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Alexandra Winter e28dd1e1bf s390/qeth: Fix kernel panic after setting hsuid
[ Upstream commit 8a2e4d37af ]

Symptom:
When the hsuid attribute is set for the first time on an IQD Layer3
device while the corresponding network interface is already UP,
the kernel will try to execute a napi function pointer that is NULL.

Example:
---------------------------------------------------------------------------
[ 2057.572696] illegal operation: 0001 ilc:1 [#1] SMP
[ 2057.572702] Modules linked in: af_iucv qeth_l3 zfcp scsi_transport_fc sunrpc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6
nft_reject nft_ct nf_tables_set nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables libcrc32c nfnetlink ghash_s390 prng xts aes_s390 des_s390 de
s_generic sha3_512_s390 sha3_256_s390 sha512_s390 vfio_ccw vfio_mdev mdev vfio_iommu_type1 eadm_sch vfio ext4 mbcache jbd2 qeth_l2 bridge stp llc dasd_eckd_mod qeth dasd_mod
 qdio ccwgroup pkey zcrypt
[ 2057.572739] CPU: 6 PID: 60182 Comm: stress_client Kdump: loaded Not tainted 4.18.0-541.el8.s390x #1
[ 2057.572742] Hardware name: IBM 3931 A01 704 (LPAR)
[ 2057.572744] Krnl PSW : 0704f00180000000 0000000000000002 (0x2)
[ 2057.572748]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3
[ 2057.572751] Krnl GPRS: 0000000000000004 0000000000000000 00000000a3b008d8 0000000000000000
[ 2057.572754]            00000000a3b008d8 cb923a29c779abc5 0000000000000000 00000000814cfd80
[ 2057.572756]            000000000000012c 0000000000000000 00000000a3b008d8 00000000a3b008d8
[ 2057.572758]            00000000bab6d500 00000000814cfd80 0000000091317e46 00000000814cfc68
[ 2057.572762] Krnl Code:#0000000000000000: 0000                illegal
                         >0000000000000002: 0000                illegal
                          0000000000000004: 0000                illegal
                          0000000000000006: 0000                illegal
                          0000000000000008: 0000                illegal
                          000000000000000a: 0000                illegal
                          000000000000000c: 0000                illegal
                          000000000000000e: 0000                illegal
[ 2057.572800] Call Trace:
[ 2057.572801] ([<00000000ec639700>] 0xec639700)
[ 2057.572803]  [<00000000913183e2>] net_rx_action+0x2ba/0x398
[ 2057.572809]  [<0000000091515f76>] __do_softirq+0x11e/0x3a0
[ 2057.572813]  [<0000000090ce160c>] do_softirq_own_stack+0x3c/0x58
[ 2057.572817] ([<0000000090d2cbd6>] do_softirq.part.1+0x56/0x60)
[ 2057.572822]  [<0000000090d2cc60>] __local_bh_enable_ip+0x80/0x98
[ 2057.572825]  [<0000000091314706>] __dev_queue_xmit+0x2be/0xd70
[ 2057.572827]  [<000003ff803dd6d6>] afiucv_hs_send+0x24e/0x300 [af_iucv]
[ 2057.572830]  [<000003ff803dd88a>] iucv_send_ctrl+0x102/0x138 [af_iucv]
[ 2057.572833]  [<000003ff803de72a>] iucv_sock_connect+0x37a/0x468 [af_iucv]
[ 2057.572835]  [<00000000912e7e90>] __sys_connect+0xa0/0xd8
[ 2057.572839]  [<00000000912e9580>] sys_socketcall+0x228/0x348
[ 2057.572841]  [<0000000091514e1a>] system_call+0x2a6/0x2c8
[ 2057.572843] Last Breaking-Event-Address:
[ 2057.572844]  [<0000000091317e44>] __napi_poll+0x4c/0x1d8
[ 2057.572846]
[ 2057.572847] Kernel panic - not syncing: Fatal exception in interrupt
-------------------------------------------------------------------------------------------

Analysis:
There is one napi structure per out_q: card->qdio.out_qs[i].napi
The napi.poll functions are set during qeth_open().

Since
commit 1cfef80d4c ("s390/qeth: Don't call dev_close/dev_open (DOWN/UP)")
qeth_set_offline()/qeth_set_online() no longer call dev_close()/
dev_open(). So if qeth_free_qdio_queues() cleared
card->qdio.out_qs[i].napi.poll while the network interface was UP and the
card was offline, they are not set again.

Reproduction:
chzdev -e $devno layer2=0
ip link set dev $network_interface up
echo 0 > /sys/bus/ccwgroup/devices/0.0.$devno/online
echo foo > /sys/bus/ccwgroup/devices/0.0.$devno/hsuid
echo 1 > /sys/bus/ccwgroup/devices/0.0.$devno/online
-> Crash (can be enforced e.g. by af_iucv connect(), ip link down/up, ...)

Note that a Completion Queue (CQ) is only enabled or disabled, when hsuid
is set for the first time or when it is removed.

Workarounds:
- Set hsuid before setting the device online for the first time
or
- Use chzdev -d $devno; chzdev $devno hsuid=xxx; chzdev -e $devno;
to set hsuid on an existing device. (this will remove and recreate the
network interface)

Fix:
There is no need to free the output queues when a completion queue is
added or removed.
card->qdio.state now indicates whether the inbound buffer pool and the
outbound queues are allocated.
card->qdio.c_q indicates whether a CQ is allocated.

Fixes: 1cfef80d4c ("s390/qeth: Don't call dev_close/dev_open (DOWN/UP)")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240430091004.2265683-1-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-05-17 12:02:06 +02:00
arch s390/vdso: Add CFI for RA register to asm macro vdso_func 2024-05-17 12:02:02 +02:00
block block: fix q->blkg_list corruption during disk rebind 2024-04-17 11:19:28 +02:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: jitter - fix CRYPTO_JITTERENTROPY help text 2024-03-26 18:19:52 -04:00
Documentation mm, treewide: introduce NR_PAGE_ORDERS 2024-05-02 16:32:41 +02:00
drivers s390/qeth: Fix kernel panic after setting hsuid 2024-05-17 12:02:06 +02:00
fs nfs: Handle error of rpc_proc_register() in nfs_net_init(). 2024-05-17 12:01:58 +02:00
include ALSA: emu10k1: move the whole GPIO event handling to the workqueue 2024-05-17 12:02:03 +02:00
init rust: make mutually exclusive with CFI_CLANG 2024-05-02 16:32:42 +02:00
io_uring io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure 2024-04-27 17:11:30 +02:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel bpf: Fix a verifier verbose message 2024-05-17 12:02:00 +02:00
lib Fix a potential infinite loop in extract_user_to_sg() 2024-05-17 12:02:02 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: turn folio_test_hugetlb into a PageType 2024-05-02 16:32:47 +02:00
net tipc: fix a possible memleak in tipc_buf_append 2024-05-17 12:02:06 +02:00
rust rust: kernel: require Send for Module implementations 2024-05-17 12:01:56 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:24:47 +01:00
scripts kbuild: rust: force alloc extern to allow "empty" Rust files 2024-05-02 16:32:42 +02:00
security selinux: avoid dereference of garbage after mount failure 2024-04-10 16:35:48 +02:00
sound ALSA: hda: intel-sdw-acpi: fix usage of device_get_named_child_node() 2024-05-17 12:02:05 +02:00
tools selftests/seccomp: Handle EINVAL on unshare(CLONE_NEWPID) 2024-05-02 16:32:42 +02:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:28:18 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ALSA: scarlett2: Rename scarlett_gen2 to scarlett2 2024-04-27 17:11:36 +02:00
Makefile Linux 6.6.30 2024-05-02 16:32:50 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.