In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Prevent crash when disable stream [Why] Disabling stream encoder invokes a function that no longer exists. [How] Check if the function declaration is NULL in disable stream encoder.

Uncontrolled resource consumption in some Intel(R) Thunderbolt(TM) controllers may allow an authenticated user to potentially enable denial of service via local access.

Uncontrolled resource consumption in some Intel(R) Thunderbolt(TM) controllers may allow an authenticated user to potentially enable denial of service via local access.

An issue was discovered in the Linux kernel before 5.4.7. The prb_calc_retire_blk_tmo() function in net/packet/af_packet.c can result in a denial of service (CPU consumption and soft lockup) in a certain failure case involving TPACKET_V3, aka CID-b43d1f9f7067.

IBM Db2 11.5.0 through 11.5.9, and 12.1.0 through 12.1.4 is vulnerable to a denial of service when executing a specially crafted query with a small statement heap.

The d_walk function in fs/dcache.c in the Linux kernel through 3.17.2 does not properly maintain the semantics of rename_lock, which allows local users to cause a denial of service (deadlock and system hang) via a crafted application.

In the Linux kernel, the following vulnerability has been resolved: pipe: wakeup wr_wait after setting max_usage Commit c73be61cede5 ("pipe: Add general notification queue support") a regression was introduced that would lock up resized pipes under certain conditions. See the reproducer in [1]. The commit resizing the pipe ring size was moved to a different function, doing that moved the wakeup for pipe->wr_wait before actually raising pipe->max_usage. If a pipe was full before the resize occured it would result in the wakeup never actually triggering pipe_write. Set @max_usage and @nr_accounted before waking writers if this isn't a watch queue. [Christian Brauner <brauner@kernel.org>: rewrite to account for watch queues]

kernel/sched/fair.c in the Linux kernel before 5.3.9, when cpu.cfs_quota_us is used (e.g., with Kubernetes), allows attackers to cause a denial of service against non-cpu-bound applications by generating a workload that triggers unwanted slice expiration, aka CID-de53fd7aedb1. (In other words, although this slice expiration would typically be seen with benign workloads, it is possible that an attacker could calculate how many stray requests are required to force an entire Kubernetes cluster into a low-performance state caused by slice expiration, and ensure that a DDoS attack sent that number of stray requests. An attack does not affect the stability of the kernel; it only causes mismanagement of application execution.)

Uncontrolled resource consumption in the Intel(R) Distribution of OpenVINOâ„¢ Toolkit before version 2021.4 may allow an unauthenticated user to potentially enable denial of service via local access.

Uncontrolled resource consumption in the Intel(R) Smart Campus Android application before version 9.9 may allow an authenticated user to potentially enable denial of service via local access.

The tcp_read_sock function in net/ipv4/tcp.c in the Linux kernel before 2.6.34 does not properly manage skb consumption, which allows local users to cause a denial of service (system crash) via a crafted splice system call for a TCP socket.

Uncontrolled resource consumption in the Intel(R) Connect M Android application before version 1.82 may allow an authenticated user to potentially enable denial of service via local access.

A locally locally exploitable DOS vulnerability was found in pax-linux versions 2.6.32.33-test79.patch, 2.6.38-test3.patch, and 2.6.37.4-test14.patch. A bad bounds check in arch_get_unmapped_area_topdown triggered by programs doing an mmap after a MAP_GROWSDOWN mmap will create an infinite loop condition without releasing the VM semaphore eventually leading to a system crash.

Visual Studio Denial of Service Vulnerability

Windows Secure Channel Denial of Service Vulnerability

Uncontrolled resource consumption in some Intel(R) Thunderbolt(TM) DCH drivers for Windows before version 88 may allow an authenticated user to potentially enable denial of service via local access.

Uncontrolled resource consumption in the Intel(R) Support Android application before version 22.02.28 may allow an authenticated user to potentially enable denial of service via local access.

Uncontrolled resource consumption in the Intel(R) Unite(R) android application before Release 17 may allow an authenticated user to potentially enable denial of service via local access.

In the Linux kernel, the following vulnerability has been resolved: net: ipv4: fix memory leak in ip_mc_add1_src BUG: memory leak unreferenced object 0xffff888101bc4c00 (size 32): comm "syz-executor527", pid 360, jiffies 4294807421 (age 19.329s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................ backtrace: [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline] [<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline] [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline] [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095 [<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416 [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline] [<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423 [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857 [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117 [<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline] [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline] [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125 [<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47 [<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae In commit 24803f38a5c0 ("igmp: do not remove igmp souce list info when set link down"), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed, because it was also called in igmpv3_clear_delrec(). Rough callgraph: inetdev_destroy -> ip_mc_destroy_dev -> igmpv3_clear_delrec -> ip_mc_clear_src -> RCU_INIT_POINTER(dev->ip_ptr, NULL) However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through inetdev_by_index() and then in_dev->mc_list->sources cannot be released by ip_mc_del1_src() in the sock_close. Rough call sequence goes like: sock_close -> __sock_release -> inet_release -> ip_mc_drop_socket -> inetdev_by_index -> ip_mc_leave_src -> ip_mc_del_src -> ip_mc_del1_src So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free in_dev->mc_list->sources.

Netty, an asynchronous, event-driven network application framework, has a vulnerability in versions up to and including 4.1.118.Final. An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attempts to load a file that does not exist. If an attacker creates such a large file, the Netty application crash. A similar issue was previously reported as CVE-2024-47535. This issue was fixed, but the fix was incomplete in that null-bytes were not counted against the input limit. Commit d1fbda62d3a47835d3fb35db8bd42ecc205a5386 contains an updated fix.

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attempts to load a file that does not exist. If an attacker creates such a large file, the Netty application crashes. This vulnerability is fixed in 4.1.115.

CVE-2026-40951 is a memory corruption vulnerability on Secure Access Windows clients prior to 14.50. Attackers with local control of the Windows client can send malformed data to an API and trigger a denial of service.

Integer signedness error in the pmcraid_ioctl_passthrough function in drivers/scsi/pmcraid.c in the Linux kernel before 3.1 might allow local users to cause a denial of service (memory consumption or memory corruption) via a negative size value in an ioctl call. NOTE: this may be a vulnerability only in unusual environments that provide a privileged program for obtaining the required file descriptor.

The I/O implementation for block devices in the Linux kernel before 2.6.33 does not properly handle the CLONE_IO feature, which allows local users to cause a denial of service (I/O instability) by starting multiple processes that share an I/O context.

The int3 handler in the Linux kernel before 3.3 relies on a per-CPU debug stack, which allows local users to cause a denial of service (stack corruption and panic) via a crafted application that triggers certain lock contention.

The pivot_root implementation in fs/namespace.c in the Linux kernel through 3.17 does not properly interact with certain locations of a chroot directory, which allows local users to cause a denial of service (mount-tree loop) via . (dot) values in both arguments to the pivot_root system call.

The kiocb_batch_free function in fs/aio.c in the Linux kernel before 3.2.2 allows local users to cause a denial of service (OOPS) via vectors that trigger incorrect iocb management.

The Performance Events subsystem in the Linux kernel before 3.1 does not properly handle event overflows associated with PERF_COUNT_SW_CPU_CLOCK events, which allows local users to cause a denial of service (system hang) via a crafted application.

A lack of CPU resource in the Linux kernel tracing module functionality in versions prior to 5.14-rc3 was found in the way user uses trace ring buffer in a specific way. Only privileged local users (with CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service.

net/unix/af_unix.c in the Linux kernel 2.6.31.4 and earlier allows local users to cause a denial of service (system hang) by creating an abstract-namespace AF_UNIX listening socket, performing a shutdown operation on this socket, and then performing a series of connect operations to this socket.

Trend Micro's Virus Scan API (VSAPI) and Advanced Threat Scan Engine (ATSE) - are vulnerable to a memory exhaustion vulnerability that may lead to denial-of-service or system freeze if exploited by an attacker using a specially crafted file.

A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allows an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability.

ext4_protect_reserved_inode in fs/ext4/block_validity.c in the Linux kernel through 5.5.3 allows attackers to cause a denial of service (soft lockup) via a crafted journal size.

A memory overflow vulnerability was found in the Linux kernel’s ipc functionality of the memcg subsystem, in the way a user calls the semget function multiple times, creating semaphores. This flaw allows a local user to starve the resources, causing a denial of service. The highest threat from this vulnerability is to system availability.

A vulnerability was found in Linux kernel where non-blocking socket in llcp_sock_connect() leads to leak and eventually hanging-up the system.

An issue was discovered in ImfHpRegFilter.sys in IOBit Malware Fighter version 8.0.2, allows local attackers to cause a denial of service (DoS).

Uncontrolled resource consumption in the Linux kernel drivers for Intel(R) SGX may allow an authenticated user to potentially enable denial of service via local access.

arch/x86/kvm/vmx.c in the KVM subsystem in the Linux kernel before 3.17.2 on Intel processors does not ensure that the value in the CR4 control register remains the same after a VM entry, which allows host OS users to kill arbitrary processes or cause a denial of service (system disruption) by leveraging /dev/kvm access, as demonstrated by PR_SET_TSC prctl calls within a modified copy of QEMU.

In the Linux kernel, the following vulnerability has been resolved: tracing: Restructure trace_clock_global() to never block It was reported that a fix to the ring buffer recursion detection would cause a hung machine when performing suspend / resume testing. The following backtrace was extracted from debugging that case: Call Trace: trace_clock_global+0x91/0xa0 __rb_reserve_next+0x237/0x460 ring_buffer_lock_reserve+0x12a/0x3f0 trace_buffer_lock_reserve+0x10/0x50 __trace_graph_return+0x1f/0x80 trace_graph_return+0xb7/0xf0 ? trace_clock_global+0x91/0xa0 ftrace_return_to_handler+0x8b/0xf0 ? pv_hash+0xa0/0xa0 return_to_handler+0x15/0x30 ? ftrace_graph_caller+0xa0/0xa0 ? trace_clock_global+0x91/0xa0 ? __rb_reserve_next+0x237/0x460 ? ring_buffer_lock_reserve+0x12a/0x3f0 ? trace_event_buffer_lock_reserve+0x3c/0x120 ? trace_event_buffer_reserve+0x6b/0xc0 ? trace_event_raw_event_device_pm_callback_start+0x125/0x2d0 ? dpm_run_callback+0x3b/0xc0 ? pm_ops_is_empty+0x50/0x50 ? platform_get_irq_byname_optional+0x90/0x90 ? trace_device_pm_callback_start+0x82/0xd0 ? dpm_run_callback+0x49/0xc0 With the following RIP: RIP: 0010:native_queued_spin_lock_slowpath+0x69/0x200 Since the fix to the recursion detection would allow a single recursion to happen while tracing, this lead to the trace_clock_global() taking a spin lock and then trying to take it again: ring_buffer_lock_reserve() { trace_clock_global() { arch_spin_lock() { queued_spin_lock_slowpath() { /* lock taken */ (something else gets traced by function graph tracer) ring_buffer_lock_reserve() { trace_clock_global() { arch_spin_lock() { queued_spin_lock_slowpath() { /* DEAD LOCK! */ Tracing should *never* block, as it can lead to strange lockups like the above. Restructure the trace_clock_global() code to instead of simply taking a lock to update the recorded "prev_time" simply use it, as two events happening on two different CPUs that calls this at the same time, really doesn't matter which one goes first. Use a trylock to grab the lock for updating the prev_time, and if it fails, simply try again the next time. If it failed to be taken, that means something else is already updating it. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212761

Uncontrolled resource consumption in some Intel(R) Ethernet E810 Adapter drivers for Linux before version 1.0.4 may allow an authenticated user to potentially enable denial of service via local access.

A memory leak flaw was found in the Linux kernel's ccp_run_aes_gcm_cmd() function that allows an attacker to cause a denial of service. The vulnerability is similar to the older CVE-2019-18808. The highest threat from this vulnerability is to system availability.

A flaw was found in the Linux kernel. Measuring usage of the shared memory does not scale with large shared memory segment counts which could lead to resource exhaustion and DoS.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: honor table dormant flag from netdev release event path Check for table dormant flag otherwise netdev release event path tries to unregister an already unregistered hook. [524854.857999] ------------[ cut here ]------------ [524854.858010] WARNING: CPU: 0 PID: 3386599 at net/netfilter/core.c:501 __nf_unregister_net_hook+0x21a/0x260 [...] [524854.858848] CPU: 0 PID: 3386599 Comm: kworker/u32:2 Not tainted 6.9.0-rc3+ #365 [524854.858869] Workqueue: netns cleanup_net [524854.858886] RIP: 0010:__nf_unregister_net_hook+0x21a/0x260 [524854.858903] Code: 24 e8 aa 73 83 ff 48 63 43 1c 83 f8 01 0f 85 3d ff ff ff e8 98 d1 f0 ff 48 8b 3c 24 e8 8f 73 83 ff 48 63 43 1c e9 26 ff ff ff <0f> 0b 48 83 c4 18 48 c7 c7 00 68 e9 82 5b 5d 41 5c 41 5d 41 5e 41 [524854.858914] RSP: 0018:ffff8881e36d79e0 EFLAGS: 00010246 [524854.858926] RAX: 0000000000000000 RBX: ffff8881339ae790 RCX: ffffffff81ba524a [524854.858936] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8881c8a16438 [524854.858945] RBP: ffff8881c8a16438 R08: 0000000000000001 R09: ffffed103c6daf34 [524854.858954] R10: ffff8881e36d79a7 R11: 0000000000000000 R12: 0000000000000005 [524854.858962] R13: ffff8881c8a16000 R14: 0000000000000000 R15: ffff8881351b5a00 [524854.858971] FS: 0000000000000000(0000) GS:ffff888390800000(0000) knlGS:0000000000000000 [524854.858982] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [524854.858991] CR2: 00007fc9be0f16f4 CR3: 00000001437cc004 CR4: 00000000001706f0 [524854.859000] Call Trace: [524854.859006] <TASK> [524854.859013] ? __warn+0x9f/0x1a0 [524854.859027] ? __nf_unregister_net_hook+0x21a/0x260 [524854.859044] ? report_bug+0x1b1/0x1e0 [524854.859060] ? handle_bug+0x3c/0x70 [524854.859071] ? exc_invalid_op+0x17/0x40 [524854.859083] ? asm_exc_invalid_op+0x1a/0x20 [524854.859100] ? __nf_unregister_net_hook+0x6a/0x260 [524854.859116] ? __nf_unregister_net_hook+0x21a/0x260 [524854.859135] nf_tables_netdev_event+0x337/0x390 [nf_tables] [524854.859304] ? __pfx_nf_tables_netdev_event+0x10/0x10 [nf_tables] [524854.859461] ? packet_notifier+0xb3/0x360 [524854.859476] ? _raw_spin_unlock_irqrestore+0x11/0x40 [524854.859489] ? dcbnl_netdevice_event+0x35/0x140 [524854.859507] ? __pfx_nf_tables_netdev_event+0x10/0x10 [nf_tables] [524854.859661] notifier_call_chain+0x7d/0x140 [524854.859677] unregister_netdevice_many_notify+0x5e1/0xae0

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Skip do PCI error slot reset during RAS recovery Why: The PCI error slot reset maybe triggered after inject ue to UMC multi times, this caused system hang. [ 557.371857] amdgpu 0000:af:00.0: amdgpu: GPU reset succeeded, trying to resume [ 557.373718] [drm] PCIE GART of 512M enabled. [ 557.373722] [drm] PTB located at 0x0000031FED700000 [ 557.373788] [drm] VRAM is lost due to GPU reset! [ 557.373789] [drm] PSP is resuming... [ 557.547012] mlx5_core 0000:55:00.0: mlx5_pci_err_detected Device state = 1 pci_status: 0. Exit, result = 3, need reset [ 557.547067] [drm] PCI error: detected callback, state(1)!! [ 557.547069] [drm] No support for XGMI hive yet... [ 557.548125] mlx5_core 0000:55:00.0: mlx5_pci_slot_reset Device state = 1 pci_status: 0. Enter [ 557.607763] mlx5_core 0000:55:00.0: wait vital counter value 0x16b5b after 1 iterations [ 557.607777] mlx5_core 0000:55:00.0: mlx5_pci_slot_reset Device state = 1 pci_status: 1. Exit, err = 0, result = 5, recovered [ 557.610492] [drm] PCI error: slot reset callback!! ... [ 560.689382] amdgpu 0000:3f:00.0: amdgpu: GPU reset(2) succeeded! [ 560.689546] amdgpu 0000:5a:00.0: amdgpu: GPU reset(2) succeeded! [ 560.689562] general protection fault, probably for non-canonical address 0x5f080b54534f611f: 0000 [#1] SMP NOPTI [ 560.701008] CPU: 16 PID: 2361 Comm: kworker/u448:9 Tainted: G OE 5.15.0-91-generic #101-Ubuntu [ 560.712057] Hardware name: Microsoft C278A/C278A, BIOS C2789.5.BS.1C11.AG.1 11/08/2023 [ 560.720959] Workqueue: amdgpu-reset-hive amdgpu_ras_do_recovery [amdgpu] [ 560.728887] RIP: 0010:amdgpu_device_gpu_recover.cold+0xbf1/0xcf5 [amdgpu] [ 560.736891] Code: ff 41 89 c6 e9 1b ff ff ff 44 0f b6 45 b0 e9 4f ff ff ff be 01 00 00 00 4c 89 e7 e8 76 c9 8b ff 44 0f b6 45 b0 e9 3c fd ff ff <48> 83 ba 18 02 00 00 00 0f 84 6a f8 ff ff 48 8d 7a 78 be 01 00 00 [ 560.757967] RSP: 0018:ffa0000032e53d80 EFLAGS: 00010202 [ 560.763848] RAX: ffa00000001dfd10 RBX: ffa0000000197090 RCX: ffa0000032e53db0 [ 560.771856] RDX: 5f080b54534f5f07 RSI: 0000000000000000 RDI: ff11000128100010 [ 560.779867] RBP: ffa0000032e53df0 R08: 0000000000000000 R09: ffffffffffe77f08 [ 560.787879] R10: 0000000000ffff0a R11: 0000000000000001 R12: 0000000000000000 [ 560.795889] R13: ffa0000032e53e00 R14: 0000000000000000 R15: 0000000000000000 [ 560.803889] FS: 0000000000000000(0000) GS:ff11007e7e800000(0000) knlGS:0000000000000000 [ 560.812973] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 560.819422] CR2: 000055a04c118e68 CR3: 0000000007410005 CR4: 0000000000771ee0 [ 560.827433] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 560.835433] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 [ 560.843444] PKRU: 55555554 [ 560.846480] Call Trace: [ 560.849225] <TASK> [ 560.851580] ? show_trace_log_lvl+0x1d6/0x2ea [ 560.856488] ? show_trace_log_lvl+0x1d6/0x2ea [ 560.861379] ? amdgpu_ras_do_recovery+0x1b2/0x210 [amdgpu] [ 560.867778] ? show_regs.part.0+0x23/0x29 [ 560.872293] ? __die_body.cold+0x8/0xd [ 560.876502] ? die_addr+0x3e/0x60 [ 560.880238] ? exc_general_protection+0x1c5/0x410 [ 560.885532] ? asm_exc_general_protection+0x27/0x30 [ 560.891025] ? amdgpu_device_gpu_recover.cold+0xbf1/0xcf5 [amdgpu] [ 560.898323] amdgpu_ras_do_recovery+0x1b2/0x210 [amdgpu] [ 560.904520] process_one_work+0x228/0x3d0 How: In RAS recovery, mode-1 reset is issued from RAS fatal error handling and expected all the nodes in a hive to be reset. no need to issue another mode-1 during this procedure.

In the Linux kernel, the following vulnerability has been resolved: s390/bpf: Fix bpf_plt pointer arithmetic Kui-Feng Lee reported a crash on s390x triggered by the dummy_st_ops/dummy_init_ptr_arg test [1]: [<0000000000000002>] 0x2 [<00000000009d5cde>] bpf_struct_ops_test_run+0x156/0x250 [<000000000033145a>] __sys_bpf+0xa1a/0xd00 [<00000000003319dc>] __s390x_sys_bpf+0x44/0x50 [<0000000000c4382c>] __do_syscall+0x244/0x300 [<0000000000c59a40>] system_call+0x70/0x98 This is caused by GCC moving memcpy() after assignments in bpf_jit_plt(), resulting in NULL pointers being written instead of the return and the target addresses. Looking at the GCC internals, the reordering is allowed because the alias analysis thinks that the memcpy() destination and the assignments' left-hand-sides are based on different objects: new_plt and bpf_plt_ret/bpf_plt_target respectively, and therefore they cannot alias. This is in turn due to a violation of the C standard: When two pointers are subtracted, both shall point to elements of the same array object, or one past the last element of the array object ... From the C's perspective, bpf_plt_ret and bpf_plt are distinct objects and cannot be subtracted. In the practical terms, doing so confuses the GCC's alias analysis. The code was written this way in order to let the C side know a few offsets defined in the assembly. While nice, this is by no means necessary. Fix the noncompliance by hardcoding these offsets. [1] https://lore.kernel.org/bpf/c9923c1d-971d-4022-8dc8-1364e929d34c@gmail.com/

In the Linux kernel, the following vulnerability has been resolved: book3s64/radix : Align section vmemmap start address to PAGE_SIZE A vmemmap altmap is a device-provided region used to provide backing storage for struct pages. For each namespace, the altmap should belong to that same namespace. If the namespaces are created unaligned, there is a chance that the section vmemmap start address could also be unaligned. If the section vmemmap start address is unaligned, the altmap page allocated from the current namespace might be used by the previous namespace also. During the free operation, since the altmap is shared between two namespaces, the previous namespace may detect that the page does not belong to its altmap and incorrectly assume that the page is a normal page. It then attempts to free the normal page, which leads to a kernel crash. Kernel attempted to read user page (18) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x00000018 Faulting instruction address: 0xc000000000530c7c Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries CPU: 32 PID: 2104 Comm: ndctl Kdump: loaded Tainted: G W NIP: c000000000530c7c LR: c000000000530e00 CTR: 0000000000007ffe REGS: c000000015e57040 TRAP: 0300 Tainted: G W MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 84482404 CFAR: c000000000530dfc DAR: 0000000000000018 DSISR: 40000000 IRQMASK: 0 GPR00: c000000000530e00 c000000015e572e0 c000000002c5cb00 c00c000101008040 GPR04: 0000000000000000 0000000000000007 0000000000000001 000000000000001f GPR08: 0000000000000005 0000000000000000 0000000000000018 0000000000002000 GPR12: c0000000001d2fb0 c0000060de6b0080 0000000000000000 c0000060dbf90020 GPR16: c00c000101008000 0000000000000001 0000000000000000 c000000125b20f00 GPR20: 0000000000000001 0000000000000000 ffffffffffffffff c00c000101007fff GPR24: 0000000000000001 0000000000000000 0000000000000000 0000000000000000 GPR28: 0000000004040201 0000000000000001 0000000000000000 c00c000101008040 NIP [c000000000530c7c] get_pfnblock_flags_mask+0x7c/0xd0 LR [c000000000530e00] free_unref_page_prepare+0x130/0x4f0 Call Trace: free_unref_page+0x50/0x1e0 free_reserved_page+0x40/0x68 free_vmemmap_pages+0x98/0xe0 remove_pte_table+0x164/0x1e8 remove_pmd_table+0x204/0x2c8 remove_pud_table+0x1c4/0x288 remove_pagetable+0x1c8/0x310 vmemmap_free+0x24/0x50 section_deactivate+0x28c/0x2a0 __remove_pages+0x84/0x110 arch_remove_memory+0x38/0x60 memunmap_pages+0x18c/0x3d0 devm_action_release+0x30/0x50 release_nodes+0x68/0x140 devres_release_group+0x100/0x190 dax_pmem_compat_release+0x44/0x80 [dax_pmem_compat] device_for_each_child+0x8c/0x100 [dax_pmem_compat_remove+0x2c/0x50 [dax_pmem_compat] nvdimm_bus_remove+0x78/0x140 [libnvdimm] device_remove+0x70/0xd0 Another issue is that if there is no altmap, a PMD-sized vmemmap page will be allocated from RAM, regardless of the alignment of the section start address. If the section start address is not aligned to the PMD size, a VM_BUG_ON will be triggered when setting the PMD-sized page to page table. In this patch, we are aligning the section vmemmap start address to PAGE_SIZE. After alignment, the start address will not be part of the current namespace, and a normal page will be allocated for the vmemmap mapping of the current section. For the remaining sections, altmaps will be allocated. During the free operation, the normal page will be correctly freed. In the same way, a PMD_SIZE vmemmap page will be allocated only if the section start address is PMD_SIZE-aligned; otherwise, it will fall back to a PAGE-sized vmemmap allocation. Without this patch ================== NS1 start NS2 start _________________________________________________________ | NS1 | NS2 | --------------------------------------------------------- | Altmap| Altmap | .....|Altmap| Altmap | ........... | NS1 | NS1 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: riscv: Fix loading 64-bit NOMMU kernels past the start of RAM commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") added logic to allow using RAM below the kernel load address. However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the kernel load address. Since that range of memory corresponds to PFNs below ARCH_PFN_OFFSET, mm initialization runs off the beginning of mem_map and corrupts adjacent kernel memory. Fix this by restoring the previous behavior for NOMMU kernels.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Fix oops during rmmod on single-CPU platforms During the removal of the idxd driver, registered offline callback is invoked as part of the clean up process. However, on systems with only one CPU online, no valid target is available to migrate the perf context, resulting in a kernel oops: BUG: unable to handle page fault for address: 000000000002a2b8 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 1470e1067 P4D 0 Oops: 0002 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 20 Comm: cpuhp/0 Not tainted 6.8.0-rc6-dsa+ #57 Hardware name: Intel Corporation AvenueCity/AvenueCity, BIOS BHSDCRB1.86B.2492.D03.2307181620 07/18/2023 RIP: 0010:mutex_lock+0x2e/0x50 ... Call Trace: <TASK> __die+0x24/0x70 page_fault_oops+0x82/0x160 do_user_addr_fault+0x65/0x6b0 __pfx___rdmsr_safe_on_cpu+0x10/0x10 exc_page_fault+0x7d/0x170 asm_exc_page_fault+0x26/0x30 mutex_lock+0x2e/0x50 mutex_lock+0x1e/0x50 perf_pmu_migrate_context+0x87/0x1f0 perf_event_cpu_offline+0x76/0x90 [idxd] cpuhp_invoke_callback+0xa2/0x4f0 __pfx_perf_event_cpu_offline+0x10/0x10 [idxd] cpuhp_thread_fun+0x98/0x150 smpboot_thread_fn+0x27/0x260 smpboot_thread_fn+0x1af/0x260 __pfx_smpboot_thread_fn+0x10/0x10 kthread+0x103/0x140 __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 <TASK> Fix the issue by preventing the migration of the perf context to an invalid target.

In the Linux kernel, the following vulnerability has been resolved: dyndbg: fix old BUG_ON in >control parser Fix a BUG_ON from 2009. Even if it looks "unreachable" (I didn't really look), lets make sure by removing it, doing pr_err and return -EINVAL instead.

In the Linux kernel, the following vulnerability has been resolved: mm: zswap: fix shrinker NULL crash with cgroup_disable=memory Christian reports a NULL deref in zswap that he bisected down to the zswap shrinker. The issue also cropped up in the bug trackers of libguestfs [1] and the Red Hat bugzilla [2]. The problem is that when memcg is disabled with the boot time flag, the zswap shrinker might get called with sc->memcg == NULL. This is okay in many places, like the lruvec operations. But it crashes in memcg_page_state() - which is only used due to the non-node accounting of cgroup's the zswap memory to begin with. Nhat spotted that the memcg can be NULL in the memcg-disabled case, and I was then able to reproduce the crash locally as well. [1] https://github.com/libguestfs/libguestfs/issues/139 [2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252