From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 10F292E3366; Thu, 13 Mar 2025 06:43:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.35 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741848230; cv=none; b=f6GW1GLqevzT292VkfDtpBXRZUYenlNKDJtcXP8xPJ7zaA3GhSJ34OMPyOpZ9mH3gzkRQI7JGA0HJTKm/gobNw4Xe32Bumj8iH65dJG1dv57zih8jXVhT7ZtfIQwTxFqS5YdJHtg60u1X4OCqxYRCyTWJWFpLrXSKQ8Zk8l+TfE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741848230; c=relaxed/simple; bh=myXCDHw0bLHm619ltOWy39pwMC6nWrYL2K/nbhJE5AA=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; 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SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 13 Mar 2025 14:43:43 +0800 Message-ID: <7cdd692b-6325-4969-919f-7606c83391c9@huawei.com> Date: Thu, 13 Mar 2025 14:43:36 +0800 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net] infiniband: fix use-after-free when rename device name To: Leon Romanovsky CC: , , , , , , , , , , , , References: <20250310064516.3633612-1-wangliang74@huawei.com> <20250310101410.GB7027@unreal> <946cac23-6348-4b18-bb94-58f470bb5a6c@huawei.com> <20250312134931.GD1322339@unreal> From: Wang Liang In-Reply-To: <20250312134931.GD1322339@unreal> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemg200005.china.huawei.com (7.202.181.32) 在 2025/3/12 21:49, Leon Romanovsky 写道: > On Tue, Mar 11, 2025 at 10:55:42AM +0800, Wang Liang wrote: >> 在 2025/3/10 18:14, Leon Romanovsky 写道: >>> On Mon, Mar 10, 2025 at 02:45:16PM +0800, Wang Liang wrote: >>>> Syzbot reported a slab-use-after-free with the following call trace: >>>> >>>> ================================================================== >>>> BUG: KASAN: slab-use-after-free in nla_put+0xd3/0x150 lib/nlattr.c:1099 >>>> Read of size 5 at addr ffff888140ea1c60 by task syz.0.988/10025 >>>> >>>> CPU: 0 UID: 0 PID: 10025 Comm: syz.0.988 Not tainted 6.14.0-rc4-syzkaller-00859-gf77f12010f67 #0 >>>> Hardware name: Google Compute Engine, BIOS Google 02/12/2025 >>>> Call Trace: >>>> >>>> __dump_stack lib/dump_stack.c:94 [inline] >>>> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 >>>> print_address_description mm/kasan/report.c:408 [inline] >>>> print_report+0x16e/0x5b0 mm/kasan/report.c:521 >>>> kasan_report+0x143/0x180 mm/kasan/report.c:634 >>>> kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 >>>> __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 >>>> nla_put+0xd3/0x150 lib/nlattr.c:1099 >>>> nla_put_string include/net/netlink.h:1621 [inline] >>>> fill_nldev_handle+0x16e/0x200 drivers/infiniband/core/nldev.c:265 >>>> rdma_nl_notify_event+0x561/0xef0 drivers/infiniband/core/nldev.c:2857 >>>> ib_device_notify_register+0x22/0x230 drivers/infiniband/core/device.c:1344 >>>> ib_register_device+0x1292/0x1460 drivers/infiniband/core/device.c:1460 >>>> rxe_register_device+0x233/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1540 >>>> rxe_net_add+0x74/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:550 >>>> rxe_newlink+0xde/0x1a0 drivers/infiniband/sw/rxe/rxe.c:212 >>>> nldev_newlink+0x5ea/0x680 drivers/infiniband/core/nldev.c:1795 >>>> rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] >>>> rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259 >>>> netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] >>>> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 >>>> netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 >>>> sock_sendmsg_nosec net/socket.c:709 [inline] >>>> __sock_sendmsg+0x221/0x270 net/socket.c:724 >>>> ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 >>>> ___sys_sendmsg net/socket.c:2618 [inline] >>>> __sys_sendmsg+0x269/0x350 net/socket.c:2650 >>>> do_syscall_x64 arch/x86/entry/common.c:52 [inline] >>>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 >>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>>> RIP: 0033:0x7f42d1b8d169 >>>> Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 ... >>>> RSP: 002b:00007f42d2960038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e >>>> RAX: ffffffffffffffda RBX: 00007f42d1da6320 RCX: 00007f42d1b8d169 >>>> RDX: 0000000000000000 RSI: 00004000000002c0 RDI: 000000000000000c >>>> RBP: 00007f42d1c0e2a0 R08: 0000000000000000 R09: 0000000000000000 >>>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 >>>> R13: 0000000000000000 R14: 00007f42d1da6320 R15: 00007ffe399344a8 >>>> >>>> >>>> Allocated by task 10025: >>>> kasan_save_stack mm/kasan/common.c:47 [inline] >>>> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 >>>> poison_kmalloc_redzone mm/kasan/common.c:377 [inline] >>>> __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 >>>> kasan_kmalloc include/linux/kasan.h:260 [inline] >>>> __do_kmalloc_node mm/slub.c:4294 [inline] >>>> __kmalloc_node_track_caller_noprof+0x28b/0x4c0 mm/slub.c:4313 >>>> __kmemdup_nul mm/util.c:61 [inline] >>>> kstrdup+0x42/0x100 mm/util.c:81 >>>> kobject_set_name_vargs+0x61/0x120 lib/kobject.c:274 >>>> dev_set_name+0xd5/0x120 drivers/base/core.c:3468 >>>> assign_name drivers/infiniband/core/device.c:1202 [inline] >>>> ib_register_device+0x178/0x1460 drivers/infiniband/core/device.c:1384 >>>> rxe_register_device+0x233/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1540 >>>> rxe_net_add+0x74/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:550 >>>> rxe_newlink+0xde/0x1a0 drivers/infiniband/sw/rxe/rxe.c:212 >>>> nldev_newlink+0x5ea/0x680 drivers/infiniband/core/nldev.c:1795 >>>> rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] >>>> rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259 >>>> netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] >>>> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 >>>> netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 >>>> sock_sendmsg_nosec net/socket.c:709 [inline] >>>> __sock_sendmsg+0x221/0x270 net/socket.c:724 >>>> ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 >>>> ___sys_sendmsg net/socket.c:2618 [inline] >>>> __sys_sendmsg+0x269/0x350 net/socket.c:2650 >>>> do_syscall_x64 arch/x86/entry/common.c:52 [inline] >>>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 >>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>>> >>>> Freed by task 10035: >>>> kasan_save_stack mm/kasan/common.c:47 [inline] >>>> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 >>>> kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 >>>> poison_slab_object mm/kasan/common.c:247 [inline] >>>> __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 >>>> kasan_slab_free include/linux/kasan.h:233 [inline] >>>> slab_free_hook mm/slub.c:2353 [inline] >>>> slab_free mm/slub.c:4609 [inline] >>>> kfree+0x196/0x430 mm/slub.c:4757 >>>> kobject_rename+0x38f/0x410 lib/kobject.c:524 >>>> device_rename+0x16a/0x200 drivers/base/core.c:4525 >>>> ib_device_rename+0x270/0x710 drivers/infiniband/core/device.c:402 >>>> nldev_set_doit+0x30e/0x4c0 drivers/infiniband/core/nldev.c:1146 >>>> rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] >>>> rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259 >>>> netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] >>>> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 >>>> netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 >>>> sock_sendmsg_nosec net/socket.c:709 [inline] >>>> __sock_sendmsg+0x221/0x270 net/socket.c:724 >>>> ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 >>>> ___sys_sendmsg net/socket.c:2618 [inline] >>>> __sys_sendmsg+0x269/0x350 net/socket.c:2650 >>>> do_syscall_x64 arch/x86/entry/common.c:52 [inline] >>>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 >>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>>> >>>> This is because if rename device happens, the old name is freed in >>>> ib_device_rename() with lock, but fill_nldev_handle() may visit the dev >>>> name locklessly triggered by rxe_newlink(). >>>> >>>> Fix this by add lock around rdma_nl_notify_event() in >>>> ib_device_notify_register(). >>>> >>>> Reported-by: syzbot+f60349ba1f9f08df349f@syzkaller.appspotmail.com >>>> Closes: https://syzkaller.appspot.com/bug?extid=25bc6f0ed2b88b9eb9b8 >>>> Fixes: 9cbed5aab5ae ("RDMA/nldev: Add support for RDMA monitoring") >>>> Signed-off-by: Wang Liang >>>> --- >>>> drivers/infiniband/core/device.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c >>>> index 0ded91f056f3..4536621ada0d 100644 >>>> --- a/drivers/infiniband/core/device.c >>>> +++ b/drivers/infiniband/core/device.c >>>> @@ -1341,7 +1341,9 @@ static void ib_device_notify_register(struct ib_device *device) >>>> u32 port; >>>> int ret; >>>> + down_write(&devices_rwsem); >>> The analysis looks correct to me, however this should be down_read(&devices_rwsem) >>> together with comment about possible race with RDMA netlink, which can change >>> internals of struct ib_device. >>> >>> I wonder if this read semaphore should be hold for whole >>> ib_device_notify_register() function and not only for RDMA_REGISTER_EVENT event. >>> >>> Thanks >> Yes, you are right! The RDMA_NETDEV_ATTACH_EVENT event in function >> ib_device_notify_register() can also visit the dev name locklessly: >> >> ...... >> >> So only hold devices_rwsem for whole ib_device_notify_register() may be not >> enough. >> >> How about add down_read(&devices_rwsem) around >> fill_dev_info()/fill_port_info()/ >> fill_res_info()/ib_device_notify_register(). > I don't think so, as all flows in nldev.c except rdma_nl_notify_event() are > single threaded and call to ib_device_rename() will make sure that no > other RDMA_NLDEV_CMD_* commands are executed. > > In your case call to rdma_nl_notify_event() can happen in parallel to > device_rename only. > > Thanks Thanks for all your comments. I will send a new patch later, and hold the devices_rwsem for whole ib_device_notify_register(). Please check it. Thanks.