_trie.c:1054 nsim_fib4_rt_hw_flags_set drivers/net/netdevsim/fib.c:350 [inline] nsim_fib4_rt_add drivers/net/netdevsim/fib.c:367 [inline] nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:429 [inline] nsim_fib4_event drivers/net/netdevsim/fib.c:461 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:881 [inline] nsim_fib_event_work+0x1852/0x2cf0 drivers/net/netdevsim/fib.c:1477 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307 process_scheduled_works kernel/workqueue.c:2370 [inline] worker_thread+0x7df/0xa70 kernel/workqueue.c:2456 kthread+0x1bf/0x1e0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 value changed: 0x00 -> 0x02 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 4872 Comm: kworker/0:0 Not tainted 5.17.0-rc3-syzkaller-00188-g1d41d2e82623-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_fib_event_work Fixes: 90b93f1b31f8 ("ipv4: Add "offload" and "trap" indications to routes") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20220216173217.3792411-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-11ipv4: add (struct uncached_list)->quarantine listEric Dumazet
This is an optimization to keep the per-cpu lists as short as possible: Whenever rt_flush_dev() changes one rtable dst.dev matching the disappearing device, it can can transfer the object to a quarantine list, waiting for a final rt_del_uncached_list(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-07ipv4: Use dscp_t in struct fib_aliasGuillaume Nault
Use the new dscp_t type to replace the fa_tos field of fib_alias. This ensures ECN bits are ignored and makes the field compatible with the fc_dscp field of struct fib_config. Converting old *tos variables and fields to dscp_t allows sparse to flag incorrect uses of DSCP and ECN bits. This patch is entirely about type annotation and shouldn't change any existing behaviour. Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-31ipv4: Make ip_idents_reserve staticDavid Ahern
ip_idents_reserve is only used in net/ipv4/route.c. Make it static and remove the export. Signed-off-by: David Ahern <dsahern@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-27ipv4: Namespaceify min_adv_mss sysctl knobxu xin
Different netns has different requirement on the setting of min_adv_mss sysctl which the advertised MSS will be never lower than. Enable min_adv_mss to be configured per network namespace. Signed-off-by: xu xin <xu.xin16@zte.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-04Namespaceify mtu_expires sysctlxu xin
This patch enables the sysctl mtu_expires to be configured per net namespace. Signed-off-by: xu xin <xu.xin16@zte.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-04Namespaceify min_pmtu sysctlxu xin
This patch enables the sysctl min_pmtu to be configured per net namespace. Signed-off-by: xu xin <xu.xin16@zte.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-06net: dst: add net device refcount tracking to dst_entryEric Dumazet
We want to track all dev_hold()/dev_put() to ease leak hunting. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-16net: align static siphash keysEric Dumazet
siphash keys use 16 bytes. Define siphash_aligned_key_t macro so that we can make sure they are not crossing a cache line boundary. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-20net/ipv4/route.c: remove superfluous header files from route.cMianhan Liu
route.c hasn't use any macro or function declared in uaccess.h, types.h, string.h, sockios.h, times.h, protocol.h, arp.h and l3mdev.h. Thus, these files can be removed from route.c safely without affecting the compilation of the net module. Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-31ipv4: fix endianness issue in inet_rtm_getroute_build_skb()Eric Dumazet
The UDP length field should be in network order. This removes the following sparse error: net/ipv4/route.c:3173:27: warning: incorrect type in assignment (different base types) net/ipv4/route.c:3173:27: expected restricted __be16 [usertype] len net/ipv4/route.c:3173:27: got unsigned long Fixes: 404eb77ea766 ("ipv4: support sport, dport and ip_proto in RTM_GETROUTE") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: David Ahern <dsahern@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-30ipv4: make exception cache less predictibleEric Dumazet
Even after commit 6457378fe796 ("ipv4: use siphash instead of Jenkins in fnhe_hashfun()"), an attacker can still use brute force to learn some secrets from a victim linux host. One way to defeat these attacks is to make the max depth of the hash table bucket a random value. Before this patch, each bucket of the hash table used to store exceptions could contain 6 items under attack. After the patch, each bucket would contains a random number of items, between 6 and 10. The attacker can no longer infer secrets. This is slightly increasing memory size used by the hash table, by 50% in average, we do not expect this to be a problem. This patch is more complex than the prior one (IPv6 equivalent), because IPv4 was reusing the oldest entry. Since we need to be able to evict more than one entry per update_or_create_fnhe() call, I had to replace fnhe_oldest() with fnhe_remove_oldest(). Also note that we will queue extra kfree_rcu() calls under stress, which hopefully wont be a too big issue. Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Keyu Man <kman001@ucr.edu> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: David Ahern <dsahern@kernel.org> Tested-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
drivers/net/wwan/mhi_wwan_mbim.c - drop the extra arg. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-26ipv4: use siphash instead of Jenkins in fnhe_hashfun()Eric Dumazet
A group of security researchers brought to our attention the weakness of hash function used in fnhe_hashfun(). Lets use siphash instead of Jenkins Hash, to considerably reduce security risks. Also remove the inline keyword, this really is distracting. Fixes: d546c621542d ("ipv4: harden fnhe_hashfun()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Keyu Man <kman001@ucr.edu> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05net: Remove redundant if statementsYajun Deng
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>
2021-08-03net: Keep vertical alignmentYajun Deng
Those files under /proc/net/stat/ don't have vertical alignment, it looks very difficult. Modify the seq_printf statement, keep vertical alignment. v2: - Use seq_puts() and seq_printf() correctly. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-21net: ipv4: Consolidate ipv4_mtu and ip_dst_mtu_maybe_forwardVadim Fedorenko
Consolidate IPv4 MTU code the same way it is done in IPv6 to have code aligned in both address families Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Trivial conflict in net/netfilter/nf_tables_api.c. Duplicate fix in tools/testing/selftests/net/devlink_port_split.py - take the net-next version. skmsg, and L4 bpf - keep the bpf code but remove the flags and err params. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-28net: lwtunnel: handle MTU calculation in forwadingVadim Fedorenko
Commit 14972cbd34ff ("net: lwtunnel: Handle fragmentation") moved fragmentation logic away from lwtunnel by carry encap headroom and use it in output MTU calculation. But the forwarding part was not covered and created difference in MTU for output and forwarding and further to silent drops on ipv4 forwarding path. Fix it by taking into account lwtunnel encap headroom. The same commit also introduced difference in how to treat RTAX_MTU in IPv4 and IPv6 where latter explicitly removes lwtunnel encap headroom from route MTU. Make IPv4 version do the same. Fixes: 14972cbd34ff ("net: lwtunnel: Handle fragmentation") Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
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>
2021-06-14ipv4: Fix device used for dst_alloc with local routesDavid Ahern
Oliver reported a use case where deleting a VRF device can hang waiting for the refcnt to drop to 0. The root cause is that the dst is allocated against the VRF device but cached on the loopback device. The use case (added to the selftests) has an implicit VRF crossing due to the ordering of the FIB rules (lookup local is before the l3mdev rule, but the problem occurs even if the FIB rules are re-ordered with local after l3mdev because the VRF table does not have a default route to terminate the lookup). The end result is is that the FIB lookup returns the loopback device as the nexthop, but the ingress device is in a VRF. The mismatch causes the dst alloc against the VRF device but then cached on the loopback. The fix is to bring the trick used for IPv6 (see ip6_rt_get_dev_rcu): pick the dst alloc device based the fib lookup result but with checks that the result has a nexthop device (e.g., not an unreachable or prohibit entry). Fixes: f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant") Reported-by: Oliver Herms <oliver.peter.herms@gmail.com> Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-18ipv4: Add custom multipath hash policyIdo Schimmel
Add a new multipath hash policy where the packet fields used for hash calculation are determined by user space via the fib_multipath_hash_fields sysctl that was introduced in the previous patch. The current set of available packet fields includes both outer and inner fields, which requires two invocations of the flow dissector. Avoid unnecessary dissection of the outer or inner flows by skipping dissection if none of the outer or inner fields are required. In accordance with the existing policies, when an skb is not available, packet fields are extracted from the provided flow key. In which case, only outer fields are considered. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>