kernel/git/stable/linux.git/net/can/raw.c, branch linux-4.9.y

can: raw: raw_setsockopt(): fix raw_rcv panic for sock UAF

2021-08-08T06:38:54+00:00

commit 54f93336d000229f72c26d8a3f69dd256b744528 upstream. We get a bug during ltp can_filter test as following. =========================================== [60919.264984] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [60919.265223] PGD 8000003dda726067 P4D 8000003dda726067 PUD 3dda727067 PMD 0 [60919.265443] Oops: 0000 [#1] SMP PTI [60919.265550] CPU: 30 PID: 3638365 Comm: can_filter Kdump: loaded Tainted: G W 4.19.90+ #1 [60919.266068] RIP: 0010:selinux_socket_sock_rcv_skb+0x3e/0x200 [60919.293289] RSP: 0018:ffff8d53bfc03cf8 EFLAGS: 00010246 [60919.307140] RAX: 0000000000000000 RBX: 000000000000001d RCX: 0000000000000007 [60919.320756] RDX: 0000000000000001 RSI: ffff8d5104a8ed00 RDI: ffff8d53bfc03d30 [60919.334319] RBP: ffff8d9338056800 R08: ffff8d53bfc29d80 R09: 0000000000000001 [60919.347969] R10: ffff8d53bfc03ec0 R11: ffffb8526ef47c98 R12: ffff8d53bfc03d30 [60919.350320] perf: interrupt took too long (3063 > 2500), lowering kernel.perf_event_max_sample_rate to 65000 [60919.361148] R13: 0000000000000001 R14: ffff8d53bcf90000 R15: 0000000000000000 [60919.361151] FS: 00007fb78b6b3600(0000) GS:ffff8d53bfc00000(0000) knlGS:0000000000000000 [60919.400812] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [60919.413730] CR2: 0000000000000010 CR3: 0000003e3f784006 CR4: 00000000007606e0 [60919.426479] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [60919.439339] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [60919.451608] PKRU: 55555554 [60919.463622] Call Trace: [60919.475617] [60919.487122] ? update_load_avg+0x89/0x5d0 [60919.498478] ? update_load_avg+0x89/0x5d0 [60919.509822] ? account_entity_enqueue+0xc5/0xf0 [60919.520709] security_sock_rcv_skb+0x2a/0x40 [60919.531413] sk_filter_trim_cap+0x47/0x1b0 [60919.542178] ? kmem_cache_alloc+0x38/0x1b0 [60919.552444] sock_queue_rcv_skb+0x17/0x30 [60919.562477] raw_rcv+0x110/0x190 [can_raw] [60919.572539] can_rcv_filter+0xbc/0x1b0 [can] [60919.582173] can_receive+0x6b/0xb0 [can] [60919.591595] can_rcv+0x31/0x70 [can] [60919.600783] __netif_receive_skb_one_core+0x5a/0x80 [60919.609864] process_backlog+0x9b/0x150 [60919.618691] net_rx_action+0x156/0x400 [60919.627310] ? sched_clock_cpu+0xc/0xa0 [60919.635714] __do_softirq+0xe8/0x2e9 [60919.644161] do_softirq_own_stack+0x2a/0x40 [60919.652154] [60919.659899] do_softirq.part.17+0x4f/0x60 [60919.667475] __local_bh_enable_ip+0x60/0x70 [60919.675089] __dev_queue_xmit+0x539/0x920 [60919.682267] ? finish_wait+0x80/0x80 [60919.689218] ? finish_wait+0x80/0x80 [60919.695886] ? sock_alloc_send_pskb+0x211/0x230 [60919.702395] ? can_send+0xe5/0x1f0 [can] [60919.708882] can_send+0xe5/0x1f0 [can] [60919.715037] raw_sendmsg+0x16d/0x268 [can_raw] It's because raw_setsockopt() concurrently with unregister_netdevice_many(). Concurrent scenario as following. cpu0 cpu1 raw_bind raw_setsockopt unregister_netdevice_many unlist_netdevice dev_get_by_index raw_notifier raw_enable_filters ...... can_rx_register can_rcv_list_find(..., net->can.rx_alldev_list) ...... sock_close raw_release(sock_a) ...... can_receive can_rcv_filter(net->can.rx_alldev_list, ...) raw_rcv(skb, sock_a) BUG After unlist_netdevice(), dev_get_by_index() return NULL in raw_setsockopt(). Function raw_enable_filters() will add sock and can_filter to net->can.rx_alldev_list. Then the sock is closed. Followed by, we sock_sendmsg() to a new vcan device use the same can_filter. Protocol stack match the old receiver whose sock has been released on net->can.rx_alldev_list in can_rcv_filter(). Function raw_rcv() uses the freed sock. UAF BUG is triggered. We can find that the key issue is that net_device has not been protected in raw_setsockopt(). Use rtnl_lock to protect net_device in raw_setsockopt(). Fixes: c18ce101f2e4 ("[CAN]: Add raw protocol") Link: https://lore.kernel.org/r/20210722070819.1048263-1-william.xuanziyang@huawei.com Cc: linux-stable Signed-off-by: Ziyang Xuan Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: bcm/raw/isotp: use per module netdevice notifier

2021-06-30T12:49:18+00:00

commit 8d0caedb759683041d9db82069937525999ada53 upstream. syzbot is reporting hung task at register_netdevice_notifier() [1] and unregister_netdevice_notifier() [2], for cleanup_net() might perform time consuming operations while CAN driver's raw/bcm/isotp modules are calling {register,unregister}_netdevice_notifier() on each socket. Change raw/bcm/isotp modules to call register_netdevice_notifier() from module's __init function and call unregister_netdevice_notifier() from module's __exit function, as with gw/j1939 modules are doing. Link: https://syzkaller.appspot.com/bug?id=391b9498827788b3cc6830226d4ff5be87107c30 [1] Link: https://syzkaller.appspot.com/bug?id=1724d278c83ca6e6df100a2e320c10d991cf2bce [2] Link: https://lore.kernel.org/r/54a5f451-05ed-f977-8534-79e7aa2bcc8f@i-love.sakura.ne.jp Cc: linux-stable Reported-by: syzbot Reported-by: syzbot Reviewed-by: Kirill Tkhai Tested-by: syzbot Tested-by: Oliver Hartkopp Signed-off-by: Tetsuo Handa Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: Fix kernel panic at security_sock_rcv_skb

2017-02-18T14:11:40+00:00

[ Upstream commit f1712c73714088a7252d276a57126d56c7d37e64 ] Zhang Yanmin reported crashes [1] and provided a patch adding a synchronize_rcu() call in can_rx_unregister() The main problem seems that the sockets themselves are not RCU protected. If CAN uses RCU for delivery, then sockets should be freed only after one RCU grace period. Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's ease stable backports with the following fix instead. [1] BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] selinux_socket_sock_rcv_skb+0x65/0x2a0 Call Trace: [] security_sock_rcv_skb+0x4c/0x60 [] sk_filter+0x41/0x210 [] sock_queue_rcv_skb+0x53/0x3a0 [] raw_rcv+0x2a3/0x3c0 [] can_rcv_filter+0x12b/0x370 [] can_receive+0xd9/0x120 [] can_rcv+0xab/0x100 [] __netif_receive_skb_core+0xd8c/0x11f0 [] __netif_receive_skb+0x24/0xb0 [] process_backlog+0x127/0x280 [] net_rx_action+0x33b/0x4f0 [] __do_softirq+0x184/0x440 [] do_softirq_own_stack+0x1c/0x30 [] do_softirq.part.18+0x3b/0x40 [] do_softirq+0x1d/0x20 [] netif_rx_ni+0xe5/0x110 [] slcan_receive_buf+0x507/0x520 [] flush_to_ldisc+0x21c/0x230 [] process_one_work+0x24f/0x670 [] worker_thread+0x9d/0x6f0 [] ? rescuer_thread+0x480/0x480 [] kthread+0x12c/0x150 [] ret_from_fork+0x3f/0x70 Reported-by: Zhang Yanmin Signed-off-by: Eric Dumazet Acked-by: Oliver Hartkopp Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

can: raw: raw_setsockopt: limit number of can_filter that can be set

2016-12-07T09:45:57+00:00

This patch adds a check to limit the number of can_filters that can be set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER are not prevented resulting in a warning. Reference: https://lkml.org/lkml/2016/12/2/230 Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Cc: linux-stable Signed-off-by: Marc Kleine-Budde

sock: enable timestamping using control messages

2016-04-04T19:50:30+00:00

Currently, SOL_TIMESTAMPING can only be enabled using setsockopt. This is very costly when users want to sample writes to gather tx timestamps. Add support for enabling SO_TIMESTAMPING via control messages by using tsflags added in `struct sockcm_cookie` (added in the previous patches in this series) to set the tx_flags of the last skb created in a sendmsg. With this patch, the timestamp recording bits in tx_flags of the skbuff is overridden if SO_TIMESTAMPING is passed in a cmsg. Please note that this is only effective for overriding the recording timestamps flags. Users should enable timestamp reporting (e.g., SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID) using socket options and then should ask for SOF_TIMESTAMPING_TX_* using control messages per sendmsg to sample timestamps for each write. Signed-off-by: Soheil Hassas Yeganeh Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

can: replace timestamp as unique skb attribute

2015-07-12T19:13:22+00:00

Commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for overlapping CAN filters" requires the skb->tstamp to be set to check for identical CAN skbs. Without timestamping to be required by user space applications this timestamp was not generated which lead to commit 36c01245eb8 "can: fix loss of CAN frames in raw_rcv" - which forces the timestamp to be set in all CAN related skbuffs by introducing several __net_timestamp() calls. This forces e.g. out of tree drivers which are not using alloc_can{,fd}_skb() to add __net_timestamp() after skbuff creation to prevent the frame loss fixed in mainline Linux. This patch removes the timestamp dependency and uses an atomic counter to create an unique identifier together with the skbuff pointer. Btw: the new skbcnt element introduced in struct can_skb_priv has to be initialized with zero in out-of-tree drivers which are not using alloc_can{,fd}_skb() too. Signed-off-by: Oliver Hartkopp Cc: linux-stable Signed-off-by: Marc Kleine-Budde

can: introduce new raw socket option to join the given CAN filters

2015-04-01T09:28:22+00:00

The CAN_RAW socket can set multiple CAN identifier specific filters that lead to multiple filters in the af_can.c filter processing. These filters are indenpendent from each other which leads to logical OR'ed filters when applied. This socket option joines the given CAN filters in the way that only CAN frames are passed to user space that matched *all* given CAN filters. The semantic for the applied filters is therefore changed to a logical AND. This is useful especially when the filterset is a combination of filters where the CAN_INV_FILTER flag is set in order to notch single CAN IDs or CAN ID ranges from the incoming traffic. As the raw_rcv() function is executed from NET_RX softirq the introduced variables are implemented as per-CPU variables to avoid extensive locking at CAN frame reception time. Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde

can: fix multiple delivery of a single CAN frame for overlapping CAN filters

2015-04-01T09:27:41+00:00

The CAN_RAW socket can set multiple CAN identifier specific filters that lead to multiple filters in the af_can.c filter processing. These filters are indenpendent from each other which leads to logical OR'ed filters when applied. This patch makes sure that every CAN frame which is filtered for a specific socket is only delivered once to the user space. This is independent from the number of matching CAN filters of this socket. As the raw_rcv() function is executed from NET_RX softirq the introduced variables are implemented as per-CPU variables to avoid extensive locking at CAN frame reception time. Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde

net: Remove iocb argument from sendmsg and recvmsg

2015-03-02T18:06:31+00:00

After TIPC doesn't depend on iocb argument in its internal implementations of sendmsg() and recvmsg() hooks defined in proto structure, no any user is using iocb argument in them at all now. Then we can drop the redundant iocb argument completely from kinds of implementations of both sendmsg() and recvmsg() in the entire networking stack. Cc: Christoph Hellwig Suggested-by: Al Viro Signed-off-by: Ying Xue Signed-off-by: David S. Miller

net: use common macro for assering skb->cb[] available size in protocol families

2015-03-02T05:19:30+00:00

As part of an effort to move skb->dropcount to skb->cb[] use a common macro in protocol families using skb->cb[] for ancillary data to validate available room in skb->cb[]. Signed-off-by: Eyal Birger Signed-off-by: David S. Miller