+++ /dev/null
-From d3747ebdfd2fd5e12d8d04ad3f6261503ce52913 Mon Sep 17 00:00:00 2001
-From: Jakub Sitnicki <jakub@cloudflare.com>
-Date: Mon, 28 Jan 2019 10:13:35 +0100
-Subject: sk_msg: Always cancel strp work before freeing the psock
-
-[ Upstream commit 1d79895aef18fa05789995d86d523c9b2ee58a02 ]
-
-Despite having stopped the parser, we still need to deinitialize it
-by calling strp_done so that it cancels its work. Otherwise the worker
-thread can run after we have freed the parser, and attempt to access
-its workqueue resulting in a use-after-free:
-
-==================================================================
-BUG: KASAN: use-after-free in pwq_activate_delayed_work+0x1b/0x1d0
-Read of size 8 at addr ffff888069975240 by task kworker/u2:2/93
-
-CPU: 0 PID: 93 Comm: kworker/u2:2 Not tainted 5.0.0-rc2-00335-g28f9d1a3d4fe-dirty #14
-Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
-Workqueue: (null) (kstrp)
-Call Trace:
- print_address_description+0x6e/0x2b0
- ? pwq_activate_delayed_work+0x1b/0x1d0
- kasan_report+0xfd/0x177
- ? pwq_activate_delayed_work+0x1b/0x1d0
- ? pwq_activate_delayed_work+0x1b/0x1d0
- pwq_activate_delayed_work+0x1b/0x1d0
- ? process_one_work+0x4aa/0x660
- pwq_dec_nr_in_flight+0x9b/0x100
- worker_thread+0x82/0x680
- ? process_one_work+0x660/0x660
- kthread+0x1b9/0x1e0
- ? __kthread_create_on_node+0x250/0x250
- ret_from_fork+0x1f/0x30
-
-Allocated by task 111:
- sk_psock_init+0x3c/0x1b0
- sock_map_link.isra.2+0x103/0x4b0
- sock_map_update_common+0x94/0x270
- sock_map_update_elem+0x145/0x160
- __se_sys_bpf+0x152e/0x1e10
- do_syscall_64+0xb2/0x3e0
- entry_SYSCALL_64_after_hwframe+0x44/0xa9
-
-Freed by task 112:
- kfree+0x7f/0x140
- process_one_work+0x40b/0x660
- worker_thread+0x82/0x680
- kthread+0x1b9/0x1e0
- ret_from_fork+0x1f/0x30
-
-The buggy address belongs to the object at ffff888069975180
- which belongs to the cache kmalloc-512 of size 512
-The buggy address is located 192 bytes inside of
- 512-byte region [ffff888069975180, ffff888069975380)
-The buggy address belongs to the page:
-page:ffffea0001a65d00 count:1 mapcount:0 mapping:ffff88806d401280 index:0x0 compound_mapcount: 0
-flags: 0x4000000000010200(slab|head)
-raw: 4000000000010200 dead000000000100 dead000000000200 ffff88806d401280
-raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
-page dumped because: kasan: bad access detected
-
-Memory state around the buggy address:
- ffff888069975100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
- ffff888069975180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
->ffff888069975200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
- ^
- ffff888069975280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
- ffff888069975300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
-==================================================================
-
-Reported-by: Marek Majkowski <marek@cloudflare.com>
-Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
-Link: https://lore.kernel.org/netdev/CAJPywTLwgXNEZ2dZVoa=udiZmtrWJ0q5SuBW64aYs0Y1khXX3A@mail.gmail.com
-Acked-by: Song Liu <songliubraving@fb.com>
-Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- net/core/skmsg.c | 3 +--
- 1 file changed, 1 insertion(+), 2 deletions(-)
-
-diff --git a/net/core/skmsg.c b/net/core/skmsg.c
-index 54d854807630..4932861d7b88 100644
---- a/net/core/skmsg.c
-+++ b/net/core/skmsg.c
-@@ -545,8 +545,7 @@ static void sk_psock_destroy_deferred(struct work_struct *gc)
- struct sk_psock *psock = container_of(gc, struct sk_psock, gc);
-
- /* No sk_callback_lock since already detached. */
-- if (psock->parser.enabled)
-- strp_done(&psock->parser.strp);
-+ strp_done(&psock->parser.strp);
-
- cancel_work_sync(&psock->work);
-
---
-2.19.1
-