kernel/linux.git/net/core, branch linux-6.0.y

bpf: pull before calling skb_postpull_rcsum()

2023-01-12T11:00:29+00:00

[ Upstream commit 54c3f1a81421f85e60ae2eaae7be3727a09916ee ] Anand hit a BUG() when pulling off headers on egress to a SW tunnel. We get to skb_checksum_help() with an invalid checksum offset (commit d7ea0d9df2a6 ("net: remove two BUG() from skb_checksum_help()") converted those BUGs to WARN_ONs()). He points out oddness in how skb_postpull_rcsum() gets used. Indeed looks like we should pull before "postpull", otherwise the CHECKSUM_PARTIAL fixup from skb_postpull_rcsum() will not be able to do its job: if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_start_offset(skb) < 0) skb->ip_summed = CHECKSUM_NONE; Reported-by: Anand Parthasarathy Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper") Signed-off-by: Jakub Kicinski Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20221220004701.402165-1-kuba@kernel.org Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

net: add atomic_long_t to net_device_stats fields

2022-12-31T12:26:44+00:00

[ Upstream commit 6c1c5097781f563b70a81683ea6fdac21637573b ] Long standing KCSAN issues are caused by data-race around some dev->stats changes. Most performance critical paths already use per-cpu variables, or per-queue ones. It is reasonable (and more correct) to use atomic operations for the slow paths. This patch adds an union for each field of net_device_stats, so that we can convert paths that are not yet protected by a spinlock or a mutex. netdev_stats_to_stats64() no longer has an #if BITS_PER_LONG==64 Note that the memcpy() we were using on 64bit arches had no provision to avoid load-tearing, while atomic_long_read() is providing the needed protection at no cost. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

bpf: make sure skb->len != 0 when redirecting to a tunneling device

2022-12-31T12:26:43+00:00

[ Upstream commit 07ec7b502800ba9f7b8b15cb01dd6556bb41aaca ] syzkaller managed to trigger another case where skb->len == 0 when we enter __dev_queue_xmit: WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 skb_assert_len include/linux/skbuff.h:2576 [inline] WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 __dev_queue_xmit+0x2069/0x35e0 net/core/dev.c:4295 Call Trace: dev_queue_xmit+0x17/0x20 net/core/dev.c:4406 __bpf_tx_skb net/core/filter.c:2115 [inline] __bpf_redirect_no_mac net/core/filter.c:2140 [inline] __bpf_redirect+0x5fb/0xda0 net/core/filter.c:2163 ____bpf_clone_redirect net/core/filter.c:2447 [inline] bpf_clone_redirect+0x247/0x390 net/core/filter.c:2419 bpf_prog_48159a89cb4a9a16+0x59/0x5e bpf_dispatcher_nop_func include/linux/bpf.h:897 [inline] __bpf_prog_run include/linux/filter.h:596 [inline] bpf_prog_run include/linux/filter.h:603 [inline] bpf_test_run+0x46c/0x890 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xbdc/0x14c0 net/bpf/test_run.c:1170 bpf_prog_test_run+0x345/0x3c0 kernel/bpf/syscall.c:3648 __sys_bpf+0x43a/0x6c0 kernel/bpf/syscall.c:5005 __do_sys_bpf kernel/bpf/syscall.c:5091 [inline] __se_sys_bpf kernel/bpf/syscall.c:5089 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5089 do_syscall_64+0x54/0x70 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x61/0xc6 The reproducer doesn't really reproduce outside of syzkaller environment, so I'm taking a guess here. It looks like we do generate correct ETH_HLEN-sized packet, but we redirect the packet to the tunneling device. Before we do so, we __skb_pull l2 header and arrive again at skb->len == 0. Doesn't seem like we can do anything better than having an explicit check after __skb_pull? Cc: Eric Dumazet Reported-by: syzbot+f635e86ec3fa0a37e019@syzkaller.appspotmail.com Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20221027225537.353077-1-sdf@google.com Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

net: stream: purge sk_error_queue in sk_stream_kill_queues()

2022-12-31T12:26:39+00:00

[ Upstream commit e0c8bccd40fc1c19e1d246c39bcf79e357e1ada3 ] Changheon Lee reported TCP socket leaks, with a nice repro. It seems we leak TCP sockets with the following sequence: 1) SOF_TIMESTAMPING_TX_ACK is enabled on the socket. Each ACK will cook an skb put in error queue, from __skb_tstamp_tx(). __skb_tstamp_tx() is using skb_clone(), unless SOF_TIMESTAMPING_OPT_TSONLY was also requested. 2) If the application is also using MSG_ZEROCOPY, then we put in the error queue cloned skbs that had a struct ubuf_info attached to them. Whenever an struct ubuf_info is allocated, sock_zerocopy_alloc() does a sock_hold(). As long as the cloned skbs are still in sk_error_queue, socket refcount is kept elevated. 3) Application closes the socket, while error queue is not empty. Since tcp_close() no longer purges the socket error queue, we might end up with a TCP socket with at least one skb in error queue keeping the socket alive forever. This bug can be (ab)used to consume all kernel memory and freeze the host. We need to purge the error queue, with proper synchronization against concurrent writers. Fixes: 24bcbe1cc69f ("net: stream: don't purge sk_error_queue in sk_stream_kill_queues()") Reported-by: Changheon Lee Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

skbuff: Account for tail adjustment during pull operations

2022-12-31T12:26:39+00:00

[ Upstream commit 2d7afdcbc9d32423f177ee12b7c93783aea338fb ] Extending the tail can have some unexpected side effects if a program uses a helper like BPF_FUNC_skb_pull_data to read partial content beyond the head skb headlen when all the skbs in the gso frag_list are linear with no head_frag - kernel BUG at net/core/skbuff.c:4219! pc : skb_segment+0xcf4/0xd2c lr : skb_segment+0x63c/0xd2c Call trace: skb_segment+0xcf4/0xd2c __udp_gso_segment+0xa4/0x544 udp4_ufo_fragment+0x184/0x1c0 inet_gso_segment+0x16c/0x3a4 skb_mac_gso_segment+0xd4/0x1b0 __skb_gso_segment+0xcc/0x12c udp_rcv_segment+0x54/0x16c udp_queue_rcv_skb+0x78/0x144 udp_unicast_rcv_skb+0x8c/0xa4 __udp4_lib_rcv+0x490/0x68c udp_rcv+0x20/0x30 ip_protocol_deliver_rcu+0x1b0/0x33c ip_local_deliver+0xd8/0x1f0 ip_rcv+0x98/0x1a4 deliver_ptype_list_skb+0x98/0x1ec __netif_receive_skb_core+0x978/0xc60 Fix this by marking these skbs as GSO_DODGY so segmentation can handle the tail updates accordingly. Fixes: 3dcbdb134f32 ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list") Signed-off-by: Sean Tranchetti Signed-off-by: Subash Abhinov Kasiviswanathan Reviewed-by: Alexander Duyck Link: https://lore.kernel.org/r/1671084718-24796-1-git-send-email-quic_subashab@quicinc.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

devlink: protect devlink dump by the instance lock

2022-12-31T12:26:39+00:00

[ Upstream commit 214964a13ab56a9757d146b79b468a7ca190fbfb ] Take the instance lock around devlink_nl_fill() when dumping, doit takes it already. We are only dumping basic info so in the worst case we were risking data races around the reload statistics. Until the big devlink mutex was removed all relevant code was protected by it, so the missing instance lock was not exposed. Fixes: d3efc2a6a6d8 ("net: devlink: remove devlink_mutex") Reviewed-by: Jiri Pirko Reviewed-by: Jacob Keller Link: https://lore.kernel.org/r/20221216044122.1863550-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

devlink: hold region lock when flushing snapshots

2022-12-31T12:26:38+00:00

[ Upstream commit b4cafb3d2c740f8d1b1234b43ac4a60e5291c960 ] Netdevsim triggers a splat on reload, when it destroys regions with snapshots pending: WARNING: CPU: 1 PID: 787 at net/core/devlink.c:6291 devlink_region_snapshot_del+0x12e/0x140 CPU: 1 PID: 787 Comm: devlink Not tainted 6.1.0-07460-g7ae9888d6e1c #580 RIP: 0010:devlink_region_snapshot_del+0x12e/0x140 Call Trace: devl_region_destroy+0x70/0x140 nsim_dev_reload_down+0x2f/0x60 [netdevsim] devlink_reload+0x1f7/0x360 devlink_nl_cmd_reload+0x6ce/0x860 genl_family_rcv_msg_doit.isra.0+0x145/0x1c0 This is the locking assert in devlink_region_snapshot_del(), we're supposed to be holding the region->snapshot_lock here. Fixes: 2dec18ad826f ("net: devlink: remove region snapshots list dependency on devlink->lock") Signed-off-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: Remove the obsolte u64_stats_fetch_*_irq() users (net).

2022-12-31T12:26:12+00:00

[ Upstream commit d120d1a63b2c484d6175873d8ee736a633f74b70 ] Now that the 32bit UP oddity is gone and 32bit uses always a sequence count, there is no need for the fetch_irq() variants anymore. Convert to the regular interface. Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Acked-by: Peter Zijlstra (Intel) Signed-off-by: Jakub Kicinski Stable-dep-of: 1dbd8d9a82e3 ("ipvs: use u64_stats_t for the per-cpu counters") Signed-off-by: Sasha Levin

bpf, sockmap: fix race in sock_map_free()

2022-12-31T12:26:09+00:00

[ Upstream commit 0a182f8d607464911756b4dbef5d6cad8de22469 ] sock_map_free() calls release_sock(sk) without owning a reference on the socket. This can cause use-after-free as syzbot found [1] Jakub Sitnicki already took care of a similar issue in sock_hash_free() in commit 75e68e5bf2c7 ("bpf, sockhash: Synchronize delete from bucket list on map free") [1] refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 0 PID: 3785 at lib/refcount.c:31 refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 Modules linked in: CPU: 0 PID: 3785 Comm: kworker/u4:6 Not tainted 6.1.0-rc7-syzkaller-00103-gef4d3ea40565 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_unbound bpf_map_free_deferred RIP: 0010:refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 Code: 68 8b 31 c0 e8 75 71 15 fd 0f 0b e9 64 ff ff ff e8 d9 6e 4e fd c6 05 62 9c 3d 0a 01 48 c7 c7 80 bb 68 8b 31 c0 e8 54 71 15 fd <0f> 0b e9 43 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a2 fe ff RSP: 0018:ffffc9000456fb60 EFLAGS: 00010246 RAX: eae59bab72dcd700 RBX: 0000000000000004 RCX: ffff8880207057c0 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: 0000000000000004 R08: ffffffff816fdabd R09: fffff520008adee5 R10: fffff520008adee5 R11: 1ffff920008adee4 R12: 0000000000000004 R13: dffffc0000000000 R14: ffff88807b1c6c00 R15: 1ffff1100f638dcf FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30c30000 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] __sock_put include/net/sock.h:779 [inline] tcp_release_cb+0x2d0/0x360 net/ipv4/tcp_output.c:1092 release_sock+0xaf/0x1c0 net/core/sock.c:3468 sock_map_free+0x219/0x2c0 net/core/sock_map.c:356 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Jakub Sitnicki Cc: John Fastabend Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Song Liu Acked-by: John Fastabend Link: https://lore.kernel.org/r/20221202111640.2745533-1-edumazet@google.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes

2022-12-31T12:26:06+00:00

[ Upstream commit a351d6087bf7d3d8440d58d3bf244ec64b89394a ] When redirecting, we use sk_msg_to_ingress() to get the BPF_F_INGRESS flag from the msg->flags. If apply_bytes is used and it is larger than the current data being processed, sk_psock_msg_verdict() will not be called when sendmsg() is called again. At this time, the msg->flags is 0, and we lost the BPF_F_INGRESS flag. So we need to save the BPF_F_INGRESS flag in sk_psock and use it when redirection. Fixes: 8934ce2fd081 ("bpf: sockmap redirect ingress support") Signed-off-by: Pengcheng Yang Signed-off-by: Daniel Borkmann Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/1669718441-2654-3-git-send-email-yangpc@wangsu.com Signed-off-by: Sasha Levin