A flaw was found in KVM. An improper check in svm_set_x2apic_msr_interception() may allow direct access to host x2apic msrs when the guest resets its apic, potentially leading to a denial of service condition.

In intel_pmu_drain_pebs_nhm in arch/x86/events/intel/ds.c in the Linux kernel through 5.11.8 on some Haswell CPUs, userspace applications (such as perf-fuzzer) can cause a system crash because the PEBS status in a PEBS record is mishandled, aka CID-d88d05a9e0b6.

In the Linux kernel before 5.3.4, fib6_rule_lookup in net/ipv6/ip6_fib.c mishandles the RT6_LOOKUP_F_DST_NOREF flag in a reference-count decision, leading to (for example) a crash that was identified by syzkaller, aka CID-7b09c2d052db.

In the Linux kernel, the following vulnerability has been resolved: static_call: Handle module init failure correctly in static_call_del_module() Module insertion invokes static_call_add_module() to initialize the static calls in a module. static_call_add_module() invokes __static_call_init(), which allocates a struct static_call_mod to either encapsulate the built-in static call sites of the associated key into it so further modules can be added or to append the module to the module chain. If that allocation fails the function returns with an error code and the module core invokes static_call_del_module() to clean up eventually added static_call_mod entries. This works correctly, when all keys used by the module were converted over to a module chain before the failure. If not then static_call_del_module() causes a #GP as it blindly assumes that key::mods points to a valid struct static_call_mod. The problem is that key::mods is not a individual struct member of struct static_call_key, it's part of a union to save space: union { /* bit 0: 0 = mods, 1 = sites */ unsigned long type; struct static_call_mod *mods; struct static_call_site *sites; }; key::sites is a pointer to the list of built-in usage sites of the static call. The type of the pointer is differentiated by bit 0. A mods pointer has the bit clear, the sites pointer has the bit set. As static_call_del_module() blidly assumes that the pointer is a valid static_call_mod type, it fails to check for this failure case and dereferences the pointer to the list of built-in call sites, which is obviously bogus. Cure it by checking whether the key has a sites or a mods pointer. If it's a sites pointer then the key is not to be touched. As the sites are walked in the same order as in __static_call_init() the site walk can be terminated because all subsequent sites have not been touched by the init code due to the error exit. If it was converted before the allocation fail, then the inner loop which searches for a module match will find nothing. A fail in the second allocation in __static_call_init() is harmless and does not require special treatment. The first allocation succeeded and converted the key to a module chain. That first entry has mod::mod == NULL and mod::next == NULL, so the inner loop of static_call_del_module() will neither find a module match nor a module chain. The next site in the walk was either already converted, but can't match the module, or it will exit the outer loop because it has a static_call_site pointer and not a static_call_mod pointer.

An issue was discovered in drivers/input/input.c in the Linux kernel before 5.17.10. An attacker can cause a denial of service (panic) because input_set_capability mishandles the situation in which an event code falls outside of a bitmap.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix error path in multi-packet WQE transmit Remove the erroneous unmap in case no DMA mapping was established The multi-packet WQE transmit code attempts to obtain a DMA mapping for the skb. This could fail, e.g. under memory pressure, when the IOMMU driver just can't allocate more memory for page tables. While the code tries to handle this in the path below the err_unmap label it erroneously unmaps one entry from the sq's FIFO list of active mappings. Since the current map attempt failed this unmap is removing some random DMA mapping that might still be required. If the PCI function now presents that IOVA, the IOMMU may assumes a rogue DMA access and e.g. on s390 puts the PCI function in error state. The erroneous behavior was seen in a stress-test environment that created memory pressure.

In the Linux kernel, the following vulnerability has been resolved: media: dvbdev: prevent the risk of out of memory access The dvbdev contains a static variable used to store dvb minors. The behavior of it depends if CONFIG_DVB_DYNAMIC_MINORS is set or not. When not set, dvb_register_device() won't check for boundaries, as it will rely that a previous call to dvb_register_adapter() would already be enforcing it. On a similar way, dvb_device_open() uses the assumption that the register functions already did the needed checks. This can be fragile if some device ends using different calls. This also generate warnings on static check analysers like Coverity. So, add explicit guards to prevent potential risk of OOM issues.

In the Linux kernel, the following vulnerability has been resolved: remoteproc: k3-r5: Fix error handling when power-up failed By simply bailing out, the driver was violating its rule and internal assumptions that either both or no rproc should be initialized. E.g., this could cause the first core to be available but not the second one, leading to crashes on its shutdown later on while trying to dereference that second instance.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: propagate directory read errors from nilfs_find_entry() Syzbot reported that a task hang occurs in vcs_open() during a fuzzing test for nilfs2. The root cause of this problem is that in nilfs_find_entry(), which searches for directory entries, ignores errors when loading a directory page/folio via nilfs_get_folio() fails. If the filesystem images is corrupted, and the i_size of the directory inode is large, and the directory page/folio is successfully read but fails the sanity check, for example when it is zero-filled, nilfs_check_folio() may continue to spit out error messages in bursts. Fix this issue by propagating the error to the callers when loading a page/folio fails in nilfs_find_entry(). The current interface of nilfs_find_entry() and its callers is outdated and cannot propagate error codes such as -EIO and -ENOMEM returned via nilfs_find_entry(), so fix it together.

In the Linux kernel, the following vulnerability has been resolved: parisc: Clear stale IIR value on instruction access rights trap When a trap 7 (Instruction access rights) occurs, this means the CPU couldn't execute an instruction due to missing execute permissions on the memory region. In this case it seems the CPU didn't even fetched the instruction from memory and thus did not store it in the cr19 (IIR) register before calling the trap handler. So, the trap handler will find some random old stale value in cr19. This patch simply overwrites the stale IIR value with a constant magic "bad food" value (0xbaadf00d), in the hope people don't start to try to understand the various random IIR values in trap 7 dumps.

In the Linux kernel, the following vulnerability has been resolved: net: tls: handle backlogging of crypto requests Since we're setting the CRYPTO_TFM_REQ_MAY_BACKLOG flag on our requests to the crypto API, crypto_aead_{encrypt,decrypt} can return -EBUSY instead of -EINPROGRESS in valid situations. For example, when the cryptd queue for AESNI is full (easy to trigger with an artificially low cryptd.cryptd_max_cpu_qlen), requests will be enqueued to the backlog but still processed. In that case, the async callback will also be called twice: first with err == -EINPROGRESS, which it seems we can just ignore, then with err == 0. Compared to Sabrina's original patch this version uses the new tls_*crypt_async_wait() helpers and converts the EBUSY to EINPROGRESS to avoid having to modify all the error handling paths. The handling is identical.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: ncm: Fix handling of zero block length packets While connecting to a Linux host with CDC_NCM_NTB_DEF_SIZE_TX set to 65536, it has been observed that we receive short packets, which come at interval of 5-10 seconds sometimes and have block length zero but still contain 1-2 valid datagrams present. According to the NCM spec: "If wBlockLength = 0x0000, the block is terminated by a short packet. In this case, the USB transfer must still be shorter than dwNtbInMaxSize or dwNtbOutMaxSize. If exactly dwNtbInMaxSize or dwNtbOutMaxSize bytes are sent, and the size is a multiple of wMaxPacketSize for the given pipe, then no ZLP shall be sent. wBlockLength= 0x0000 must be used with extreme care, because of the possibility that the host and device may get out of sync, and because of test issues. wBlockLength = 0x0000 allows the sender to reduce latency by starting to send a very large NTB, and then shortening it when the sender discovers that there’s not sufficient data to justify sending a large NTB" However, there is a potential issue with the current implementation, as it checks for the occurrence of multiple NTBs in a single giveback by verifying if the leftover bytes to be processed is zero or not. If the block length reads zero, we would process the same NTB infintely because the leftover bytes is never zero and it leads to a crash. Fix this by bailing out if block length reads zero.

In nf_tables_updtable, if nf_tables_table_enable returns an error, nft_trans_destroy is called to free the transaction object. nft_trans_destroy() calls list_del(), but the transaction was never placed on a list -- the list head is all zeroes, this results in a NULL pointer dereference.

The Linux kernel io_uring IORING_OP_SOCKET operation contained a double free in function __sys_socket_file() in file net/socket.c. This issue was introduced in da214a475f8bd1d3e9e7a19ddfeb4d1617551bab and fixed in 649c15c7691e9b13cbe9bf6c65c365350e056067.

A vulnerability was reported in the Open vSwitch sub-component in the Linux Kernel. The flaw occurs when a recursive operation of code push recursively calls into the code block. The OVS module does not validate the stack depth, pushing too many frames and causing a stack overflow. As a result, this can lead to a crash or other related issues.

In the Linux kernel, the following vulnerability has been resolved: md/raid10: wait barrier before returning discard request with REQ_NOWAIT raid10_handle_discard should wait barrier before returning a discard bio which has REQ_NOWAIT. And there is no need to print warning calltrace if a discard bio has REQ_NOWAIT flag. Quality engineer usually checks dmesg and reports error if dmesg has warning/error calltrace.

A flaw was found in the Linux Kernel before 5.8-rc6 in the ZRAM kernel module, where a user with a local account and the ability to read the /sys/class/zram-control/hot_add file can create ZRAM device nodes in the /dev/ directory. This read allocates kernel memory and is not accounted for a user that triggers the creation of that ZRAM device. With this vulnerability, continually reading the device may consume a large amount of system memory and cause the Out-of-Memory (OOM) killer to activate and terminate random userspace processes, possibly making the system inoperable.

A flaw was found in the Linux kernel. A denial of service problem is identified if an extent tree is corrupted in a crafted ext4 filesystem in fs/ext4/extents.c in ext4_es_cache_extent. Fabricating an integer overflow, A local attacker with a special user privilege may cause a system crash problem which can lead to an availability threat.

In the Linux kernel, the following vulnerability has been resolved: x86/vmscape: Add conditional IBPB mitigation VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit. Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB. This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace. The intent is to integrate and optimize these cases post-embargo. [ dhansen: elaborate on suboptimal IBPB solution ]

The (1) real_lookup and (2) __lookup_hash functions in fs/namei.c in the vfs implementation in the Linux kernel before 2.6.25.15 do not prevent creation of a child dentry for a deleted (aka S_DEAD) directory, which allows local users to cause a denial of service ("overflow" of the UBIFS orphan area) via a series of attempted file creations within deleted directories.

An issue was discovered in drivers/tty/n_gsm.c in the Linux kernel 6.2. There is a sleeping function called from an invalid context in gsmld_write, which will block the kernel. Note: This has been disputed by 3rd parties as not a valid vulnerability.

In the Linux kernel, the following vulnerability has been resolved: usbnet: Fix using smp_processor_id() in preemptible code warnings Syzbot reported the following warning: BUG: using smp_processor_id() in preemptible [00000000] code: dhcpcd/2879 caller is usbnet_skb_return+0x74/0x490 drivers/net/usb/usbnet.c:331 CPU: 1 UID: 0 PID: 2879 Comm: dhcpcd Not tainted 6.15.0-rc4-syzkaller-00098-g615dca38c2ea #0 PREEMPT(voluntary) Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 check_preemption_disabled+0xd0/0xe0 lib/smp_processor_id.c:49 usbnet_skb_return+0x74/0x490 drivers/net/usb/usbnet.c:331 usbnet_resume_rx+0x4b/0x170 drivers/net/usb/usbnet.c:708 usbnet_change_mtu+0x1be/0x220 drivers/net/usb/usbnet.c:417 __dev_set_mtu net/core/dev.c:9443 [inline] netif_set_mtu_ext+0x369/0x5c0 net/core/dev.c:9496 netif_set_mtu+0xb0/0x160 net/core/dev.c:9520 dev_set_mtu+0xae/0x170 net/core/dev_api.c:247 dev_ifsioc+0xa31/0x18d0 net/core/dev_ioctl.c:572 dev_ioctl+0x223/0x10e0 net/core/dev_ioctl.c:821 sock_do_ioctl+0x19d/0x280 net/socket.c:1204 sock_ioctl+0x42f/0x6a0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f For historical and portability reasons, the netif_rx() is usually run in the softirq or interrupt context, this commit therefore add local_bh_disable/enable() protection in the usbnet_resume_rx().

In the Linux kernel, the following vulnerability has been resolved: ceph: fix crash after fscrypt_encrypt_pagecache_blocks() error The function move_dirty_folio_in_page_array() was created by commit ce80b76dd327 ("ceph: introduce ceph_process_folio_batch() method") by moving code from ceph_writepages_start() to this function. This new function is supposed to return an error code which is checked by the caller (now ceph_process_folio_batch()), and on error, the caller invokes redirty_page_for_writepage() and then breaks from the loop. However, the refactoring commit has gone wrong, and it by accident, it always returns 0 (= success) because it first NULLs the pointer and then returns PTR_ERR(NULL) which is always 0. This means errors are silently ignored, leaving NULL entries in the page array, which may later crash the kernel. The simple solution is to call PTR_ERR() before clearing the pointer.

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Optimize module load time by optimizing PLT/GOT counting When enabling CONFIG_KASAN, CONFIG_PREEMPT_VOLUNTARY_BUILD and CONFIG_PREEMPT_VOLUNTARY at the same time, there will be soft deadlock, the relevant logs are as follows: rcu: INFO: rcu_sched self-detected stall on CPU ... Call Trace: [<900000000024f9e4>] show_stack+0x5c/0x180 [<90000000002482f4>] dump_stack_lvl+0x94/0xbc [<9000000000224544>] rcu_dump_cpu_stacks+0x1fc/0x280 [<900000000037ac80>] rcu_sched_clock_irq+0x720/0xf88 [<9000000000396c34>] update_process_times+0xb4/0x150 [<90000000003b2474>] tick_nohz_handler+0xf4/0x250 [<9000000000397e28>] __hrtimer_run_queues+0x1d0/0x428 [<9000000000399b2c>] hrtimer_interrupt+0x214/0x538 [<9000000000253634>] constant_timer_interrupt+0x64/0x80 [<9000000000349938>] __handle_irq_event_percpu+0x78/0x1a0 [<9000000000349a78>] handle_irq_event_percpu+0x18/0x88 [<9000000000354c00>] handle_percpu_irq+0x90/0xf0 [<9000000000348c74>] handle_irq_desc+0x94/0xb8 [<9000000001012b28>] handle_cpu_irq+0x68/0xa0 [<9000000001def8c0>] handle_loongarch_irq+0x30/0x48 [<9000000001def958>] do_vint+0x80/0xd0 [<9000000000268a0c>] kasan_mem_to_shadow.part.0+0x2c/0x2a0 [<90000000006344f4>] __asan_load8+0x4c/0x120 [<900000000025c0d0>] module_frob_arch_sections+0x5c8/0x6b8 [<90000000003895f0>] load_module+0x9e0/0x2958 [<900000000038b770>] __do_sys_init_module+0x208/0x2d0 [<9000000001df0c34>] do_syscall+0x94/0x190 [<900000000024d6fc>] handle_syscall+0xbc/0x158 After analysis, this is because the slow speed of loading the amdgpu module leads to the long time occupation of the cpu and then the soft deadlock. When loading a module, module_frob_arch_sections() tries to figure out the number of PLTs/GOTs that will be needed to handle all the RELAs. It will call the count_max_entries() to find in an out-of-order date which counting algorithm has O(n^2) complexity. To make it faster, we sort the relocation list by info and addend. That way, to check for a duplicate relocation, it just needs to compare with the previous entry. This reduces the complexity of the algorithm to O(n log n), as done in commit d4e0340919fb ("arm64/module: Optimize module load time by optimizing PLT counting"). This gives sinificant reduction in module load time for modules with large number of relocations. After applying this patch, the soft deadlock problem has been solved, and the kernel starts normally without "Call Trace". Using the default configuration to test some modules, the results are as follows: Module Size ip_tables 36K fat 143K radeon 2.5MB amdgpu 16MB Without this patch: Module Module load time (ms) Count(PLTs/GOTs) ip_tables 18 59/6 fat 0 162/14 radeon 54 1221/84 amdgpu 1411 4525/1098 With this patch: Module Module load time (ms) Count(PLTs/GOTs) ip_tables 18 59/6 fat 0 162/14 radeon 22 1221/84 amdgpu 45 4525/1098

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix refcount leak causing resource not released When ksmbd_conn_releasing(opinfo->conn) returns true,the refcount was not decremented properly, causing a refcount leak that prevents the count from reaching zero and the memory from being released.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Remove skb secpath if xfrm state is not found Hardware returns a unique identifier for a decrypted packet's xfrm state, this state is looked up in an xarray. However, the state might have been freed by the time of this lookup. Currently, if the state is not found, only a counter is incremented. The secpath (sp) extension on the skb is not removed, resulting in sp->len becoming 0. Subsequently, functions like __xfrm_policy_check() attempt to access fields such as xfrm_input_state(skb)->xso.type (which dereferences sp->xvec[sp->len - 1]) without first validating sp->len. This leads to a crash when dereferencing an invalid state pointer. This patch prevents the crash by explicitly removing the secpath extension from the skb if the xfrm state is not found after hardware decryption. This ensures downstream functions do not operate on a zero-length secpath. BUG: unable to handle page fault for address: ffffffff000002c8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 282e067 P4D 282e067 PUD 0 Oops: Oops: 0000 [#1] SMP CPU: 12 UID: 0 PID: 0 Comm: swapper/12 Not tainted 6.15.0-rc7_for_upstream_min_debug_2025_05_27_22_44 #1 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:__xfrm_policy_check+0x61a/0xa30 Code: b6 77 7f 83 e6 02 74 14 4d 8b af d8 00 00 00 41 0f b6 45 05 c1 e0 03 48 98 49 01 c5 41 8b 45 00 83 e8 01 48 98 49 8b 44 c5 10 <0f> b6 80 c8 02 00 00 83 e0 0c 3c 04 0f 84 0c 02 00 00 31 ff 80 fa RSP: 0018:ffff88885fb04918 EFLAGS: 00010297 RAX: ffffffff00000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffffff8311af80 R08: 0000000000000020 R09: 00000000c2eda353 R10: ffff88812be2bbc8 R11: 000000001faab533 R12: ffff88885fb049c8 R13: ffff88812be2bbc8 R14: 0000000000000000 R15: ffff88811896ae00 FS: 0000000000000000(0000) GS:ffff8888dca82000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff000002c8 CR3: 0000000243050002 CR4: 0000000000372eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> ? try_to_wake_up+0x108/0x4c0 ? udp4_lib_lookup2+0xbe/0x150 ? udp_lib_lport_inuse+0x100/0x100 ? __udp4_lib_lookup+0x2b0/0x410 __xfrm_policy_check2.constprop.0+0x11e/0x130 udp_queue_rcv_one_skb+0x1d/0x530 udp_unicast_rcv_skb+0x76/0x90 __udp4_lib_rcv+0xa64/0xe90 ip_protocol_deliver_rcu+0x20/0x130 ip_local_deliver_finish+0x75/0xa0 ip_local_deliver+0xc1/0xd0 ? ip_protocol_deliver_rcu+0x130/0x130 ip_sublist_rcv+0x1f9/0x240 ? ip_rcv_finish_core+0x430/0x430 ip_list_rcv+0xfc/0x130 __netif_receive_skb_list_core+0x181/0x1e0 netif_receive_skb_list_internal+0x200/0x360 ? mlx5e_build_rx_skb+0x1bc/0xda0 [mlx5_core] gro_receive_skb+0xfd/0x210 mlx5e_handle_rx_cqe_mpwrq+0x141/0x280 [mlx5_core] mlx5e_poll_rx_cq+0xcc/0x8e0 [mlx5_core] ? mlx5e_handle_rx_dim+0x91/0xd0 [mlx5_core] mlx5e_napi_poll+0x114/0xab0 [mlx5_core] __napi_poll+0x25/0x170 net_rx_action+0x32d/0x3a0 ? mlx5_eq_comp_int+0x8d/0x280 [mlx5_core] ? notifier_call_chain+0x33/0xa0 handle_softirqs+0xda/0x250 irq_exit_rcu+0x6d/0xc0 common_interrupt+0x81/0xa0 </IRQ>

In the Linux kernel, the following vulnerability has been resolved: jfs: Regular file corruption check The reproducer builds a corrupted file on disk with a negative i_size value. Add a check when opening this file to avoid subsequent operation failures.

In the Linux kernel, the following vulnerability has been resolved: drm/mediatek: Add error handling for old state CRTC in atomic_disable Introduce error handling to address an issue where, after a hotplug event, the cursor continues to update. This situation can lead to a kernel panic due to accessing the NULL `old_state->crtc`. E,g. Unable to handle kernel NULL pointer dereference at virtual address Call trace: mtk_crtc_plane_disable+0x24/0x140 mtk_plane_atomic_update+0x8c/0xa8 drm_atomic_helper_commit_planes+0x114/0x2c8 drm_atomic_helper_commit_tail_rpm+0x4c/0x158 commit_tail+0xa0/0x168 drm_atomic_helper_commit+0x110/0x120 drm_atomic_commit+0x8c/0xe0 drm_atomic_helper_update_plane+0xd4/0x128 __setplane_atomic+0xcc/0x110 drm_mode_cursor_common+0x250/0x440 drm_mode_cursor_ioctl+0x44/0x70 drm_ioctl+0x264/0x5d8 __arm64_sys_ioctl+0xd8/0x510 invoke_syscall+0x6c/0xe0 do_el0_svc+0x68/0xe8 el0_svc+0x34/0x60 el0t_64_sync_handler+0x1c/0xf8 el0t_64_sync+0x180/0x188 Adding NULL pointer checks to ensure stability by preventing operations on an invalid CRTC state.

In the Linux kernel, the following vulnerability has been resolved: PCI: pnv_php: Clean up allocated IRQs on unplug When the root of a nested PCIe bridge configuration is unplugged, the pnv_php driver leaked the allocated IRQ resources for the child bridges' hotplug event notifications, resulting in a panic. Fix this by walking all child buses and deallocating all its IRQ resources before calling pci_hp_remove_devices(). Also modify the lifetime of the workqueue at struct pnv_php_slot::wq so that it is only destroyed in pnv_php_free_slot(), instead of pnv_php_disable_irq(). This is required since pnv_php_disable_irq() will now be called by workers triggered by hot unplug interrupts, so the workqueue needs to stay allocated. The abridged kernel panic that occurs without this patch is as follows: WARNING: CPU: 0 PID: 687 at kernel/irq/msi.c:292 msi_device_data_release+0x6c/0x9c CPU: 0 UID: 0 PID: 687 Comm: bash Not tainted 6.14.0-rc5+ #2 Call Trace: msi_device_data_release+0x34/0x9c (unreliable) release_nodes+0x64/0x13c devres_release_all+0xc0/0x140 device_del+0x2d4/0x46c pci_destroy_dev+0x5c/0x194 pci_hp_remove_devices+0x90/0x128 pci_hp_remove_devices+0x44/0x128 pnv_php_disable_slot+0x54/0xd4 power_write_file+0xf8/0x18c pci_slot_attr_store+0x40/0x5c sysfs_kf_write+0x64/0x78 kernfs_fop_write_iter+0x1b0/0x290 vfs_write+0x3bc/0x50c ksys_write+0x84/0x140 system_call_exception+0x124/0x230 system_call_vectored_common+0x15c/0x2ec [bhelgaas: tidy comments]

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_nfacct: don't assume acct name is null-terminated BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721 Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851 [..] string+0x231/0x2b0 lib/vsprintf.c:721 vsnprintf+0x739/0xf00 lib/vsprintf.c:2874 [..] nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41 xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523 nfnl_acct_find_get() handles non-null input, but the error printk relied on its presence.

In the Linux kernel, the following vulnerability has been resolved: i2c: rtl9300: ensure data length is within supported range Add an explicit check for the xfer length to 'rtl9300_i2c_config_xfer' to ensure the data length isn't within the supported range. In particular a data length of 0 is not supported by the hardware and causes unintended or destructive behaviour. This limitation becomes obvious when looking at the register documentation [1]. 4 bits are reserved for DATA_WIDTH and the value of these 4 bits is used as N + 1, allowing a data length range of 1 <= len <= 16. Affected by this is the SMBus Quick Operation which works with a data length of 0. Passing 0 as the length causes an underflow of the value due to: (len - 1) & 0xf and effectively specifying a transfer length of 16 via the registers. This causes a 16-byte write operation instead of a Quick Write. For example, on SFP modules without write-protected EEPROM this soft-bricks them by overwriting some initial bytes. For completeness, also add a quirk for the zero length. [1] https://svanheule.net/realtek/longan/register/i2c_mst1_ctrl2

In the Linux kernel, the following vulnerability has been resolved: ice: fix NULL pointer dereference in ice_unplug_aux_dev() on reset Issuing a reset when the driver is loaded without RDMA support, will results in a crash as it attempts to remove RDMA's non-existent auxbus device: echo 1 > /sys/class/net/<if>/device/reset BUG: kernel NULL pointer dereference, address: 0000000000000008 ... RIP: 0010:ice_unplug_aux_dev+0x29/0x70 [ice] ... Call Trace: <TASK> ice_prepare_for_reset+0x77/0x260 [ice] pci_dev_save_and_disable+0x2c/0x70 pci_reset_function+0x88/0x130 reset_store+0x5a/0xa0 kernfs_fop_write_iter+0x15e/0x210 vfs_write+0x273/0x520 ksys_write+0x6b/0xe0 do_syscall_64+0x79/0x3b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ice_unplug_aux_dev() checks pf->cdev_info->adev for NULL pointer, but pf->cdev_info will also be NULL, leading to the deref in the trace above. Introduce a flag to be set when the creation of the auxbus device is successful, to avoid multiple NULL pointer checks in ice_unplug_aux_dev().

In the Linux kernel, the following vulnerability has been resolved: nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails Have nvmet_req_init() and req->execute() complete failed commands. Description of the problem: nvmet_req_init() calls __nvmet_req_complete() internally upon failure, e.g., unsupported opcode, which calls the "queue_response" callback, this results in nvmet_pci_epf_queue_response() being called, which will call nvmet_pci_epf_complete_iod() if data_len is 0 or if dma_dir is different from DMA_TO_DEVICE. This results in a double completion as nvmet_pci_epf_exec_iod_work() also calls nvmet_pci_epf_complete_iod() when nvmet_req_init() fails. Steps to reproduce: On the host send a command with an unsupported opcode with nvme-cli, For example the admin command "security receive" $ sudo nvme security-recv /dev/nvme0n1 -n1 -x4096 This triggers a double completion as nvmet_req_init() fails and nvmet_pci_epf_queue_response() is called, here iod->dma_dir is still in the default state of "DMA_NONE" as set by default in nvmet_pci_epf_alloc_iod(), so nvmet_pci_epf_complete_iod() is called. Because nvmet_req_init() failed nvmet_pci_epf_complete_iod() is also called in nvmet_pci_epf_exec_iod_work() leading to a double completion. This not only sends two completions to the host but also corrupts the state of the PCI NVMe target leading to kernel oops. This patch lets nvmet_req_init() and req->execute() complete all failed commands, and removes the double completion case in nvmet_pci_epf_exec_iod_work() therefore fixing the edge cases where double completions occurred.

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: Remove WARN_ON for device endpoint command timeouts This commit addresses a rarely observed endpoint command timeout which causes kernel panic due to warn when 'panic_on_warn' is enabled and unnecessary call trace prints when 'panic_on_warn' is disabled. It is seen during fast software-controlled connect/disconnect testcases. The following is one such endpoint command timeout that we observed: 1. Connect ======= ->dwc3_thread_interrupt ->dwc3_ep0_interrupt ->configfs_composite_setup ->composite_setup ->usb_ep_queue ->dwc3_gadget_ep0_queue ->__dwc3_gadget_ep0_queue ->__dwc3_ep0_do_control_data ->dwc3_send_gadget_ep_cmd 2. Disconnect ========== ->dwc3_thread_interrupt ->dwc3_gadget_disconnect_interrupt ->dwc3_ep0_reset_state ->dwc3_ep0_end_control_data ->dwc3_send_gadget_ep_cmd In the issue scenario, in Exynos platforms, we observed that control transfers for the previous connect have not yet been completed and end transfer command sent as a part of the disconnect sequence and processing of USB_ENDPOINT_HALT feature request from the host timeout. This maybe an expected scenario since the controller is processing EP commands sent as a part of the previous connect. It maybe better to remove WARN_ON in all places where device endpoint commands are sent to avoid unnecessary kernel panic due to warn.

In the Linux kernel, the following vulnerability has been resolved: mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE With CONFIG_HIGHPTE on 32-bit ARM, move_pages_pte() maps PTE pages using kmap_local_page(), which requires unmapping in Last-In-First-Out order. The current code maps dst_pte first, then src_pte, but unmaps them in the same order (dst_pte, src_pte), violating the LIFO requirement. This causes the warning in kunmap_local_indexed(): WARNING: CPU: 0 PID: 604 at mm/highmem.c:622 kunmap_local_indexed+0x178/0x17c addr \!= __fix_to_virt(FIX_KMAP_BEGIN + idx) Fix this by reversing the unmap order to respect LIFO ordering. This issue follows the same pattern as similar fixes: - commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order") - commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename") Both of which addressed the same fundamental requirement that kmap_local operations must follow LIFO ordering.

In the Linux kernel, the following vulnerability has been resolved: ocfs2: prevent release journal inode after journal shutdown Before calling ocfs2_delete_osb(), ocfs2_journal_shutdown() has already been executed in ocfs2_dismount_volume(), so osb->journal must be NULL. Therefore, the following calltrace will inevitably fail when it reaches jbd2_journal_release_jbd_inode(). ocfs2_dismount_volume()-> ocfs2_delete_osb()-> ocfs2_free_slot_info()-> __ocfs2_free_slot_info()-> evict()-> ocfs2_evict_inode()-> ocfs2_clear_inode()-> jbd2_journal_release_jbd_inode(osb->journal->j_journal, Adding osb->journal checks will prevent null-ptr-deref during the above execution path.

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: add missing check for rx wcid entries Non-station wcid entries must not be passed to the rx functions. In case of the global wcid entry, it could even lead to corruption in the wcid array due to pointer being casted to struct mt7996_sta_link using container_of.

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() BUG: kernel NULL pointer dereference, address: 00000000000002ec PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Workqueue: smc_hs_wq smc_listen_work [smc] RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc] ... Call Trace: <TASK> smcr_buf_map_link+0x211/0x2a0 [smc] __smc_buf_create+0x522/0x970 [smc] smc_buf_create+0x3a/0x110 [smc] smc_find_rdma_v2_device_serv+0x18f/0x240 [smc] ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc] smc_listen_find_device+0x1dd/0x2b0 [smc] smc_listen_work+0x30f/0x580 [smc] process_one_work+0x18c/0x340 worker_thread+0x242/0x360 kthread+0xe7/0x220 ret_from_fork+0x13a/0x160 ret_from_fork_asm+0x1a/0x30 </TASK> If the software RoCE device is used, ibdev->dma_device is a null pointer. As a result, the problem occurs. Null pointer detection is added to prevent problems.

In the Linux kernel, the following vulnerability has been resolved: powercap: dtpm_cpu: Fix NULL pointer dereference in get_pd_power_uw() The get_pd_power_uw() function can crash with a NULL pointer dereference when em_cpu_get() returns NULL. This occurs when a CPU becomes impossible during runtime, causing get_cpu_device() to return NULL, which propagates through em_cpu_get() and leads to a crash when em_span_cpus() dereferences the NULL pointer. Add a NULL check after em_cpu_get() and return 0 if unavailable, matching the existing fallback behavior in __dtpm_cpu_setup(). [ rjw: Drop an excess empty code line ]

In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject invalid file types when reading inodes To prevent inodes with invalid file types from tripping through the vfs and causing malfunctions or assertion failures, add a missing sanity check when reading an inode from a block device. If the file type is not valid, treat it as a filesystem error.

In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix fp initialization for exception boundary In the ARM64 BPF JIT when prog->aux->exception_boundary is set for a BPF program, find_used_callee_regs() is not called because for a program acting as exception boundary, all callee saved registers are saved. find_used_callee_regs() sets `ctx->fp_used = true;` when it sees FP being used in any of the instructions. For programs acting as exception boundary, ctx->fp_used remains false even if frame pointer is used by the program and therefore, FP is not set-up for such programs in the prologue. This can cause the kernel to crash due to a pagefault. Fix it by setting ctx->fp_used = true for exception boundary programs as fp is always saved in such programs.

In the Linux kernel, the following vulnerability has been resolved: staging: gpib: Fix cb7210 pcmcia Oops The pcmcia_driver struct was still only using the old .name initialization in the drv field. This led to a NULL pointer deref Oops in strcmp called from pcmcia_register_driver. Initialize the pcmcia_driver struct name field.

In the Linux kernel, the following vulnerability has been resolved: fbdev: imxfb: Check fb_add_videomode to prevent null-ptr-deref fb_add_videomode() can fail with -ENOMEM when its internal kmalloc() cannot allocate a struct fb_modelist. If that happens, the modelist stays empty but the driver continues to register. Add a check for its return value to prevent poteintial null-ptr-deref, which is similar to the commit 17186f1f90d3 ("fbdev: Fix do_register_framebuffer to prevent null-ptr-deref in fb_videomode_to_var").

In the Linux kernel, the following vulnerability has been resolved: bpf, ktls: Fix data corruption when using bpf_msg_pop_data() in ktls When sending plaintext data, we initially calculated the corresponding ciphertext length. However, if we later reduced the plaintext data length via socket policy, we failed to recalculate the ciphertext length. This results in transmitting buffers containing uninitialized data during ciphertext transmission. This causes uninitialized bytes to be appended after a complete "Application Data" packet, leading to errors on the receiving end when parsing TLS record.

In the Linux kernel, the following vulnerability has been resolved: sched: Fix sched_numa_find_nth_cpu() if mask offline sched_numa_find_nth_cpu() uses a bsearch to look for the 'closest' CPU in sched_domains_numa_masks and given cpus mask. However they might not intersect if all CPUs in the cpus mask are offline. bsearch will return NULL in that case, bail out instead of dereferencing a bogus pointer. The previous behaviour lead to this bug when using maxcpus=4 on an rk3399 (LLLLbb) (i.e. booting with all big CPUs offline): [ 1.422922] Unable to handle kernel paging request at virtual address ffffff8000000000 [ 1.423635] Mem abort info: [ 1.423889] ESR = 0x0000000096000006 [ 1.424227] EC = 0x25: DABT (current EL), IL = 32 bits [ 1.424715] SET = 0, FnV = 0 [ 1.424995] EA = 0, S1PTW = 0 [ 1.425279] FSC = 0x06: level 2 translation fault [ 1.425735] Data abort info: [ 1.425998] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 [ 1.426499] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 1.426952] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 1.427428] swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000004a9f000 [ 1.428038] [ffffff8000000000] pgd=18000000f7fff403, p4d=18000000f7fff403, pud=18000000f7fff403, pmd=0000000000000000 [ 1.429014] Internal error: Oops: 0000000096000006 [#1] SMP [ 1.429525] Modules linked in: [ 1.429813] CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-rc4-dirty #343 PREEMPT [ 1.430559] Hardware name: Pine64 RockPro64 v2.1 (DT) [ 1.431012] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 1.431634] pc : sched_numa_find_nth_cpu+0x2a0/0x488 [ 1.432094] lr : sched_numa_find_nth_cpu+0x284/0x488 [ 1.432543] sp : ffffffc084e1b960 [ 1.432843] x29: ffffffc084e1b960 x28: ffffff80078a8800 x27: ffffffc0846eb1d0 [ 1.433495] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 1.434144] x23: 0000000000000000 x22: fffffffffff7f093 x21: ffffffc081de6378 [ 1.434792] x20: 0000000000000000 x19: 0000000ffff7f093 x18: 00000000ffffffff [ 1.435441] x17: 3030303866666666 x16: 66663d736b73616d x15: ffffffc104e1b5b7 [ 1.436091] x14: 0000000000000000 x13: ffffffc084712860 x12: 0000000000000372 [ 1.436739] x11: 0000000000000126 x10: ffffffc08476a860 x9 : ffffffc084712860 [ 1.437389] x8 : 00000000ffffefff x7 : ffffffc08476a860 x6 : 0000000000000000 [ 1.438036] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000 [ 1.438683] x2 : 0000000000000000 x1 : ffffffc0846eb000 x0 : ffffff8000407b68 [ 1.439332] Call trace: [ 1.439559] sched_numa_find_nth_cpu+0x2a0/0x488 (P) [ 1.440016] smp_call_function_any+0xc8/0xd0 [ 1.440416] armv8_pmu_init+0x58/0x27c [ 1.440770] armv8_cortex_a72_pmu_init+0x20/0x2c [ 1.441199] arm_pmu_device_probe+0x1e4/0x5e8 [ 1.441603] armv8_pmu_device_probe+0x1c/0x28 [ 1.442007] platform_probe+0x5c/0xac [ 1.442347] really_probe+0xbc/0x298 [ 1.442683] __driver_probe_device+0x78/0x12c [ 1.443087] driver_probe_device+0xdc/0x160 [ 1.443475] __driver_attach+0x94/0x19c [ 1.443833] bus_for_each_dev+0x74/0xd4 [ 1.444190] driver_attach+0x24/0x30 [ 1.444525] bus_add_driver+0xe4/0x208 [ 1.444874] driver_register+0x60/0x128 [ 1.445233] __platform_driver_register+0x24/0x30 [ 1.445662] armv8_pmu_driver_init+0x28/0x4c [ 1.446059] do_one_initcall+0x44/0x25c [ 1.446416] kernel_init_freeable+0x1dc/0x3bc [ 1.446820] kernel_init+0x20/0x1d8 [ 1.447151] ret_from_fork+0x10/0x20 [ 1.447493] Code: 90022e21 f000e5f5 910de2b5 2a1703e2 (f8767803) [ 1.448040] ---[ end trace 0000000000000000 ]--- [ 1.448483] note: swapper/0[1] exited with preempt_count 1 [ 1.449047] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.449741] SMP: stopping secondary CPUs [ 1.450105] Kernel Offset: disabled [ 1.450419] CPU features: 0x000000,00080000,20002001,0400421b [ ---truncated---

In the Linux kernel, the following vulnerability has been resolved: mm/slub: avoid accessing metadata when pointer is invalid in object_err() object_err() reports details of an object for further debugging, such as the freelist pointer, redzone, etc. However, if the pointer is invalid, attempting to access object metadata can lead to a crash since it does not point to a valid object. One known path to the crash is when alloc_consistency_checks() determines the pointer to the allocated object is invalid because of a freelist corruption, and calls object_err() to report it. The debug code should report and handle the corruption gracefully and not crash in the process. In case the pointer is NULL or check_valid_pointer() returns false for the pointer, only print the pointer value and skip accessing metadata.

In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: tas2781: Fix wrong reference of tasdevice_priv During the conversion to unify the calibration data management, the reference to tasdevice_priv was wrongly set to h->hda_priv instead of h->priv. This resulted in memory corruption and crashes eventually. Unfortunately it's a void pointer, hence the compiler couldn't know that it's wrong.

In the Linux kernel, the following vulnerability has been resolved: ceph: always call ceph_shift_unused_folios_left() The function ceph_process_folio_batch() sets folio_batch entries to NULL, which is an illegal state. Before folio_batch_release() crashes due to this API violation, the function ceph_shift_unused_folios_left() is supposed to remove those NULLs from the array. However, since commit ce80b76dd327 ("ceph: introduce ceph_process_folio_batch() method"), this shifting doesn't happen anymore because the "for" loop got moved to ceph_process_folio_batch(), and now the `i` variable that remains in ceph_writepages_start() doesn't get incremented anymore, making the shifting effectively unreachable much of the time. Later, commit 1551ec61dc55 ("ceph: introduce ceph_submit_write() method") added more preconditions for doing the shift, replacing the `i` check (with something that is still just as broken): - if ceph_process_folio_batch() fails, shifting never happens - if ceph_move_dirty_page_in_page_array() was never called (because ceph_process_folio_batch() has returned early for some of various reasons), shifting never happens - if `processed_in_fbatch` is zero (because ceph_process_folio_batch() has returned early for some of the reasons mentioned above or because ceph_move_dirty_page_in_page_array() has failed), shifting never happens Since those two commits, any problem in ceph_process_folio_batch() could crash the kernel, e.g. this way: BUG: kernel NULL pointer dereference, address: 0000000000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] SMP NOPTI CPU: 172 UID: 0 PID: 2342707 Comm: kworker/u778:8 Not tainted 6.15.10-cm4all1-es #714 NONE Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.10 12/08/2023 Workqueue: writeback wb_workfn (flush-ceph-1) RIP: 0010:folios_put_refs+0x85/0x140 Code: 83 c5 01 39 e8 7e 76 48 63 c5 49 8b 5c c4 08 b8 01 00 00 00 4d 85 ed 74 05 41 8b 44 ad 00 48 8b 15 b0 > RSP: 0018:ffffb880af8db778 EFLAGS: 00010207 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000003 RDX: ffffe377cc3b0000 RSI: 0000000000000000 RDI: ffffb880af8db8c0 RBP: 0000000000000000 R08: 000000000000007d R09: 000000000102b86f R10: 0000000000000001 R11: 00000000000000ac R12: ffffb880af8db8c0 R13: 0000000000000000 R14: 0000000000000000 R15: ffff9bd262c97000 FS: 0000000000000000(0000) GS:ffff9c8efc303000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000034 CR3: 0000000160958004 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> ceph_writepages_start+0xeb9/0x1410 The crash can be reproduced easily by changing the ceph_check_page_before_write() return value to `-E2BIG`. (Interestingly, the crash happens only if `huge_zero_folio` has already been allocated; without `huge_zero_folio`, is_huge_zero_folio(NULL) returns true and folios_put_refs() skips NULL entries instead of dereferencing them. That makes reproducing the bug somewhat unreliable. See https://lore.kernel.org/20250826231626.218675-1-max.kellermann@ionos.com for a discussion of this detail.) My suggestion is to move the ceph_shift_unused_folios_left() to right after ceph_process_folio_batch() to ensure it always gets called to fix up the illegal folio_batch state.

In the Linux kernel, the following vulnerability has been resolved: wifi: rtl818x: Kill URBs before clearing tx status queue In rtl8187_stop() move the call of usb_kill_anchored_urbs() before clearing b_tx_status.queue. This change prevents callbacks from using already freed skb due to anchor was not killed before freeing such skb. BUG: kernel NULL pointer dereference, address: 0000000000000080 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 7 UID: 0 PID: 0 Comm: swapper/7 Not tainted 6.15.0 #8 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ieee80211_tx_status_irqsafe+0x21/0xc0 [mac80211] Call Trace: <IRQ> rtl8187_tx_cb+0x116/0x150 [rtl8187] __usb_hcd_giveback_urb+0x9d/0x120 usb_giveback_urb_bh+0xbb/0x140 process_one_work+0x19b/0x3c0 bh_worker+0x1a7/0x210 tasklet_action+0x10/0x30 handle_softirqs+0xf0/0x340 __irq_exit_rcu+0xcd/0xf0 common_interrupt+0x85/0xa0 </IRQ> Tested on RTL8187BvE device. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: eventpoll: Fix semi-unbounded recursion Ensure that epoll instances can never form a graph deeper than EP_MAX_NESTS+1 links. Currently, ep_loop_check_proc() ensures that the graph is loop-free and does some recursion depth checks, but those recursion depth checks don't limit the depth of the resulting tree for two reasons: - They don't look upwards in the tree. - If there are multiple downwards paths of different lengths, only one of the paths is actually considered for the depth check since commit 28d82dc1c4ed ("epoll: limit paths"). Essentially, the current recursion depth check in ep_loop_check_proc() just serves to prevent it from recursing too deeply while checking for loops. A more thorough check is done in reverse_path_check() after the new graph edge has already been created; this checks, among other things, that no paths going upwards from any non-epoll file with a length of more than 5 edges exist. However, this check does not apply to non-epoll files. As a result, it is possible to recurse to a depth of at least roughly 500, tested on v6.15. (I am unsure if deeper recursion is possible; and this may have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion problem").) To fix it: 1. In ep_loop_check_proc(), note the subtree depth of each visited node, and use subtree depths for the total depth calculation even when a subtree has already been visited. 2. Add ep_get_upwards_depth_proc() for similarly determining the maximum depth of an upwards walk. 3. In ep_loop_check(), use these values to limit the total path length between epoll nodes to EP_MAX_NESTS edges.