{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89483","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.712Z","datePublished":"2026-09-11T19:43:38.076Z","dateUpdated":"2026-09-14T12:00:20.304Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T12:00:20.304Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvme: zero the discard fallback page\n\nnvme_setup_discard() always maps sizeof(struct nvme_dsm_range) *\nNVME_DSM_MAX_RANGES = 4096 bytes as the DSM payload however many ranges\nthe command declares, because some devices ignore the 'Number of Ranges'\nfield - the Fixes: commit records two that read past the declared ranges.\nA single-range discard fills only the first 16 bytes.\n\nNormally the buffer comes from kzalloc() and the other 4080 bytes are\nzero.  When that allocation fails the code falls back to the\nper-controller ctrl->discard_page, which nvme_init_ctrl() obtains with\nalloc_page(GFP_KERNEL) and nothing ever zeroes, so those 4080 bytes are\nwhatever the page last held and are handed to the controller.  Reaching\nit requires the kzalloc(GFP_ATOMIC | __GFP_NOWARN) to fail, that is\nmemory pressure; it is not remotely triggerable.  Failing the allocation\nunder KMSAN reproduces it, with the leaked tail full of vmemmap struct\npage pointers.  The extent in the report is a partial transfer of the\npayload, not the whole 4096 bytes; the 16-byte boundary in it is the one\ndeclared range:\n\n[   11.991601] BUG: KMSAN: uninit-value in dma_map_phys+0x14c8/0x1900\n[   11.991969]  dma_map_phys+0x14c8/0x1900\n[   11.992220]  dma_map_page_attrs+0xcf/0x130\n[   11.992485]  e1000_xmit_frame+0x4099/0x6d10\n[   11.992768]  dev_hard_start_xmit+0x22f/0xa80\n[   11.993068]  sch_direct_xmit+0x35c/0xcb0\n[   11.993315]  __dev_queue_xmit+0x1ee5/0x5eb0\n[   11.993608]  ip_finish_output2+0x1903/0x1c30\n[   11.993881]  ip_finish_output+0x288/0x870\n[   11.994125]  ip_output+0x15e/0x400\n[   11.994365]  __ip_queue_xmit+0x1e85/0x1fb0\n[   11.994639]  ip_queue_xmit+0x60/0x80\n[   11.994899]  __tcp_transmit_skb+0x4e71/0x5fa0\n[   11.995210]  tcp_write_xmit+0x3a36/0x9160\n[   11.995533]  __tcp_push_pending_frames+0xc5/0x3c0\n[   11.995854]  tcp_push+0x7dc/0x840\n[   11.996076]  tcp_sendmsg_locked+0x766c/0x8400\n[   11.996371]  tcp_sendmsg+0x4b/0x90\n[   11.996572]  inet_sendmsg+0x134/0x2a0\n[   11.996823]  __sock_sendmsg+0x265/0x360\n[   11.997076]  sock_sendmsg+0x100/0x1e0\n[   11.997293]  nvme_tcp_try_send+0x196f/0x6370\n[   11.997605]  nvme_tcp_queue_rq+0x1d54/0x20b0\n[   11.997882]  blk_mq_dispatch_rq_list+0x5ee/0x2e50\n[   11.998175]  __blk_mq_sched_dispatch_requests+0x16dc/0x24a0\n[   11.998539]  blk_mq_sched_dispatch_requests+0x11b/0x2c0\n[   11.998865]  blk_mq_run_work_fn+0x13b/0x280\n[   11.999146]  process_scheduled_works+0x966/0x1ad0\n[   11.999465]  worker_thread+0xe44/0x1480\n[   11.999709]  kthread+0x53b/0x600\n[   11.999927]  ret_from_fork+0x29f/0x7c0\n[   12.000191]  ret_from_fork_asm+0x1a/0x30\n[   12.000460]\n[   12.000558] Uninit was created at:\n[   12.000788]  __alloc_frozen_pages_noprof+0x8bf/0xd30\n[   12.001096]  alloc_pages_mpol+0x1d0/0x5f0\n[   12.001326]  alloc_pages_noprof+0x102/0x290\n[   12.001627]  nvme_init_ctrl+0x5a3/0x9f0\n[   12.001891]  nvme_tcp_create_ctrl+0xd75/0x19b0\n[   12.002170]  nvmf_dev_write+0x4c68/0x4fd0\n[   12.002426]  vfs_write+0x587/0x1a10\n[   12.002636]  __x64_sys_write+0x207/0x4f0\n[   12.002874]  x64_sys_call+0x2ff0/0x3ea0\n[   12.003123]  do_syscall_64+0x147/0x3b0\n[   12.003400]  entry_SYSCALL_64_after_hwframe+0x77/0x7f\n[   12.003680]\n[   12.003777] Bytes 16-2843 of 2844 are uninitialized\n[   12.004068] Memory access of size 2844 starts at ffff888109f82000\n[   12.004412]\n[   12.004530] CPU: 0 UID: 0 PID: 101 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMECTL-gf5098b6bae76 #1 PREEMPT(lazy)\n[   12.005127] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   12.005762] Workqueue: kblockd blk_mq_run_work_fn\n[   12.006073] =====================================================\n\nAllocate the page with __GFP_ZERO.  The single allocation site covers\nevery use of it: bytes no discard has written stay zero, and bytes one\ndid write hold that controller's own range list, which it has already\nbeen sent."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - nvme_setup_discard() DMA-maps a 4096-byte DSM buffer that nvme-tcp (KMSAN: nvme_tcp_try_send), nvme-rdma, and nvme-fc transmit to the remote controller, so a malicious NVMe-oF target on the storage fabric receives the leftover kernel page.\nAC:L - The fallback is used when kzalloc(GFP_ATOMIC|__GFP_NOWARN) fails; a fabric peer can drive watermarks with high queue-depth I/O while discards run and retry until discard_page is used, with no race or unknown layout required.\nPR:N - A compromised NVMe-oF target needs no Linux account or capability on the initiator; once the host is attached to fabric storage, DSM payloads are sent without further local authorization.\nUI:N - REQ_OP_DISCARD is issued automatically by mount-discard, fstrim timers, hole-punch, and thin-provision UNMAP during normal operation once an NVMe controller exists; no extra victim mount or click is required at exploit time.\nS:U - The disclosure is host kernel memory to the NVMe controller/peer within the same kernel authority and is not a VM escape, IOMMU bypass, or other cross-boundary scope change.\nC:H - nvme_init_ctrl() allocated discard_page with alloc_page(GFP_KERNEL) and no __GFP_ZERO, so up to 4080 bytes of stale buddy-page contents (KMSAN showed kernel/vmemmap pointers) are sent in the DSM payload, a page-sized leak rather than a few bounded bytes.\nI:N - The flaw only transmits leftover page bytes to the controller; it does not overwrite kernel objects, provide a write primitive, or enable control-flow hijacking.\nA:N - DMA/send of the uninitialized DSM padding completes without oops, panic, or hang; the KMSAN uninit-value report is a sanitizer finding on the transmit path, not a host denial of service."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/host/core.c"],"versions":[{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"76139b5bbf531e675934b97227be3521c7fdd537","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"3f84d2bd0d8ae8c7e8e0f8fc3cbf018a282971a1","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"415f2772ebcbc7f3f1ab1a71915dab82cee3465e","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"66b5af23b6f956e57f8205c46aa80b054631be34","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"dc4d4b70a863f7e39ef8bd137634be4e6db8b084","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"67551d8430df94c827e1830bd3a5fae1f66a5219","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"f5827817b4fc7feeabf4f53fb4b626e6edc52fef","status":"affected","versionType":"git"},{"version":"530436c45ef2e446c12538a400e465929a0b3ade","lessThan":"bededeaaeff404978a5a8e2a605a6c3017cddd3e","status":"affected","versionType":"git"},{"version":"ffa56cbdd2409b522b4cb56461bea1c45889417b","status":"affected","versionType":"git"},{"version":"8b0acb768a06083b0d28bace1481c1f6679e76f4","status":"affected","versionType":"git"},{"version":"4.19.92","lessThan":"4.20","status":"affected","versionType":"semver"},{"version":"5.4.7","lessThan":"5.5","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/nvme/host/core.c"],"versions":[{"version":"5.5","status":"affected"},{"version":"0","lessThan":"5.5","status":"unaffected","versionType":"semver"},{"version":"5.10.270","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.221","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.188","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.109","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.50","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","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":"5.5","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"7.3-rc1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.7"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/76139b5bbf531e675934b97227be3521c7fdd537"},{"url":"https://git.kernel.org/stable/c/3f84d2bd0d8ae8c7e8e0f8fc3cbf018a282971a1"},{"url":"https://git.kernel.org/stable/c/415f2772ebcbc7f3f1ab1a71915dab82cee3465e"},{"url":"https://git.kernel.org/stable/c/66b5af23b6f956e57f8205c46aa80b054631be34"},{"url":"https://git.kernel.org/stable/c/dc4d4b70a863f7e39ef8bd137634be4e6db8b084"},{"url":"https://git.kernel.org/stable/c/67551d8430df94c827e1830bd3a5fae1f66a5219"},{"url":"https://git.kernel.org/stable/c/f5827817b4fc7feeabf4f53fb4b626e6edc52fef"},{"url":"https://git.kernel.org/stable/c/bededeaaeff404978a5a8e2a605a6c3017cddd3e"}],"title":"nvme: zero the discard fallback page","x_generator":{"engine":"bippy-1.2.0"}}}}