kernel/linux.git/net/iucv, branch v6.12.101

net/iucv: fix use-after-free of a severed iucv_path

2026-08-03T09:17:26+00:00

commit be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a upstream. af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connection's iucv_path. When the peer severs the connection, iucv_sever_path() frees that path with iucv_path_free() but leaves the notifications queued. A later recvmsg() drains message_q via iucv_process_message_q() and hands the stale path to message_receive() -- a use-after-free of the freed iucv_path. Drop the queued notifications when the path is severed; once the path is gone they can no longer be received. This also frees the notifications leaked when a socket is closed with messages still queued. Fixes: f0703c80e515 ("[AF_IUCV]: postpone receival of iucv-packets") Closes: https://sashiko.dev/#/patchset/20260705-b4-disp-fc79c0dc-v1-1-d2cdcb57afa9@proton.me?part=1 Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Link: https://patch.msgid.link/20260707-b4-disp-783fedbb-v1-1-463b9dbda2ea@proton.me Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

net/af_iucv: fix NULL deref in afiucv_hs_callback_syn()

2026-08-03T09:17:26+00:00

commit 47a5116e56a6b6fe1e909f244e39cd0fc26ceee4 upstream. afiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC. If the allocation fails, nsk is NULL. The connection-refused path is entered when the listen state check fails, the accept backlog is full, or nsk is NULL. The code unconditionally calls iucv_sock_kill(nsk) in that path. iucv_sock_kill() does not accept a NULL socket pointer and immediately dereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL, calling iucv_sock_kill(nsk) results in a NULL pointer dereference. Only call iucv_sock_kill() when a child socket was successfully allocated. Fixes: 3881ac441f64 ("af_iucv: add HiperSockets transport") Cc: stable@vger.kernel.org Reviewed-by: Alexandra Winter Signed-off-by: Hidayath Khan Link: https://patch.msgid.link/20260709191732.124092-1-hidayath@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/iucv: take a reference on the socket found in afiucv_hs_rcv()

2026-08-03T09:17:04+00:00

[ Upstream commit 4fa349156043dc119721d067329714179f501749 ] afiucv_hs_rcv() looks up the destination socket under iucv_sk_list.lock, drops the lock, and then passes the socket to the afiucv_hs_callback_*() handlers without holding a reference. AF_IUCV sockets are not RCU-protected and are freed synchronously by iucv_sock_kill() -> sock_put(), so a concurrent close can free the socket in the window between read_unlock() and the handler, which then dereferences freed memory (for example sk->sk_data_ready() in afiucv_hs_callback_syn()). Take a reference with sock_hold() while the socket is still on the list and release it with sock_put() once the handler has run. Fixes: 3881ac441f64 ("af_iucv: add HiperSockets transport") Signed-off-by: Bryam Vargas Reviewed-by: Hidayath Khan Link: https://patch.msgid.link/20260705-b4-disp-fc79c0dc-v1-1-d2cdcb57afa9@proton.me Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/iucv: fix locking in .getsockopt

2026-06-09T10:25:39+00:00

[ Upstream commit 3589d20a666caf30ad100c960a2de7de390fce88 ] Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops. Suggested-by: Stanislav Fomichev Fixes: 51363b8751a6 ("af_iucv: allow retrieval of maximum message size") Signed-off-by: Breno Leitao Reviewed-by: Alexandra Winter Tested-by: Alexandra Winter Link: https://patch.msgid.link/20260521-af_iucv_fix2-v1-1-f16b1c510aa9@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

s390/iucv: MSG_PEEK causes memory leak in iucv_sock_destruct()

2024-12-05T13:02:31+00:00

[ Upstream commit ebaf81317e42aa990ad20b113cfe3a7b20d4e937 ] Passing MSG_PEEK flag to skb_recv_datagram() increments skb refcount (skb->users) and iucv_sock_recvmsg() does not decrement skb refcount at exit. This results in skb memory leak in skb_queue_purge() and WARN_ON in iucv_sock_destruct() during socket close. To fix this decrease skb refcount by one if MSG_PEEK is set in order to prevent memory leak and WARN_ON. WARNING: CPU: 2 PID: 6292 at net/iucv/af_iucv.c:286 iucv_sock_destruct+0x144/0x1a0 [af_iucv] CPU: 2 PID: 6292 Comm: afiucv_test_msg Kdump: loaded Tainted: G W 6.10.0-rc7 #1 Hardware name: IBM 3931 A01 704 (z/VM 7.3.0) Call Trace: [<001587c682c4aa98>] iucv_sock_destruct+0x148/0x1a0 [af_iucv] [<001587c682c4a9d0>] iucv_sock_destruct+0x80/0x1a0 [af_iucv] [<001587c704117a32>] __sk_destruct+0x52/0x550 [<001587c704104a54>] __sock_release+0xa4/0x230 [<001587c704104c0c>] sock_close+0x2c/0x40 [<001587c702c5f5a8>] __fput+0x2e8/0x970 [<001587c7024148c4>] task_work_run+0x1c4/0x2c0 [<001587c7023b0716>] do_exit+0x996/0x1050 [<001587c7023b13aa>] do_group_exit+0x13a/0x360 [<001587c7023b1626>] __s390x_sys_exit_group+0x56/0x60 [<001587c7022bccca>] do_syscall+0x27a/0x380 [<001587c7049a6a0c>] __do_syscall+0x9c/0x160 [<001587c7049ce8a8>] system_call+0x70/0x98 Last Breaking-Event-Address: [<001587c682c4a9d4>] iucv_sock_destruct+0x84/0x1a0 [af_iucv] Fixes: eac3731bd04c ("[S390]: Add AF_IUCV socket support") Reviewed-by: Alexandra Winter Reviewed-by: Thorsten Winkler Signed-off-by: Sidraya Jayagond Signed-off-by: Alexandra Winter Reviewed-by: David Wei Link: https://patch.msgid.link/20241119152219.3712168-1-wintera@linux.ibm.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

s390/iucv: Fix vargs handling in iucv_alloc_device()

2024-08-22T20:09:20+00:00

iucv_alloc_device() gets a format string and a varying number of arguments. This is incorrectly forwarded by calling dev_set_name() with the format string and a va_list, while dev_set_name() expects also a varying number of arguments. Symptoms: Corrupted iucv device names, which can result in log messages like: sysfs: cannot create duplicate filename '/devices/iucv/hvc_iucv1827699952' Fixes: 4452e8ef8c36 ("s390/iucv: Provide iucv_alloc_device() / iucv_release_device()") Link: https://bugzilla.suse.com/show_bug.cgi?id=1228425 Signed-off-by: Alexandra Winter Reviewed-by: Thorsten Winkler Reviewed-by: Przemek Kitszel Link: https://patch.msgid.link/20240821091337.3627068-1-wintera@linux.ibm.com Signed-off-by: Jakub Kicinski

net/iucv: fix use after free in iucv_sock_close()

2024-07-30T13:01:50+00:00

iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn(). Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8 [452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48 [452744.124820] [<00000000d5421642>] __fput+0xba/0x268 [452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0 [452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90 [452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8 [452744.125319] Last Breaking-Event-Address: [452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138 [452744.125324] [452744.125325] Kernel panic - not syncing: Fatal exception in interrupt Note that bh_lock_sock() is not serializing the tasklet context against process context, because the check for sock_owned_by_user() and corresponding handling is missing. Ideas for a future clean-up patch: A) Correct usage of bh_lock_sock() in tasklet context, as described in Link: https://lore.kernel.org/netdev/1280155406.2899.407.camel@edumazet-laptop/ Re-enqueue, if needed. This may require adding return values to the tasklet functions and thus changes to all users of iucv. B) Change iucv tasklet into worker and use only lock_sock() in af_iucv. Fixes: 7d316b945352 ("af_iucv: remove IUCV-pathes completely") Reviewed-by: Halil Pasic Signed-off-by: Alexandra Winter Link: https://patch.msgid.link/20240729122818.947756-1-wintera@linux.ibm.com Signed-off-by: Paolo Abeni

driver core: have match() callback in struct bus_type take a const *

2024-07-03T13:16:54+00:00

In the match() callback, the struct device_driver * should not be changed, so change the function callback to be a const *. This is one step of many towards making the driver core safe to have struct device_driver in read-only memory. Because the match() callback is in all busses, all busses are modified to handle this properly. This does entail switching some container_of() calls to container_of_const() to properly handle the constant *. For some busses, like PCI and USB and HV, the const * is cast away in the match callback as those busses do want to modify those structures at this point in time (they have a local lock in the driver structure.) That will have to be changed in the future if they wish to have their struct device * in read-only-memory. Cc: Rafael J. Wysocki Reviewed-by: Alex Elder Acked-by: Sumit Garg Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh Signed-off-by: Greg Kroah-Hartman

Merge tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2024-05-21T19:09:36+00:00

Pull more s390 updates from Alexander Gordeev: - Switch read and write software bits for PUDs - Add missing hardware bits for PUDs and PMDs - Generate unwind information for C modules to fix GDB unwind error for vDSO functions - Create .build-id links for unstripped vDSO files to enable vDSO debugging with symbols - Use standard stack frame layout for vDSO generated stack frames to manually walk stack frames without DWARF information - Rework perf_callchain_user() and arch_stack_walk_user() functions to reduce code duplication - Skip first stack frame when walking user stack - Add basic checks to identify invalid instruction pointers when walking stack frames - Introduce and use struct stack_frame_vdso_wrapper within vDSO user wrapper code to automatically generate an asm-offset define. Also use STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document that the code works with user space stack - Clear the backchain of the extra stack frame added by the vDSO user wrapper code. This allows the user stack walker to detect and skip the non-standard stack frame. Without this an incorrect instruction pointer would be added to stack traces. - Rewrite psw_idle() function in C to ease maintenance and further enhancements - Remove get_vtimer() function and use get_cpu_timer() instead - Mark psw variable in __load_psw_mask() as __unitialized to avoid superfluous clearing of PSW - Remove obsolete and superfluous comment about removed TIF_FPU flag - Replace memzero_explicit() and kfree() with kfree_sensitive() to fix warnings reported by Coccinelle - Wipe sensitive data and all copies of protected- or secure-keys from stack when an IOCTL fails - Both do_airq_interrupt() and do_io_interrupt() functions set CIF_NOHZ_DELAY flag. Move it in do_io_irq() to simplify the code - Provide iucv_alloc_device() and iucv_release_device() helpers, which can be used to deduplicate more or less identical IUCV device allocation and release code in four different drivers - Make use of iucv_alloc_device() and iucv_release_device() helpers to get rid of quite some code and also remove a cast to an incompatible function (clang W=1) - There is no user of iucv_root outside of the core IUCV code left. Therefore remove the EXPORT_SYMBOL - __apply_alternatives() contains a runtime check which verifies that the size of the to be patched code area is even. Convert this to a compile time check - Increase size of buffers for sending z/VM CP DIAGNOSE X'008' commands from 128 to 240 - Do not accept z/VM CP DIAGNOSE X'008' commands longer than maximally allowed - Use correct defines IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN instead of IPL_BP_FCP_LEN and IPL_BP0_FCP_LEN ones to initialize NVMe reIPL block on 'scp_data' sysfs attribute update - Initialize the correct fields of the NVMe dump block, which were confused with FCP fields - Refactor macros for 'scp_data' (re-)IPL sysfs attribute to reduce code duplication - Introduce 'scp_data' sysfs attribute for dump IPL to allow tools such as dumpconf passing additional kernel command line parameters to a stand-alone dumper - Rework the CPACF query functions to use the correct RRE or RRF instruction formats and set instruction register fields correctly - Instead of calling BUG() at runtime force a link error during compile when a unsupported opcode is used with __cpacf_query() or __cpacf_check_opcode() functions - Fix a crash in ap_parse_bitmap_str() function on /sys/bus/ap/apmask or /sys/bus/ap/aqmask sysfs file update with a relative mask value - Fix "bindings complete" udev event which should be sent once all AP devices have been bound to device drivers and again when unbind/bind actions take place and all AP devices are bound again - Facility list alt_stfle_fac_list is nowhere used in the decompressor, therefore remove it there - Remove custom kprobes insn slot allocator in favour of the standard module_alloc() one, since kernel image and module areas are located within 4GB - Use kvcalloc() instead of kvmalloc_array() in zcrypt driver to avoid calling memset() with a large byte count and get rid of the sparse warning as result * tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390/zcrypt: Use kvcalloc() instead of kvmalloc_array() s390/kprobes: Remove custom insn slot allocator s390/boot: Remove alt_stfle_fac_list from decompressor s390/ap: Fix bind complete udev event sent after each AP bus scan s390/ap: Fix crash in AP internal function modify_bitmap() s390/cpacf: Make use of invalid opcode produce a link error s390/cpacf: Split and rework cpacf query functions s390/ipl: Introduce sysfs attribute 'scp_data' for dump ipl s390/ipl: Introduce macros for (re)ipl sysfs attribute 'scp_data' s390/ipl: Fix incorrect initialization of nvme dump block s390/ipl: Fix incorrect initialization of len fields in nvme reipl block s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds s390/alternatives: Convert runtime sanity check into compile time check s390/iucv: Unexport iucv_root tty: hvc-iucv: Make use of iucv_alloc_device() s390/smsgiucv_app: Make use of iucv_alloc_device() s390/netiucv: Make use of iucv_alloc_device() s390/vmlogrdr: Make use of iucv_alloc_device() s390/iucv: Provide iucv_alloc_device() / iucv_release_device() ...

s390/iucv: Unexport iucv_root

2024-05-14T18:21:04+00:00

There is no user of iucv_root outside of the core IUCV code left. Therefore remove the EXPORT_SYMBOL. Acked-by: Alexandra Winter Link: https://lore.kernel.org/r/20240506194454.1160315-7-hca@linux.ibm.com Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev