CVE-2025-38619

Published Aug 22, 2025

Last updated 8 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: media: ti: j721e-csi2rx: fix list_del corruption If ti_csi2rx_start_dma() fails in ti_csi2rx_dma_callback(), the buffer is marked done with VB2_BUF_STATE_ERROR but is not removed from the DMA queue. This causes the same buffer to be retried in the next iteration, resulting in a double list_del() and eventual list corruption. Fix this by removing the buffer from the queue before calling vb2_buffer_done() on error. This resolves a crash due to list_del corruption: [ 37.811243] j721e-csi2rx 30102000.ticsi2rx: Failed to queue the next buffer for DMA [ 37.832187] slab kmalloc-2k start ffff00000255b000 pointer offset 1064 size 2048 [ 37.839761] list_del corruption. next->prev should be ffff00000255bc28, but was ffff00000255d428. (next=ffff00000255b428) [ 37.850799] ------------[ cut here ]------------ [ 37.855424] kernel BUG at lib/list_debug.c:65! [ 37.859876] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 37.866061] Modules linked in: i2c_dev usb_f_rndis u_ether libcomposite dwc3 udc_core usb_common aes_ce_blk aes_ce_cipher ghash_ce gf128mul sha1_ce cpufreq_dt dwc3_am62 phy_gmii_sel sa2ul [ 37.882830] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc3+ #28 VOLUNTARY [ 37.890851] Hardware name: Bosch STLA-GSRV2-B0 (DT) [ 37.895737] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 37.902703] pc : __list_del_entry_valid_or_report+0xdc/0x114 [ 37.908390] lr : __list_del_entry_valid_or_report+0xdc/0x114 [ 37.914059] sp : ffff800080003db0 [ 37.917375] x29: ffff800080003db0 x28: 0000000000000007 x27: ffff800080e50000 [ 37.924521] x26: 0000000000000000 x25: ffff0000016abb50 x24: dead000000000122 [ 37.931666] x23: ffff0000016abb78 x22: ffff0000016ab080 x21: ffff800080003de0 [ 37.938810] x20: ffff00000255bc00 x19: ffff00000255b800 x18: 000000000000000a [ 37.945956] x17: 20747562202c3832 x16: 6362353532303030 x15: 0720072007200720 [ 37.953101] x14: 0720072007200720 x13: 0720072007200720 x12: 00000000ffffffea [ 37.960248] x11: ffff800080003b18 x10: 00000000ffffefff x9 : ffff800080f5b568 [ 37.967396] x8 : ffff800080f5b5c0 x7 : 0000000000017fe8 x6 : c0000000ffffefff [ 37.974542] x5 : ffff00000fea6688 x4 : 0000000000000000 x3 : 0000000000000000 [ 37.981686] x2 : 0000000000000000 x1 : ffff800080ef2b40 x0 : 000000000000006d [ 37.988832] Call trace: [ 37.991281] __list_del_entry_valid_or_report+0xdc/0x114 (P) [ 37.996959] ti_csi2rx_dma_callback+0x84/0x1c4 [ 38.001419] udma_vchan_complete+0x1e0/0x344 [ 38.005705] tasklet_action_common+0x118/0x310 [ 38.010163] tasklet_action+0x30/0x3c [ 38.013832] handle_softirqs+0x10c/0x2e0 [ 38.017761] __do_softirq+0x14/0x20 [ 38.021256] ____do_softirq+0x10/0x20 [ 38.024931] call_on_irq_stack+0x24/0x60 [ 38.028873] do_softirq_own_stack+0x1c/0x40 [ 38.033064] __irq_exit_rcu+0x130/0x15c [ 38.036909] irq_exit_rcu+0x10/0x20 [ 38.040403] el1_interrupt+0x38/0x60 [ 38.043987] el1h_64_irq_handler+0x18/0x24 [ 38.048091] el1h_64_irq+0x6c/0x70 [ 38.051501] default_idle_call+0x34/0xe0 (P) [ 38.055783] do_idle+0x1f8/0x250 [ 38.059021] cpu_startup_entry+0x34/0x3c [ 38.062951] rest_init+0xb4/0xc0 [ 38.066186] console_on_rootfs+0x0/0x6c [ 38.070031] __primary_switched+0x88/0x90 [ 38.074059] Code: b00037e0 91378000 f9400462 97e9bf49 (d4210000) [ 38.080168] ---[ end trace 0000000000000000 ]--- [ 38.084795] Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt [ 38.092197] SMP: stopping secondary CPUs [ 38.096139] Kernel Offset: disabled [ 38.099631] CPU features: 0x0000,00002000,02000801,0400420b [ 38.105202] Memory Limit: none [ 38.108260] ---[ end Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt ]---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level When recovering hugepages in the shadow MMU, verify that the base gfn of the shadow page is actually contained within the target memslot, *before* querying the max mapping level given the shadow page's gfn. Failure to pre-check the validity of the gfn can lead to an out-of-bounds access to the slot's lpage_info (which typically manifests as a host #PF because the lpage_info is vmalloc'd) if the guest creates a hugepage mapping (in its PTEs) that extends "below" the bounds of a memslot. When faulting in memory for a guest, and the size of the guest mapping is greater than KVM's (current) max mapping, then KVM will create a "direct" shadow page (direct in that there are no gPTEs to shadow, and so the target gfn is a direct calculation given the base gfn of the shadow page). The hugepage recovery flow looks for such direct shadow pages, as forcing 4KiB mappings when dirty logging generates the guest > host mapping size case. When the 4KiB restriction is lifted, then KVM can replace the shadow page with a hugepage. But if KVM originally used a smaller mapping than the guest because the range of memory covered by the guest hugepage exceeds the bounds of a memslot, then KVM will link a direct shadow page with a gfn that is outside the bounds of the memslot being used to fault in memory. The rmap entry added for the leaf mapping is correct and within bounds, but the gfn of the leaf SPTE's parent shadow page will be out of bounds. BUG: unable to handle page fault for address: ffffc90000806ffc #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 100000067 P4D 100000067 PUD 1002a7067 PMD 10612f067 PTE 0 Oops: Oops: 0000 [#1] SMP CPU: 13 UID: 1000 PID: 757 Comm: mmu_stress_test Not tainted 7.1.0-rc1-48ce1e26eace-x86_pir_to_irr_comments-vm #341 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_mmu_max_mapping_level+0x79/0x2b0 [kvm] Call Trace: <TASK> kvm_mmu_recover_huge_pages+0x21b/0x320 [kvm] kvm_set_memslot+0x1ee/0x590 [kvm] kvm_set_memory_region.part.0+0x3a1/0x4d0 [kvm] kvm_vm_ioctl+0x9bf/0x15d0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0xbb0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f21c0f1a9bf </TASK> Don't bother pre-checking the bounds of the potential hugepage, i.e. don't check that e.g. sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level + 1) is also within the memslot, as the checks performed by kvm_mmu_max_mapping_level() are a superset of the basic bounds checks. I.e. pre-checking the full range would be a dubious micro-optimization.CVE-2026-63807
  2. In the Linux kernel, the following vulnerability has been resolved: KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned() Drop a BUG_ON() that has been reachable since it was first added, way back in 2009, and instead use get_unaligned() to perform potentially-unaligned accesses. For a given store, KVM x86's emulator tracks the entire value in the destination operand, x86_emulate_ctxt.dst. If the destination is memory, and the target splits multiple pages and/or is emulated MMIO, then KVM handles each fragment independently. E.g. on a page split starting at page offset 0xffc, KVM writes 4 bytes to the first page, then the remaining bytes to the second page, using ctxt->dst as the source for both (with appropriate offsets). If the destination splits a page *and* hits emulated MMIO on the second page, then KVM will complete the write to the first page, then emulate the MMIO access to the second page. If there is a datamatch-enabled ioeventfd at offset 0 of the second page, then KVM will process the remainder of the store as a potential ioeventfd signal. Putting it all together, if the guest emits a store that splits a page starting at page offset N, and the second page has a datamatch-enabled ioeventfd at offset 0, then KVM will check for datamatch using &dst.valptr[N] as the source. Due to dst (and thus dst.valptr) being 32-byte aligned, if N is not aligned to @len, the BUG_ON() fires. E.g. with a 16-byte store at page offset 0xffc, to an ioeventfd of len 8, all initial checks in ioeventfd_in_range() will succeed, and the BUG_ON() fires due to @val being 4-byte aligned, but not 8-byte aligned. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/../../../virt/kvm/eventfd.c:783! Oops: invalid opcode: 0000 [#1] SMP CPU: 0 UID: 1000 PID: 615 Comm: repro Not tainted 7.1.0-rc2-ff238429d1ea #365 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:ioeventfd_write+0x6c/0x70 [kvm] Call Trace: <TASK> __kvm_io_bus_write+0x85/0xb0 [kvm] kvm_io_bus_write+0x53/0x80 [kvm] vcpu_mmio_write+0x66/0xf0 [kvm] emulator_read_write_onepage+0x12a/0x540 [kvm] emulator_read_write+0x109/0x2b0 [kvm] x86_emulate_insn+0x4f8/0xfb0 [kvm] x86_emulate_instruction+0x181/0x790 [kvm] kvm_mmu_page_fault+0x313/0x630 [kvm] vmx_handle_exit+0x18a/0x590 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xc81/0x1c90 [kvm] kvm_vcpu_ioctl+0x2d5/0x970 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0x890 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f19c931a9bf </TASK> Modules linked in: kvm_intel kvm irqbypass ---[ end trace 0000000000000000 ]--- In a perfect world, the fix would be to simply delete the BUG_ON(), as KVM x86 doesn't perform alignment checks on "normal" memory accesses at CPL0. Sadly, C99 ruins all the fun; while the x86 architecture plays nice, dereferencing an unaligned pointer directly is undefined behavior in C, e.g. triggers splats when running with CONFIG_UBSAN_ALIGNMENT=y.CVE-2026-63806
  3. In the Linux kernel, the following vulnerability has been resolved: hdlc_ppp: sync per-proto timers before freeing hdlc state Each PPP control protocol (LCP/IPCP/IPV6CP) embedded in struct ppp registers a timer via timer_setup(). That struct ppp is the hdlc->state allocation, which detach_hdlc_protocol() frees with kfree() in both teardown paths: unregister_hdlc_device() and the re-attach inside attach_hdlc_protocol(). The ppp proto never registered a .detach callback, so detach_hdlc_protocol() performs no timer synchronization before the kfree(). The only cancel, timer_delete(&proto->timer) in ppp_cp_event(), is partial (it does not wait for a running callback) and only runs on the ->CLOSED transition; ppp_stop()/ppp_close() do not sync either. A ppp_timer callback already executing (blocked on ppp->lock) survives the kfree and then dereferences proto->state / ppp->lock in freed memory, leading to a use-after-free. Fix this by adding a .detach helper that calls timer_shutdown_sync() on every per-proto timer. detach_hdlc_protocol() invokes proto->detach(dev) before kfree(hdlc->state), so timer_shutdown_sync() now runs on both free paths. timer_shutdown_sync() is used instead of timer_delete_sync() because the keepalive path re-arms the timer through add_timer()/mod_timer() and shutdown blocks any re-activation during teardown. Initialize the per-protocol timers in ppp_ioctl() when the protocol is attached, and remove the now-redundant timer_setup() from ppp_start(), so that the timers are initialized exactly once at attach time and ppp_timer_release() never operates on uninitialized timer_list structures. attach_hdlc_protocol() uses kmalloc() (not kzalloc), so struct ppp's protos[i].timer is uninitialized garbage until the first timer_setup(); without this init-at-attach, attaching the PPP protocol without ever bringing the device up would leave timer_shutdown_sync() operating on uninitialized memory in .detach. Moving the init out of ppp_start() (which only runs on NETDEV_UP) into the attach path makes the initialization unconditional and avoids initializing the same timer_list twice. This bug was found by static analysis.CVE-2026-63803