{"schema_version":"1.7.2","id":"OESA-2026-2076","modified":"2026-04-25T05:49:53Z","published":"2026-04-25T05:49:53Z","upstream":["CVE-2025-39955","CVE-2025-71078","CVE-2026-23171","CVE-2026-23450","CVE-2026-31392","CVE-2026-31426"],"summary":"kernel security update","details":"The Linux Kernel, the operating system core itself.\r\n\r\nSecurity Fix(es):\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().\n\nsyzbot reported the splat below where a socket had tcp_sk(sk)->fastopen_rsk\nin the TCP_ESTABLISHED state. [0]\n\nsyzbot reused the server-side TCP Fast Open socket as a new client before\nthe TFO socket completes 3WHS:\n\n  1. accept()\n  2. connect(AF_UNSPEC)\n  3. connect() to another destination\n\nAs of accept(), sk->sk_state is TCP_SYN_RECV, and tcp_disconnect() changes\nit to TCP_CLOSE and makes connect() possible, which restarts timers.\n\nSince tcp_disconnect() forgot to clear tcp_sk(sk)->fastopen_rsk, the\nretransmit timer triggered the warning and the intended packet was not\nretransmitted.\n\nLet's call reqsk_fastopen_remove() in tcp_disconnect().\n\n[0]:\nWARNING: CPU: 2 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))\nModules linked in:\nCPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))\nCode: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e\nRSP: 0018:ffffc900002f8d40 EFLAGS: 00010293\nRAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017\nRDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400\nRBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8\nR10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540\nR13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0\nFS:  0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0\nCall Trace:\n <IRQ>\n tcp_write_timer (net/ipv4/tcp_timer.c:738)\n call_timer_fn (kernel/time/timer.c:1747)\n __run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2372)\n timer_expire_remote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135)\n tmigr_handle_remote_up (kernel/time/timer_migration.c:944 kernel/time/timer_migration.c:1035)\n __walk_groups.isra.0 (kernel/time/timer_migration.c:533 (discriminator 1))\n tmigr_handle_remote (kernel/time/timer_migration.c:1096)\n handle_softirqs (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580)\n irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696)\n sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35))\n </IRQ>(CVE-2025-39955)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s/slb: Fix SLB multihit issue during SLB preload\n\nOn systems using the hash MMU, there is a software SLB preload cache that\nmirrors the entries loaded into the hardware SLB buffer. This preload\ncache is subject to periodic eviction — typically after every 256 context\nswitches — to remove old entry.\n\nTo optimize performance, the kernel skips switch_mmu_context() in\nswitch_mm_irqs_off() when the prev and next mm_struct are the same.\nHowever, on hash MMU systems, this can lead to inconsistencies between\nthe hardware SLB and the software preload cache.\n\nIf an SLB entry for a process is evicted from the software cache on one\nCPU, and the same process later runs on another CPU without executing\nswitch_mmu_context(), the hardware SLB may retain stale entries. If the\nkernel then attempts to reload that entry, it can trigger an SLB\nmulti-hit error.\n\nThe following timeline shows how stale SLB entries are created and can\ncause a multi-hit error when a process moves between CPUs without a\nMMU context switch.\n\nCPU 0                                   CPU 1\n-----                                    -----\nProcess P\nexec                                    swapper/1\n load_elf_binary\n  begin_new_exc\n    activate_mm\n     switch_mm_irqs_off\n      switch_mmu_context\n       switch_slb\n       /*\n        * This invalidates all\n        * the entries in the HW\n        * and setup the new HW\n        * SLB entries as per the\n        * preload cache.\n        */\ncontext_switch\nsched_migrate_task migrates process P to cpu-1\n\nProcess swapper/0                       context switch (to process P)\n(uses mm_struct of Process P)           switch_mm_irqs_off()\n                                         switch_slb\n                                           load_slb++\n                                            /*\n                                            * load_slb becomes 0 here\n                                            * and we evict an entry from\n                                            * the preload cache with\n                                            * preload_age(). We still\n                                            * keep HW SLB and preload\n                                            * cache in sync, that is\n                                            * because all HW SLB entries\n                                            * anyways gets evicted in\n                                            * switch_slb during SLBIA.\n                                            * We then only add those\n                                            * entries back in HW SLB,\n                                            * which are currently\n                                            * present in preload_cache\n                                            * (after eviction).\n                                            */\n                                        load_elf_binary continues...\n                                         setup_new_exec()\n                                          slb_setup_new_exec()\n\n                                        sched_switch event\n                                        sched_migrate_task migrates\n                                        process P to cpu-0\n\ncontext_switch from swapper/0 to Process P\n switch_mm_irqs_off()\n  /*\n   * Since both prev and next mm struct are same we don't call\n   * switch_mmu_context(). This will cause the HW SLB and SW preload\n   * cache to go out of sync in preload_new_slb_context. Because there\n   * was an SLB entry which was evicted from both HW and preload cache\n   * on cpu-1. Now later in preload_new_slb_context(), when we will try\n   * to add the same preload entry again, we will add this to the SW\n   * preload cache and then will add it to the HW SLB. Since on cpu-0\n   * this entry was never invalidated, hence adding this entry to the HW\n   * SLB will cause a SLB multi-hit error.\n   */\nload_elf_binary cont\n---truncated---(CVE-2025-71078)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbonding: fix use-after-free due to enslave fail after slave array update\n\nFix a use-after-free which happens due to enslave failure after the new\nslave has been added to the array. Since the new slave can be used for Tx\nimmediately, we can use it after it has been freed by the enslave error\ncleanup path which frees the allocated slave memory. Slave update array is\nsupposed to be called last when further enslave failures are not expected.\nMove it after xdp setup to avoid any problems.\n\nIt is very easy to reproduce the problem with a simple xdp_pass prog:\n ip l add bond1 type bond mode balance-xor\n ip l set bond1 up\n ip l set dev bond1 xdp object xdp_pass.o sec xdp_pass\n ip l add dumdum type dummy\n\nThen run in parallel:\n while :; do ip l set dumdum master bond1 1>/dev/null 2>&1; done;\n mausezahn bond1 -a own -b rand -A rand -B 1.1.1.1 -c 0 -t tcp "dp=1-1023, flags=syn"\n\nThe crash happens almost immediately:\n [  605.602850] Oops: general protection fault, probably for non-canonical address 0xe0e6fc2460000137: 0000 [#1] SMP KASAN NOPTI\n [  605.602916] KASAN: maybe wild-memory-access in range [0x07380123000009b8-0x07380123000009bf]\n [  605.602946] CPU: 0 UID: 0 PID: 2445 Comm: mausezahn Kdump: loaded Tainted: G    B               6.19.0-rc6+ #21 PREEMPT(voluntary)\n [  605.602979] Tainted: [B]=BAD_PAGE\n [  605.602998] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n [  605.603032] RIP: 0010:netdev_core_pick_tx+0xcd/0x210\n [  605.603063] Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 3e 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 6b 08 49 8d 7d 30 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 25 01 00 00 49 8b 45 30 4c 89 e2 48 89 ee 48 89\n [  605.603111] RSP: 0018:ffff88817b9af348 EFLAGS: 00010213\n [  605.603145] RAX: dffffc0000000000 RBX: ffff88817d28b420 RCX: 0000000000000000\n [  605.603172] RDX: 00e7002460000137 RSI: 0000000000000008 RDI: 07380123000009be\n [  605.603199] RBP: ffff88817b541a00 R08: 0000000000000001 R09: fffffbfff3ed8c0c\n [  605.603226] R10: ffffffff9f6c6067 R11: 0000000000000001 R12: 0000000000000000\n [  605.603253] R13: 073801230000098e R14: ffff88817d28b448 R15: ffff88817b541a84\n [  605.603286] FS:  00007f6570ef67c0(0000) GS:ffff888221dfa000(0000) knlGS:0000000000000000\n [  605.603319] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n [  605.603343] CR2: 00007f65712fae40 CR3: 000000011371b000 CR4: 0000000000350ef0\n [  605.603373] Call Trace:\n [  605.603392]  <TASK>\n [  605.603410]  __dev_queue_xmit+0x448/0x32a0\n [  605.603434]  ? __pfx_vprintk_emit+0x10/0x10\n [  605.603461]  ? __pfx_vprintk_emit+0x10/0x10\n [  605.603484]  ? __pfx___dev_queue_xmit+0x10/0x10\n [  605.603507]  ? bond_start_xmit+0xbfb/0xc20 [bonding]\n [  605.603546]  ? _printk+0xcb/0x100\n [  605.603566]  ? __pfx__printk+0x10/0x10\n [  605.603589]  ? bond_start_xmit+0xbfb/0xc20 [bonding]\n [  605.603627]  ? add_taint+0x5e/0x70\n [  605.603648]  ? add_taint+0x2a/0x70\n [  605.603670]  ? end_report.cold+0x51/0x75\n [  605.603693]  ? bond_start_xmit+0xbfb/0xc20 [bonding]\n [  605.603731]  bond_start_xmit+0x623/0xc20 [bonding](CVE-2026-23171)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix NULL dereference and UAF in smc_tcp_syn_recv_sock()\n\nSyzkaller reported a panic in smc_tcp_syn_recv_sock() [1].\n\nsmc_tcp_syn_recv_sock() is called in the TCP receive path\n(softirq) via icsk_af_ops->syn_recv_sock on the clcsock (TCP\nlistening socket). It reads sk_user_data to get the smc_sock\npointer. However, when the SMC listen socket is being closed\nconcurrently, smc_close_active() sets clcsock->sk_user_data\nto NULL under sk_callback_lock, and then the smc_sock itself\ncan be freed via sock_put() in smc_release().\n\nThis leads to two issues:\n\n1) NULL pointer dereference: sk_user_data is NULL when\n   accessed.\n2) Use-after-free: sk_user_data is read as non-NULL, but the\n   smc_sock is freed before its fields (e.g., queued_smc_hs,\n   ori_af_ops) are accessed.\n\nThe race window looks like this (the syzkaller crash [1]\ntriggers via the SYN cookie path: tcp_get_cookie_sock() ->\nsmc_tcp_syn_recv_sock(), but the normal tcp_check_req() path\nhas the same race):\n\n  CPU A (softirq)              CPU B (process ctx)\n\n  tcp_v4_rcv()\n    TCP_NEW_SYN_RECV:\n    sk = req->rsk_listener\n    sock_hold(sk)\n    /* No lock on listener */\n                               smc_close_active():\n                                 write_lock_bh(cb_lock)\n                                 sk_user_data = NULL\n                                 write_unlock_bh(cb_lock)\n                                 ...\n                                 smc_clcsock_release()\n                                 sock_put(smc->sk) x2\n                                   -> smc_sock freed!\n    tcp_check_req()\n      smc_tcp_syn_recv_sock():\n        smc = user_data(sk)\n          -> NULL or dangling\n        smc->queued_smc_hs\n          -> crash!\n\nNote that the clcsock and smc_sock are two independent objects\nwith separate refcounts. TCP stack holds a reference on the\nclcsock, which keeps it alive, but this does NOT prevent the\nsmc_sock from being freed.\n\nFix this by using RCU and refcount_inc_not_zero() to safely\naccess smc_sock. Since smc_tcp_syn_recv_sock() is called in\nthe TCP three-way handshake path, taking read_lock_bh on\nsk_callback_lock is too heavy and would not survive a SYN\nflood attack. Using rcu_read_lock() is much more lightweight.\n\n- Set SOCK_RCU_FREE on the SMC listen socket so that\n  smc_sock freeing is deferred until after the RCU grace\n  period. This guarantees the memory is still valid when\n  accessed inside rcu_read_lock().\n- Use rcu_read_lock() to protect reading sk_user_data.\n- Use refcount_inc_not_zero(&smc->sk.sk_refcnt) to pin the\n  smc_sock. If the refcount has already reached zero (close\n  path completed), it returns false and we bail out safely.\n\nNote: smc_hs_congested() has a similar lockless read of\nsk_user_data without rcu_read_lock(), but it only checks for\nNULL and accesses the global smc_hs_wq, never dereferencing\nany smc_sock field, so it is not affected.\n\nReproducer was verified with mdelay injection and smc_run,\nthe issue no longer occurs with this patch applied.\n\n[1] https://syzkaller.appspot.com/bug?extid=827ae2bfb3a3529333e9(CVE-2026-23450)\n\nIn the Linux kernel, the following vulnerability has been resolved: smb: client: fix krb5 mount with username option. Customer reported that some of their krb5 mounts were failing against a single server as the client was trying to mount the shares with wrong credentials. It turned out the client was reusing SMB session from first mount to try mounting the other shares, even though a different username= option had been specified to the other mounts. By using username mount option along with sec=krb5 to search for principals from keytab is supported by cifs.upcall(8) since cifs-utils-4.8. So fix this by matching username mount option in match_session() even with Kerberos.(CVE-2026-31392)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nACPI: EC: clean up handlers on probe failure in acpi_ec_setup()\n\nWhen ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware\nplatforms, it has already started the EC and installed the address\nspace handler with the struct acpi_ec pointer as handler context.\nHowever, acpi_ec_setup() propagates the error without any cleanup.\n\nThe caller acpi_ec_add() then frees the struct acpi_ec for non-boot\ninstances, leaving a dangling handler context in ACPICA.\n\nAny subsequent AML evaluation that accesses an EC OpRegion field\ndispatches into acpi_ec_space_handler() with the freed pointer,\ncausing a use-after-free:\n\n BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289)\n Write of size 8 at addr ffff88800721de38 by task init/1\n Call Trace:\n  <TASK>\n  mutex_lock (kernel/locking/mutex.c:289)\n  acpi_ec_space_handler (drivers/acpi/ec.c:1362)\n  acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293)\n  acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246)\n  acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509)\n  acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700)\n  acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327)\n  acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392)\n  </TASK>\n\n Allocated by task 1:\n  acpi_ec_alloc (drivers/acpi/ec.c:1424)\n  acpi_ec_add (drivers/acpi/ec.c:1692)\n\n Freed by task 1:\n  kfree (mm/slub.c:6876)\n  acpi_ec_add (drivers/acpi/ec.c:1751)\n\nThe bug triggers on reduced-hardware EC platforms (ec->gpe < 0)\nwhen the GPIO IRQ provider defers probing. Once the stale handler\nexists, any unprivileged sysfs read that causes AML to touch an\nEC OpRegion (battery, thermal, backlight) exercises the dangling\npointer.\n\nFix this by calling ec_remove_handlers() in the error path of\nacpi_ec_setup() before clearing first_ec. ec_remove_handlers()\nchecks each EC_FLAGS_* bit before acting, so it is safe to call\nregardless of how far ec_install_handlers() progressed:\n\n  -ENODEV  (handler not installed): only calls acpi_ec_stop()\n  -EPROBE_DEFER (handler installed): removes handler, stops EC(CVE-2026-31426)","affected":[{"package":{"ecosystem":"openEuler:22.03-LTS-SP4","name":"kernel","purl":"pkg:rpm/openEuler/kernel&distro=openEuler-22.03-LTS-SP4"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.0-310.0.0.213.oe2203sp4"}]}],"ecosystem_specific":{"aarch64":["bpftool-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","bpftool-debuginfo-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-debuginfo-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-debugsource-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-devel-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-headers-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-source-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-tools-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-tools-debuginfo-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","kernel-tools-devel-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","perf-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","perf-debuginfo-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","python3-perf-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm","python3-perf-debuginfo-5.10.0-310.0.0.213.oe2203sp4.aarch64.rpm"],"src":["kernel-5.10.0-310.0.0.213.oe2203sp4.src.rpm"],"x86_64":["bpftool-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","bpftool-debuginfo-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-debuginfo-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-debugsource-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-devel-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-headers-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-source-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-tools-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-tools-debuginfo-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","kernel-tools-devel-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","perf-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","perf-debuginfo-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","python3-perf-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm","python3-perf-debuginfo-5.10.0-310.0.0.213.oe2203sp4.x86_64.rpm"]}}],"references":[{"type":"ADVISORY","url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2076"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39955"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-71078"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23171"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23450"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31392"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31426"}],"database_specific":{"severity":"High"}}