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2023-10-20net: do not leave an empty skb in write queueEric Dumazet
Under memory stress conditions, tcp_sendmsg_locked() might call sk_stream_wait_memory(), thus releasing the socket lock. If a fresh skb has been allocated prior to this, we should not leave it in the write queue otherwise tcp_write_xmit() could panic. This apparently does not happen often, but a future change in __sk_mem_raise_allocated() that Shakeel and others are considering would increase chances of being hurt. Under discussion is to remove this controversial part: /* Fail only if socket is _under_ its sndbuf. * In this case we cannot block, so that we have to fail. */ if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) { /* Force charge with __GFP_NOFAIL */ if (memcg_charge && !charged) { mem_cgroup_charge_skmem(sk->sk_memcg, amt, gfp_memcg_charge() | __GFP_NOFAIL); } return 1; } Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Link: https://lore.kernel.org/r/20231019112457.1190114-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-13tcp: allow again tcp_disconnect() when threads are waitingPaolo Abeni
As reported by Tom, .NET and applications build on top of it rely on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP socket. The blamed commit below caused a regression, as such cancellation can now fail. As suggested by Eric, this change addresses the problem explicitly causing blocking I/O operation to terminate immediately (with an error) when a concurrent disconnect() is executed. Instead of tracking the number of threads blocked on a given socket, track the number of disconnect() issued on such socket. If such counter changes after a blocking operation releasing and re-acquiring the socket lock, error out the current operation. Fixes: 4faeee0cf8a5 ("tcp: deny tcp_disconnect() when threads are waiting") Reported-by: Tom Deseyn <tdeseyn@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-09-29bpf: tcp_read_skb needs to pop skb regardless of seqJohn Fastabend
Before fix e5c6de5fa0258 tcp_read_skb() would increment the tp->copied-seq value. This (as described in the commit) would cause an error for apps because once that is incremented the application might believe there is no data to be read. Then some apps would stall or abort believing no data is available. However, the fix is incomplete because it introduces another issue in the skb dequeue. The loop does tcp_recv_skb() in a while loop to consume as many skbs as possible. The problem is the call is ... tcp_recv_skb(sk, seq, &offset) ... where 'seq' is: u32 seq = tp->copied_seq; Now we can hit a case where we've yet incremented copied_seq from BPF side, but then tcp_recv_skb() fails this test ... if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) ... so that instead of returning the skb we call tcp_eat_recv_skb() which frees the skb. This is because the routine believes the SKB has been collapsed per comment: /* This looks weird, but this can happen if TCP collapsing * splitted a fat GRO packet, while we released socket lock * in skb_splice_bits() */ This can't happen here we've unlinked the full SKB and orphaned it. Anyways it would confuse any BPF programs if the data were suddenly moved underneath it. To fix this situation do simpler operation and just skb_peek() the data of the queue followed by the unlink. It shouldn't need to check this condition and tcp_read_skb() reads entire skbs so there is no need to handle the 'offset!=0' case as we would see in tcp_read_sock(). Fixes: e5c6de5fa0258 ("bpf, sockmap: Incorrectly handling copied_seq") Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20230926035300.135096-2-john.fastabend@gmail.com
2023-09-07Merge tag 'net-6.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking updates from Jakub Kicinski: "Including fixes from netfilter and bpf. Current release - regressions: - eth: stmmac: fix failure to probe without MAC interface specified Current release - new code bugs: - docs: netlink: fix missing classic_netlink doc reference Previous releases - regressions: - deal with integer overflows in kmalloc_reserve() - use sk_forward_alloc_get() in sk_get_meminfo() - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc - fib: avoid warn splat in flow dissector after packet mangling - skb_segment: call zero copy functions before using skbuff frags - eth: sfc: check for zero length in EF10 RX prefix Previous releases - always broken: - af_unix: fix msg_controllen test in scm_pidfd_recv() for MSG_CMSG_COMPAT - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR() - netfilter: - nft_exthdr: fix non-linear header modification - xt_u32, xt_sctp: validate user space input - nftables: exthdr: fix 4-byte stack OOB write - nfnetlink_osf: avoid OOB read - one more fix for the garbage collection work from last release - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t - handshake: fix null-deref in handshake_nl_done_doit() - ip: ignore dst hint for multipath routes to ensure packets are hashed across the nexthops - phy: micrel: - correct bit assignments for cable test errata - disable EEE according to the KSZ9477 errata Misc: - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations - Revert "net: macsec: preserve ingress frame ordering", it appears to have been developed against an older kernel, problem doesn't exist upstream" * tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (95 commits) net: enetc: distinguish error from valid pointers in enetc_fixup_clear_rss_rfs() Revert "net: team: do not use dynamic lockdep key" net: hns3: remove GSO partial feature bit net: hns3: fix the port information display when sfp is absent net: hns3: fix invalid mutex between tc qdisc and dcb ets command issue net: hns3: fix debugfs concurrency issue between kfree buffer and read net: hns3: fix byte order conversion issue in hclge_dbg_fd_tcam_read() net: hns3: Support query tx timeout threshold by debugfs net: hns3: fix tx timeout issue net: phy: Provide Module 4 KSZ9477 errata (DS80000754C) netfilter: nf_tables: Unbreak audit log reset netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction netfilter: nf_tables: uapi: Describe NFTA_RULE_CHAIN_ID netfilter: nfnetlink_osf: avoid OOB read netfilter: nftables: exthdr: fix 4-byte stack OOB write selftests/bpf: Check bpf_sk_storage has uncharged sk_omem_alloc bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc bpf: bpf_sk_storage: Fix invalid wait context lockdep report s390/bpf: Pass through tail call counter in trampolines ...
2023-09-01net: annotate data-races around sk->sk_tsflagsEric Dumazet
sk->sk_tsflags can be read locklessly, add corresponding annotations. Fixes: b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-29Merge tag 'mm-stable-2023-08-28-18-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which reduces the special-case code for handling hugetlb pages in GUP. It also speeds up GUP handling of transparent hugepages. - Peng Zhang provides some maple tree speedups ("Optimize the fast path of mas_store()"). - Sergey Senozhatsky has improved te performance of zsmalloc during compaction (zsmalloc: small compaction improvements"). - Domenico Cerasuolo has developed additional selftest code for zswap ("selftests: cgroup: add zswap test program"). - xu xin has doe some work on KSM's handling of zero pages. These changes are mainly to enable the user to better understand the effectiveness of KSM's treatment of zero pages ("ksm: support tracking KSM-placed zero-pages"). - Jeff Xu has fixes the behaviour of memfd's MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED"). - David Howells has fixed an fscache optimization ("mm, netfs, fscache: Stop read optimisation when folio removed from pagecache"). - Axel Rasmussen has given userfaultfd the ability to simulate memory poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD"). - Miaohe Lin has contributed some routine maintenance work on the memory-failure code ("mm: memory-failure: remove unneeded PageHuge() check"). - Peng Zhang has contributed some maintenance work on the maple tree code ("Improve the validation for maple tree and some cleanup"). - Hugh Dickins has optimized the collapsing of shmem or file pages into THPs ("mm: free retracted page table by RCU"). - Jiaqi Yan has a patch series which permits us to use the healthy subpages within a hardware poisoned huge page for general purposes ("Improve hugetlbfs read on HWPOISON hugepages"). - Kemeng Shi has done some maintenance work on the pagetable-check code ("Remove unused parameters in page_table_check"). - More folioification work from Matthew Wilcox ("More filesystem folio conversions for 6.6"), ("Followup folio conversions for zswap"). And from ZhangPeng ("Convert several functions in page_io.c to use a folio"). - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext"). - Baoquan He has converted some architectures to use the GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take GENERIC_IOREMAP way"). - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support batched/deferred tlb shootdown during page reclamation/migration"). - Better maple tree lockdep checking from Liam Howlett ("More strict maple tree lockdep"). Liam also developed some efficiency improvements ("Reduce preallocations for maple tree"). - Cleanup and optimization to the secondary IOMMU TLB invalidation, from Alistair Popple ("Invalidate secondary IOMMU TLB on permission upgrade"). - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes for arm64"). - Kemeng Shi provides some maintenance work on the compaction code ("Two minor cleanups for compaction"). - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most file-backed faults under the VMA lock"). - Aneesh Kumar contributes code to use the vmemmap optimization for DAX on ppc64, under some circumstances ("Add support for DAX vmemmap optimization for ppc64"). - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client data in page_ext"), ("minor cleanups to page_ext header"). - Some zswap cleanups from Johannes Weiner ("mm: zswap: three cleanups"). - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan"). - VMA handling cleanups from Kefeng Wang ("mm: convert to vma_is_initial_heap/stack()"). - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes: implement DAMOS tried total bytes file"), ("Extend DAMOS filters for address ranges and DAMON monitoring targets"). - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction"). - Liam Howlett has improved the maple tree node replacement code ("maple_tree: Change replacement strategy"). - ZhangPeng has a general code cleanup - use the K() macro more widely ("cleanup with helper macro K()"). - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap on memory feature on ppc64"). - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list in page_alloc"), ("Two minor cleanups for get pageblock migratetype"). - Vishal Moola introduces a memory descriptor for page table tracking, "struct ptdesc" ("Split ptdesc from struct page"). - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups for vm.memfd_noexec"). - MM include file rationalization from Hugh Dickins ("arch: include asm/cacheflush.h in asm/hugetlb.h"). - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text output"). - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use object_cache instead of kmemleak_initialized"). - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor and _folio_order"). - A VMA locking scalability improvement from Suren Baghdasaryan ("Per-VMA lock support for swap and userfaults"). - pagetable handling cleanups from Matthew Wilcox ("New page table range API"). - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop using page->private on tail pages for THP_SWAP + cleanups"). - Cleanups and speedups to the hugetlb fault handling from Matthew Wilcox ("Change calling convention for ->huge_fault"). - Matthew Wilcox has also done some maintenance work on the MM subsystem documentation ("Improve mm documentation"). * tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits) maple_tree: shrink struct maple_tree maple_tree: clean up mas_wr_append() secretmem: convert page_is_secretmem() to folio_is_secretmem() nios2: fix flush_dcache_page() for usage from irq context hugetlb: add documentation for vma_kernel_pagesize() mm: add orphaned kernel-doc to the rst files. mm: fix clean_record_shared_mapping_range kernel-doc mm: fix get_mctgt_type() kernel-doc mm: fix kernel-doc warning from tlb_flush_rmaps() mm: remove enum page_entry_size mm: allow ->huge_fault() to be called without the mmap_lock held mm: move PMD_ORDER to pgtable.h mm: remove checks for pte_index memcg: remove duplication detection for mem_cgroup_uncharge_swap mm/huge_memory: work on folio->swap instead of page->private when splitting folio mm/swap: inline folio_set_swap_entry() and folio_swap_entry() mm/swap: use dedicated entry for swap in folio mm/swap: stop using page->private on tail pages for THP_SWAP selftests/mm: fix WARNING comparing pointer to 0 selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check ...
2023-08-18mm: allow per-VMA locks on file-backed VMAsMatthew Wilcox (Oracle)
Remove the TCP layering violation by allowing per-VMA locks on all VMAs. The fault path will immediately fail in handle_mm_fault(). There may be a small performance reduction from this patch as a little unnecessary work will be done on each page fault. See later patches for the improvement. Link: https://lkml.kernel.org/r/20230724185410.1124082-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Arjun Roy <arjunroy@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Punit Agrawal <punit.agrawal@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-16inet: move inet->defer_connect to inet->inet_flagsEric Dumazet
Make room in struct inet_sock by removing this bit field, using one available bit in inet_flags instead. Also move local_port_range to fill the resulting hole, saving 8 bytes on 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-06tcp: set TCP_DEFER_ACCEPT locklesslyEric Dumazet
rskq_defer_accept field can be read/written without the need of holding the socket lock. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-06tcp: set TCP_LINGER2 locklesslyEric Dumazet
tp->linger2 can be set locklessly as long as readers use READ_ONCE(). Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-06tcp: set TCP_KEEPCNT locklesslyEric Dumazet
tp->keepalive_probes can be set locklessly, readers are already taking care of this field being potentially set by other threads. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-06tcp: set TCP_KEEPINTVL locklesslyEric Dumazet
tp->keepalive_intvl can be set locklessly, readers are already taking care of this field being potentially set by other threads. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-06tcp: set TCP_USER_TIMEOUT locklesslyEric Dumazet
icsk->icsk_user_timeout can be set locklessly, if all read sides use READ_ONCE(). Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-06tcp: set TCP_SYNCNT locklesslyEric Dumazet
icsk->icsk_syn_retries can safely be set without locking the socket. We have to add READ_ONCE() annotations in tcp_fastopen_synack_timer() and tcp_write_timeout(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around fastopenq.max_qlenEric Dumazet
This field can be read locklessly. Fixes: 1536e2857bd3 ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-12-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around icsk->icsk_user_timeoutEric Dumazet
This field can be read locklessly from do_tcp_getsockopt() Fixes: dca43c75e7e5 ("tcp: Add TCP_USER_TIMEOUT socket option.") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-11-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->notsent_lowatEric Dumazet
tp->notsent_lowat can be read locklessly from do_tcp_getsockopt() and tcp_poll(). Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-10-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around rskq_defer_acceptEric Dumazet
do_tcp_getsockopt() reads rskq_defer_accept while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->linger2Eric Dumazet
do_tcp_getsockopt() reads tp->linger2 while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around icsk->icsk_syn_retriesEric Dumazet
do_tcp_getsockopt() and reqsk_timer_handler() read icsk->icsk_syn_retries while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->keepalive_probesEric Dumazet
do_tcp_getsockopt() reads tp->keepalive_probes while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->keepalive_intvlEric Dumazet
do_tcp_getsockopt() reads tp->keepalive_intvl while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->keepalive_timeEric Dumazet
do_tcp_getsockopt() reads tp->keepalive_time while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->tsoffsetEric Dumazet
do_tcp_getsockopt() reads tp->tsoffset while another cpu might change its value. Fixes: 93be6ce0e91b ("tcp: set and get per-socket timestamp") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->tcp_tx_delayEric Dumazet
do_tcp_getsockopt() reads tp->tcp_tx_delay while another cpu might change its value. Fixes: a842fe1425cb ("tcp: add optional per socket transmit delay") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-18tcp: get rid of sysctl_tcp_adv_win_scaleEric Dumazet
With modern NIC drivers shifting to full page allocations per received frame, we face the following issue: TCP has one per-netns sysctl used to tweak how to translate a memory use into an expected payload (RWIN), in RX path. tcp_win_from_space() implementation is limited to few cases. For hosts dealing with various MSS, we either under estimate or over estimate the RWIN we send to the remote peers. For instance with the default sysctl_tcp_adv_win_scale value, we expect to store 50% of payload per allocated chunk of memory. For the typical use of MTU=1500 traffic, and order-0 pages allocations by NIC drivers, we are sending too big RWIN, leading to potential tcp collapse operations, which are extremely expensive and source of latency spikes. This patch makes sysctl_tcp_adv_win_scale obsolete, and instead uses a per socket scaling factor, so that we can precisely adjust the RWIN based on effective skb->len/skb->truesize ratio. This patch alone can double TCP receive performance when receivers are too slow to drain their receive queue, or by allowing a bigger RWIN when MSS is close to PAGE_SIZE. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Link: https://lore.kernel.org/r/20230717152917.751987-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)David Howells
Remove ->sendpage() and ->sendpage_locked(). sendmsg() with MSG_SPLICE_PAGES should be used instead. This allows multiple pages and multipage folios to be passed through. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> cc: linux-afs@lists.infradead.org cc: mptcp@lists.linux.dev cc: rds-devel@oss.oracle.com cc: tipc-discussion@lists.sourceforge.net cc: virtualization@lists.linux-foundation.org Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24net/tcp: optimise locking for blocking splicePavel Begunkov
Even when tcp_splice_read() reads all it was asked for, for blocking sockets it'll release and immediately regrab the socket lock, loop around and break on the while check. Check tss.len right after we adjust it, and return if we're done. That saves us one release_sock(); lock_sock(); pair per successful blocking splice read. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/80736a2cc6d478c383ea565ba825eaf4d1abd876.1687523671.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-18tcp: Use per-vma locking for receive zerocopyArjun Roy
Per-VMA locking allows us to lock a struct vm_area_struct without taking the process-wide mmap lock in read mode. Consider a process workload where the mmap lock is taken constantly in write mode. In this scenario, all zerocopy receives are periodically blocked during that period of time - though in principle, the memory ranges being used by TCP are not touched by the operations that need the mmap write lock. This results in performance degradation. Now consider another workload where the mmap lock is never taken in write mode, but there are many TCP connections using receive zerocopy that are concurrently receiving. These connections all take the mmap lock in read mode, but this does induce a lot of contention and atomic ops for this process-wide lock. This results in additional CPU overhead caused by contending on the cache line for this lock. However, with per-vma locking, both of these problems can be avoided. As a test, I ran an RPC-style request/response workload with 4KB payloads and receive zerocopy enabled, with 100 simultaneous TCP connections. I measured perf cycles within the find_tcp_vma/mmap_read_lock/mmap_read_unlock codepath, with and without per-vma locking enabled. When using process-wide mmap semaphore read locking, about 1% of measured perf cycles were within this path. With per-VMA locking, this value dropped to about 0.45%. Signed-off-by: Arjun Roy <arjunroy@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-15net: ioctl: Use kernel memory on protocol ioctl callbacksBreno Leitao
Most of the ioctls to net protocols operates directly on userspace argument (arg). Usually doing get_user()/put_user() directly in the ioctl callback. This is not flexible, because it is hard to reuse these functions without passing userspace buffers. Change the "struct proto" ioctls to avoid touching userspace memory and operate on kernel buffers, i.e., all protocol's ioctl callbacks is adapted to operate on a kernel memory other than on userspace (so, no more {put,get}_user() and friends being called in the ioctl callback). This changes the "struct proto" ioctl format in the following way: int (*ioctl)(struct sock *sk, int cmd, - unsigned long arg); + int *karg); (Important to say that this patch does not touch the "struct proto_ops" protocols) So, the "karg" argument, which is passed to the ioctl callback, is a pointer allocated to kernel space memory (inside a function wrapper). This buffer (karg) may contain input argument (copied from userspace in a prep function) and it might return a value/buffer, which is copied back to userspace if necessary. There is not one-size-fits-all format (that is I am using 'may' above), but basically, there are three type of ioctls: 1) Do not read from userspace, returns a result to userspace 2) Read an input parameter from userspace, and does not return anything to userspace 3) Read an input from userspace, and return a buffer to userspace. The default case (1) (where no input parameter is given, and an "int" is returned to userspace) encompasses more than 90% of the cases, but there are two other exceptions. Here is a list of exceptions: * Protocol RAW: * cmd = SIOCGETVIFCNT: * input and output = struct sioc_vif_req * cmd = SIOCGETSGCNT * input and output = struct sioc_sg_req * Explanation: for the SIOCGETVIFCNT case, userspace passes the input argument, which is struct sioc_vif_req. Then the callback populates the struct, which is copied back to userspace. * Protocol RAW6: * cmd = SIOCGETMIFCNT_IN6 * input and output = struct sioc_mif_req6 * cmd = SIOCGETSGCNT_IN6 * input and output = struct sioc_sg_req6 * Protocol PHONET: * cmd == SIOCPNADDRESOURCE | SIOCPNDELRESOURCE * input int (4 bytes) * Nothing is copied back to userspace. For the exception cases, functions sock_sk_ioctl_inout() will copy the userspace input, and copy it back to kernel space. The wrapper that prepare the buffer and put the buffer back to user is sk_ioctl(), so, instead of calling sk->sk_prot->ioctl(), the callee now calls sk_ioctl(), which will handle all cases. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230609152800.830401-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-12tcp: remove size parameter from tcp_stream_alloc_skb()Eric Dumazet
Now all tcp_stream_alloc_skb() callers pass @size == 0, we can remove this parameter. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-12tcp: let tcp_send_syn_data() build headless packetsEric Dumazet
tcp_send_syn_data() is the last component in TCP transmit path to put payload in skb->head. Switch it to use page frags, so that we can remove dead code later. This allows to put more payload than previous implementation. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-08ipv4, ipv6: Use splice_eof() to flushDavid Howells
Allow splice to undo the effects of MSG_MORE after prematurely ending a splice/sendfile due to getting an EOF condition (->splice_read() returned 0) after splice had called sendmsg() with MSG_MORE set when the user didn't set MSG_MORE. For UDP, a pending packet will not be emitted if the socket is closed before it is flushed; with this change, it be flushed by ->splice_eof(). For TCP, it's not clear that MSG_MORE is actually effective. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/ Signed-off-by: David Howells <dhowells@redhat.com> cc: Kuniyuki Iwashima <kuniyu@amazon.com> cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: drivers/net/ethernet/sfc/tc.c 622ab656344a ("sfc: fix error unwinds in TC offload") b6583d5e9e94 ("sfc: support TC decap rules matching on enc_src_port") net/mptcp/protocol.c 5b825727d087 ("mptcp: add annotations around msk->subflow accesses") e76c8ef5cc5b ("mptcp: refactor mptcp_stream_accept()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-29tcp: Return user_mss for TCP_MAXSEG in CLOSE/LISTEN state if user_mss setCambda Zhu
This patch replaces the tp->mss_cache check in getting TCP_MAXSEG with tp->rx_opt.user_mss check for CLOSE/LISTEN sock. Since tp->mss_cache is initialized with TCP_MSS_DEFAULT, checking if it's zero is probably a bug. With this change, getting TCP_MAXSEG before connecting will return default MSS normally, and return user_mss if user_mss is set. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Jack Yang <mingliang@linux.alibaba.com> Suggested-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/CANn89i+3kL9pYtkxkwxwNMzvC_w3LNUum_2=3u+UyLBmGmifHA@mail.gmail.com/#t Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com> Link: https://lore.kernel.org/netdev/14D45862-36EA-4076-974C-EA67513C92F6@linux.alibaba.com/ Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230527040317.68247-1-cambda@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-29tcp: deny tcp_disconnect() when threads are waitingEric Dumazet
Historically connect(AF_UNSPEC) has been abused by syzkaller and other fuzzers to trigger various bugs. A recent one triggers a divide-by-zero [1], and Paolo Abeni was able to diagnose the issue. tcp_recvmsg_locked() has tests about sk_state being not TCP_LISTEN and TCP REPAIR mode being not used. Then later if socket lock is released in sk_wait_data(), another thread can call connect(AF_UNSPEC), then make this socket a TCP listener. When recvmsg() is resumed, it can eventually call tcp_cleanup_rbuf() and attempt a divide by 0 in tcp_rcv_space_adjust() [1] This patch adds a new socket field, counting number of threads blocked in sk_wait_event() and inet_wait_for_connect(). If this counter is not zero, tcp_disconnect() returns an error. This patch adds code in blocking socket system calls, thus should not hurt performance of non blocking ones. Note that we probably could revert commit 499350a5a6e7 ("tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0") to restore original tcpi_rcv_mss meaning (was 0 if no payload was ever received on a socket) [1] divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13832 Comm: syz-executor.5 Not tainted 6.3.0-rc4-syzkaller-00224-g00c7b5f4ddc5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 RIP: 0010:tcp_rcv_space_adjust+0x36e/0x9d0 net/ipv4/tcp_input.c:740 Code: 00 00 00 00 fc ff df 4c 89 64 24 48 8b 44 24 04 44 89 f9 41 81 c7 80 03 00 00 c1 e1 04 44 29 f0 48 63 c9 48 01 e9 48 0f af c1 <49> f7 f6 48 8d 04 41 48 89 44 24 40 48 8b 44 24 30 48 c1 e8 03 48 RSP: 0018:ffffc900033af660 EFLAGS: 00010206 RAX: 4a66b76cbade2c48 RBX: ffff888076640cc0 RCX: 00000000c334e4ac RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000001 RBP: 00000000c324e86c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880766417f8 R13: ffff888028fbb980 R14: 0000000000000000 R15: 0000000000010344 FS: 00007f5bffbfe700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32f25000 CR3: 000000007ced0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_recvmsg_locked+0x100e/0x22e0 net/ipv4/tcp.c:2616 tcp_recvmsg+0x117/0x620 net/ipv4/tcp.c:2681 inet6_recvmsg+0x114/0x640 net/ipv6/af_inet6.c:670 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg+0xe2/0x160 net/socket.c:1038 ____sys_recvmsg+0x210/0x5a0 net/socket.c:2720 ___sys_recvmsg+0xf2/0x180 net/socket.c:2762 do_recvmmsg+0x25e/0x6e0 net/socket.c:2856 __sys_recvmmsg net/socket.c:2935 [inline] __do_sys_recvmmsg net/socket.c:2958 [inline] __se_sys_recvmmsg net/socket.c:2951 [inline] __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5c0108c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5bffbfe168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f5c011ac050 RCX: 00007f5c0108c0f9 RDX: 0000000000000001 RSI: 0000000020000bc0 RDI: 0000000000000003 RBP: 00007f5c010e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000122 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5c012cfb1f R14: 00007f5bffbfe300 R15: 0000000000022000 </TASK> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: Paolo Abeni <pabeni@redhat.com> Diagnosed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20230526163458.2880232-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-26Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-05-26 We've added 54 non-merge commits during the last 10 day(s) which contain a total of 76 files changed, 2729 insertions(+), 1003 deletions(-). The main changes are: 1) Add the capability to destroy sockets in BPF through a new kfunc, from Aditi Ghag. 2) Support O_PATH fds in BPF_OBJ_PIN and BPF_OBJ_GET commands, from Andrii Nakryiko. 3) Add capability for libbpf to resize datasec maps when backed via mmap, from JP Kobryn. 4) Move all the test kfuncs for CI out of the kernel and into bpf_testmod, from Jiri Olsa. 5) Big batch of xsk selftest improvements to prep for multi-buffer testing, from Magnus Karlsson. 6) Show the target_{obj,btf}_id in tracing link's fdinfo and dump it via bpftool, from Yafang Shao. 7) Various misc BPF selftest improvements to work with upcoming LLVM 17, from Yonghong Song. 8) Extend bpftool to specify netdevice for resolving XDP hints, from Larysa Zaremba. 9) Document masking in shift operations for the insn set document, from Dave Thaler. 10) Extend BPF selftests to check xdp_feature support for bond driver, from Lorenzo Bianconi. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits) bpf: Fix bad unlock balance on freeze_mutex libbpf: Ensure FD >= 3 during bpf_map__reuse_fd() libbpf: Ensure libbpf always opens files with O_CLOEXEC selftests/bpf: Check whether to run selftest libbpf: Change var type in datasec resize func bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command libbpf: Selftests for resizing datasec maps libbpf: Add capability for resizing datasec maps selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands libbpf: Start v1.3 development cycle bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM bpftool: Specify XDP Hints ifname when loading program selftests/bpf: Add xdp_feature selftest for bond device selftests/bpf: Test bpf_sock_destroy selftests/bpf: Add helper to get port using getsockname bpf: Add bpf_sock_destroy kfunc bpf: Add kfunc filter function to 'struct btf_kfunc_id_set' bpf: udp: Implement batching for sockets iterator ... ==================== Link: https://lore.kernel.org/r/20230526222747.17775-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/raw.c 3632679d9e4f ("ipv{4,6}/raw: fix output xfrm lookup wrt protocol") c85be08fc4fa ("raw: Stop using RTO_ONLINK.") https://lore.kernel.org/all/20230525110037.2b532b83@canb.auug.org.au/ Adjacent changes: drivers/net/ethernet/freescale/fec_main.c 9025944fddfe ("net: fec: add dma_wmb to ensure correct descriptor values") 144470c88c5d ("net: fec: using the standard return codes when xdp xmit errors") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23tcp: Fold do_tcp_sendpages() into tcp_sendpage_locked()David Howells
Fold do_tcp_sendpages() into its last remaining caller, tcp_sendpage_locked(). Signed-off-by: David Howells <dhowells@redhat.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23tcp: Convert do_tcp_sendpages() to use MSG_SPLICE_PAGESDavid Howells
Convert do_tcp_sendpages() to use sendmsg() with MSG_SPLICE_PAGES rather than directly splicing in the pages itself. do_tcp_sendpages() can then be inlined in subsequent patches into its callers. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells <dhowells@redhat.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23tcp: Support MSG_SPLICE_PAGESDavid Howells
Make TCP's sendmsg() support MSG_SPLICE_PAGES. This causes pages to be spliced or copied (if it cannot be spliced) from the source iterator. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells <dhowells@redhat.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-23bpf, sockmap: Incorrectly handling copied_seqJohn Fastabend
The read_skb() logic is incrementing the tcp->copied_seq which is used for among other things calculating how many outstanding bytes can be read by the application. This results in application errors, if the application does an ioctl(FIONREAD) we return zero because this is calculated from the copied_seq value. To fix this we move tcp->copied_seq accounting into the recv handler so that we update these when the recvmsg() hook is called and data is in fact copied into user buffers. This gives an accurate FIONREAD value as expected and improves ACK handling. Before we were calling the tcp_rcv_space_adjust() which would update 'number of bytes copied to user in last RTT' which is wrong for programs returning SK_PASS. The bytes are only copied to the user when recvmsg is handled. Doing the fix for recvmsg is straightforward, but fixing redirect and SK_DROP pkts is a bit tricker. Build a tcp_psock_eat() helper and then call this from skmsg handlers. This fixes another issue where a broken socket with a BPF program doing a resubmit could hang the receiver. This happened because although read_skb() consumed the skb through sock_drop() it did not update the copied_seq. Now if a single reccv socket is redirecting to many sockets (for example for lb) the receiver sk will be hung even though we might expect it to continue. The hang comes from not updating the copied_seq numbers and memory pressure resulting from that. We have a slight layer problem of calling tcp_eat_skb even if its not a TCP socket. To fix we could refactor and create per type receiver handlers. I decided this is more work than we want in the fix and we already have some small tweaks depending on caller that use the helper skb_bpf_strparser(). So we extend that a bit and always set the strparser bit when it is in use and then we can gate the seq_copied updates on this. Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20230523025618.113937-9-john.fastabend@gmail.com
2023-05-23bpf, sockmap: Pass skb ownership through read_skbJohn Fastabend
The read_skb hook calls consume_skb() now, but this means that if the recv_actor program wants to use the skb it needs to inc the ref cnt so that the consume_skb() doesn't kfree the sk_buff. This is problematic because in some error cases under memory pressure we may need to linearize the sk_buff from sk_psock_skb_ingress_enqueue(). Then we get this, skb_linearize() __pskb_pull_tail() pskb_expand_head() BUG_ON(skb_shared(skb)) Because we incremented users refcnt from sk_psock_verdict_recv() we hit the bug on with refcnt > 1 and trip it. To fix lets simply pass ownership of the sk_buff through the skb_read call. Then we can drop the consume from read_skb handlers and assume the verdict recv does any required kfree. Bug found while testing in our CI which runs in VMs that hit memory constraints rather regularly. William tested TCP read_skb handlers. [ 106.536188] ------------[ cut here ]------------ [ 106.536197] kernel BUG at net/core/skbuff.c:1693! [ 106.536479] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 106.536726] CPU: 3 PID: 1495 Comm: curl Not tainted 5.19.0-rc5 #1 [ 106.537023] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.16.0-1 04/01/2014 [ 106.537467] RIP: 0010:pskb_expand_head+0x269/0x330 [ 106.538585] RSP: 0018:ffffc90000138b68 EFLAGS: 00010202 [ 106.538839] RAX: 000000000000003f RBX: ffff8881048940e8 RCX: 0000000000000a20 [ 106.539186] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff8881048940e8 [ 106.539529] RBP: ffffc90000138be8 R08: 00000000e161fd1a R09: 0000000000000000 [ 106.539877] R10: 0000000000000018 R11: 0000000000000000 R12: ffff8881048940e8 [ 106.540222] R13: 0000000000000003 R14: 0000000000000000 R15: ffff8881048940e8 [ 106.540568] FS: 00007f277dde9f00(0000) GS:ffff88813bd80000(0000) knlGS:0000000000000000 [ 106.540954] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 106.541227] CR2: 00007f277eeede64 CR3: 000000000ad3e000 CR4: 00000000000006e0 [ 106.541569] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 106.541915] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 106.542255] Call Trace: [ 106.542383] <IRQ> [ 106.542487] __pskb_pull_tail+0x4b/0x3e0 [ 106.542681] skb_ensure_writable+0x85/0xa0 [ 106.542882] sk_skb_pull_data+0x18/0x20 [ 106.543084] bpf_prog_b517a65a242018b0_bpf_skskb_http_verdict+0x3a9/0x4aa9 [ 106.543536] ? migrate_disable+0x66/0x80 [ 106.543871] sk_psock_verdict_recv+0xe2/0x310 [ 106.544258] ? sk_psock_write_space+0x1f0/0x1f0 [ 106.544561] tcp_read_skb+0x7b/0x120 [ 106.544740] tcp_data_queue+0x904/0xee0 [ 106.544931] tcp_rcv_established+0x212/0x7c0 [ 106.545142] tcp_v4_do_rcv+0x174/0x2a0 [ 106.545326] tcp_v4_rcv+0xe70/0xf60 [ 106.545500] ip_protocol_deliver_rcu+0x48/0x290 [ 106.545744] ip_local_deliver_finish+0xa7/0x150 Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()") Reported-by: William Findlay <will@isovalent.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: William Findlay <will@isovalent.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20230523025618.113937-2-john.fastabend@gmail.com
2023-05-19bpf: Add bpf_sock_destroy kfuncAditi Ghag
The socket destroy kfunc is used to forcefully terminate sockets from certain BPF contexts. We plan to use the capability in Cilium load-balancing to terminate client sockets that continue to connect to deleted backends. The other use case is on-the-fly policy enforcement where existing socket connections prevented by policies need to be forcefully terminated. The kfunc also allows terminating sockets that may or may not be actively sending traffic. The kfunc can currently be called only from BPF TCP and UDP iterators where users can filter, and terminate selected sockets. More specifically, it can only be called from BPF contexts that ensure socket locking in order to allow synchronous execution of protocol specific `diag_destroy` handlers. The previous commit that batches UDP sockets during iteration facilitated a synchronous invocation of the UDP destroy callback from BPF context by skipping socket locks in `udp_abort`. TCP iterator already supported batching of sockets being iterated. To that end, `tracing_iter_filter` callback filter is added so that verifier can restrict the kfunc to programs with `BPF_TRACE_ITER` attach type, and reject other programs. The kfunc takes `sock_common` type argument, even though it expects, and casts them to a `sock` pointer. This enables the verifier to allow the sock_destroy kfunc to be called for TCP with `sock_common` and UDP with `sock` structs. Furthermore, as `sock_common` only has a subset of certain fields of `sock`, casting pointer to the latter type might not always be safe for certain sockets like request sockets, but these have a special handling in the diag_destroy handlers. Additionally, the kfunc is defined with `KF_TRUSTED_ARGS` flag to avoid the cases where a `PTR_TO_BTF_ID` sk is obtained by following another pointer. eg. getting a sk pointer (may be even NULL) by following another sk pointer. The pointer socket argument passed in TCP and UDP iterators is tagged as `PTR_TRUSTED` in {tcp,udp}_reg_info. The TRUSTED arg changes are contributed by Martin KaFai Lau <martin.lau@kernel.org>. Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com> Link: https://lore.kernel.org/r/20230519225157.760788-8-aditi.ghag@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-17net/tcp: optimise io_uring zc ubuf refcountingPavel Begunkov
io_uring keeps a reference to ubuf_info during submission, so if tcp_sendmsg_locked() sees msghdr::msg_ubuf in can be sure the buffer will be kept alive and doesn't need to additionally pin it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-17net/tcp: don't peek at tail for io_uring zcPavel Begunkov
Move tcp_write_queue_tail() to SOCK_ZEROCOPY specific flag as zerocopy setup for msghdr->ubuf_info doesn't need to peek into the last request. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10tcp: add annotations around sk->sk_shutdown accessesEric Dumazet
Now sk->sk_shutdown is no longer a bitfield, we can add standard READ_ONCE()/WRITE_ONCE() annotations to silence KCSAN reports like the following: BUG: KCSAN: data-race in tcp_disconnect / tcp_poll write to 0xffff88814588582c of 1 bytes by task 3404 on cpu 1: tcp_disconnect+0x4d6/0xdb0 net/ipv4/tcp.c:3121 __inet_stream_connect+0x5dd/0x6e0 net/ipv4/af_inet.c:715 inet_stream_connect+0x48/0x70 net/ipv4/af_inet.c:727 __sys_connect_file net/socket.c:2001 [inline] __sys_connect+0x19b/0x1b0 net/socket.c:2018 __do_sys_connect net/socket.c:2028 [inline] __se_sys_connect net/socket.c:2025 [inline] __x64_sys_connect+0x41/0x50 net/socket.c:2025 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88814588582c of 1 bytes by task 3374 on cpu 0: tcp_poll+0x2e6/0x7d0 net/ipv4/tcp.c:562 sock_poll+0x253/0x270 net/socket.c:1383 vfs_poll include/linux/poll.h:88 [inline] io_poll_check_events io_uring/poll.c:281 [inline] io_poll_task_func+0x15a/0x820 io_uring/poll.c:333 handle_tw_list io_uring/io_uring.c:1184 [inline] tctx_task_work+0x1fe/0x4d0 io_uring/io_uring.c:1246 task_work_run+0x123/0x160 kernel/task_work.c:179 get_signal+0xe64/0xff0 kernel/signal.c:2635 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x03 -> 0x00 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-14net: Ensure ->msg_control_user is used for user buffersKevin Brodsky
Since commit 1f466e1f15cf ("net: cleanly handle kernel vs user buffers for ->msg_control"), pointers to user buffers should be stored in struct msghdr::msg_control_user, instead of the msg_control field. Most users of msg_control have already been converted (where user buffers are involved), but not all of them. This patch attempts to address the remaining cases. An exception is made for null checks, as it should be safe to use msg_control unconditionally for that purpose. Cc: Christoph Hellwig <hch@lst.de> Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-18tcp: preserve const qualifier in tcp_sk()Eric Dumazet
We can change tcp_sk() to propagate its argument const qualifier, thanks to container_of_const(). We have two places where a const sock pointer has to be upgraded to a write one. We have been using const qualifier for lockless listeners to clearly identify points where writes could happen. Add tcp_sk_rw() helper to better document these. tcp_inbound_md5_hash(), __tcp_grow_window(), tcp_reset_check() and tcp_rack_reo_wnd() get an additional const qualififer for their @tp local variables. smc_check_reset_syn_req() also needs a similar change. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>