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2022-11-03net: gso: fix panic on frag_list with mixed head alloc typesJiri Benc1-17/+19
Since commit 3dcbdb134f32 ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list"), it is allowed to change gso_size of a GRO packet. However, that commit assumes that "checking the first list_skb member suffices; i.e if either of the list_skb members have non head_frag head, then the first one has too". It turns out this assumption does not hold. We've seen BUG_ON being hit in skb_segment when skbs on the frag_list had differing head_frag with the vmxnet3 driver. This happens because __netdev_alloc_skb and __napi_alloc_skb can return a skb that is page backed or kmalloced depending on the requested size. As the result, the last small skb in the GRO packet can be kmalloced. There are three different locations where this can be fixed: (1) We could check head_frag in GRO and not allow GROing skbs with different head_frag. However, that would lead to performance regression on normal forward paths with unmodified gso_size, where !head_frag in the last packet is not a problem. (2) Set a flag in bpf_skb_net_grow and bpf_skb_net_shrink indicating that NETIF_F_SG is undesirable. That would need to eat a bit in sk_buff. Furthermore, that flag can be unset when all skbs on the frag_list are page backed. To retain good performance, bpf_skb_net_grow/shrink would have to walk the frag_list. (3) Walk the frag_list in skb_segment when determining whether NETIF_F_SG should be cleared. This of course slows things down. This patch implements (3). To limit the performance impact in skb_segment, the list is walked only for skbs with SKB_GSO_DODGY set that have gso_size changed. Normal paths thus will not hit it. We could check only the last skb but since we need to walk the whole list anyway, let's stay on the safe side. Fixes: 3dcbdb134f32 ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list") Signed-off-by: Jiri Benc <jbenc@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/e04426a6a91baf4d1081e1b478c82b5de25fdf21.1667407944.git.jbenc@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-27net: do not sense pfmemalloc status in skb_append_pagefrags()Eric Dumazet1-1/+1
skb_append_pagefrags() is used by af_unix and udp sendpage() implementation so far. In commit 326140063946 ("tcp: TX zerocopy should not sense pfmemalloc status") we explained why we should not sense pfmemalloc status for pages owned by user space. We should also use skb_fill_page_desc_noacc() in skb_append_pagefrags() to avoid following KCSAN report: BUG: KCSAN: data-race in lru_add_fn / skb_append_pagefrags write to 0xffffea00058fc1c8 of 8 bytes by task 17319 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:323 [inline] lru_add_fn+0x327/0x410 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 lru_add_drain_cpu+0x73/0x250 mm/swap.c:669 lru_add_drain+0x21/0x60 mm/swap.c:773 free_pages_and_swap_cache+0x16/0x70 mm/swap_state.c:311 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:256 [inline] tlb_flush_mmu+0x5b2/0x640 mm/mmu_gather.c:263 tlb_finish_mmu+0x86/0x100 mm/mmu_gather.c:363 exit_mmap+0x190/0x4d0 mm/mmap.c:3098 __mmput+0x27/0x1b0 kernel/fork.c:1185 mmput+0x3d/0x50 kernel/fork.c:1207 copy_process+0x19fc/0x2100 kernel/fork.c:2518 kernel_clone+0x166/0x550 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0xc3/0xf0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea00058fc1c8 of 8 bytes by task 17325 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1817 [inline] __skb_fill_page_desc include/linux/skbuff.h:2432 [inline] skb_fill_page_desc include/linux/skbuff.h:2453 [inline] skb_append_pagefrags+0x210/0x600 net/core/skbuff.c:3974 unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2338 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea00058fc188 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17325 Comm: syz-executor.0 Not tainted 6.1.0-rc1-syzkaller-00158-g440b7895c990-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Fixes: 326140063946 ("tcp: TX zerocopy should not sense pfmemalloc status") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20221027040346.1104204-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net: skb: introduce and use a single page frag cachePaolo Abeni1-5/+103
After commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs") we are observing 10-20% regressions in performance tests with small packets. The perf trace points to high pressure on the slab allocator. This change tries to improve the allocation schema for small packets using an idea originally suggested by Eric: a new per CPU page frag is introduced and used in __napi_alloc_skb to cope with small allocation requests. To ensure that the above does not lead to excessive truesize underestimation, the frag size for small allocation is inflated to 1K and all the above is restricted to build with 4K page size. Note that we need to update accordingly the run-time check introduced with commit fd9ea57f4e95 ("net: add napi_get_frags_check() helper"). Alex suggested a smart page refcount schema to reduce the number of atomic operations and deal properly with pfmemalloc pages. Under small packet UDP flood, I measure a 15% peak tput increases. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Suggested-by: Alexander H Duyck <alexanderduyck@fb.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://lore.kernel.org/r/6b6f65957c59f86a353fc09a5127e83a32ab5999.1664350652.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-28net: shrink struct ubuf_infoPavel Begunkov1-17/+21
We can benefit from a smaller struct ubuf_info, so leave only mandatory fields and let users to decide how they want to extend it. Convert MSG_ZEROCOPY to struct ubuf_info_msgzc and remove duplicated fields. This reduces the size from 48 bytes to just 16. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni1-1/+5
drivers/net/ethernet/freescale/fec.h 7d650df99d52 ("net: fec: add pm_qos support on imx6q platform") 40c79ce13b03 ("net: fec: add stop mode support for imx8 platform") Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-07net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUMMenglong Dong1-1/+5
As Eric reported, the 'reason' field is not presented when trace the kfree_skb event by perf: $ perf record -e skb:kfree_skb -a sleep 10 $ perf script ip_defrag 14605 [021] 221.614303: skb:kfree_skb: skbaddr=0xffff9d2851242700 protocol=34525 location=0xffffffffa39346b1 reason: The cause seems to be passing kernel address directly to TP_printk(), which is not right. As the enum 'skb_drop_reason' is not exported to user space through TRACE_DEFINE_ENUM(), perf can't get the drop reason string from the 'reason' field, which is a number. Therefore, we introduce the macro DEFINE_DROP_REASON(), which is used to define the trace enum by TRACE_DEFINE_ENUM(). With the help of DEFINE_DROP_REASON(), now we can remove the auto-generate that we introduced in the commit ec43908dd556 ("net: skb: use auto-generation to convert skb drop reason to string"), and define the string array 'drop_reasons'. Hmmmm...now we come back to the situation that have to maintain drop reasons in both enum skb_drop_reason and DEFINE_DROP_REASON. But they are both in dropreason.h, which makes it easier. After this commit, now the format of kfree_skb is like this: $ cat /tracing/events/skb/kfree_skb/format name: kfree_skb ID: 1524 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:void * skbaddr; offset:8; size:8; signed:0; field:void * location; offset:16; size:8; signed:0; field:unsigned short protocol; offset:24; size:2; signed:0; field:enum skb_drop_reason reason; offset:28; size:4; signed:0; print fmt: "skbaddr=%p protocol=%u location=%p reason: %s", REC->skbaddr, REC->protocol, REC->location, __print_symbolic(REC->reason, { 1, "NOT_SPECIFIED" }, { 2, "NO_SOCKET" } ...... Fixes: ec43908dd556 ("net: skb: use auto-generation to convert skb drop reason to string") Link: https://lore.kernel.org/netdev/CANn89i+bx0ybvE55iMYf5GJM48WwV1HNpdm9Q6t-HaEstqpCSA@mail.gmail.com/ Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-4/+3
drivers/net/ethernet/mellanox/mlx5/core/en_fs.c 21234e3a84c7 ("net/mlx5e: Fix use after free in mlx5e_fs_init()") c7eafc5ed068 ("net/mlx5e: Convert ethtool_steering member of flow_steering struct to pointer") https://lore.kernel.org/all/20220825104410.67d4709c@canb.auug.org.au/ https://lore.kernel.org/all/20220823055533.334471-1-saeed@kernel.org/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-24net: Fix a data-race around sysctl_tstamp_allow_data.Kuniyuki Iwashima1-1/+1
While reading sysctl_tstamp_allow_data, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: b245be1f4db1 ("net-timestamp: no-payload only sysctl") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-24net/core/skbuff: Check the return value of skb_copy_bits()lily1-3/+2
skb_copy_bits() could fail, which requires a check on the return value. Signed-off-by: Li Zhong <floridsleeves@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-24net: skb: prevent the split of kfree_skb_reason() by gccMenglong Dong1-2/+3
Sometimes, gcc will optimize the function by spliting it to two or more functions. In this case, kfree_skb_reason() is splited to kfree_skb_reason and kfree_skb_reason.part.0. However, the function/tracepoint trace_kfree_skb() in it needs the return address of kfree_skb_reason(). This split makes the call chains becomes: kfree_skb_reason() -> kfree_skb_reason.part.0 -> trace_kfree_skb() which makes the return address that passed to trace_kfree_skb() be kfree_skb(). Therefore, introduce '__fix_address', which is the combination of '__noclone' and 'noinline', and apply it to kfree_skb_reason() to prevent to from being splited or made inline. (Is it better to simply apply '__noclone oninline' to kfree_skb_reason? I'm thinking maybe other functions have the same problems) Meanwhile, wrap 'skb_unref()' with 'unlikely()', as the compiler thinks it is likely return true and splits kfree_skb_reason(). Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-19Merge branch 'io_uring-zerocopy-send' of git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linuxJakub Kicinski1-4/+33
Pavel Begunkov says: ==================== io_uring zerocopy send The patchset implements io_uring zerocopy send. It works with both registered and normal buffers, mixing is allowed but not recommended. Apart from usual request completions, just as with MSG_ZEROCOPY, io_uring separately notifies the userspace when buffers are freed and can be reused (see API design below), which is delivered into io_uring's Completion Queue. Those "buffer-free" notifications are not necessarily per request, but the userspace has control over it and should explicitly attaching a number of requests to a single notification. The series also adds some internal optimisations when used with registered buffers like removing page referencing. From the kernel networking perspective there are two main changes. The first one is passing ubuf_info into the network layer from io_uring (inside of an in kernel struct msghdr). This allows extra optimisations, e.g. ubuf_info caching on the io_uring side, but also helps to avoid cross-referencing and synchronisation problems. The second part is an optional optimisation removing page referencing for requests with registered buffers. Benchmarking UDP with an optimised version of the selftest (see [1]), which sends a bunch of requests, waits for completions and repeats. "+ flush" column posts one additional "buffer-free" notification per request, and just "zc" doesn't post buffer notifications at all. NIC (requests / second): IO size | non-zc | zc | zc + flush 4000 | 495134 | 606420 (+22%) | 558971 (+12%) 1500 | 551808 | 577116 (+4.5%) | 565803 (+2.5%) 1000 | 584677 | 592088 (+1.2%) | 560885 (-4%) 600 | 596292 | 598550 (+0.4%) | 555366 (-6.7%) dummy (requests / second): IO size | non-zc | zc | zc + flush 8000 | 1299916 | 2396600 (+84%) | 2224219 (+71%) 4000 | 1869230 | 2344146 (+25%) | 2170069 (+16%) 1200 | 2071617 | 2361960 (+14%) | 2203052 (+6%) 600 | 2106794 | 2381527 (+13%) | 2195295 (+4%) Previously it also brought a massive performance speedup compared to the msg_zerocopy tool (see [3]), which is probably not super interesting. There is also an additional bunch of refcounting optimisations that was omitted from the series for simplicity and as they don't change the picture drastically, they will be sent as follow up, as well as flushing optimisations closing the performance gap b/w two last columns. For TCP on localhost (with hacks enabling localhost zerocopy) and including additional overhead for receive: IO size | non-zc | zc 1200 | 4174 | 4148 4096 | 7597 | 11228 Using a real NIC 1200 bytes, zc is worse than non-zc ~5-10%, maybe the omitted optimisations will somewhat help, should look better for 4000, but couldn't test properly because of setup problems. Links: liburing (benchmark + tests): [1] https://github.com/isilence/liburing/tree/zc_v4 kernel repo: [2] https://github.com/isilence/linux/tree/zc_v4 RFC v1: [3] https://lore.kernel.org/io-uring/cover.1638282789.git.asml.silence@gmail.com/ RFC v2: https://lore.kernel.org/io-uring/cover.1640029579.git.asml.silence@gmail.com/ Net patches based: git@github.com:isilence/linux.git zc_v4-net-base or https://github.com/isilence/linux/tree/zc_v4-net-base API design overview: The series introduces an io_uring concept of notifactors. From the userspace perspective it's an entity to which it can bind one or more requests and then requesting to flush it. Flushing a notifier makes it impossible to attach new requests to it, and instructs the notifier to post a completion once all requests attached to it are completed and the kernel doesn't need the buffers anymore. Notifications are stored in notification slots, which should be registered as an array in io_uring. Each slot stores only one notifier at any particular moment. Flushing removes it from the slot and the slot automatically replaces it with a new notifier. All operations with notifiers are done by specifying an index of a slot it's currently in. When registering a notification the userspace specifies a u64 tag for each slot, which will be copied in notification completion entries as cqe::user_data. cqe::res is 0 and cqe::flags is equal to wrap around u32 sequence number counting notifiers of a slot. ==================== Link: https://lore.kernel.org/r/cover.1657643355.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-19net: introduce managed frags infrastructurePavel Begunkov1-2/+27
Some users like io_uring can do page pinning more efficiently, so we want a way to delegate referencing to other subsystems. For that add a new flag called SKBFL_MANAGED_FRAG_REFS. When set, skb doesn't hold page references and upper layers are responsivle to managing page lifetime. It's allowed to convert skbs from managed to normal by calling skb_zcopy_downgrade_managed(). The function will take all needed page references and clear the flag. It's needed, for instance, to avoid mixing managed modes. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-19net: Allow custom iter handler in msghdrDavid Ahern1-1/+1
Add support for custom iov_iter handling to msghdr. The idea is that in-kernel subsystems want control over how an SG is split. Signed-off-by: David Ahern <dsahern@kernel.org> [pavel: move callback into msghdr] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-18skbuff: add SKBFL_DONT_ORPHAN flagPavel Begunkov1-1/+1
We don't want to list every single ubuf_info callback in skb_orphan_frags(), add a flag controlling the behaviour. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-18skbuff: don't mix ubuf_info from different sourcesPavel Begunkov1-0/+4
We should not append MSG_ZEROCOPY requests to skbuff with non MSG_ZEROCOPY ubuf_info, they might be not compatible. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-08net: minor optimization in __alloc_skb()Eric Dumazet1-2/+1
TCP allocates 'fast clones' skbs for packets in tx queues. Currently, __alloc_skb() initializes the companion fclone field to SKB_FCLONE_CLONE, and leaves other fields untouched. It makes sense to defer this init much later in skb_clone(), because all fclone fields are copied and hot in cpu caches at that time. This removes one cache line miss in __alloc_skb(), cost seen on an host with 256 cpus all competing on memory accesses. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-24net: helper function skb_len_addRichard Gobert1-10/+3
Move the len fields manipulation in the skbs to a helper function. There is a comment specifically requesting this and there are several other areas in the code displaying the same pattern which can be refactored. This improves code readability. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Link: https://lore.kernel.org/r/20220622160853.GA6478@debian Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-15net: don't check skb_count twiceSieng Piaw Liew1-3/+4
NAPI cache skb_count is being checked twice without condition. Change to checking the second time only if the first check is run. Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-09net: add debug checks in napi_consume_skb and __napi_alloc_skb()Eric Dumazet1-1/+2
Commit 6454eca81eae ("net: Use lockdep_assert_in_softirq() in napi_consume_skb()") added a check in napi_consume_skb() which is a bit weak. napi_consume_skb() and __napi_alloc_skb() should only be used from BH context, not from hard irq or nmi context, otherwise we could have races. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-09net: use DEBUG_NET_WARN_ON_ONCE() in skb_release_head_state()Eric Dumazet1-1/+1
Remove this check from fast path unless CONFIG_DEBUG_NET=y Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-07net: skb: use auto-generation to convert skb drop reason to stringMenglong Dong1-0/+3
It is annoying to add new skb drop reasons to 'enum skb_drop_reason' and TRACE_SKB_DROP_REASON in trace/event/skb.h, and it's easy to forget to add the new reasons we added to TRACE_SKB_DROP_REASON. TRACE_SKB_DROP_REASON is used to convert drop reason of type number to string. For now, the string we passed to user space is exactly the same as the name in 'enum skb_drop_reason' with a 'SKB_DROP_REASON_' prefix. Therefore, we can use 'auto-generation' to generate these drop reasons to string at build time. The new source 'dropreason_str.c' will be auto generated during build time, which contains the string array 'const char * const drop_reasons[]'. Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-05-20net: avoid strange behavior with skb_defer_max == 1Jakub Kicinski1-8/+5
When user sets skb_defer_max to 1 the kick threshold is 0 (half of 1). If we increment queue length before the check the kick will never happen, and the skb may get stranded. This is likely harmless but can be avoided by moving the increment after the check. This way skb_defer_max == 1 will always kick. Still a silly config to have, but somehow that feels more correct. While at it drop a comment which seems to be outdated or confusing, and wrap the defer_count write with a WRITE_ONCE() since it's read on the fast path that avoids taking the lock. Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220518185522.2038683-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-16net: add skb_defer_max sysctlEric Dumazet1-6/+9
commit 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") added another per-cpu cache of skbs. It was expected to be small, and an IPI was forced whenever the list reached 128 skbs. We might need to be able to control more precisely queue capacity and added latency. An IPI is generated whenever queue reaches half capacity. Default value of the new limit is 64. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-16net: fix possible race in skb_attempt_defer_free()Eric Dumazet1-3/+2
A cpu can observe sd->defer_count reaching 128, and call smp_call_function_single_async() Problem is that the remote CPU can clear sd->defer_count before the IPI is run/acknowledged. Other cpus can queue more packets and also decide to call smp_call_function_single_async() while the pending IPI was not yet delivered. This is a common issue with smp_call_function_single_async(). Callers must ensure correct synchronization and serialization. I triggered this issue while experimenting smaller threshold. Performing the call to smp_call_function_single_async() under sd->defer_lock protection did not solve the problem. Commit 5a18ceca6350 ("smp: Allow smp_call_function_single_async() to insert locked csd") replaced an informative WARN_ON_ONCE() with a return of -EBUSY, which is often ignored. Test of CSD_FLAG_LOCK presence is racy anyway. Fixes: 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-16net: skb: check the boundrary of drop reason in kfree_skb_reason()Menglong Dong1-0/+2
Sometimes, we may forget to reset skb drop reason to NOT_SPECIFIED after we make it the return value of the functions with return type of enum skb_drop_reason, such as tcp_inbound_md5_hash. Therefore, its value can be SKB_NOT_DROPPED_YET(0), which is invalid for kfree_skb_reason(). So we check the range of drop reason in kfree_skb_reason() with DEBUG_NET_WARN_ON_ONCE(). Reviewed-by: Jiang Biao <benbjiang@tencent.com> Reviewed-by: Hao Peng <flyingpeng@tencent.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+3
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>
2022-05-09net: fix wrong network header lengthLina Wang1-1/+3
When clatd starts with ebpf offloaing, and NETIF_F_GRO_FRAGLIST is enable, several skbs are gathered in skb_shinfo(skb)->frag_list. The first skb's ipv6 header will be changed to ipv4 after bpf_skb_proto_6_to_4, network_header\transport_header\mac_header have been updated as ipv4 acts, but other skbs in frag_list didnot update anything, just ipv6 packets. udp_queue_rcv_skb will call skb_segment_list to traverse other skbs in frag_list and make sure right udp payload is delivered to user space. Unfortunately, other skbs in frag_list who are still ipv6 packets are updated like the first skb and will have wrong transport header length. e.g.before bpf_skb_proto_6_to_4,the first skb and other skbs in frag_list has the same network_header(24)& transport_header(64), after bpf_skb_proto_6_to_4, ipv6 protocol has been changed to ipv4, the first skb's network_header is 44,transport_header is 64, other skbs in frag_list didnot change.After skb_segment_list, the other skbs in frag_list has different network_header(24) and transport_header(44), so there will be 20 bytes different from original,that is difference between ipv6 header and ipv4 header. Just change transport_header to be the same with original. Actually, there are two solutions to fix it, one is traversing all skbs and changing every skb header in bpf_skb_proto_6_to_4, the other is modifying frag_list skb's header in skb_segment_list. Considering efficiency, adopt the second one--- when the first skb and other skbs in frag_list has different network_header length, restore them to make sure right udp payload is delivered to user space. Signed-off-by: Lina Wang <lina.wang@mediatek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-05net: Make msg_zerocopy_alloc staticDavid Ahern1-2/+1
msg_zerocopy_alloc is only used by msg_zerocopy_realloc; remove the export and make static in skbuff.c Signed-off-by: David Ahern <dsahern@kernel.org> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/r/20220504170947.18773-1-dsahern@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-02tcp: optimise skb_zerocopy_iter_stream()Pavel Begunkov1-2/+1
It's expensive to make a copy of 40B struct iov_iter to the point it was taking 0.2-0.5% of all cycles in my tests. iov_iter_revert() should be fine as it's a simple case without nested reverts/truncates. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a7e1690c00c5dfe700c30eb9a8a81ec59f6545dd.1650884401.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-30net: inline skb_zerocopy_iter_dgramPavel Begunkov1-7/+0
skb_zerocopy_iter_dgram() is a small proxy function, inline it. For that, move __zerocopy_sg_from_iter into linux/skbuff.h Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-27Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski1-1/+1
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-04-27 We've added 85 non-merge commits during the last 18 day(s) which contain a total of 163 files changed, 4499 insertions(+), 1521 deletions(-). The main changes are: 1) Teach libbpf to enhance BPF verifier log with human-readable and relevant information about failed CO-RE relocations, from Andrii Nakryiko. 2) Add typed pointer support in BPF maps and enable it for unreferenced pointers (via probe read) and referenced ones that can be passed to in-kernel helpers, from Kumar Kartikeya Dwivedi. 3) Improve xsk to break NAPI loop when rx queue gets full to allow for forward progress to consume descriptors, from Maciej Fijalkowski & Björn Töpel. 4) Fix a small RCU read-side race in BPF_PROG_RUN routines which dereferenced the effective prog array before the rcu_read_lock, from Stanislav Fomichev. 5) Implement BPF atomic operations for RV64 JIT, and add libbpf parsing logic for USDT arguments under riscv{32,64}, from Pu Lehui. 6) Implement libbpf parsing of USDT arguments under aarch64, from Alan Maguire. 7) Enable bpftool build for musl and remove nftw with FTW_ACTIONRETVAL usage so it can be shipped under Alpine which is musl-based, from Dominique Martinet. 8) Clean up {sk,task,inode} local storage trace RCU handling as they do not need to use call_rcu_tasks_trace() barrier, from KP Singh. 9) Improve libbpf API documentation and fix error return handling of various API functions, from Grant Seltzer. 10) Enlarge offset check for bpf_skb_{load,store}_bytes() helpers given data length of frags + frag_list may surpass old offset limit, from Liu Jian. 11) Various improvements to prog_tests in area of logging, test execution and by-name subtest selection, from Mykola Lysenko. 12) Simplify map_btf_id generation for all map types by moving this process to build time with help of resolve_btfids infra, from Menglong Dong. 13) Fix a libbpf bug in probing when falling back to legacy bpf_probe_read*() helpers; the probing caused always to use old helpers, from Runqing Yang. 14) Add support for ARCompact and ARCv2 platforms for libbpf's PT_REGS tracing macros, from Vladimir Isaev. 15) Cleanup BPF selftests to remove old & unneeded rlimit code given kernel switched to memcg-based memory accouting a while ago, from Yafang Shao. 16) Refactor of BPF sysctl handlers to move them to BPF core, from Yan Zhu. 17) Fix BPF selftests in two occasions to work around regressions caused by latest LLVM to unblock CI until their fixes are worked out, from Yonghong Song. 18) Misc cleanups all over the place, from various others. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (85 commits) selftests/bpf: Add libbpf's log fixup logic selftests libbpf: Fix up verifier log for unguarded failed CO-RE relos libbpf: Simplify bpf_core_parse_spec() signature libbpf: Refactor CO-RE relo human description formatting routine libbpf: Record subprog-resolved CO-RE relocations unconditionally selftests/bpf: Add CO-RE relos and SEC("?...") to linked_funcs selftests libbpf: Avoid joining .BTF.ext data with BPF programs by section name libbpf: Fix logic for finding matching program for CO-RE relocation libbpf: Drop unhelpful "program too large" guess libbpf: Fix anonymous type check in CO-RE logic bpf: Compute map_btf_id during build time selftests/bpf: Add test for strict BTF type check selftests/bpf: Add verifier tests for kptr selftests/bpf: Add C tests for kptr libbpf: Add kptr type tag macros to bpf_helpers.h bpf: Make BTF type match stricter for release arguments bpf: Teach verifier about kptr_get kfunc helpers bpf: Wire up freeing of referenced kptr bpf: Populate pairs of btf_id and destructor kfunc in btf bpf: Adapt copy_map_value for multiple offset case ... ==================== Link: https://lore.kernel.org/r/20220427224758.20976-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-26net: generalize skb freeing deferral to per-cpu listsEric Dumazet1-1/+50
Logic added in commit f35f821935d8 ("tcp: defer skb freeing after socket lock is released") helped bulk TCP flows to move the cost of skbs frees outside of critical section where socket lock was held. But for RPC traffic, or hosts with RFS enabled, the solution is far from being ideal. For RPC traffic, recvmsg() has to return to user space right after skb payload has been consumed, meaning that BH handler has no chance to pick the skb before recvmsg() thread. This issue is more visible with BIG TCP, as more RPC fit one skb. For RFS, even if BH handler picks the skbs, they are still picked from the cpu on which user thread is running. Ideally, it is better to free the skbs (and associated page frags) on the cpu that originally allocated them. This patch removes the per socket anchor (sk->defer_list) and instead uses a per-cpu list, which will hold more skbs per round. This new per-cpu list is drained at the end of net_action_rx(), after incoming packets have been processed, to lower latencies. In normal conditions, skbs are added to the per-cpu list with no further action. In the (unlikely) cases where the cpu does not run net_action_rx() handler fast enough, we use an IPI to raise NET_RX_SOFTIRQ on the remote cpu. Also, we do not bother draining the per-cpu list from dev_cpu_dead() This is because skbs in this list have no requirement on how fast they should be freed. Note that we can add in the future a small per-cpu cache if we see any contention on sd->defer_lock. Tested on a pair of hosts with 100Gbit NIC, RFS enabled, and /proc/sys/net/ipv4/tcp_rmem[2] tuned to 16MB to work around page recycling strategy used by NIC driver (its page pool capacity being too small compared to number of skbs/pages held in sockets receive queues) Note that this tuning was only done to demonstrate worse conditions for skb freeing for this particular test. These conditions can happen in more general production workload. 10 runs of one TCP_STREAM flow Before: Average throughput: 49685 Mbit. Kernel profiles on cpu running user thread recvmsg() show high cost for skb freeing related functions (*) 57.81% [kernel] [k] copy_user_enhanced_fast_string (*) 12.87% [kernel] [k] skb_release_data (*) 4.25% [kernel] [k] __free_one_page (*) 3.57% [kernel] [k] __list_del_entry_valid 1.85% [kernel] [k] __netif_receive_skb_core 1.60% [kernel] [k] __skb_datagram_iter (*) 1.59% [kernel] [k] free_unref_page_commit (*) 1.16% [kernel] [k] __slab_free 1.16% [kernel] [k] _copy_to_iter (*) 1.01% [kernel] [k] kfree (*) 0.88% [kernel] [k] free_unref_page 0.57% [kernel] [k] ip6_rcv_core 0.55% [kernel] [k] ip6t_do_table 0.54% [kernel] [k] flush_smp_call_function_queue (*) 0.54% [kernel] [k] free_pcppages_bulk 0.51% [kernel] [k] llist_reverse_order 0.38% [kernel] [k] process_backlog (*) 0.38% [kernel] [k] free_pcp_prepare 0.37% [kernel] [k] tcp_recvmsg_locked (*) 0.37% [kernel] [k] __list_add_valid 0.34% [kernel] [k] sock_rfree 0.34% [kernel] [k] _raw_spin_lock_irq (*) 0.33% [kernel] [k] __page_cache_release 0.33% [kernel] [k] tcp_v6_rcv (*) 0.33% [kernel] [k] __put_page (*) 0.29% [kernel] [k] __mod_zone_page_state 0.27% [kernel] [k] _raw_spin_lock After patch: Average throughput: 73076 Mbit. Kernel profiles on cpu running user thread recvmsg() looks better: 81.35% [kernel] [k] copy_user_enhanced_fast_string 1.95% [kernel] [k] _copy_to_iter 1.95% [kernel] [k] __skb_datagram_iter 1.27% [kernel] [k] __netif_receive_skb_core 1.03% [kernel] [k] ip6t_do_table 0.60% [kernel] [k] sock_rfree 0.50% [kernel] [k] tcp_v6_rcv 0.47% [kernel] [k] ip6_rcv_core 0.45% [kernel] [k] read_tsc 0.44% [kernel] [k] _raw_spin_lock_irqsave 0.37% [kernel] [k] _raw_spin_lock 0.37% [kernel] [k] native_irq_return_iret 0.33% [kernel] [k] __inet6_lookup_established 0.31% [kernel] [k] ip6_protocol_deliver_rcu 0.29% [kernel] [k] tcp_rcv_established 0.29% [kernel] [k] llist_reverse_order v2: kdoc issue (kernel bots) do not defer if (alloc_cpu == smp_processor_id()) (Paolo) replace the sk_buff_head with a single-linked list (Jakub) add a READ_ONCE()/WRITE_ONCE() for the lockless read of sd->defer_list Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220422201237.416238-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-20net: Change skb_ensure_writable()'s write_len param to unsigned int typeLiu Jian1-1/+1
Both pskb_may_pull() and skb_clone_writable()'s length parameters are of type unsigned int already. Therefore, change this function's write_len param to unsigned int type. Signed-off-by: Liu Jian <liujian56@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20220416105801.88708-3-liujian56@huawei.com
2022-04-01skbuff: fix coalescing for page_pool fragment recyclingJean-Philippe Brucker1-4/+11
Fix a use-after-free when using page_pool with page fragments. We encountered this problem during normal RX in the hns3 driver: (1) Initially we have three descriptors in the RX queue. The first one allocates PAGE1 through page_pool, and the other two allocate one half of PAGE2 each. Page references look like this: RX_BD1 _______ PAGE1 RX_BD2 _______ PAGE2 RX_BD3 _________/ (2) Handle RX on the first descriptor. Allocate SKB1, eventually added to the receive queue by tcp_queue_rcv(). (3) Handle RX on the second descriptor. Allocate SKB2 and pass it to netif_receive_skb(): netif_receive_skb(SKB2) ip_rcv(SKB2) SKB3 = skb_clone(SKB2) SKB2 and SKB3 share a reference to PAGE2 through skb_shinfo()->dataref. The other ref to PAGE2 is still held by RX_BD3: SKB2 ---+- PAGE2 SKB3 __/ / RX_BD3 _________/ (3b) Now while handling TCP, coalesce SKB3 with SKB1: tcp_v4_rcv(SKB3) tcp_try_coalesce(to=SKB1, from=SKB3) // succeeds kfree_skb_partial(SKB3) skb_release_data(SKB3) // drops one dataref SKB1 _____ PAGE1 \____ SKB2 _____ PAGE2 / RX_BD3 _________/ In skb_try_coalesce(), __skb_frag_ref() takes a page reference to PAGE2, where it should instead have increased the page_pool frag reference, pp_frag_count. Without coalescing, when releasing both SKB2 and SKB3, a single reference to PAGE2 would be dropped. Now when releasing SKB1 and SKB2, two references to PAGE2 will be dropped, resulting in underflow. (3c) Drop SKB2: af_packet_rcv(SKB2) consume_skb(SKB2) skb_release_data(SKB2) // drops second dataref page_pool_return_skb_page(PAGE2) // drops one pp_frag_count SKB1 _____ PAGE1 \____ PAGE2 / RX_BD3 _________/ (4) Userspace calls recvmsg() Copies SKB1 and releases it. Since SKB3 was coalesced with SKB1, we release the SKB3 page as well: tcp_eat_recv_skb(SKB1) skb_release_data(SKB1) page_pool_return_skb_page(PAGE1) page_pool_return_skb_page(PAGE2) // drops second pp_frag_count (5) PAGE2 is freed, but the third RX descriptor was still using it! In our case this causes IOMMU faults, but it would silently corrupt memory if the IOMMU was disabled. Change the logic that checks whether pp_recycle SKBs can be coalesced. We still reject differing pp_recycle between 'from' and 'to' SKBs, but in order to avoid the situation described above, we also reject coalescing when both 'from' and 'to' are pp_recycled and 'from' is cloned. The new logic allows coalescing a cloned pp_recycle SKB into a page refcounted one, because in this case the release (4) will drop the right reference, the one taken by skb_try_coalesce(). Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool") Suggested-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-04net: skb: introduce the function kfree_skb_list_reason()Menglong Dong1-3/+4
To report reasons of skb drops, introduce the function kfree_skb_list_reason() and make kfree_skb_list() an inline call to it. This function will be used in the next commit in __dev_xmit_skb(). Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+1
net/batman-adv/hard-interface.c commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check") commit 6ee3c393eeb7 ("batman-adv: Demote batadv-on-batadv skip error message") https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/ net/smc/af_smc.c commit 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails") commit 462791bbfa35 ("net/smc: add sysctl interface for SMC") https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-03net: Clear mono_delivery_time bit in __skb_tstamp_tx()Martin KaFai Lau1-1/+1
In __skb_tstamp_tx(), it may clone the egress skb and queues the clone to the sk_error_queue. The outgoing skb may have the mono delivery_time while the (rcv) timestamp is expected for the clone, so the skb->mono_delivery_time bit needs to be cleared from the clone. This patch adds the skb->mono_delivery_time clearing to the existing __net_timestamp() and use it in __skb_tstamp_tx(). The __net_timestamp() fast path usage in dev.c is changed to directly call ktime_get_real() since the mono_delivery_time bit is not set at that point. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03net: Add skb_clear_tstamp() to keep the mono delivery_timeMartin KaFai Lau1-1/+1
Right now, skb->tstamp is reset to 0 whenever the skb is forwarded. If skb->tstamp has the mono delivery_time, clearing it can hurt the performance when it finally transmits out to fq@phy-dev. The earlier patch added a skb->mono_delivery_time bit to flag the skb->tstamp carrying the mono delivery_time. This patch adds skb_clear_tstamp() helper which keeps the mono delivery_time and clears everything else. The delivery_time clearing will be postponed until the stack knows the skb will be delivered locally. It will be done in a latter patch. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-02net: fix up skbs delta_truesize in UDP GRO frag_listlena wang1-1/+1
The truesize for a UDP GRO packet is added by main skb and skbs in main skb's frag_list: skb_gro_receive_list p->truesize += skb->truesize; The commit 53475c5dd856 ("net: fix use-after-free when UDP GRO with shared fraglist") introduced a truesize increase for frag_list skbs. When uncloning skb, it will call pskb_expand_head and trusesize for frag_list skbs may increase. This can occur when allocators uses __netdev_alloc_skb and not jump into __alloc_skb. This flow does not use ksize(len) to calculate truesize while pskb_expand_head uses. skb_segment_list err = skb_unclone(nskb, GFP_ATOMIC); pskb_expand_head if (!skb->sk || skb->destructor == sock_edemux) skb->truesize += size - osize; If we uses increased truesize adding as delta_truesize, it will be larger than before and even larger than previous total truesize value if skbs in frag_list are abundant. The main skb truesize will become smaller and even a minus value or a huge value for an unsigned int parameter. Then the following memory check will drop this abnormal skb. To avoid this error we should use the original truesize to segment the main skb. Fixes: 53475c5dd856 ("net: fix use-after-free when UDP GRO with shared fraglist") Signed-off-by: lena wang <lena.wang@mediatek.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/1646133431-8948-1-git-send-email-lena.wang@mediatek.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-3/+3
tools/testing/selftests/net/mptcp/mptcp_join.sh 34aa6e3bccd8 ("selftests: mptcp: add ip mptcp wrappers") 857898eb4b28 ("selftests: mptcp: add missing join check") 6ef84b1517e0 ("selftests: mptcp: more robust signal race test") https://lore.kernel.org/all/20220221131842.468893-1-broonie@kernel.org/ drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.h drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/ct.c fb7e76ea3f3b6 ("net/mlx5e: TC, Skip redundant ct clear actions") c63741b426e11 ("net/mlx5e: Fix MPLSoUDP encap to use MPLS action information") 09bf97923224f ("net/mlx5e: TC, Move pedit_headers_action to parse_attr") 84ba8062e383 ("net/mlx5e: Test CT and SAMPLE on flow attr") efe6f961cd2e ("net/mlx5e: CT, Don't set flow flag CT for ct clear flow") 3b49a7edec1d ("net/mlx5e: TC, Reject rules with multiple CT actions") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-22net: preserve skb_end_offset() in skb_unclone_keeptruesize()Eric Dumazet1-0/+32
syzbot found another way to trigger the infamous WARN_ON_ONCE(delta < len) in skb_try_coalesce() [1] I was able to root cause the issue to kfence. When kfence is in action, the following assertion is no longer true: int size = xxxx; void *ptr1 = kmalloc(size, gfp); void *ptr2 = kmalloc(size, gfp); if (ptr1 && ptr2) ASSERT(ksize(ptr1) == ksize(ptr2)); We attempted to fix these issues in the blamed commits, but forgot that TCP was possibly shifting data after skb_unclone_keeptruesize() has been used, notably from tcp_retrans_try_collapse(). So we not only need to keep same skb->truesize value, we also need to make sure TCP wont fill new tailroom that pskb_expand_head() was able to get from a addr = kmalloc(...) followed by ksize(addr) Split skb_unclone_keeptruesize() into two parts: 1) Inline skb_unclone_keeptruesize() for the common case, when skb is not cloned. 2) Out of line __skb_unclone_keeptruesize() for the 'slow path'. WARNING: CPU: 1 PID: 6490 at net/core/skbuff.c:5295 skb_try_coalesce+0x1235/0x1560 net/core/skbuff.c:5295 Modules linked in: CPU: 1 PID: 6490 Comm: syz-executor161 Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_try_coalesce+0x1235/0x1560 net/core/skbuff.c:5295 Code: bf 01 00 00 00 0f b7 c0 89 c6 89 44 24 20 e8 62 24 4e fa 8b 44 24 20 83 e8 01 0f 85 e5 f0 ff ff e9 87 f4 ff ff e8 cb 20 4e fa <0f> 0b e9 06 f9 ff ff e8 af b2 95 fa e9 69 f0 ff ff e8 95 b2 95 fa RSP: 0018:ffffc900063af268 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 00000000ffffffd5 RCX: 0000000000000000 RDX: ffff88806fc05700 RSI: ffffffff872abd55 RDI: 0000000000000003 RBP: ffff88806e675500 R08: 00000000ffffffd5 R09: 0000000000000000 R10: ffffffff872ab659 R11: 0000000000000000 R12: ffff88806dd554e8 R13: ffff88806dd9bac0 R14: ffff88806dd9a2c0 R15: 0000000000000155 FS: 00007f18014f9700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002000 CR3: 000000006be7a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_try_coalesce net/ipv4/tcp_input.c:4651 [inline] tcp_try_coalesce+0x393/0x920 net/ipv4/tcp_input.c:4630 tcp_queue_rcv+0x8a/0x6e0 net/ipv4/tcp_input.c:4914 tcp_data_queue+0x11fd/0x4bb0 net/ipv4/tcp_input.c:5025 tcp_rcv_established+0x81e/0x1ff0 net/ipv4/tcp_input.c:5947 tcp_v4_do_rcv+0x65e/0x980 net/ipv4/tcp_ipv4.c:1719 sk_backlog_rcv include/net/sock.h:1037 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2779 release_sock+0x54/0x1b0 net/core/sock.c:3311 sk_wait_data+0x177/0x450 net/core/sock.c:2821 tcp_recvmsg_locked+0xe28/0x1fd0 net/ipv4/tcp.c:2457 tcp_recvmsg+0x137/0x610 net/ipv4/tcp.c:2572 inet_recvmsg+0x11b/0x5e0 net/ipv4/af_inet.c:850 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] sock_recvmsg net/socket.c:962 [inline] ____sys_recvmsg+0x2c4/0x600 net/socket.c:2632 ___sys_recvmsg+0x127/0x200 net/socket.c:2674 __sys_recvmsg+0xe2/0x1a0 net/socket.c:2704 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: c4777efa751d ("net: add and use skb_unclone_keeptruesize() helper") Fixes: 097b9146c0e2 ("net: fix up truesize of cloned skb in skb_prepare_for_shift()") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-22net: add skb_set_end_offset() helperEric Dumazet1-14/+5
We have multiple places where this helper is convenient, and plan using it in the following patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-22net: __pskb_pull_tail() & pskb_carve_frag_list() drop_monitor friendsEric Dumazet1-2/+2
Whenever one of these functions pull all data from an skb in a frag_list, use consume_skb() instead of kfree_skb() to avoid polluting drop monitoring. Fixes: 6fa01ccd8830 ("skbuff: Add pskb_extract() helper function") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220220154052.1308469-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-18net-timestamp: convert sk->sk_tskey to atomic_tEric Dumazet1-1/+1
UDP sendmsg() can be lockless, this is causing all kinds of data races. This patch converts sk->sk_tskey to remove one of these races. BUG: KCSAN: data-race in __ip_append_data / __ip_append_data read to 0xffff8881035d4b6c of 4 bytes by task 8877 on cpu 1: __ip_append_data+0x1c1/0x1de0 net/ipv4/ip_output.c:994 ip_make_skb+0x13f/0x2d0 net/ipv4/ip_output.c:1636 udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff8881035d4b6c of 4 bytes by task 8880 on cpu 0: __ip_append_data+0x1d8/0x1de0 net/ipv4/ip_output.c:994 ip_make_skb+0x13f/0x2d0 net/ipv4/ip_output.c:1636 udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000054d -> 0x0000054e Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8880 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 09c2d251b707 ("net-timestamp: add key to disambiguate concurrent datagrams") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-10skbuff: cleanup double word in commentTom Rix1-1/+1
Remove the second 'to'. Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-09net: skb: introduce kfree_skb_reason()Menglong Dong1-5/+7
Introduce the interface kfree_skb_reason(), which is able to pass the reason why the skb is dropped to 'kfree_skb' tracepoint. Add the 'reason' field to 'trace_kfree_skb', therefor user can get more detail information about abnormal skb with 'drop_monitor' or eBPF. All drop reasons are defined in the enum 'skb_drop_reason', and they will be print as string in 'kfree_skb' tracepoint in format of 'reason: XXX'. ( Maybe the reasons should be defined in a uapi header file, so that user space can use them? ) Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-29Merge tag 'for-net-next-2021-12-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-nextJakub Kicinski1-0/+24
Luiz Augusto von Dentz says: ==================== bluetooth-next pull request for net-next: - Add support for Foxconn MT7922A - Add support for Realtek RTL8852AE - Rework HCI event handling to use skb_pull_data * tag 'for-net-next-2021-12-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next: (62 commits) Bluetooth: MGMT: Fix spelling mistake "simultanous" -> "simultaneous" Bluetooth: vhci: Set HCI_QUIRK_VALID_LE_STATES Bluetooth: MGMT: Fix LE simultaneous roles UUID if not supported Bluetooth: hci_sync: Add check simultaneous roles support Bluetooth: hci_sync: Wait for proper events when connecting LE Bluetooth: hci_sync: Add support for waiting specific LE subevents Bluetooth: hci_sync: Add hci_le_create_conn_sync Bluetooth: hci_event: Use skb_pull_data when processing inquiry results Bluetooth: hci_sync: Push sync command cancellation to workqueue Bluetooth: hci_qca: Stop IBS timer during BT OFF Bluetooth: btusb: Add support for Foxconn MT7922A Bluetooth: btintel: Add missing quirks and msft ext for legacy bootloader Bluetooth: btusb: Add two more Bluetooth parts for WCN6855 Bluetooth: L2CAP: Fix using wrong mode Bluetooth: hci_sync: Fix not always pausing advertising when necessary Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_CONNECTED Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_FOUND Bluetooth: mgmt: Introduce mgmt_alloc_skb and mgmt_send_event_skb Bluetooth: btusb: Return error code when getting patch status failed Bluetooth: btusb: Handle download_firmware failure cases ... ==================== Link: https://lore.kernel.org/r/20211229211258.2290966-1-luiz.dentz@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+1
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-16net: Fix double 0x prefix print in SKB dumpGal Pressman1-1/+1
When printing netdev features %pNF already takes care of the 0x prefix, remove the explicit one. Fixes: 6413139dfc64 ("skbuff: increase verbosity when dumping skb data") Signed-off-by: Gal Pressman <gal@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-07skbuff: introduce skb_pull_dataLuiz Augusto von Dentz1-0/+24
Like skb_pull but returns the original data pointer before pulling the data after performing a check against sbk->len. This allows to change code that does "struct foo *p = (void *)skb->data;" which is hard to audit and error prone, to: p = skb_pull_data(skb, sizeof(*p)); if (!p) return; Which is both safer and cleaner. Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>