kernel/linux.git/drivers/s390/net, branch v6.6.132

s390/ctcm: Fix double-kfree

2025-12-01T10:41:47+00:00

[ Upstream commit da02a1824884d6c84c5e5b5ac373b0c9e3288ec2 ] The function 'mpc_rcvd_sweep_req(mpcginfo)' is called conditionally from function 'ctcmpc_unpack_skb'. It frees passed mpcginfo. After that a call to function 'kfree' in function 'ctcmpc_unpack_skb' frees it again. Remove 'kfree' call in function 'mpc_rcvd_sweep_req(mpcginfo)'. Bug detected by the clang static analyzer. Fixes: 0c0b20587b9f25a2 ("s390/ctcm: fix potential memory leak") Reviewed-by: Aswin Karuvally Signed-off-by: Aleksei Nikiforov Signed-off-by: Aswin Karuvally Reviewed-by: Simon Horman Link: https://patch.msgid.link/20251112182724.1109474-1-aswin@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

s390/ism: fix concurrency management in ism_cmd()

2025-08-01T08:47:29+00:00

[ Upstream commit 897e8601b9cff1d054cdd53047f568b0e1995726 ] The s390x ISM device data sheet clearly states that only one request-response sequence is allowable per ISM function at any point in time. Unfortunately as of today the s390/ism driver in Linux does not honor that requirement. This patch aims to rectify that. This problem was discovered based on Aliaksei's bug report which states that for certain workloads the ISM functions end up entering error state (with PEC 2 as seen from the logs) after a while and as a consequence connections handled by the respective function break, and for future connection requests the ISM device is not considered -- given it is in a dysfunctional state. During further debugging PEC 3A was observed as well. A kernel message like [ 1211.244319] zpci: 061a:00:00.0: Event 0x2 reports an error for PCI function 0x61a is a reliable indicator of the stated function entering error state with PEC 2. Let me also point out that a kernel message like [ 1211.244325] zpci: 061a:00:00.0: The ism driver bound to the device does not support error recovery is a reliable indicator that the ISM function won't be auto-recovered because the ISM driver currently lacks support for it. On a technical level, without this synchronization, commands (inputs to the FW) may be partially or fully overwritten (corrupted) by another CPU trying to issue commands on the same function. There is hard evidence that this can lead to DMB token values being used as DMB IOVAs, leading to PEC 2 PCI events indicating invalid DMA. But this is only one of the failure modes imaginable. In theory even completely losing one command and executing another one twice and then trying to interpret the outputs as if the command we intended to execute was actually executed and not the other one is also possible. Frankly, I don't feel confident about providing an exhaustive list of possible consequences. Fixes: 684b89bc39ce ("s390/ism: add device driver for internal shared memory") Reported-by: Aliaksei Makarau Tested-by: Mahanta Jambigi Tested-by: Aliaksei Makarau Signed-off-by: Halil Pasic Reviewed-by: Alexandra Winter Signed-off-by: Alexandra Winter Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250722161817.1298473-1-wintera@linux.ibm.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

s390/ism: add release function for struct device

2025-02-27T12:10:48+00:00

[ Upstream commit 915e34d5ad35a6a9e56113f852ade4a730fb88f0 ] According to device_release() in /drivers/base/core.c, a device without a release function is a broken device and must be fixed. The current code directly frees the device after calling device_add() without waiting for other kernel parts to release their references. Thus, a reference could still be held to a struct device, e.g., by sysfs, leading to potential use-after-free issues if a proper release function is not set. Fixes: 8c81ba20349d ("net/smc: De-tangle ism and smc device initialization") Reviewed-by: Alexandra Winter Reviewed-by: Wenjia Zhang Signed-off-by: Julian Ruess Signed-off-by: Alexandra Winter Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250214120137.563409-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/smc: compatible with 128-bits extended GID of virtual ISM device

2024-12-14T18:59:36+00:00

[ Upstream commit b40584d145700addc70cc29e4f0850a4ed955b1c ] According to virtual ISM support feature defined by SMCv2.1, GIDs of virtual ISM device are UUIDs defined by RFC4122, which are 128-bits long. So some adaptation work is required. And note that the GIDs of existing platform firmware ISM devices still remain 64-bits long. Signed-off-by: Wen Gu Reviewed-by: Alexandra Winter Signed-off-by: David S. Miller Stable-dep-of: 0541db8ee32c ("net/smc: initialize close_work early to avoid warning") Signed-off-by: Sasha Levin

ipv6: introduce dst_rt6_info() helper

2024-12-14T18:59:35+00:00

[ Upstream commit e8dfd42c17faf183415323db1ef0c977be0d6489 ] Instead of (struct rt6_info *)dst casts, we can use : #define dst_rt6_info(_ptr) \ container_of_const(_ptr, struct rt6_info, dst) Some places needed missing const qualifiers : ip6_confirm_neigh(), ipv6_anycast_destination(), ipv6_unicast_destination(), has_gateway() v2: added missing parts (David Ahern) Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller Stable-dep-of: 3301ab7d5aeb ("net/ipv6: release expired exception dst cached in socket") Signed-off-by: Sasha Levin

s390/qeth: Fix kernel panic after setting hsuid

2024-05-17T10:02:06+00:00

[ Upstream commit 8a2e4d37afb8500b276e5ee903dee06f50ab0494 ] 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 1cfef80d4c2b ("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: 1cfef80d4c2b ("s390/qeth: Don't call dev_close/dev_open (DOWN/UP)") Signed-off-by: Alexandra Winter Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20240430091004.2265683-1-wintera@linux.ibm.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

s390/ism: Properly fix receive message buffer allocation

2024-04-27T15:11:33+00:00

[ Upstream commit 83781384a96b95e2b6403d3c8a002b2c89031770 ] Since [1], dma_alloc_coherent() does not accept requests for GFP_COMP anymore, even on archs that may be able to fulfill this. Functionality that relied on the receive buffer being a compound page broke at that point: The SMC-D protocol, that utilizes the ism device driver, passes receive buffers to the splice processor in a struct splice_pipe_desc with a single entry list of struct pages. As the buffer is no longer a compound page, the splice processor now rejects requests to handle more than a page worth of data. Replace dma_alloc_coherent() and allocate a buffer with folio_alloc and create a DMA map for it with dma_map_page(). Since only receive buffers on ISM devices use DMA, qualify the mapping as FROM_DEVICE. Since ISM devices are available on arch s390, only, and on that arch all DMA is coherent, there is no need to introduce and export some kind of dma_sync_to_cpu() method to be called by the SMC-D protocol layer. Analogously, replace dma_free_coherent by a two step dma_unmap_page, then folio_put to free the receive buffer. [1] https://lore.kernel.org/all/20221113163535.884299-1-hch@lst.de/ Fixes: c08004eede4b ("s390/ism: don't pass bogus GFP_ flags to dma_alloc_coherent") Signed-off-by: Gerd Bayer Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

Revert "s390/ism: fix receive message buffer allocation"

2024-04-17T09:19:31+00:00

[ Upstream commit d51dc8dd6ab6f93a894ff8b38d3b8d02c98eb9fb ] This reverts commit 58effa3476536215530c9ec4910ffc981613b413. Review was not finished on this patch. So it's not ready for upstreaming. Signed-off-by: Gerd Bayer Link: https://lore.kernel.org/r/20240409113753.2181368-1-gbayer@linux.ibm.com Fixes: 58effa347653 ("s390/ism: fix receive message buffer allocation") Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

s390/ism: fix receive message buffer allocation

2024-04-17T09:19:28+00:00

[ Upstream commit 58effa3476536215530c9ec4910ffc981613b413 ] Since [1], dma_alloc_coherent() does not accept requests for GFP_COMP anymore, even on archs that may be able to fulfill this. Functionality that relied on the receive buffer being a compound page broke at that point: The SMC-D protocol, that utilizes the ism device driver, passes receive buffers to the splice processor in a struct splice_pipe_desc with a single entry list of struct pages. As the buffer is no longer a compound page, the splice processor now rejects requests to handle more than a page worth of data. Replace dma_alloc_coherent() and allocate a buffer with folio_alloc and create a DMA map for it with dma_map_page(). Since only receive buffers on ISM devices use DMA, qualify the mapping as FROM_DEVICE. Since ISM devices are available on arch s390, only and on that arch all DMA is coherent, there is no need to introduce and export some kind of dma_sync_to_cpu() method to be called by the SMC-D protocol layer. Analogously, replace dma_free_coherent by a two step dma_unmap_page, then folio_put to free the receive buffer. [1] https://lore.kernel.org/all/20221113163535.884299-1-hch@lst.de/ Fixes: c08004eede4b ("s390/ism: don't pass bogus GFP_ flags to dma_alloc_coherent") Signed-off-by: Gerd Bayer Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

s390/qeth: handle deferred cc1

2024-04-10T14:35:42+00:00

[ Upstream commit afb373ff3f54c9d909efc7f810dc80a9742807b2 ] The IO subsystem expects a driver to retry a ccw_device_start, when the subsequent interrupt response block (irb) contains a deferred condition code 1. Symptoms before this commit: On the read channel we always trigger the next read anyhow, so no different behaviour here. On the write channel we may experience timeout errors, because the expected reply will never be received without the retry. Other callers of qeth_send_control_data() may wrongly assume that the ccw was successful, which may cause problems later. Note that since commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") and commit 5ef1dc40ffa6 ("s390/cio: fix invalid -EBUSY on ccw_device_start") deferred CC1s are much more likely to occur. See the commit message of the latter for more background information. Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") Signed-off-by: Alexandra Winter Co-developed-by: Thorsten Winkler Signed-off-by: Thorsten Winkler Reviewed-by: Peter Oberparleiter Link: https://lore.kernel.org/r/20240321115337.3564694-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin