An issue was discovered in xenvif_set_hash_mapping in drivers/net/xen-netback/hash.c in the Linux kernel through 4.18.1, as used in Xen through 4.11.x and other products. The Linux netback driver allows frontends to control mapping of requests to request queues. When processing a request to set or change this mapping, some input validation (e.g., for an integer overflow) was missing or flawed, leading to OOB access in hash handling. A malicious or buggy frontend may cause the (usually privileged) backend to make out of bounds memory accesses, potentially resulting in one or more of privilege escalation, Denial of Service (DoS), or information leaks.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix dangling pointer in krb_authenticate krb_authenticate frees sess->user and does not set the pointer to NULL. It calls ksmbd_krb5_authenticate to reinitialise sess->user but that function may return without doing so. If that happens then smb2_sess_setup, which calls krb_authenticate, will be accessing free'd memory when it later uses sess->user.

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Use local fence in error path of xe_migrate_clear The intent of the error path in xe_migrate_clear is to wait on locally generated fence and then return. The code is waiting on m->fence which could be the local fence but this is only stable under the job mutex leading to a possible UAF. Fix code to wait on local fence. (cherry picked from commit 762b7e95362170b3e13a8704f38d5e47eca4ba74)

In the Linux kernel, the following vulnerability has been resolved: alloc_tag: allocate percpu counters for module tags dynamically When a module gets unloaded it checks whether any of its tags are still in use and if so, we keep the memory containing module's allocation tags alive until all tags are unused. However percpu counters referenced by the tags are freed by free_module(). This will lead to UAF if the memory allocated by a module is accessed after module was unloaded. To fix this we allocate percpu counters for module allocation tags dynamically and we keep it alive for tags which are still in use after module unloading. This also removes the requirement of a larger PERCPU_MODULE_RESERVE when memory allocation profiling is enabled because percpu memory for counters does not need to be reserved anymore.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent out-of-bounds stream writes by validating *pos ksmbd_vfs_stream_write() did not validate whether the write offset (*pos) was within the bounds of the existing stream data length (v_len). If *pos was greater than or equal to v_len, this could lead to an out-of-bounds memory write. This patch adds a check to ensure *pos is less than v_len before proceeding. If the condition fails, -EINVAL is returned.

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Fix isochronous Ring Underrun/Overrun event handling The TRB pointer of these events points at enqueue at the time of error occurrence on xHCI 1.1+ HCs or it's NULL on older ones. By the time we are handling the event, a new TD may be queued at this ring position. I can trigger this race by rising interrupt moderation to increase IRQ handling delay. Similar delay may occur naturally due to system load. If this ever happens after a Missed Service Error, missed TDs will be skipped and the new TD processed as if it matched the event. It could be given back prematurely, risking data loss or buffer UAF by the xHC. Don't complete TDs on xrun events and don't warn if queued TDs don't match the event's TRB pointer, which can be NULL or a link/no-op TRB. Don't warn if there are no queued TDs at all. Now that it's safe, also handle xrun events if the skip flag is clear. This ensures completion of any TD stuck in 'error mid TD' state right before the xrun event, which could happen if a driver submits a finite number of URBs to a buggy HC and then an error occurs on the last TD.

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix buffer locking in ring_buffer_subbuf_order_set() Enlarge the critical section in ring_buffer_subbuf_order_set() to ensure that error handling takes place with per-buffer mutex held, thus preventing list corruption and other concurrency-related issues.

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: Set n_channels after allocating struct cfg80211_scan_request Make sure that n_channels is set after allocating the struct cfg80211_registered_device::int_scan_req member. Seen with syzkaller: UBSAN: array-index-out-of-bounds in net/mac80211/scan.c:1208:5 index 0 is out of range for type 'struct ieee80211_channel *[] __counted_by(n_channels)' (aka 'struct ieee80211_channel *[]') This was missed in the initial conversions because I failed to locate the allocation likely due to the "sizeof(void *)" not matching the "channels" array type.

In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class handling This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class handling. The issue occurs due to a time-of-check/time-of-use condition in hfsc_change_class() when working with certain child qdiscs like netem or codel. The vulnerability works as follows: 1. hfsc_change_class() checks if a class has packets (q.qlen != 0) 2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g., codel, netem) might drop packets and empty the queue 3. The code continues assuming the queue is still non-empty, adding the class to vttree 4. This breaks HFSC scheduler assumptions that only non-empty classes are in vttree 5. Later, when the class is destroyed, this can lead to a Use-After-Free The fix adds a second queue length check after qdisc_peek_len() to verify the queue wasn't emptied.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in ksmbd_session_rpc_open A UAF issue can occur due to a race condition between ksmbd_session_rpc_open() and __session_rpc_close(). Add rpc_lock to the session to protect it.

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix uaf in ath12k_core_init() When the execution of ath12k_core_hw_group_assign() or ath12k_core_hw_group_create() fails, the registered notifier chain is not unregistered properly. Its memory is freed after rmmod, which may trigger to a use-after-free (UAF) issue if there is a subsequent access to this notifier chain. Fixes the issue by calling ath12k_core_panic_notifier_unregister() in failure cases. Call trace: notifier_chain_register+0x4c/0x1f0 (P) atomic_notifier_chain_register+0x38/0x68 ath12k_core_init+0x50/0x4e8 [ath12k] ath12k_pci_probe+0x5f8/0xc28 [ath12k] pci_device_probe+0xbc/0x1a8 really_probe+0xc8/0x3a0 __driver_probe_device+0x84/0x1b0 driver_probe_device+0x44/0x130 __driver_attach+0xcc/0x208 bus_for_each_dev+0x84/0x100 driver_attach+0x2c/0x40 bus_add_driver+0x130/0x260 driver_register+0x70/0x138 __pci_register_driver+0x68/0x80 ath12k_pci_init+0x30/0x68 [ath12k] ath12k_init+0x28/0x78 [ath12k] Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in kerberos authentication Setting sess->user = NULL was introduced to fix the dangling pointer created by ksmbd_free_user. However, it is possible another thread could be operating on the session and make use of sess->user after it has been passed to ksmbd_free_user but before sess->user is set to NULL.

In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue() When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list, causing further consequences like use-after-free. This patch fixes the bug by moving the increment of sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures that queue length and backlog are always accurate when packet drops or dequeues are triggered during the peek.

In the Linux kernel, the following vulnerability has been resolved: mm, slab: clean up slab->obj_exts always When memory allocation profiling is disabled at runtime or due to an error, shutdown_mem_profiling() is called: slab->obj_exts which previously allocated remains. It won't be cleared by unaccount_slab() because of mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts should always be cleaned up in unaccount_slab() to avoid following error: [...]BUG: Bad page state in process... .. [...]page dumped because: page still charged to cgroup [andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]

In the Linux kernel, the following vulnerability has been resolved: net/sched: fix use-after-free in taprio_dev_notifier Since taprio’s taprio_dev_notifier() isn’t protected by an RCU read-side critical section, a race with advance_sched() can lead to a use-after-free. Adding rcu_read_lock() inside taprio_dev_notifier() prevents this.

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Avoid using sk_socket after free when sending The sk->sk_socket is not locked or referenced in backlog thread, and during the call to skb_send_sock(), there is a race condition with the release of sk_socket. All types of sockets(tcp/udp/unix/vsock) will be affected. Race conditions: ''' CPU0 CPU1 backlog::skb_send_sock sendmsg_unlocked sock_sendmsg sock_sendmsg_nosec close(fd): ... ops->release() -> sock_map_close() sk_socket->ops = NULL free(socket) sock->ops->sendmsg ^ panic here ''' The ref of psock become 0 after sock_map_close() executed. ''' void sock_map_close() { ... if (likely(psock)) { ... // !! here we remove psock and the ref of psock become 0 sock_map_remove_links(sk, psock) psock = sk_psock_get(sk); if (unlikely(!psock)) goto no_psock; <=== Control jumps here via goto ... cancel_delayed_work_sync(&psock->work); <=== not executed sk_psock_put(sk, psock); ... } ''' Based on the fact that we already wait for the workqueue to finish in sock_map_close() if psock is held, we simply increase the psock reference count to avoid race conditions. With this patch, if the backlog thread is running, sock_map_close() will wait for the backlog thread to complete and cancel all pending work. If no backlog running, any pending work that hasn't started by then will fail when invoked by sk_psock_get(), as the psock reference count have been zeroed, and sk_psock_drop() will cancel all jobs via cancel_delayed_work_sync(). In summary, we require synchronization to coordinate the backlog thread and close() thread. The panic I catched: ''' Workqueue: events sk_psock_backlog RIP: 0010:sock_sendmsg+0x21d/0x440 RAX: 0000000000000000 RBX: ffffc9000521fad8 RCX: 0000000000000001 ... Call Trace: <TASK> ? die_addr+0x40/0xa0 ? exc_general_protection+0x14c/0x230 ? asm_exc_general_protection+0x26/0x30 ? sock_sendmsg+0x21d/0x440 ? sock_sendmsg+0x3e0/0x440 ? __pfx_sock_sendmsg+0x10/0x10 __skb_send_sock+0x543/0xb70 sk_psock_backlog+0x247/0xb80 ... '''

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Forcibly leave SMM mode on SHUTDOWN interception Previously, commit ed129ec9057f ("KVM: x86: forcibly leave nested mode on vCPU reset") addressed an issue where a triple fault occurring in nested mode could lead to use-after-free scenarios. However, the commit did not handle the analogous situation for System Management Mode (SMM). This omission results in triggering a WARN when KVM forces a vCPU INIT after SHUTDOWN interception while the vCPU is in SMM. This situation was reprodused using Syzkaller by: 1) Creating a KVM VM and vCPU 2) Sending a KVM_SMI ioctl to explicitly enter SMM 3) Executing invalid instructions causing consecutive exceptions and eventually a triple fault The issue manifests as follows: WARNING: CPU: 0 PID: 25506 at arch/x86/kvm/x86.c:12112 kvm_vcpu_reset+0x1d2/0x1530 arch/x86/kvm/x86.c:12112 Modules linked in: CPU: 0 PID: 25506 Comm: syz-executor.0 Not tainted 6.1.130-syzkaller-00157-g164fe5dde9b6 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:kvm_vcpu_reset+0x1d2/0x1530 arch/x86/kvm/x86.c:12112 Call Trace: <TASK> shutdown_interception+0x66/0xb0 arch/x86/kvm/svm/svm.c:2136 svm_invoke_exit_handler+0x110/0x530 arch/x86/kvm/svm/svm.c:3395 svm_handle_exit+0x424/0x920 arch/x86/kvm/svm/svm.c:3457 vcpu_enter_guest arch/x86/kvm/x86.c:10959 [inline] vcpu_run+0x2c43/0x5a90 arch/x86/kvm/x86.c:11062 kvm_arch_vcpu_ioctl_run+0x50f/0x1cf0 arch/x86/kvm/x86.c:11283 kvm_vcpu_ioctl+0x570/0xf00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4122 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Architecturally, INIT is blocked when the CPU is in SMM, hence KVM's WARN() in kvm_vcpu_reset() to guard against KVM bugs, e.g. to detect improper emulation of INIT. SHUTDOWN on SVM is a weird edge case where KVM needs to do _something_ sane with the VMCB, since it's technically undefined, and INIT is the least awful choice given KVM's ABI. So, double down on stuffing INIT on SHUTDOWN, and force the vCPU out of SMM to avoid any weirdness (and the WARN). Found by Linux Verification Center (linuxtesting.org) with Syzkaller. [sean: massage changelog, make it clear this isn't architectural behavior]

In the Linux kernel, the following vulnerability has been resolved: mtd: inftlcore: Add error check for inftl_read_oob() In INFTL_findwriteunit(), the return value of inftl_read_oob() need to be checked. A proper implementation can be found in INFTL_deleteblock(). The status will be set as SECTOR_IGNORE to break from the while-loop correctly if the inftl_read_oob() fails.

In the Linux kernel, the following vulnerability has been resolved: scsi: smartpqi: Use is_kdump_kernel() to check for kdump The smartpqi driver checks the reset_devices variable to determine whether special adjustments need to be made for kdump. This has the effect that after a regular kexec reboot, some driver parameters such as max_transfer_size are much lower than usual. More importantly, kexec reboot tests have revealed memory corruption caused by the driver log being written to system memory after a kexec. Fix this by testing is_kdump_kernel() rather than reset_devices where appropriate.

In the Linux kernel, the following vulnerability has been resolved: s390/pci: Fix duplicate pci_dev_put() in disable_slot() when PF has child VFs With commit bcb5d6c76903 ("s390/pci: introduce lock to synchronize state of zpci_dev's") the code to ignore power off of a PF that has child VFs was changed from a direct return to a goto to the unlock and pci_dev_put() section. The change however left the existing pci_dev_put() untouched resulting in a doubple put. This can subsequently cause a use after free if the struct pci_dev is released in an unexpected state. Fix this by removing the extra pci_dev_put().

An issue was discovered in yurex_read in drivers/usb/misc/yurex.c in the Linux kernel before 4.17.7. Local attackers could use user access read/writes with incorrect bounds checking in the yurex USB driver to crash the kernel or potentially escalate privileges.

In the Linux kernel, the following vulnerability has been resolved: net_sched: ets: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of ets, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. In addition to checking for qlen being zero, this patch checks whether the class was already added to the active_list (cl_is_active) before doing the addition to cater for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Fix potential buffer overflow in parse_ivrs_acpihid There is a string parsing logic error which can lead to an overflow of hid or uid buffers. Comparing ACPIID_LEN against a total string length doesn't take into account the lengths of individual hid and uid buffers so the check is insufficient in some cases. For example if the length of hid string is 4 and the length of the uid string is 260, the length of str will be equal to ACPIID_LEN + 1 but uid string will overflow uid buffer which size is 256. The same applies to the hid string with length 13 and uid string with length 250. Check the length of hid and uid strings separately to prevent buffer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix mode1 reset crash issue If HW scheduler hangs and mode1 reset is used to recover GPU, KFD signal user space to abort the processes. After process abort exit, user queues still use the GPU to access system memory before h/w is reset while KFD cleanup worker free system memory and free VRAM. There is use-after-free race bug that KFD allocate and reuse the freed system memory, and user queue write to the same system memory to corrupt the data structure and cause driver crash. To fix this race, KFD cleanup worker terminate user queues, then flush reset_domain wq to wait for any GPU ongoing reset complete, and then free outstanding BOs.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix max_sge overflow in smb_extract_folioq_to_rdma() This fixes the following problem: [ 749.901015] [ T8673] run fstests cifs/001 at 2025-06-17 09:40:30 [ 750.346409] [ T9870] ================================================================== [ 750.346814] [ T9870] BUG: KASAN: slab-out-of-bounds in smb_set_sge+0x2cc/0x3b0 [cifs] [ 750.347330] [ T9870] Write of size 8 at addr ffff888011082890 by task xfs_io/9870 [ 750.347705] [ T9870] [ 750.348077] [ T9870] CPU: 0 UID: 0 PID: 9870 Comm: xfs_io Kdump: loaded Not tainted 6.16.0-rc2-metze.02+ #1 PREEMPT(voluntary) [ 750.348082] [ T9870] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 750.348085] [ T9870] Call Trace: [ 750.348086] [ T9870] <TASK> [ 750.348088] [ T9870] dump_stack_lvl+0x76/0xa0 [ 750.348106] [ T9870] print_report+0xd1/0x640 [ 750.348116] [ T9870] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 750.348120] [ T9870] ? kasan_complete_mode_report_info+0x26/0x210 [ 750.348124] [ T9870] kasan_report+0xe7/0x130 [ 750.348128] [ T9870] ? smb_set_sge+0x2cc/0x3b0 [cifs] [ 750.348262] [ T9870] ? smb_set_sge+0x2cc/0x3b0 [cifs] [ 750.348377] [ T9870] __asan_report_store8_noabort+0x17/0x30 [ 750.348381] [ T9870] smb_set_sge+0x2cc/0x3b0 [cifs] [ 750.348496] [ T9870] smbd_post_send_iter+0x1990/0x3070 [cifs] [ 750.348625] [ T9870] ? __pfx_smbd_post_send_iter+0x10/0x10 [cifs] [ 750.348741] [ T9870] ? update_stack_state+0x2a0/0x670 [ 750.348749] [ T9870] ? cifs_flush+0x153/0x320 [cifs] [ 750.348870] [ T9870] ? cifs_flush+0x153/0x320 [cifs] [ 750.348990] [ T9870] ? update_stack_state+0x2a0/0x670 [ 750.348995] [ T9870] smbd_send+0x58c/0x9c0 [cifs] [ 750.349117] [ T9870] ? __pfx_smbd_send+0x10/0x10 [cifs] [ 750.349231] [ T9870] ? unwind_get_return_address+0x65/0xb0 [ 750.349235] [ T9870] ? __pfx_stack_trace_consume_entry+0x10/0x10 [ 750.349242] [ T9870] ? arch_stack_walk+0xa7/0x100 [ 750.349250] [ T9870] ? stack_trace_save+0x92/0xd0 [ 750.349254] [ T9870] __smb_send_rqst+0x931/0xec0 [cifs] [ 750.349374] [ T9870] ? kernel_text_address+0x173/0x190 [ 750.349379] [ T9870] ? kasan_save_stack+0x39/0x70 [ 750.349382] [ T9870] ? kasan_save_track+0x18/0x70 [ 750.349385] [ T9870] ? __kasan_slab_alloc+0x9d/0xa0 [ 750.349389] [ T9870] ? __pfx___smb_send_rqst+0x10/0x10 [cifs] [ 750.349508] [ T9870] ? smb2_mid_entry_alloc+0xb4/0x7e0 [cifs] [ 750.349626] [ T9870] ? cifs_call_async+0x277/0xb00 [cifs] [ 750.349746] [ T9870] ? cifs_issue_write+0x256/0x610 [cifs] [ 750.349867] [ T9870] ? netfs_do_issue_write+0xc2/0x340 [netfs] [ 750.349900] [ T9870] ? netfs_advance_write+0x45b/0x1270 [netfs] [ 750.349929] [ T9870] ? netfs_write_folio+0xd6c/0x1be0 [netfs] [ 750.349958] [ T9870] ? netfs_writepages+0x2e9/0xa80 [netfs] [ 750.349987] [ T9870] ? do_writepages+0x21f/0x590 [ 750.349993] [ T9870] ? filemap_fdatawrite_wbc+0xe1/0x140 [ 750.349997] [ T9870] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 750.350002] [ T9870] smb_send_rqst+0x22e/0x2f0 [cifs] [ 750.350131] [ T9870] ? __pfx_smb_send_rqst+0x10/0x10 [cifs] [ 750.350255] [ T9870] ? local_clock_noinstr+0xe/0xd0 [ 750.350261] [ T9870] ? kasan_save_alloc_info+0x37/0x60 [ 750.350268] [ T9870] ? __kasan_check_write+0x14/0x30 [ 750.350271] [ T9870] ? _raw_spin_lock+0x81/0xf0 [ 750.350275] [ T9870] ? __pfx__raw_spin_lock+0x10/0x10 [ 750.350278] [ T9870] ? smb2_setup_async_request+0x293/0x580 [cifs] [ 750.350398] [ T9870] cifs_call_async+0x477/0xb00 [cifs] [ 750.350518] [ T9870] ? __pfx_smb2_writev_callback+0x10/0x10 [cifs] [ 750.350636] [ T9870] ? __pfx_cifs_call_async+0x10/0x10 [cifs] [ 750.350756] [ T9870] ? __pfx__raw_spin_lock+0x10/0x10 [ 750.350760] [ T9870] ? __kasan_check_write+0x14/0x30 [ 750.350763] [ T98 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: mcb: fix a double free bug in chameleon_parse_gdd() In chameleon_parse_gdd(), if mcb_device_register() fails, 'mdev' would be released in mcb_device_register() via put_device(). Thus, goto 'err' label and free 'mdev' again causes a double free. Just return if mcb_device_register() fails.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix UAF in __close_file_table_ids A use-after-free is possible if one thread destroys the file via __ksmbd_close_fd while another thread holds a reference to it. The existing checks on fp->refcount are not sufficient to prevent this. The fix takes ft->lock around the section which removes the file from the file table. This prevents two threads acquiring the same file pointer via __close_file_table_ids, as well as the other functions which retrieve a file from the IDR and which already use this same lock.

In the Linux kernel, the following vulnerability has been resolved: gpio: virtuser: fix potential out-of-bound write If the caller wrote more characters, count is truncated to the max available space in "simple_write_to_buffer". Check that the input size does not exceed the buffer size. Write a zero termination afterwards.

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix oob write in trace_seq_to_buffer() syzbot reported this bug: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260 CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 .... ================================================================== It has been reported that trace_seq_to_buffer() tries to copy more data than PAGE_SIZE to buf. Therefore, to prevent this, we should use the smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument.

In the Linux kernel through 4.14.13, drivers/block/loop.c mishandles lo_release serialization, which allows attackers to cause a denial of service (__lock_acquire use-after-free) or possibly have unspecified other impact.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in session logoff The sess->user object can currently be in use by another thread, for example if another connection has sent a session setup request to bind to the session being free'd. The handler for that connection could be in the smb2_sess_setup function which makes use of sess->user.

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: fix nested key length validation in the set() action It's not safe to access nla_len(ovs_key) if the data is smaller than the netlink header. Check that the attribute is OK first.

In the Linux kernel, the following vulnerability has been resolved: jffs2: fix use-after-free in jffs2_clear_xattr_subsystem When we mount a jffs2 image, assume that the first few blocks of the image are normal and contain at least one xattr-related inode, but the next block is abnormal. As a result, an error is returned in jffs2_scan_eraseblock(). jffs2_clear_xattr_subsystem() is then called in jffs2_build_filesystem() and then again in jffs2_do_fill_super(). Finally we can observe the following report: ================================================================== BUG: KASAN: use-after-free in jffs2_clear_xattr_subsystem+0x95/0x6ac Read of size 8 at addr ffff8881243384e0 by task mount/719 Call Trace: dump_stack+0x115/0x16b jffs2_clear_xattr_subsystem+0x95/0x6ac jffs2_do_fill_super+0x84f/0xc30 jffs2_fill_super+0x2ea/0x4c0 mtd_get_sb+0x254/0x400 mtd_get_sb_by_nr+0x4f/0xd0 get_tree_mtd+0x498/0x840 jffs2_get_tree+0x25/0x30 vfs_get_tree+0x8d/0x2e0 path_mount+0x50f/0x1e50 do_mount+0x107/0x130 __se_sys_mount+0x1c5/0x2f0 __x64_sys_mount+0xc7/0x160 do_syscall_64+0x45/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Allocated by task 719: kasan_save_stack+0x23/0x60 __kasan_kmalloc.constprop.0+0x10b/0x120 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0x1c0/0x870 jffs2_alloc_xattr_ref+0x2f/0xa0 jffs2_scan_medium.cold+0x3713/0x4794 jffs2_do_mount_fs.cold+0xa7/0x2253 jffs2_do_fill_super+0x383/0xc30 jffs2_fill_super+0x2ea/0x4c0 [...] Freed by task 719: kmem_cache_free+0xcc/0x7b0 jffs2_free_xattr_ref+0x78/0x98 jffs2_clear_xattr_subsystem+0xa1/0x6ac jffs2_do_mount_fs.cold+0x5e6/0x2253 jffs2_do_fill_super+0x383/0xc30 jffs2_fill_super+0x2ea/0x4c0 [...] The buggy address belongs to the object at ffff8881243384b8 which belongs to the cache jffs2_xattr_ref of size 48 The buggy address is located 40 bytes inside of 48-byte region [ffff8881243384b8, ffff8881243384e8) [...] ================================================================== The triggering of the BUG is shown in the following stack: ----------------------------------------------------------- jffs2_fill_super jffs2_do_fill_super jffs2_do_mount_fs jffs2_build_filesystem jffs2_scan_medium jffs2_scan_eraseblock <--- ERROR jffs2_clear_xattr_subsystem <--- free jffs2_clear_xattr_subsystem <--- free again ----------------------------------------------------------- An error is returned in jffs2_do_mount_fs(). If the error is returned by jffs2_sum_init(), the jffs2_clear_xattr_subsystem() does not need to be executed. If the error is returned by jffs2_build_filesystem(), the jffs2_clear_xattr_subsystem() also does not need to be executed again. So move jffs2_clear_xattr_subsystem() from 'out_inohash' to 'out_root' to fix this UAF problem.

In the Linux kernel, the following vulnerability has been resolved: skbuff: fix coalescing for page_pool fragment recycling Fix a use-after-free when using page_pool with page fragments. We encountered this problem during normal RX in the hns3 driver: (1) Initially we have three descriptors in the RX queue. The first one allocates PAGE1 through page_pool, and the other two allocate one half of PAGE2 each. Page references look like this: RX_BD1 _______ PAGE1 RX_BD2 _______ PAGE2 RX_BD3 _________/ (2) Handle RX on the first descriptor. Allocate SKB1, eventually added to the receive queue by tcp_queue_rcv(). (3) Handle RX on the second descriptor. Allocate SKB2 and pass it to netif_receive_skb(): netif_receive_skb(SKB2) ip_rcv(SKB2) SKB3 = skb_clone(SKB2) SKB2 and SKB3 share a reference to PAGE2 through skb_shinfo()->dataref. The other ref to PAGE2 is still held by RX_BD3: SKB2 ---+- PAGE2 SKB3 __/ / RX_BD3 _________/ (3b) Now while handling TCP, coalesce SKB3 with SKB1: tcp_v4_rcv(SKB3) tcp_try_coalesce(to=SKB1, from=SKB3) // succeeds kfree_skb_partial(SKB3) skb_release_data(SKB3) // drops one dataref SKB1 _____ PAGE1 \____ SKB2 _____ PAGE2 / RX_BD3 _________/ In skb_try_coalesce(), __skb_frag_ref() takes a page reference to PAGE2, where it should instead have increased the page_pool frag reference, pp_frag_count. Without coalescing, when releasing both SKB2 and SKB3, a single reference to PAGE2 would be dropped. Now when releasing SKB1 and SKB2, two references to PAGE2 will be dropped, resulting in underflow. (3c) Drop SKB2: af_packet_rcv(SKB2) consume_skb(SKB2) skb_release_data(SKB2) // drops second dataref page_pool_return_skb_page(PAGE2) // drops one pp_frag_count SKB1 _____ PAGE1 \____ PAGE2 / RX_BD3 _________/ (4) Userspace calls recvmsg() Copies SKB1 and releases it. Since SKB3 was coalesced with SKB1, we release the SKB3 page as well: tcp_eat_recv_skb(SKB1) skb_release_data(SKB1) page_pool_return_skb_page(PAGE1) page_pool_return_skb_page(PAGE2) // drops second pp_frag_count (5) PAGE2 is freed, but the third RX descriptor was still using it! In our case this causes IOMMU faults, but it would silently corrupt memory if the IOMMU was disabled. Change the logic that checks whether pp_recycle SKBs can be coalesced. We still reject differing pp_recycle between 'from' and 'to' SKBs, but in order to avoid the situation described above, we also reject coalescing when both 'from' and 'to' are pp_recycled and 'from' is cloned. The new logic allows coalescing a cloned pp_recycle SKB into a page refcounted one, because in this case the release (4) will drop the right reference, the one taken by skb_try_coalesce().

In the Linux kernel, the following vulnerability has been resolved: tracing: fprobe events: Fix possible UAF on modules Commit ac91052f0ae5 ("tracing: tprobe-events: Fix leakage of module refcount") moved try_module_get() from __find_tracepoint_module_cb() to find_tracepoint() caller, but that introduced a possible UAF because the module can be unloaded before try_module_get(). In this case, the module object should be freed too. Thus, try_module_get() does not only fail but may access to the freed object. To avoid that, try_module_get() in __find_tracepoint_module_cb() again.

In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a potential UAF in hfsc_dequeue() too Similarly to the previous patch, we need to safe guard hfsc_dequeue() too. But for this one, we don't have a reliable reproducer.

In the Linux kernel, the following vulnerability has been resolved: page_pool: Fix use-after-free in page_pool_recycle_in_ring syzbot reported a uaf in page_pool_recycle_in_ring: BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30 kernel/locking/lockdep.c:5862 Read of size 8 at addr ffff8880286045a0 by task syz.0.284/6943 CPU: 0 UID: 0 PID: 6943 Comm: syz.0.284 Not tainted 6.13.0-rc3-syzkaller-gdfa94ce54f41 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 lock_release+0x151/0xa30 kernel/locking/lockdep.c:5862 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] ptr_ring_produce_bh include/linux/ptr_ring.h:164 [inline] page_pool_recycle_in_ring net/core/page_pool.c:707 [inline] page_pool_put_unrefed_netmem+0x748/0xb00 net/core/page_pool.c:826 page_pool_put_netmem include/net/page_pool/helpers.h:323 [inline] page_pool_put_full_netmem include/net/page_pool/helpers.h:353 [inline] napi_pp_put_page+0x149/0x2b0 net/core/skbuff.c:1036 skb_pp_recycle net/core/skbuff.c:1047 [inline] skb_free_head net/core/skbuff.c:1094 [inline] skb_release_data+0x6c4/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] sk_skb_reason_drop+0x1c9/0x380 net/core/skbuff.c:1242 kfree_skb_reason include/linux/skbuff.h:1263 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3343 [inline] root cause is: page_pool_recycle_in_ring ptr_ring_produce spin_lock(&r->producer_lock); WRITE_ONCE(r->queue[r->producer++], ptr) //recycle last page to pool page_pool_release page_pool_scrub page_pool_empty_ring ptr_ring_consume page_pool_return_page //release all page __page_pool_destroy free_percpu(pool->recycle_stats); free(pool) //free spin_unlock(&r->producer_lock); //pool->ring uaf read recycle_stat_inc(pool, ring); page_pool can be free while page pool recycle the last page in ring. Add producer-lock barrier to page_pool_release to prevent the page pool from being free before all pages have been recycled. recycle_stat_inc() is empty when CONFIG_PAGE_POOL_STATS is not enabled, which will trigger Wempty-body build warning. Add definition for pool stat macro to fix warning.

In the Linux kernel, the following vulnerability has been resolved: dm: fix dm_blk_report_zones If dm_get_live_table() returned NULL, dm_put_live_table() was never called. Also, it is possible that md->zone_revalidate_map will change while calling this function. Only read it once, so that we are always using the same value. Otherwise we might miss a call to dm_put_live_table(). Finally, while md->zone_revalidate_map is set and a process is calling blk_revalidate_disk_zones() to set up the zone append emulation resources, it is possible that another process, perhaps triggered by blkdev_report_zones_ioctl(), will call dm_blk_report_zones(). If blk_revalidate_disk_zones() fails, these resources can be freed while the other process is still using them, causing a use-after-free error. blk_revalidate_disk_zones() will only ever be called when initially setting up the zone append emulation resources, such as when setting up a zoned dm-crypt table for the first time. Further table swaps will not set md->zone_revalidate_map or call blk_revalidate_disk_zones(). However it must be called using the new table (referenced by md->zone_revalidate_map) and the new queue limits while the DM device is suspended. dm_blk_report_zones() needs some way to distinguish between a call from blk_revalidate_disk_zones(), which must be allowed to use md->zone_revalidate_map to access this not yet activated table, and all other calls to dm_blk_report_zones(), which should not be allowed while the device is suspended and cannot use md->zone_revalidate_map, since the zone resources might be freed by the process currently calling blk_revalidate_disk_zones(). Solve this by tracking the process that sets md->zone_revalidate_map in dm_revalidate_zones() and only allowing that process to make use of it in dm_blk_report_zones().

In the Linux kernel, the following vulnerability has been resolved: platform/x86: dell-wmi-sysman: Avoid buffer overflow in current_password_store() If the 'buf' array received from the user contains an empty string, the 'length' variable will be zero. Accessing the 'buf' array element with index 'length - 1' will result in a buffer overflow. Add a check for an empty string. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: jbd2: remove wrong sb->s_sequence check Journal emptiness is not determined by sb->s_sequence == 0 but rather by sb->s_start == 0 (which is set a few lines above). Furthermore 0 is a valid transaction ID so the check can spuriously trigger. Remove the invalid WARN_ON.

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: Fix the dead loop of MPLS parse The unexpected MPLS packet may not end with the bottom label stack. When there are many stacks, The label count value has wrapped around. A dead loop occurs, soft lockup/CPU stuck finally. stack backtrace: UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26 index -1 is out of range for type '__be32 [3]' CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G OE 5.15.0-121-generic #131-Ubuntu Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021 Call Trace: <IRQ> show_stack+0x52/0x5c dump_stack_lvl+0x4a/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x36 __ubsan_handle_out_of_bounds.cold+0x44/0x49 key_extract_l3l4+0x82a/0x840 [openvswitch] ? kfree_skbmem+0x52/0xa0 key_extract+0x9c/0x2b0 [openvswitch] ovs_flow_key_extract+0x124/0x350 [openvswitch] ovs_vport_receive+0x61/0xd0 [openvswitch] ? kernel_init_free_pages.part.0+0x4a/0x70 ? get_page_from_freelist+0x353/0x540 netdev_port_receive+0xc4/0x180 [openvswitch] ? netdev_port_receive+0x180/0x180 [openvswitch] netdev_frame_hook+0x1f/0x40 [openvswitch] __netif_receive_skb_core.constprop.0+0x23a/0xf00 __netif_receive_skb_list_core+0xfa/0x240 netif_receive_skb_list_internal+0x18e/0x2a0 napi_complete_done+0x7a/0x1c0 bnxt_poll+0x155/0x1c0 [bnxt_en] __napi_poll+0x30/0x180 net_rx_action+0x126/0x280 ? bnxt_msix+0x67/0x80 [bnxt_en] handle_softirqs+0xda/0x2d0 irq_exit_rcu+0x96/0xc0 common_interrupt+0x8e/0xa0 </IRQ>

In the Linux kernel, the following vulnerability has been resolved: net_sched: qfq: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of qfq, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. This patch checks whether the class was already added to the agg->active list (cl_is_active) before doing the addition to cater for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

In the Linux kernel, the following vulnerability has been resolved: crypto: lzo - Fix compression buffer overrun Unlike the decompression code, the compression code in LZO never checked for output overruns. It instead assumes that the caller always provides enough buffer space, disregarding the buffer length provided by the caller. Add a safe compression interface that checks for the end of buffer before each write. Use the safe interface in crypto/lzo.

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: check that event count does not exceed event buffer length The event count is read from register DWC3_GEVNTCOUNT. There is a check for the count being zero, but not for exceeding the event buffer length. Check that event count does not exceed event buffer length, avoiding an out-of-bounds access when memcpy'ing the event. Crash log: Unable to handle kernel paging request at virtual address ffffffc0129be000 pc : __memcpy+0x114/0x180 lr : dwc3_check_event_buf+0xec/0x348 x3 : 0000000000000030 x2 : 000000000000dfc4 x1 : ffffffc0129be000 x0 : ffffff87aad60080 Call trace: __memcpy+0x114/0x180 dwc3_interrupt+0x24/0x34

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: pci-epf-test: Fix double free that causes kernel to oops Fix a kernel oops found while testing the stm32_pcie Endpoint driver with handling of PERST# deassertion: During EP initialization, pci_epf_test_alloc_space() allocates all BARs, which are further freed if epc_set_bar() fails (for instance, due to no free inbound window). However, when pci_epc_set_bar() fails, the error path: pci_epc_set_bar() -> pci_epf_free_space() does not clear the previous assignment to epf_test->reg[bar]. Then, if the host reboots, the PERST# deassertion restarts the BAR allocation sequence with the same allocation failure (no free inbound window), creating a double free situation since epf_test->reg[bar] was deallocated and is still non-NULL. Thus, make sure that pci_epf_alloc_space() and pci_epf_free_space() invocations are symmetric, and as such, set epf_test->reg[bar] to NULL when memory is freed. [kwilczynski: commit log]

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad4851: fix ad4858 chan pointer handling The pointer returned from ad4851_parse_channels_common() is incremented internally as each channel is populated. In ad4858_parse_channels(), the same pointer was further incremented while setting ext_scan_type fields for each channel. This resulted in indio_dev->channels being set to a pointer past the end of the allocated array, potentially causing memory corruption or undefined behavior. Fix this by iterating over the channels using an explicit index instead of incrementing the pointer. This preserves the original base pointer and ensures all channel metadata is set correctly.

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode() With ACPI in place, gicv2m_get_fwnode() is registered with the pci subsystem as pci_msi_get_fwnode_cb(), which may get invoked at runtime during a PCI host bridge probe. But, the call back is wrongly marked as __init, causing it to be freed, while being registered with the PCI subsystem and could trigger: Unable to handle kernel paging request at virtual address ffff8000816c0400 gicv2m_get_fwnode+0x0/0x58 (P) pci_set_bus_msi_domain+0x74/0x88 pci_register_host_bridge+0x194/0x548 This is easily reproducible on a Juno board with ACPI boot. Retain the function for later use.

IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 could allow a local user to overflow a buffer which may result in a privilege escalation to the DB2 instance owner. IBM X-Force ID: 142648.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix use-after-free bug of ns_writer on remount If a nilfs2 filesystem is downgraded to read-only due to metadata corruption on disk and is remounted read/write, or if emergency read-only remount is performed, detaching a log writer and synchronizing the filesystem can be done at the same time. In these cases, use-after-free of the log writer (hereinafter nilfs->ns_writer) can happen as shown in the scenario below: Task1 Task2 -------------------------------- ------------------------------ nilfs_construct_segment nilfs_segctor_sync init_wait init_waitqueue_entry add_wait_queue schedule nilfs_remount (R/W remount case) nilfs_attach_log_writer nilfs_detach_log_writer nilfs_segctor_destroy kfree finish_wait _raw_spin_lock_irqsave __raw_spin_lock_irqsave do_raw_spin_lock debug_spin_lock_before <-- use-after-free While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1 waked up, Task1 accesses nilfs->ns_writer which is already freed. This scenario diagram is based on the Shigeru Yoshida's post [1]. This patch fixes the issue by not detaching nilfs->ns_writer on remount so that this UAF race doesn't happen. Along with this change, this patch also inserts a few necessary read-only checks with superblock instance where only the ns_writer pointer was used to check if the filesystem is read-only.

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix skb length check in ieee80211_scan_rx() Replace hard-coded compile-time constants for header length check with dynamic determination based on the frame type. Otherwise, we hit a validation WARN_ON in cfg80211 later. [style fixes, reword commit message]