linux-stable.git/net, branch v5.4.71

net_sched: commit action insertions together

2020-10-14T08:33:06+00:00

commit 0fedc63fadf0404a729e73a35349481c8009c02f upstream.

syzbot is able to trigger a failure case inside the loop in
tcf_action_init(), and when this happens we clean up with
tcf_action_destroy(). But, as these actions are already inserted
into the global IDR, other parallel process could free them
before tcf_action_destroy(), then we will trigger a use-after-free.

Fix this by deferring the insertions even later, after the loop,
and committing all the insertions in a separate loop, so we will
never fail in the middle of the insertions any more.

One side effect is that the window between alloction and final
insertion becomes larger, now it is more likely that the loop in
tcf_del_walker() sees the placeholder -EBUSY pointer. So we have
to check for error pointer in tcf_del_walker().

Reported-and-tested-by: syzbot+2287853d392e4b42374a@syzkaller.appspotmail.com
Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action")
Cc: Vlad Buslov 
Cc: Jamal Hadi Salim 
Cc: Jiri Pirko 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net_sched: defer tcf_idr_insert() in tcf_action_init_1()

2020-10-14T08:33:06+00:00

commit e49d8c22f1261c43a986a7fdbf677ac309682a07 upstream.

All TC actions call tcf_idr_insert() for new action at the end
of their ->init(), so we can actually move it to a central place
in tcf_action_init_1().

And once the action is inserted into the global IDR, other parallel
process could free it immediately as its refcnt is still 1, so we can
not fail after this, we need to move it after the goto action
validation to avoid handling the failure case after insertion.

This is found during code review, is not directly triggered by syzbot.
And this prepares for the next patch.

Cc: Vlad Buslov 
Cc: Jamal Hadi Salim 
Cc: Jiri Pirko 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/tls: race causes kernel panic

2020-10-14T08:33:06+00:00

commit 38f7e1c0c43dd25b06513137bb6fd35476f9ec6d upstream.

BUG: kernel NULL pointer dereference, address: 00000000000000b8
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 80000008b6fef067 P4D 80000008b6fef067 PUD 8b6fe6067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 12 PID: 23871 Comm: kworker/12:80 Kdump: loaded Tainted: G S
 5.9.0-rc3+ #1
 Hardware name: Supermicro X10SRA-F/X10SRA-F, BIOS 2.1 03/29/2018
 Workqueue: events tx_work_handler [tls]
 RIP: 0010:tx_work_handler+0x1b/0x70 [tls]
 Code: dc fe ff ff e8 16 d4 a3 f6 66 0f 1f 44 00 00 0f 1f 44 00 00 55 53 48 8b
 6f 58 48 8b bd a0 04 00 00 48 85 ff 74 1c 48 8b 47 28 <48> 8b 90 b8 00 00 00 83
 e2 02 75 0c f0 48 0f ba b0 b8 00 00 00 00
 RSP: 0018:ffffa44ace61fe88 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff91da9e45cc30 RCX: dead000000000122
 RDX: 0000000000000001 RSI: ffff91da9e45cc38 RDI: ffff91d95efac200
 RBP: ffff91da133fd780 R08: 0000000000000000 R09: 000073746e657665
 R10: 8080808080808080 R11: 0000000000000000 R12: ffff91dad7d30700
 R13: ffff91dab6561080 R14: 0ffff91dad7d3070 R15: ffff91da9e45cc38
 FS:  0000000000000000(0000) GS:ffff91dad7d00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00000000000000b8 CR3: 0000000906478003 CR4: 00000000003706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  process_one_work+0x1a7/0x370
  worker_thread+0x30/0x370
  ? process_one_work+0x370/0x370
  kthread+0x114/0x130
  ? kthread_park+0x80/0x80
  ret_from_fork+0x22/0x30

tls_sw_release_resources_tx() waits for encrypt_pending, which
can have race, so we need similar changes as in commit
0cada33241d9de205522e3858b18e506ca5cce2c here as well.

Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Rohit Maheshwari 
Acked-by: Jakub Kicinski 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/core: check length before updating Ethertype in skb_mpls_{push,pop}

2020-10-14T08:33:06+00:00

commit 4296adc3e32f5d544a95061160fe7e127be1b9ff upstream.

Openvswitch allows to drop a packet's Ethernet header, therefore
skb_mpls_push() and skb_mpls_pop() might be called with ethernet=true
and mac_len=0. In that case the pointer passed to skb_mod_eth_type()
doesn't point to an Ethernet header and the new Ethertype is written at
unexpected locations.

Fix this by verifying that mac_len is big enough to contain an Ethernet
header.

Fixes: fa4e0f8855fc ("net/sched: fix corrupted L2 header with MPLS 'push' and 'pop' actions")
Signed-off-by: Guillaume Nault 
Acked-by: Davide Caratti 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: fix receive window update in tcp_add_backlog()

2020-10-14T08:33:06+00:00

commit 86bccd0367130f481ca99ba91de1c6a5aa1c78c1 upstream.

We got reports from GKE customers flows being reset by netfilter
conntrack unless nf_conntrack_tcp_be_liberal is set to 1.

Traces seemed to suggest ACK packet being dropped by the
packet capture, or more likely that ACK were received in the
wrong order.

 wscale=7, SYN and SYNACK not shown here.

 This ACK allows the sender to send 1871*128 bytes from seq 51359321 :
 New right edge of the window -> 51359321+1871*128=51598809

 09:17:23.389210 IP A > B: Flags [.], ack 51359321, win 1871, options [nop,nop,TS val 10 ecr 999], length 0

 09:17:23.389212 IP B > A: Flags [.], seq 51422681:51424089, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 1408
 09:17:23.389214 IP A > B: Flags [.], ack 51422681, win 1376, options [nop,nop,TS val 10 ecr 999], length 0
 09:17:23.389253 IP B > A: Flags [.], seq 51424089:51488857, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 64768
 09:17:23.389272 IP A > B: Flags [.], ack 51488857, win 859, options [nop,nop,TS val 10 ecr 999], length 0
 09:17:23.389275 IP B > A: Flags [.], seq 51488857:51521241, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 32384

 Receiver now allows to send 606*128=77568 from seq 51521241 :
 New right edge of the window -> 51521241+606*128=51598809

 09:17:23.389296 IP A > B: Flags [.], ack 51521241, win 606, options [nop,nop,TS val 10 ecr 999], length 0

 09:17:23.389308 IP B > A: Flags [.], seq 51521241:51553625, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 32384

 It seems the sender exceeds RWIN allowance, since 51611353 > 51598809

 09:17:23.389346 IP B > A: Flags [.], seq 51553625:51611353, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 57728
 09:17:23.389356 IP B > A: Flags [.], seq 51611353:51618393, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 7040

 09:17:23.389367 IP A > B: Flags [.], ack 51611353, win 0, options [nop,nop,TS val 10 ecr 999], length 0

 netfilter conntrack is not happy and sends RST

 09:17:23.389389 IP A > B: Flags [R], seq 92176528, win 0, length 0
 09:17:23.389488 IP B > A: Flags [R], seq 174478967, win 0, length 0

 Now imagine ACK were delivered out of order and tcp_add_backlog() sets window based on wrong packet.
 New right edge of the window -> 51521241+859*128=51631193

Normally TCP stack handles OOO packets just fine, but it
turns out tcp_add_backlog() does not. It can update the window
field of the aggregated packet even if the ACK sequence
of the last received packet is too old.

Many thanks to Alexandre Ferrieux for independently reporting the issue
and suggesting a fix.

Fixes: 4f693b55c3d2 ("tcp: implement coalescing on backlog queue")
Signed-off-by: Eric Dumazet 
Reported-by: Alexandre Ferrieux 
Acked-by: Soheil Hassas Yeganeh 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix server keyring leak

2020-10-14T08:33:05+00:00

[ Upstream commit 38b1dc47a35ba14c3f4472138ea56d014c2d609b ]

If someone calls setsockopt() twice to set a server key keyring, the first
keyring is leaked.

Fix it to return an error instead if the server key keyring is already set.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

rxrpc: The server keyring isn't network-namespaced

2020-10-14T08:33:05+00:00

[ Upstream commit fea99111244bae44e7d82a973744d27ea1567814 ]

The keyring containing the server's tokens isn't network-namespaced, so it
shouldn't be looked up with a network namespace.  It is expected to be
owned specifically by the server, so namespacing is unnecessary.

Fixes: a58946c158a0 ("keys: Pass the network namespace into request_key mechanism")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

rxrpc: Fix some missing _bh annotations on locking conn->state_lock

2020-10-14T08:33:05+00:00

[ Upstream commit fa1d113a0f96f9ab7e4fe4f8825753ba1e34a9d3 ]

conn->state_lock may be taken in softirq mode, but a previous patch
replaced an outer lock in the response-packet event handling code, and lost
the _bh from that when doing so.

Fix this by applying the _bh annotation to the state_lock locking.

Fixes: a1399f8bb033 ("rxrpc: Call channels should have separate call number spaces")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

rxrpc: Downgrade the BUG() for unsupported token type in rxrpc_read()

2020-10-14T08:33:05+00:00

[ Upstream commit 9a059cd5ca7d9c5c4ca5a6e755cf72f230176b6a ]

If rxrpc_read() (which allows KEYCTL_READ to read a key), sees a token of a
type it doesn't recognise, it can BUG in a couple of places, which is
unnecessary as it can easily get back to userspace.

Fix this to print an error message instead.

Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

rxrpc: Fix rxkad token xdr encoding

2020-10-14T08:33:05+00:00

[ Upstream commit 56305118e05b2db8d0395bba640ac9a3aee92624 ]

The session key should be encoded with just the 8 data bytes and
no length; ENCODE_DATA precedes it with a 4 byte length, which
confuses some existing tools that try to parse this format.

Add an ENCODE_BYTES macro that does not include a length, and use
it for the key.  Also adjust the expected length.

Note that commit 774521f353e1d ("rxrpc: Fix an assertion in
rxrpc_read()") had fixed a BUG by changing the length rather than
fixing the encoding.  The original length was correct.

Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: Marc Dionne 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin