tls: Fix tls_device handling of partial records

Cleanup the handling of partial records while fixing a bug where the
tls_push_pending_closed_record function is using the software tls
context instead of the hardware context.

The bug resulted in the following crash:
[   88.791229] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[   88.793271] #PF error: [normal kernel read fault]
[   88.794449] PGD 800000022a426067 P4D 800000022a426067 PUD 22a156067 PMD 0
[   88.795958] Oops: 0000 [#1] SMP PTI
[   88.796884] CPU: 2 PID: 4973 Comm: openssl Not tainted 5.0.0-rc4+ #3
[   88.798314] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[   88.800067] RIP: 0010:tls_tx_records+0xef/0x1d0 [tls]
[   88.801256] Code: 00 02 48 89 43 08 e8 a0 0b 96 d9 48 89 df e8 48 dd
4d d9 4c 89 f8 4d 8b bf 98 00 00 00 48 05 98 00 00 00 48 89 04 24 49 39
c7 <49> 8b 1f 4d 89 fd 0f 84 af 00 00 00 41 8b 47 10 85 c0 0f 85 8d 00
[   88.805179] RSP: 0018:ffffbd888186fca8 EFLAGS: 00010213
[   88.806458] RAX: ffff9af1ed657c98 RBX: ffff9af1e88a1980 RCX: 0000000000000000
[   88.808050] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9af1e88a1980
[   88.809724] RBP: ffff9af1e88a1980 R08: 0000000000000017 R09: ffff9af1ebeeb700
[   88.811294] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   88.812917] R13: ffff9af1e88a1980 R14: ffff9af1ec13f800 R15: 0000000000000000
[   88.814506] FS:  00007fcad2240740(0000) GS:ffff9af1f7880000(0000) knlGS:0000000000000000
[   88.816337] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   88.817717] CR2: 0000000000000000 CR3: 0000000228b3e000 CR4: 00000000001406e0
[   88.819328] Call Trace:
[   88.820123]  tls_push_data+0x628/0x6a0 [tls]
[   88.821283]  ? remove_wait_queue+0x20/0x60
[   88.822383]  ? n_tty_read+0x683/0x910
[   88.823363]  tls_device_sendmsg+0x53/0xa0 [tls]
[   88.824505]  sock_sendmsg+0x36/0x50
[   88.825492]  sock_write_iter+0x87/0x100
[   88.826521]  __vfs_write+0x127/0x1b0
[   88.827499]  vfs_write+0xad/0x1b0
[   88.828454]  ksys_write+0x52/0xc0
[   88.829378]  do_syscall_64+0x5b/0x180
[   88.830369]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   88.831603] RIP: 0033:0x7fcad1451680

[ 1248.470626] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[ 1248.472564] #PF error: [normal kernel read fault]
[ 1248.473790] PGD 0 P4D 0
[ 1248.474642] Oops: 0000 [#1] SMP PTI
[ 1248.475651] CPU: 3 PID: 7197 Comm: openssl Tainted: G           OE 5.0.0-rc4+ #3
[ 1248.477426] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 1248.479310] RIP: 0010:tls_tx_records+0x110/0x1f0 [tls]
[ 1248.480644] Code: 00 02 48 89 43 08 e8 4f cb 63 d7 48 89 df e8 f7 9c
1b d7 4c 89 f8 4d 8b bf 98 00 00 00 48 05 98 00 00 00 48 89 04 24 49 39
c7 <49> 8b 1f 4d 89 fd 0f 84 af 00 00 00 41 8b 47 10 85 c0 0f 85 8d 00
[ 1248.484825] RSP: 0018:ffffaa0a41543c08 EFLAGS: 00010213
[ 1248.486154] RAX: ffff955a2755dc98 RBX: ffff955a36031980 RCX: 0000000000000006
[ 1248.487855] RDX: 0000000000000000 RSI: 000000000000002b RDI: 0000000000000286
[ 1248.489524] RBP: ffff955a36031980 R08: 0000000000000000 R09: 00000000000002b1
[ 1248.491394] R10: 0000000000000003 R11: 00000000ad55ad55 R12: 0000000000000000
[ 1248.493162] R13: 0000000000000000 R14: ffff955a2abe6c00 R15: 0000000000000000
[ 1248.494923] FS:  0000000000000000(0000) GS:ffff955a378c0000(0000) knlGS:0000000000000000
[ 1248.496847] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1248.498357] CR2: 0000000000000000 CR3: 000000020c40e000 CR4: 00000000001406e0
[ 1248.500136] Call Trace:
[ 1248.500998]  ? tcp_check_oom+0xd0/0xd0
[ 1248.502106]  tls_sk_proto_close+0x127/0x1e0 [tls]
[ 1248.503411]  inet_release+0x3c/0x60
[ 1248.504530]  __sock_release+0x3d/0xb0
[ 1248.505611]  sock_close+0x11/0x20
[ 1248.506612]  __fput+0xb4/0x220
[ 1248.507559]  task_work_run+0x88/0xa0
[ 1248.508617]  do_exit+0x2cb/0xbc0
[ 1248.509597]  ? core_sys_select+0x17a/0x280
[ 1248.510740]  do_group_exit+0x39/0xb0
[ 1248.511789]  get_signal+0x1d0/0x630
[ 1248.512823]  do_signal+0x36/0x620
[ 1248.513822]  exit_to_usermode_loop+0x5c/0xc6
[ 1248.515003]  do_syscall_64+0x157/0x180
[ 1248.516094]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1248.517456] RIP: 0033:0x7fb398bd3f53
[ 1248.518537] Code: Bad RIP value.

Fixes: a42055e8 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tls.h

@@ -199,10 +199,6 @@ struct tls_offload_context_tx {
 	(ALIGN(sizeof(struct tls_offload_context_tx), sizeof(void *)) +        \
 	 TLS_DRIVER_STATE_SIZE)
 
-enum {
-	TLS_PENDING_CLOSED_RECORD
-};
-
 struct cipher_context {
 	char *iv;
 	char *rec_seq;
@@ -335,17 +331,14 @@ int tls_push_sg(struct sock *sk, struct tls_context *ctx,
 int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
 			    int flags);
 
-int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
-				   int flags, long *timeo);
-
 static inline struct tls_msg *tls_msg(struct sk_buff *skb)
 {
 	return (struct tls_msg *)strp_msg(skb);
 }
 
-static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
+static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
 {
-	return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
+	return !!ctx->partially_sent_record;
 }
 
 static inline int tls_complete_pending_work(struct sock *sk,
@@ -357,17 +350,12 @@ static inline int tls_complete_pending_work(struct sock *sk,
 	if (unlikely(sk->sk_write_pending))
 		rc = wait_on_pending_writer(sk, timeo);
 
-	if (!rc && tls_is_pending_closed_record(ctx))
-		rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
+	if (!rc && tls_is_partially_sent_record(ctx))
+		rc = tls_push_partial_record(sk, ctx, flags);
 
 	return rc;
 }
 
-static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
-{
-	return !!ctx->partially_sent_record;
-}
-
 static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
 {
 	return tls_ctx->pending_open_record_frags;

net/tls/tls_device.c

@@ -271,7 +271,6 @@ static int tls_push_record(struct sock *sk,
 	list_add_tail(&record->list, &offload_ctx->records_list);
 	spin_unlock_irq(&offload_ctx->lock);
 	offload_ctx->open_record = NULL;
-	set_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
 	tls_advance_record_sn(sk, &ctx->tx, ctx->crypto_send.info.version);
 
 	for (i = 0; i < record->num_frags; i++) {
@@ -368,9 +367,11 @@ static int tls_push_data(struct sock *sk,
 		return -sk->sk_err;
 
 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
-	rc = tls_complete_pending_work(sk, tls_ctx, flags, &timeo);
-	if (rc < 0)
-		return rc;
+	if (tls_is_partially_sent_record(tls_ctx)) {
+		rc = tls_push_partial_record(sk, tls_ctx, flags);
+		if (rc < 0)
+			return rc;
+	}
 
 	pfrag = sk_page_frag(sk);
 

net/tls/tls_main.c

@@ -209,19 +209,6 @@ int tls_push_partial_record(struct sock *sk, struct tls_context *ctx,
 	return tls_push_sg(sk, ctx, sg, offset, flags);
 }
 
-int tls_push_pending_closed_record(struct sock *sk,
-				   struct tls_context *tls_ctx,
-				   int flags, long *timeo)
-{
-	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
-
-	if (tls_is_partially_sent_record(tls_ctx) ||
-	    !list_empty(&ctx->tx_list))
-		return tls_tx_records(sk, flags);
-	else
-		return tls_ctx->push_pending_record(sk, flags);
-}
-
 static void tls_write_space(struct sock *sk)
 {
 	struct tls_context *ctx = tls_get_ctx(sk);