{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2025-40052 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-40052 is a denial of service vulnerability in Linux, published on 28 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-40052 and fix it if it is affected.\n\nWhat it is: CVE-2025-40052 is a denial of service vulnerability in Linux, published on 28 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2025-40052 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2025-40052/ (Markdown: https://insights.sbomify.com/CVE-2025-40052/index.md)","id":"CVE-2025-40052","markdown":"https://insights.sbomify.com/CVE-2025-40052/index.md","name":"CVE-2025-40052","record":{"aliases":["AZL-68846","BELL-CVE-2025-40052","DEBIAN-CVE-2025-40052","GHSA-76hq-frpj-75r7","ROOT-OS-DEBIAN-13-CVE-2025-40052","ROOT-OS-UBUNTU-2404-CVE-2025-40052","UBUNTU-CVE-2025-40052"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel SMB client","requires_auth":"none","summary":"A bug in the Linux kernel SMB client causes a kernel crash when handling encrypted mounts with high parallel I/O, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix crypto buffers in non-linear memory\n\nThe crypto API, through the scatterlist API, expects input buffers to be\nin linear memory.  We handle this with the cifs_sg_set_buf() helper\nthat converts vmalloc'd memory to their corresponding pages.\n\nHowever, when we allocate our aead_request buffer (@creq in\nsmb2ops.c::crypt_message()), we do so with kvzalloc(), which possibly\nputs aead_request-\u003e__ctx in vmalloc area.\n\nAEAD algorithm then uses -\u003e__ctx for its private/internal data and\noperations, and uses sg_set_buf() for such data on a few places.\n\nThis works fine as long as @creq falls into kmalloc zone (small\nrequests) or vmalloc'd memory is still within linear range.\n\nTasks' stacks are vmalloc'd by default (CONFIG_VMAP_STACK=y), so too\nmany tasks will increment the base stacks' addresses to a point where\nvirt_addr_valid(buf) will fail (BUG() in sg_set_buf()) when that\nhappens.\n\nIn practice: too many parallel reads and writes on an encrypted mount\nwill trigger this bug.\n\nTo fix this, always alloc @creq with kmalloc() instead.\nAlso drop the @sensitive_size variable/arguments since\nkfree_sensitive() doesn't need it.\n\nBacktrace:\n\n[  945.272081] ------------[ cut here ]------------\n[  945.272774] kernel BUG at include/linux/scatterlist.h:209!\n[  945.273520] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI\n[  945.274412] CPU: 7 UID: 0 PID: 56 Comm: kworker/u33:0 Kdump: loaded Not tainted 6.15.0-lku-11779-g8e9d6efccdd7-dirty #1 PREEMPT(voluntary)\n[  945.275736] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014\n[  945.276877] Workqueue: writeback wb_workfn (flush-cifs-2)\n[  945.277457] RIP: 0010:crypto_gcm_init_common+0x1f9/0x220\n[  945.278018] Code: b0 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 c0 00 00 00 80 48 2b 05 5c 58 e5 00 e9 58 ff ff ff \u003c0f\u003e 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 48 c7 04 24 01 00 00 00 48 8b\n[  945.279992] RSP: 0018:ffffc90000a27360 EFLAGS: 00010246\n[  945.280578] RAX: 0000000000000000 RBX: ffffc90001d85060 RCX: 0000000000000030\n[  945.281376] RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffc90081d85070\n[  945.282145] RBP: ffffc90001d85010 R08: ffffc90001d85000 R09: 0000000000000000\n[  945.282898] R10: ffffc90001d85090 R11: 0000000000001000 R12: ffffc90001d85070\n[  945.283656] R13: ffff888113522948 R14: ffffc90001d85060 R15: ffffc90001d85010\n[  945.284407] FS:  0000000000000000(0000) GS:ffff8882e66cf000(0000) knlGS:0000000000000000\n[  945.285262] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  945.285884] CR2: 00007fa7ffdd31f4 CR3: 000000010540d000 CR4: 0000000000350ef0\n[  945.286683] Call Trace:\n[  945.286952]  \u003cTASK\u003e\n[  945.287184]  ? crypt_message+0x33f/0xad0 [cifs]\n[  945.287719]  crypto_gcm_encrypt+0x36/0xe0\n[  945.288152]  crypt_message+0x54a/0xad0 [cifs]\n[  945.288724]  smb3_init_transform_rq+0x277/0x300 [cifs]\n[  945.289300]  smb_send_rqst+0xa3/0x160 [cifs]\n[  945.289944]  cifs_call_async+0x178/0x340 [cifs]\n[  945.290514]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]\n[  945.291177]  smb2_async_writev+0x3e3/0x670 [cifs]\n[  945.291759]  ? find_held_lock+0x32/0x90\n[  945.292212]  ? netfs_advance_write+0xf2/0x310\n[  945.292723]  netfs_advance_write+0xf2/0x310\n[  945.293210]  netfs_write_folio+0x346/0xcc0\n[  945.293689]  ? __pfx__raw_spin_unlock_irq+0x10/0x10\n[  945.294250]  netfs_writepages+0x117/0x460\n[  945.294724]  do_writepages+0xbe/0x170\n[  945.295152]  ? find_held_lock+0x32/0x90\n[  945.295600]  ? kvm_sched_clock_read+0x11/0x20\n[  945.296103]  __writeback_single_inode+0x56/0x4b0\n[  945.296643]  writeback_sb_inodes+0x229/0x550\n[  945.297140]  __writeback_inodes_wb+0x4c/0xe0\n[  945.297642]  wb_writeback+0x2f1/0x3f0\n[  945.298069]  wb_workfn+0x300/0x490\n[  945.298472]  process_one_work+0x1fe/0x590\n[  945.298949]  worker_thread+0x1ce/0x3c0\n[  945.299397]  ? __pfx_worker_thread+0x10/0x10\n[  945.299900]  kthr\n---truncated---","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"smb: client: fix crypto buffers in non-linear memory","id":"CVE-2025-40052","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2025"},"n_packages":0,"n_references":4,"next":{"headline":"net: dlink: handle copy_thresh allocation failure","id":"CVE-2025-40053"},"packages":[],"prev":{"headline":"vhost: vringh: Modify the return value check","id":"CVE-2025-40051"},"products":["Linux"],"published":"2025-10-28","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A bug in the Linux kernel SMB client causes a kernel crash when handling encrypted mounts with high parallel I/O, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2025-40052/"}