BMC/Intel-BMC/linux.git/net, branch v5.4.20

bpf, sockmap: Check update requirements after locking

2020-02-14T21:34:10+00:00

commit 85b8ac01a421791d66c3a458a7f83cfd173fe3fa upstream. It's currently possible to insert sockets in unexpected states into a sockmap, due to a TOCTTOU when updating the map from a syscall. sock_map_update_elem checks that sk->sk_state == TCP_ESTABLISHED, locks the socket and then calls sock_map_update_common. At this point, the socket may have transitioned into another state, and the earlier assumptions don't hold anymore. Crucially, it's conceivable (though very unlikely) that a socket has become unhashed. This breaks the sockmap's assumption that it will get a callback via sk->sk_prot->unhash. Fix this by checking the (fixed) sk_type and sk_protocol without the lock, followed by a locked check of sk_state. Unfortunately it's not possible to push the check down into sock_(map|hash)_update_common, since BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB run before the socket has transitioned from TCP_SYN_RECV into TCP_ESTABLISHED. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Lorenz Bauer Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20200207103713.28175-1-lmb@cloudflare.com Signed-off-by: Greg Kroah-Hartman

bpf: Improve bucket_log calculation logic

2020-02-14T21:34:10+00:00

commit 88d6f130e5632bbf419a2e184ec7adcbe241260b upstream. It was reported that the max_t, ilog2, and roundup_pow_of_two macros have exponential effects on the number of states in the sparse checker. This patch breaks them up by calculating the "nbuckets" first so that the "bucket_log" only needs to take ilog2(). In addition, Linus mentioned: Patch looks good, but I'd like to point out that it's not just sparse. You can see it with a simple make net/core/bpf_sk_storage.i grep 'smap->bucket_log = ' net/core/bpf_sk_storage.i | wc and see the end result: 1 365071 2686974 That's one line (the assignment line) that is 2,686,974 characters in length. Now, sparse does happen to react particularly badly to that (I didn't look to why, but I suspect it's just that evaluating all the types that don't actually ever end up getting used ends up being much more expensive than it should be), but I bet it's not good for gcc either. Fixes: 6ac99e8f23d4 ("bpf: Introduce bpf sk local storage") Reported-by: Randy Dunlap Reported-by: Luc Van Oostenryck Suggested-by: Linus Torvalds Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Reviewed-by: Luc Van Oostenryck Link: https://lore.kernel.org/bpf/20200207081810.3918919-1-kafai@fb.com Signed-off-by: Greg Kroah-Hartman

bpf, sockhash: Synchronize_rcu before free'ing map

2020-02-14T21:34:09+00:00

commit 0b2dc83906cf1e694e48003eae5df8fa63f76fd9 upstream. We need to have a synchronize_rcu before free'ing the sockhash because any outstanding psock references will have a pointer to the map and when they use it, this could trigger a use after free. This is a sister fix for sockhash, following commit 2bb90e5cc90e ("bpf: sockmap, synchronize_rcu before free'ing map") which addressed sockmap, which comes from a manual audit. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200206111652.694507-3-jakub@cloudflare.com Signed-off-by: Greg Kroah-Hartman

bpf, sockmap: Don't sleep while holding RCU lock on tear-down

2020-02-14T21:34:09+00:00

commit db6a5018b6e008c1d69c6628cdaa9541b8e70940 upstream. rcu_read_lock is needed to protect access to psock inside sock_map_unref when tearing down the map. However, we can't afford to sleep in lock_sock while in RCU read-side critical section. Grab the RCU lock only after we have locked the socket. This fixes RCU warnings triggerable on a VM with 1 vCPU when free'ing a sockmap/sockhash that contains at least one socket: | ============================= | WARNING: suspicious RCU usage | 5.5.0-04005-g8fc91b972b73 #450 Not tainted | ----------------------------- | include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section! | | other info that might help us debug this: | | | rcu_scheduler_active = 2, debug_locks = 1 | 4 locks held by kworker/0:1/62: | #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0 | #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0 | #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_map_free+0x5/0x170 | #3: ffff8881368c5df8 (&stab->lock){+...}, at: sock_map_free+0x64/0x170 | | stack backtrace: | CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73 #450 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 | Workqueue: events bpf_map_free_deferred | Call Trace: | dump_stack+0x71/0xa0 | ___might_sleep+0x105/0x190 | lock_sock_nested+0x28/0x90 | sock_map_free+0x95/0x170 | bpf_map_free_deferred+0x58/0x80 | process_one_work+0x260/0x5e0 | worker_thread+0x4d/0x3e0 | kthread+0x108/0x140 | ? process_one_work+0x5e0/0x5e0 | ? kthread_park+0x90/0x90 | ret_from_fork+0x3a/0x50 | ============================= | WARNING: suspicious RCU usage | 5.5.0-04005-g8fc91b972b73-dirty #452 Not tainted | ----------------------------- | include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section! | | other info that might help us debug this: | | | rcu_scheduler_active = 2, debug_locks = 1 | 4 locks held by kworker/0:1/62: | #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0 | #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0 | #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_hash_free+0x5/0x1d0 | #3: ffff888139966e00 (&htab->buckets[i].lock){+...}, at: sock_hash_free+0x92/0x1d0 | | stack backtrace: | CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73-dirty #452 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 | Workqueue: events bpf_map_free_deferred | Call Trace: | dump_stack+0x71/0xa0 | ___might_sleep+0x105/0x190 | lock_sock_nested+0x28/0x90 | sock_hash_free+0xec/0x1d0 | bpf_map_free_deferred+0x58/0x80 | process_one_work+0x260/0x5e0 | worker_thread+0x4d/0x3e0 | kthread+0x108/0x140 | ? process_one_work+0x5e0/0x5e0 | ? kthread_park+0x90/0x90 | ret_from_fork+0x3a/0x50 Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down") Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200206111652.694507-2-jakub@cloudflare.com Signed-off-by: Greg Kroah-Hartman

hv_sock: Remove the accept port restriction

2020-02-14T21:34:07+00:00

[ Upstream commit c742c59e1fbd022b64d91aa9a0092b3a699d653c ] Currently, hv_sock restricts the port the guest socket can accept connections on. hv_sock divides the socket port namespace into two parts for server side (listening socket), 0-0x7FFFFFFF & 0x80000000-0xFFFFFFFF (there are no restrictions on client port namespace). The first part (0-0x7FFFFFFF) is reserved for sockets where connections can be accepted. The second part (0x80000000-0xFFFFFFFF) is reserved for allocating ports for the peer (host) socket, once a connection is accepted. This reservation of the port namespace is specific to hv_sock and not known by the generic vsock library (ex: af_vsock). This is problematic because auto-binds/ephemeral ports are handled by the generic vsock library and it has no knowledge of this port reservation and could allocate a port that is not compatible with hv_sock (and legitimately so). The issue hasn't surfaced so far because the auto-bind code of vsock (__vsock_bind_stream) prior to the change 'VSOCK: bind to random port for VMADDR_PORT_ANY' would start walking up from LAST_RESERVED_PORT (1023) and start assigning ports. That will take a large number of iterations to hit 0x7FFFFFFF. But, after the above change to randomize port selection, the issue has started coming up more frequently. There has really been no good reason to have this port reservation logic in hv_sock from the get go. Reserving a local port for peer ports is not how things are handled generally. Peer ports should reflect the peer port. This fixes the issue by lifting the port reservation, and also returns the right peer port. Since the code converts the GUID to the peer port (by using the first 4 bytes), there is a possibility of conflicts, but that seems like a reasonable risk to take, given this is limited to vsock and that only applies to all local sockets. Signed-off-by: Sunil Muthuswamy Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

rxrpc: Fix service call disconnection

2020-02-11T12:35:55+00:00

[ Upstream commit b39a934ec72fa2b5a74123891f25273a38378b90 ] The recent patch that substituted a flag on an rxrpc_call for the connection pointer being NULL as an indication that a call was disconnected puts the set_bit in the wrong place for service calls. This is only a problem if a call is implicitly terminated by a new call coming in on the same connection channel instead of a terminating ACK packet. In such a case, rxrpc_input_implicit_end_call() calls __rxrpc_disconnect_call(), which is now (incorrectly) setting the disconnection bit, meaning that when rxrpc_release_call() is later called, it doesn't call rxrpc_disconnect_call() and so the call isn't removed from the peer's error distribution list and the list gets corrupted. KASAN finds the issue as an access after release on a call, but the position at which it occurs is confusing as it appears to be related to a different call (the call site is where the latter call is being removed from the error distribution list and either the next or pprev pointer points to a previously released call). Fix this by moving the setting of the flag from __rxrpc_disconnect_call() to rxrpc_disconnect_call() in the same place that the connection pointer was being cleared. Fixes: 5273a191dca6 ("rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnect") Signed-off-by: David Howells Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

drop_monitor: Do not cancel uninitialized work item

2020-02-11T12:35:51+00:00

[ Upstream commit dfa7f709596be5ca46c070d4f8acbb344322056a ] Drop monitor uses a work item that takes care of constructing and sending netlink notifications to user space. In case drop monitor never started to monitor, then the work item is uninitialized and not associated with a function. Therefore, a stop command from user space results in canceling an uninitialized work item which leads to the following warning [1]. Fix this by not processing a stop command if drop monitor is not currently monitoring. [1] [ 31.735402] ------------[ cut here ]------------ [ 31.736470] WARNING: CPU: 0 PID: 143 at kernel/workqueue.c:3032 __flush_work+0x89f/0x9f0 ... [ 31.738120] CPU: 0 PID: 143 Comm: dwdump Not tainted 5.5.0-custom-09491-g16d4077796b8 #727 [ 31.741968] RIP: 0010:__flush_work+0x89f/0x9f0 ... [ 31.760526] Call Trace: [ 31.771689] __cancel_work_timer+0x2a6/0x3b0 [ 31.776809] net_dm_cmd_trace+0x300/0xef0 [ 31.777549] genl_rcv_msg+0x5c6/0xd50 [ 31.781005] netlink_rcv_skb+0x13b/0x3a0 [ 31.784114] genl_rcv+0x29/0x40 [ 31.784720] netlink_unicast+0x49f/0x6a0 [ 31.787148] netlink_sendmsg+0x7cf/0xc80 [ 31.790426] ____sys_sendmsg+0x620/0x770 [ 31.793458] ___sys_sendmsg+0xfd/0x170 [ 31.802216] __sys_sendmsg+0xdf/0x1a0 [ 31.806195] do_syscall_64+0xa0/0x540 [ 31.806885] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 8e94c3bc922e ("drop_monitor: Allow user to start monitoring hardware drops") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6/addrconf: fix potential NULL deref in inet6_set_link_af()

2020-02-11T12:35:51+00:00

[ Upstream commit db3fa271022dacb9f741b96ea4714461a8911bb9 ] __in6_dev_get(dev) called from inet6_set_link_af() can return NULL. The needed check has been recently removed, let's add it back. While do_setlink() does call validate_linkmsg() : ... err = validate_linkmsg(dev, tb); /* OK at this point */ ... It is possible that the following call happening before the ->set_link_af() removes IPv6 if MTU is less than 1280 : if (tb[IFLA_MTU]) { err = dev_set_mtu_ext(dev, nla_get_u32(tb[IFLA_MTU]), extack); if (err < 0) goto errout; status |= DO_SETLINK_MODIFIED; } ... if (tb[IFLA_AF_SPEC]) { ... err = af_ops->set_link_af(dev, af); ->inet6_set_link_af() // CRASH because idev is NULL Please note that IPv4 is immune to the bug since inet_set_link_af() does : struct in_device *in_dev = __in_dev_get_rcu(dev); if (!in_dev) return -EAFNOSUPPORT; This problem has been mentioned in commit cf7afbfeb8ce ("rtnl: make link af-specific updates atomic") changelog : This method is not fail proof, while it is currently sufficient to make set_link_af() inerrable and thus 100% atomic, the validation function method will not be able to detect all error scenarios in the future, there will likely always be errors depending on states which are f.e. not protected by rtnl_mutex and thus may change between validation and setting. IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready general protection fault, probably for non-canonical address 0xdffffc0000000056: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000002b0-0x00000000000002b7] CPU: 0 PID: 9698 Comm: syz-executor712 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:inet6_set_link_af+0x66e/0xae0 net/ipv6/addrconf.c:5733 Code: 38 d0 7f 08 84 c0 0f 85 20 03 00 00 48 8d bb b0 02 00 00 45 0f b6 64 24 04 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 1a 03 00 00 44 89 a3 b0 02 00 RSP: 0018:ffffc90005b06d40 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff86df39a6 RDX: 0000000000000056 RSI: ffffffff86df3e74 RDI: 00000000000002b0 RBP: ffffc90005b06e70 R08: ffff8880a2ac0380 R09: ffffc90005b06db0 R10: fffff52000b60dbe R11: ffffc90005b06df7 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880a1fcc424 R15: dffffc0000000000 FS: 0000000000c46880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f0494ca0d0 CR3: 000000009e4ac000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_setlink+0x2a9f/0x3720 net/core/rtnetlink.c:2754 rtnl_group_changelink net/core/rtnetlink.c:3103 [inline] __rtnl_newlink+0xdd1/0x1790 net/core/rtnetlink.c:3257 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3377 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4402e9 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffd62fbcf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402e9 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000008 R09: 00000000004002c8 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000401b70 R13: 0000000000401c00 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace cfa7664b8fdcdff3 ]--- RIP: 0010:inet6_set_link_af+0x66e/0xae0 net/ipv6/addrconf.c:5733 Code: 38 d0 7f 08 84 c0 0f 85 20 03 00 00 48 8d bb b0 02 00 00 45 0f b6 64 24 04 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 1a 03 00 00 44 89 a3 b0 02 00 RSP: 0018:ffffc90005b06d40 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff86df39a6 RDX: 0000000000000056 RSI: ffffffff86df3e74 RDI: 00000000000002b0 RBP: ffffc90005b06e70 R08: ffff8880a2ac0380 R09: ffffc90005b06db0 R10: fffff52000b60dbe R11: ffffc90005b06df7 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880a1fcc424 R15: dffffc0000000000 FS: 0000000000c46880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000004 CR3: 000000009e4ac000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 7dc2bccab0ee ("Validate required parameters in inet6_validate_link_af") Signed-off-by: Eric Dumazet Bisected-and-reported-by: syzbot Cc: Maxim Mikityanskiy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

taprio: Fix dropping packets when using taprio + ETF offloading

2020-02-11T12:35:51+00:00

[ Upstream commit bfabd41da34180d05382312533a3adc2e012dee0 ] When using taprio offloading together with ETF offloading, configured like this, for example: $ tc qdisc replace dev $IFACE parent root handle 100 taprio \ num_tc 4 \ map 2 2 1 0 3 2 2 2 2 2 2 2 2 2 2 2 \ queues 1@0 1@1 1@2 1@3 \ base-time $BASE_TIME \ sched-entry S 01 1000000 \ sched-entry S 0e 1000000 \ flags 0x2 $ tc qdisc replace dev $IFACE parent 100:1 etf \ offload delta 300000 clockid CLOCK_TAI During enqueue, it works out that the verification added for the "txtime" assisted mode is run when using taprio + ETF offloading, the only thing missing is initializing the 'next_txtime' of all the cycle entries. (if we don't set 'next_txtime' all packets from SO_TXTIME sockets are dropped) Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode") Signed-off-by: Vinicius Costa Gomes Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

taprio: Use taprio_reset_tc() to reset Traffic Classes configuration

2020-02-11T12:35:51+00:00

[ Upstream commit 7c16680a08ee1e444a67d232c679ccf5b30fad16 ] When destroying the current taprio instance, which can happen when the creation of one fails, we should reset the traffic class configuration back to the default state. netdev_reset_tc() is a better way because in addition to setting the number of traffic classes to zero, it also resets the priority to traffic classes mapping to the default value. Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler") Signed-off-by: Vinicius Costa Gomes Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman