lwn.git/net/llc/af_llc.c, branch v5.13-rc7

net: pass a sockptr_t into ->setsockopt

2020-07-24T22:41:54+00:00

Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig Acked-by: Stefan Schmidt [ieee802154] Acked-by: Matthieu Baerts Signed-off-by: David S. Miller

net: llc: kerneldoc fixes

2020-07-14T00:20:39+00:00

Simple fixes which require no deep knowledge of the code. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller

llc: make sure applications use ARPHRD_ETHER

2020-06-29T04:41:23+00:00

syzbot was to trigger a bug by tricking AF_LLC with non sensible addr->sllc_arphrd It seems clear LLC requires an Ethernet device. Back in commit abf9d537fea2 ("llc: add support for SO_BINDTODEVICE") Octavian Purdila added possibility for application to use a zero value for sllc_arphrd, convert it to ARPHRD_ETHER to not cause regressions on existing applications. BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:199 [inline] BUG: KASAN: use-after-free in list_empty include/linux/list.h:268 [inline] BUG: KASAN: use-after-free in waitqueue_active include/linux/wait.h:126 [inline] BUG: KASAN: use-after-free in wq_has_sleeper include/linux/wait.h:160 [inline] BUG: KASAN: use-after-free in skwq_has_sleeper include/net/sock.h:2092 [inline] BUG: KASAN: use-after-free in sock_def_write_space+0x642/0x670 net/core/sock.c:2813 Read of size 8 at addr ffff88801e0b4078 by task ksoftirqd/3/27 CPU: 3 PID: 27 Comm: ksoftirqd/3 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 __read_once_size include/linux/compiler.h:199 [inline] list_empty include/linux/list.h:268 [inline] waitqueue_active include/linux/wait.h:126 [inline] wq_has_sleeper include/linux/wait.h:160 [inline] skwq_has_sleeper include/net/sock.h:2092 [inline] sock_def_write_space+0x642/0x670 net/core/sock.c:2813 sock_wfree+0x1e1/0x260 net/core/sock.c:1958 skb_release_head_state+0xeb/0x260 net/core/skbuff.c:652 skb_release_all+0x16/0x60 net/core/skbuff.c:663 __kfree_skb net/core/skbuff.c:679 [inline] consume_skb net/core/skbuff.c:838 [inline] consume_skb+0xfb/0x410 net/core/skbuff.c:832 __dev_kfree_skb_any+0xa4/0xd0 net/core/dev.c:2967 dev_kfree_skb_any include/linux/netdevice.h:3650 [inline] e1000_unmap_and_free_tx_resource.isra.0+0x21b/0x3a0 drivers/net/ethernet/intel/e1000/e1000_main.c:1963 e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3854 [inline] e1000_clean+0x4cc/0x1d10 drivers/net/ethernet/intel/e1000/e1000_main.c:3796 napi_poll net/core/dev.c:6532 [inline] net_rx_action+0x508/0x1120 net/core/dev.c:6600 __do_softirq+0x262/0x98c kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:603 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 8247: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3484 sock_alloc_inode+0x1c/0x1d0 net/socket.c:240 alloc_inode+0x68/0x1e0 fs/inode.c:230 new_inode_pseudo+0x19/0xf0 fs/inode.c:919 sock_alloc+0x41/0x270 net/socket.c:560 __sock_create+0xc2/0x730 net/socket.c:1384 sock_create net/socket.c:1471 [inline] __sys_socket+0x103/0x220 net/socket.c:1513 __do_sys_socket net/socket.c:1522 [inline] __se_sys_socket net/socket.c:1520 [inline] __ia32_sys_socket+0x73/0xb0 net/socket.c:1520 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 17: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:335 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3694 sock_free_inode+0x20/0x30 net/socket.c:261 i_callback+0x44/0x80 fs/inode.c:219 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2183 [inline] rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417 __do_softirq+0x262/0x98c kernel/softirq.c:292 The buggy address belongs to the object at ffff88801e0b4000 which belongs to the cache sock_inode_cache of size 1152 The buggy address is located 120 bytes inside of 1152-byte region [ffff88801e0b4000, ffff88801e0b4480) The buggy address belongs to the page: page:ffffea0000782d00 refcount:1 mapcount:0 mapping:ffff88807aa59c40 index:0xffff88801e0b4ffd raw: 00fffe0000000200 ffffea00008e6c88 ffffea0000782d48 ffff88807aa59c40 raw: ffff88801e0b4ffd ffff88801e0b4000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801e0b3f00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88801e0b3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801e0b4000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801e0b4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801e0b4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: abf9d537fea2 ("llc: add support for SO_BINDTODEVICE") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

af_llc: fix if-statement empty body warning

2020-02-27T04:38:13+00:00

When debugging via dprintk() is not enabled, make the dprintk() macro be an empty do-while loop, as is done in . This fixes a gcc warning when -Wextra is set: ../net/llc/af_llc.c:974:51: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] I have verified that there is not object code change (with gcc 7.5.0). Signed-off-by: Randy Dunlap Cc: netdev@vger.kernel.org Cc: "David S. Miller" Signed-off-by: David S. Miller

net: silence data-races on sk_backlog.tail

2019-11-07T05:35:34+00:00

sk->sk_backlog.tail might be read without holding the socket spinlock, we need to add proper READ_ONCE()/WRITE_ONCE() to silence the warnings. KCSAN reported : BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg write to 0xffff8881265109f8 of 8 bytes by interrupt on cpu 1: __sk_add_backlog include/net/sock.h:907 [inline] sk_add_backlog include/net/sock.h:938 [inline] tcp_add_backlog+0x476/0xce0 net/ipv4/tcp_ipv4.c:1759 tcp_v4_rcv+0x1a70/0x1bd0 net/ipv4/tcp_ipv4.c:1947 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:4929 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5043 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5133 napi_skb_finish net/core/dev.c:5596 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5629 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6311 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6379 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] do_IRQ+0xa6/0x180 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x19 native_safe_halt+0xe/0x10 arch/x86/kernel/paravirt.c:71 arch_cpu_idle+0x1f/0x30 arch/x86/kernel/process.c:571 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1af/0x280 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 start_secondary+0x208/0x260 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 read to 0xffff8881265109f8 of 8 bytes by task 8057 on cpu 0: tcp_recvmsg+0x46e/0x1b40 net/ipv4/tcp.c:2050 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1889 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x4c/0x60 fs/read_write.c:595 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8057 Comm: syz-fuzzer Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: use helpers to change sk_ack_backlog

2019-11-07T00:14:48+00:00

Writers are holding a lock, but many readers do not. Following patch will add appropriate barriers in sk_acceptq_removed() and sk_acceptq_added(). Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

llc: fix another potential sk_buff leak in llc_ui_sendmsg()

2019-10-08T20:23:05+00:00

All callers of llc_conn_state_process() except llc_build_and_send_pkt() (via llc_ui_sendmsg() -> llc_ui_send_data()) assume that it always consumes a reference to the skb. Fix this caller to do the same. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Biggers Signed-off-by: Jakub Kicinski

llc: Check address length before reading address field

2019-04-12T17:25:03+00:00

KMSAN will complain if valid address length passed to bind() is shorter than sizeof(struct sockaddr_llc) bytes. Signed-off-by: Tetsuo Handa Signed-off-by: David S. Miller

llc: do not use sk_eat_skb()

2018-10-23T02:59:20+00:00

syzkaller triggered a use-after-free [1], caused by a combination of skb_get() in llc_conn_state_process() and usage of sk_eat_skb() sk_eat_skb() is assuming the skb about to be freed is only used by the current thread. TCP/DCCP stacks enforce this because current thread holds the socket lock. llc_conn_state_process() wants to make sure skb does not disappear, and holds a reference on the skb it manipulates. But as soon as this skb is added to socket receive queue, another thread can consume it. This means that llc must use regular skb_unlink() and kfree_skb() so that both producer and consumer can safely work on the same skb. [1] BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline] BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:967 [inline] BUG: KASAN: use-after-free in kfree_skb+0xb7/0x580 net/core/skbuff.c:655 Read of size 4 at addr ffff8801d1f6fba4 by task ksoftirqd/1/18 CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.0-rc8+ #295 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b6 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_read include/linux/refcount.h:43 [inline] skb_unref include/linux/skbuff.h:967 [inline] kfree_skb+0xb7/0x580 net/core/skbuff.c:655 llc_sap_state_process+0x9b/0x550 net/llc/llc_sap.c:224 llc_sap_rcv+0x156/0x1f0 net/llc/llc_sap.c:297 llc_sap_handler+0x65e/0xf80 net/llc/llc_sap.c:438 llc_rcv+0x79e/0xe20 net/llc/llc_input.c:208 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023 process_backlog+0x218/0x6f0 net/core/dev.c:5829 napi_poll net/core/dev.c:6249 [inline] net_rx_action+0x7c5/0x1950 net/core/dev.c:6315 __do_softirq+0x30c/0xb03 kernel/softirq.c:292 run_ksoftirqd+0x94/0x100 kernel/softirq.c:653 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Allocated by task 18: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644 __alloc_skb+0x119/0x770 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:995 [inline] llc_alloc_frame+0xbc/0x370 net/llc/llc_sap.c:54 llc_station_ac_send_xid_r net/llc/llc_station.c:52 [inline] llc_station_rcv+0x1dc/0x1420 net/llc/llc_station.c:111 llc_rcv+0xc32/0xe20 net/llc/llc_input.c:220 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023 process_backlog+0x218/0x6f0 net/core/dev.c:5829 napi_poll net/core/dev.c:6249 [inline] net_rx_action+0x7c5/0x1950 net/core/dev.c:6315 __do_softirq+0x30c/0xb03 kernel/softirq.c:292 Freed by task 16383: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3756 kfree_skbmem+0x154/0x230 net/core/skbuff.c:582 __kfree_skb+0x1d/0x20 net/core/skbuff.c:642 sk_eat_skb include/net/sock.h:2366 [inline] llc_ui_recvmsg+0xec2/0x1610 net/llc/af_llc.c:882 sock_recvmsg_nosec net/socket.c:794 [inline] sock_recvmsg+0xd0/0x110 net/socket.c:801 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2278 __sys_recvmmsg+0x303/0xb90 net/socket.c:2390 do_sys_recvmmsg+0x181/0x1a0 net/socket.c:2466 __do_sys_recvmmsg net/socket.c:2484 [inline] __se_sys_recvmmsg net/socket.c:2480 [inline] __x64_sys_recvmmsg+0xbe/0x150 net/socket.c:2480 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801d1f6fac0 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 228 bytes inside of 232-byte region [ffff8801d1f6fac0, ffff8801d1f6fba8) The buggy address belongs to the page: page:ffffea000747dbc0 count:1 mapcount:0 mapping:ffff8801d9be7680 index:0xffff8801d1f6fe80 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0007346e88 ffffea000705b108 ffff8801d9be7680 raw: ffff8801d1f6fe80 ffff8801d1f6f0c0 000000010000000b 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d1f6fa80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801d1f6fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d1f6fb80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801d1f6fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d1f6fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL

2018-06-28T17:40:47+00:00

The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro Cc: Christoph Hellwig Signed-off-by: Linus Torvalds