{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43232", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:55.995Z", "datePublished": "2026-05-06T11:28:28.910Z", "dateUpdated": "2026-08-05T12:26:45.086Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:26:45.086Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: wan: farsync: Fix use-after-free bugs caused by unfinished tasklets\n\nWhen the FarSync T-series card is being detached, the fst_card_info is\ndeallocated in fst_remove_one(). However, the fst_tx_task or fst_int_task\nmay still be running or pending, leading to use-after-free bugs when the\nalready freed fst_card_info is accessed in fst_process_tx_work_q() or\nfst_process_int_work_q().\n\nA typical race condition is depicted below:\n\nCPU 0 (cleanup) | CPU 1 (tasklet)\n | fst_start_xmit()\nfst_remove_one() | tasklet_schedule()\n unregister_hdlc_device()|\n | fst_process_tx_work_q() //handler\n kfree(card) //free | do_bottom_half_tx()\n | card-> //use\n\nThe following KASAN trace was captured:\n\n==================================================================\n BUG: KASAN: slab-use-after-free in do_bottom_half_tx+0xb88/0xd00\n Read of size 4 at addr ffff88800aad101c by task ksoftirqd/3/32\n ...\n Call Trace:\n \n dump_stack_lvl+0x55/0x70\n print_report+0xcb/0x5d0\n ? do_bottom_half_tx+0xb88/0xd00\n kasan_report+0xb8/0xf0\n ? do_bottom_half_tx+0xb88/0xd00\n do_bottom_half_tx+0xb88/0xd00\n ? _raw_spin_lock_irqsave+0x85/0xe0\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n ? __pfx___hrtimer_run_queues+0x10/0x10\n fst_process_tx_work_q+0x67/0x90\n tasklet_action_common+0x1fa/0x720\n ? hrtimer_interrupt+0x31f/0x780\n handle_softirqs+0x176/0x530\n __irq_exit_rcu+0xab/0xe0\n sysvec_apic_timer_interrupt+0x70/0x80\n ...\n\n Allocated by task 41 on cpu 3 at 72.330843s:\n kasan_save_stack+0x24/0x50\n kasan_save_track+0x17/0x60\n __kasan_kmalloc+0x7f/0x90\n fst_add_one+0x1a5/0x1cd0\n local_pci_probe+0xdd/0x190\n pci_device_probe+0x341/0x480\n really_probe+0x1c6/0x6a0\n __driver_probe_device+0x248/0x310\n driver_probe_device+0x48/0x210\n __device_attach_driver+0x160/0x320\n bus_for_each_drv+0x101/0x190\n __device_attach+0x198/0x3a0\n device_initial_probe+0x78/0xa0\n pci_bus_add_device+0x81/0xc0\n pci_bus_add_devices+0x7e/0x190\n enable_slot+0x9b9/0x1130\n acpiphp_check_bridge.part.0+0x2e1/0x460\n acpiphp_hotplug_notify+0x36c/0x3c0\n acpi_device_hotplug+0x203/0xb10\n acpi_hotplug_work_fn+0x59/0x80\n ...\n\n Freed by task 41 on cpu 1 at 75.138639s:\n kasan_save_stack+0x24/0x50\n kasan_save_track+0x17/0x60\n kasan_save_free_info+0x3b/0x60\n __kasan_slab_free+0x43/0x70\n kfree+0x135/0x410\n fst_remove_one+0x2ca/0x540\n pci_device_remove+0xa6/0x1d0\n device_release_driver_internal+0x364/0x530\n pci_stop_bus_device+0x105/0x150\n pci_stop_and_remove_bus_device+0xd/0x20\n disable_slot+0x116/0x260\n acpiphp_disable_and_eject_slot+0x4b/0x190\n acpiphp_hotplug_notify+0x230/0x3c0\n acpi_device_hotplug+0x203/0xb10\n acpi_hotplug_work_fn+0x59/0x80\n ...\n\n The buggy address belongs to the object at ffff88800aad1000\n which belongs to the cache kmalloc-1k of size 1024\n The buggy address is located 28 bytes inside of\n freed 1024-byte region\n The buggy address belongs to the physical page:\n page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xaad0\n head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0\n flags: 0x100000000000040(head|node=0|zone=1)\n page_type: f5(slab)\n raw: 0100000000000040 ffff888007042dc0 dead000000000122 0000000000000000\n raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000\n head: 0100000000000040 ffff888007042dc0 dead000000000122 0000000000000000\n head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000\n head: 0100000000000003 ffffea00002ab401 00000000ffffffff 00000000ffffffff\n head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffff88800aad0f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n ffff88800aad0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n >ffff88800aad1000: fa fb\n---truncated---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable tasklets can be queued by received frames/interrupts from a remote peer on the FarSync HDLC/WAN network link. The required device detach is accounted for under UI.\nAC:L - An attacker can keep RX/interrupt work pending by continuously sending traffic, and the bug is an unsynchronized tasklet teardown rather than a condition requiring special memory layout. The race is therefore reasonably triggerable during detach.\nPR:N - The remote peer does not need local privileges or authentication to generate receive interrupts that queue the vulnerable work. Administrative privilege is only needed for the victim-side detach action, not for the attacker’s network input.\nUI:R - The remote attack scenario requires another user or administrator to detach, unbind, hot-unplug, or unload the FarSync device while tasklet work is pending. Without that detach path, the freed-card use-after-free is not reached.\nS:U - The bug is within a kernel device driver and impacts kernel memory in the same security authority. It is not a VM escape, IOMMU bypass, or other cross-scope boundary violation.\nC:H - This is a slab use-after-free of the kmalloc-1k fst_card_info object, whose stale pointers and state are dereferenced by tasklet handlers. Kernel UAFs can be leveraged for memory disclosure, so confidentiality impact is High.\nI:H - The freed card object controls subsequent I/O, DMA/status updates, queue handling, and netdev/port state accesses. As kernel UAF memory corruption, it can plausibly be shaped into write/control-flow corruption, so integrity impact is High.\nA:H - The reported KASAN trace shows a slab-use-after-free in softirq/tasklet context, which can crash or panic the kernel. Repeated triggering during detach can therefore cause high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/wan/farsync.c" ], "versions": [ { "version": "51e2d1b84acac39f79cacb60e6e154ce00a9d308", "lessThan": "cac048ebfbb92d91d719f74b59177cb70a7633b8", "status": "affected", "versionType": "git" }, { "version": "998b4e54f517961d3d75144c088a24423e003005", "lessThan": "086131807d119238cd464e5b0845e48d938dfd79", "status": "affected", "versionType": "git" }, { "version": "bb1715a6bfb0c57a68524732a376498a2569f016", "lessThan": "ae894e47e1cd5a6bf8a0423d888c45df8b2b02dc", "status": "affected", "versionType": "git" }, { "version": "2f623aaf9f31de968dea6169849706a2f9be444c", "lessThan": "337d7b4112a47984ee319171b75b73bab47e7924", "status": "affected", "versionType": "git" }, { "version": "2f623aaf9f31de968dea6169849706a2f9be444c", "lessThan": "200bdb8d367ca9b478f9c56ebe56411604d55c81", "status": "affected", "versionType": "git" }, { "version": "2f623aaf9f31de968dea6169849706a2f9be444c", "lessThan": "21d341fe514fd07e345ed264c9eee21cb2061ca2", "status": "affected", "versionType": "git" }, { "version": "2f623aaf9f31de968dea6169849706a2f9be444c", "lessThan": "04edfdfdfcdefc02408ab670607261b0a0a9a02e", "status": "affected", "versionType": "git" }, { "version": "2f623aaf9f31de968dea6169849706a2f9be444c", "lessThan": "bae8a5d2e759da2e0cba33ab2080deee96a09373", "status": "affected", "versionType": "git" }, { "version": "41798a063fd4721b609e11ad839b6820f5070ca7", "status": "affected", "versionType": "git" }, { "version": "b1fe377b43c405b169cffd1b3aa39c1dde16f3ed", "status": "affected", "versionType": "git" }, { "version": "ce9dc768767bbe73d2dd330a9075e849cb8a84d4", "status": "affected", "versionType": "git" }, { "version": "0c5f2c7700cb18aeab1574588d3bb9c0454bf228", "status": "affected", "versionType": "git" }, { "version": "024d2a7c8ee5bfe14357f20cf1bbbbcc5d228cc9", "status": "affected", "versionType": "git" }, { "version": "5.10.163", "lessThan": "5.10.252", "status": "affected", "versionType": "semver" }, { "version": "5.15.86", "lessThan": "5.15.202", "status": "affected", "versionType": "semver" }, { "version": "6.1.2", "lessThan": "6.1.165", "status": "affected", "versionType": "semver" }, { "version": "4.9.337", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.14.303", "lessThan": "4.15", "status": "affected", "versionType": "semver" }, { "version": "4.19.270", "lessThan": "4.20", "status": "affected", "versionType": "semver" }, { "version": "5.4.229", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "6.0.16", "lessThan": "6.1", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/wan/farsync.c" ], "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "lessThan": "6.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.252", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.202", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.165", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.128", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.75", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.16", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.6", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.163", "versionEndExcluding": "5.10.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.86", "versionEndExcluding": "5.15.202" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.2", "versionEndExcluding": "6.1.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.18.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.19.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.337" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.303" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.229" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/cac048ebfbb92d91d719f74b59177cb70a7633b8" }, { "url": "https://git.kernel.org/stable/c/086131807d119238cd464e5b0845e48d938dfd79" }, { "url": "https://git.kernel.org/stable/c/ae894e47e1cd5a6bf8a0423d888c45df8b2b02dc" }, { "url": "https://git.kernel.org/stable/c/337d7b4112a47984ee319171b75b73bab47e7924" }, { "url": "https://git.kernel.org/stable/c/200bdb8d367ca9b478f9c56ebe56411604d55c81" }, { "url": "https://git.kernel.org/stable/c/21d341fe514fd07e345ed264c9eee21cb2061ca2" }, { "url": "https://git.kernel.org/stable/c/04edfdfdfcdefc02408ab670607261b0a0a9a02e" }, { "url": "https://git.kernel.org/stable/c/bae8a5d2e759da2e0cba33ab2080deee96a09373" } ], "title": "net: wan: farsync: Fix use-after-free bugs caused by unfinished tasklets", "x_generator": { "engine": "bippy-1.2.0" } } } }