linux/net/core, branch v6.0

Revert "net: set proper memcg for net_init hooks allocations"

2022-09-28T16:20:37Z

This reverts commit 1d0403d20f6c281cb3d14c5f1db5317caeec48e9. Anatoly Pugachev reported that the commit 1d0403d20f6c ("net: set proper memcg for net_init hooks allocations") is somehow causing the sparc64 VMs failed to boot and the VMs boot fine with that patch reverted. So, revert the patch for now and later we can debug the issue. Link: https://lore.kernel.org/all/20220918092849.GA10314@u164.east.ru/ Reported-by: Anatoly Pugachev Signed-off-by: Shakeel Butt Cc: Vasily Averin Cc: Jakub Kicinski Cc: Michal Koutný Cc: Andrew Morton Cc: cgroups@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Tested-by: Anatoly Pugachev Acked-by: Johannes Weiner Fixes: 1d0403d20f6c ("net: set proper memcg for net_init hooks allocations") Reviewed-by: Muchun Song Acked-by: Roman Gushchin Signed-off-by: Linus Torvalds

net: core: fix flow symmetric hash

2022-09-09T11:48:00Z

__flow_hash_consistentify() wrongly swaps ipv4 addresses in few cases. This function is indirectly used by __skb_get_hash_symmetric(), which is used to fanout packets in AF_PACKET. Intrusion detection systems may be impacted by this issue. __flow_hash_consistentify() computes the addresses difference then swaps them if the difference is negative. In few cases src - dst and dst - src are both negative. The following snippet mimics __flow_hash_consistentify(): ``` #include #include int main(int argc, char** argv) { int diffs_d, diffd_s; uint32_t dst = 0xb225a8c0; /* 178.37.168.192 --> 192.168.37.178 */ uint32_t src = 0x3225a8c0; /* 50.37.168.192 --> 192.168.37.50 */ uint32_t dst2 = 0x3325a8c0; /* 51.37.168.192 --> 192.168.37.51 */ diffs_d = src - dst; diffd_s = dst - src; printf("src:%08x dst:%08x, diff(s-d)=%d(0x%x) diff(d-s)=%d(0x%x)\n", src, dst, diffs_d, diffs_d, diffd_s, diffd_s); diffs_d = src - dst2; diffd_s = dst2 - src; printf("src:%08x dst:%08x, diff(s-d)=%d(0x%x) diff(d-s)=%d(0x%x)\n", src, dst2, diffs_d, diffs_d, diffd_s, diffd_s); return 0; } ``` Results: src:3225a8c0 dst:b225a8c0, \ diff(s-d)=-2147483648(0x80000000) \ diff(d-s)=-2147483648(0x80000000) src:3225a8c0 dst:3325a8c0, \ diff(s-d)=-16777216(0xff000000) \ diff(d-s)=16777216(0x1000000) In the first case the addresses differences are always < 0, therefore __flow_hash_consistentify() always swaps, thus dst->src and src->dst packets have differents hashes. Fixes: c3f8324188fa8 ("net: Add full IPv6 addresses to flow_keys") Signed-off-by: Ludovic Cintrat Signed-off-by: David S. Miller

net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUM

2022-09-07T14:28:08Z

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 Signed-off-by: Menglong Dong Signed-off-by: David S. Miller

tcp: TX zerocopy should not sense pfmemalloc status

2022-09-02T11:29:02Z

We got a recent syzbot report [1] showing a possible misuse of pfmemalloc page status in TCP zerocopy paths. Indeed, for pages coming from user space or other layers, using page_is_pfmemalloc() is moot, and possibly could give false positives. There has been attempts to make page_is_pfmemalloc() more robust, but not using it in the first place in this context is probably better, removing cpu cycles. Note to stable teams : You need to backport 84ce071e38a6 ("net: introduce __skb_fill_page_desc_noacc") as a prereq. Race is more probable after commit c07aea3ef4d4 ("mm: add a signature in struct page") because page_is_pfmemalloc() is now using low order bit from page->lru.next, which can change more often than page->index. Low order bit should never be set for lru.next (when used as an anchor in LRU list), so KCSAN report is mostly a false positive. Backporting to older kernel versions seems not necessary. [1] BUG: KCSAN: data-race in lru_add_fn / tcp_build_frag write to 0xffffea0004a1d2c8 of 8 bytes by task 18600 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:105 [inline] lru_add_fn+0x440/0x520 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 folio_batch_add_and_move mm/swap.c:263 [inline] folio_add_lru+0xf1/0x140 mm/swap.c:490 filemap_add_folio+0xf8/0x150 mm/filemap.c:948 __filemap_get_folio+0x510/0x6d0 mm/filemap.c:1981 pagecache_get_page+0x26/0x190 mm/folio-compat.c:104 grab_cache_page_write_begin+0x2a/0x30 mm/folio-compat.c:116 ext4_da_write_begin+0x2dd/0x5f0 fs/ext4/inode.c:2988 generic_perform_write+0x1d4/0x3f0 mm/filemap.c:3738 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270 ext4_file_write_iter+0x2e3/0x1210 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x468/0x760 fs/read_write.c:578 ksys_write+0xe8/0x1a0 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write fs/read_write.c:640 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:640 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 0xffffea0004a1d2c8 of 8 bytes by task 18611 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1740 [inline] __skb_fill_page_desc include/linux/skbuff.h:2422 [inline] skb_fill_page_desc include/linux/skbuff.h:2443 [inline] tcp_build_frag+0x613/0xb20 net/ipv4/tcp.c:1018 do_tcp_sendpages+0x3e8/0xaf0 net/ipv4/tcp.c:1075 tcp_sendpage_locked net/ipv4/tcp.c:1140 [inline] tcp_sendpage+0x89/0xb0 net/ipv4/tcp.c:1150 inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833 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:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1303 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303 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 -> 0xffffea0004a1d288 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 18611 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Fixes: c07aea3ef4d4 ("mm: add a signature in struct page") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Shakeel Butt Reviewed-by: Shakeel Butt Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2022-08-26T11:19:09Z

Daniel borkmann says: ==================== The following pull-request contains BPF updates for your *net* tree. We've added 11 non-merge commits during the last 14 day(s) which contain a total of 13 files changed, 61 insertions(+), 24 deletions(-). The main changes are: 1) Fix BPF verifier's precision tracking around BPF ring buffer, from Kumar Kartikeya Dwivedi. 2) Fix regression in tunnel key infra when passing FLOWI_FLAG_ANYSRC, from Eyal Birger. 3) Fix insufficient permissions for bpf_sys_bpf() helper, from YiFei Zhu. 4) Fix splat from hitting BUG when purging effective cgroup programs, from Pu Lehui. 5) Fix range tracking for array poke descriptors, from Daniel Borkmann. 6) Fix corrupted packets for XDP_SHARED_UMEM in aligned mode, from Magnus Karlsson. 7) Fix NULL pointer splat in BPF sockmap sk_msg_recvmsg(), from Liu Jian. 8) Add READ_ONCE() to bpf_jit_limit when reading from sysctl, from Kuniyuki Iwashima. 9) Add BPF selftest lru_bug check to s390x deny list, from Daniel Müller. ==================== Signed-off-by: David S. Miller

net: Fix a data-race around netdev_unregister_timeout_secs.

2022-08-24T12:46:58Z

While reading netdev_unregister_timeout_secs, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 5aa3afe107d9 ("net: make unregister netdev warning timeout configurable") Signed-off-by: Kuniyuki Iwashima Acked-by: Dmitry Vyukov Signed-off-by: David S. Miller

net: Fix a data-race around netdev_budget_usecs.

2022-08-24T12:46:58Z

While reading netdev_budget_usecs, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Fix a data-race around netdev_budget.

2022-08-24T12:46:58Z

While reading netdev_budget, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 51b0bdedb8e7 ("[NET]: Separate two usages of netdev_max_backlog.") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Fix a data-race around sysctl_net_busy_read.

2022-08-24T12:46:58Z

While reading sysctl_net_busy_read, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 2d48d67fa8cd ("net: poll/select low latency socket support") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: Fix a data-race around sysctl_tstamp_allow_data.

2022-08-24T12:46:58Z

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 Signed-off-by: David S. Miller