From 9354544cbccf68da1b047f8fb7b47630e3c8a59d Mon Sep 17 00:00:00 2001 From: Dirk van der Merwe Date: Sun, 23 Jun 2019 21:26:58 -0700 Subject: [PATCH] net/tls: fix page double free on TX cleanup With commit 94850257cf0f ("tls: Fix tls_device handling of partial records") a new path was introduced to cleanup partial records during sk_proto_close. This path does not handle the SW KTLS tx_list cleanup. This is unnecessary though since the free_resources calls for both SW and offload paths will cleanup a partial record. The visible effect is the following warning, but this bug also causes a page double free. WARNING: CPU: 7 PID: 4000 at net/core/stream.c:206 sk_stream_kill_queues+0x103/0x110 RIP: 0010:sk_stream_kill_queues+0x103/0x110 RSP: 0018:ffffb6df87e07bd0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff8c21db4971c0 RCX: 0000000000000007 RDX: ffffffffffffffa0 RSI: 000000000000001d RDI: ffff8c21db497270 RBP: ffff8c21db497270 R08: ffff8c29f4748600 R09: 000000010020001a R10: ffffb6df87e07aa0 R11: ffffffff9a445600 R12: 0000000000000007 R13: 0000000000000000 R14: ffff8c21f03f2900 R15: ffff8c21f03b8df0 Call Trace: inet_csk_destroy_sock+0x55/0x100 tcp_close+0x25d/0x400 ? tcp_check_oom+0x120/0x120 tls_sk_proto_close+0x127/0x1c0 inet_release+0x3c/0x60 __sock_release+0x3d/0xb0 sock_close+0x11/0x20 __fput+0xd8/0x210 task_work_run+0x84/0xa0 do_exit+0x2dc/0xb90 ? release_sock+0x43/0x90 do_group_exit+0x3a/0xa0 get_signal+0x295/0x720 do_signal+0x36/0x610 ? SYSC_recvfrom+0x11d/0x130 exit_to_usermode_loop+0x69/0xb0 do_syscall_64+0x173/0x180 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7fe9b9abc10d RSP: 002b:00007fe9b19a1d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 0000000000000006 RCX: 00007fe9b9abc10d RDX: 0000000000000002 RSI: 0000000000000080 RDI: 00007fe948003430 RBP: 00007fe948003410 R08: 00007fe948003430 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00005603739d9080 R13: 00007fe9b9ab9f90 R14: 00007fe948003430 R15: 0000000000000000 Fixes: 94850257cf0f ("tls: Fix tls_device handling of partial records") Signed-off-by: Dirk van der Merwe Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- include/net/tls.h | 15 --------------- net/tls/tls_main.c | 3 ++- 2 files changed, 2 insertions(+), 16 deletions(-) diff --git a/include/net/tls.h b/include/net/tls.h index 4a55ce6a303f..53d96bca220d 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -373,21 +373,6 @@ static inline bool tls_is_partially_sent_record(struct tls_context *ctx) return !!ctx->partially_sent_record; } -static inline int tls_complete_pending_work(struct sock *sk, - struct tls_context *ctx, - int flags, long *timeo) -{ - int rc = 0; - - if (unlikely(sk->sk_write_pending)) - rc = wait_on_pending_writer(sk, timeo); - - if (!rc && tls_is_partially_sent_record(ctx)) - rc = tls_push_partial_record(sk, ctx, flags); - - return rc; -} - static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx) { return tls_ctx->pending_open_record_frags; diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index fc81ae18cc44..e2b69e805d46 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -279,7 +279,8 @@ static void tls_sk_proto_close(struct sock *sk, long timeout) goto skip_tx_cleanup; } - if (!tls_complete_pending_work(sk, ctx, 0, &timeo)) + if (unlikely(sk->sk_write_pending) && + !wait_on_pending_writer(sk, &timeo)) tls_handle_open_record(sk, 0); /* We need these for tls_sw_fallback handling of other packets */ -- 2.20.1