Liu Jian f18d9b3abf net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()
[ Upstream commit ba1e9421cf1a8369d25c3832439702a015d6b5f9 ]

BUG: kernel NULL pointer dereference, address: 00000000000002ec
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G        OE       6.17.0-rc2+ #9 NONE
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Workqueue: smc_hs_wq smc_listen_work [smc]
RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
...
Call Trace:
 <TASK>
 smcr_buf_map_link+0x211/0x2a0 [smc]
 __smc_buf_create+0x522/0x970 [smc]
 smc_buf_create+0x3a/0x110 [smc]
 smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
 ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
 smc_listen_find_device+0x1dd/0x2b0 [smc]
 smc_listen_work+0x30f/0x580 [smc]
 process_one_work+0x18c/0x340
 worker_thread+0x242/0x360
 kthread+0xe7/0x220
 ret_from_fork+0x13a/0x160
 ret_from_fork_asm+0x1a/0x30
 </TASK>

If the software RoCE device is used, ibdev->dma_device is a null pointer.
As a result, the problem occurs. Null pointer detection is added to
prevent problems.

Fixes: 0ef69e7884 ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Link: https://patch.msgid.link/20250828124117.2622624-1-liujian56@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09 18:56:22 +02:00
2025-09-04 15:30:29 +02:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%