{"id":"CVE-2026-89483","revision":"b5b2748000994359a6c3a3993f12928b","records":[{"revision":"b5b2748000994359a6c3a3993f12928b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89483","aliases":[],"title":"nvme: zero the discard fallback page","description":"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.","state":0,"publishedAt":"2026-09-11T19:43:38.076+00:00","modifiedAt":"2026-10-19T08:47:33.684+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/nvme/host/core.c\"\n ],\n \"versions\": [\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"76139b5bbf531e675934b97227be3521c7fdd537\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"3f84d2bd0d8ae8c7e8e0f8fc3cbf018a282971a1\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"415f2772ebcbc7f3f1ab1a71915dab82cee3465e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"66b5af23b6f956e57f8205c46aa80b054631be34\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"dc4d4b70a863f7e39ef8bd137634be4e6db8b084\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"67551d8430df94c827e1830bd3a5fae1f66a5219\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"f5827817b4fc7feeabf4f53fb4b626e6edc52fef\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"530436c45ef2e446c12538a400e465929a0b3ade\",\n \"lessThan\": \"bededeaaeff404978a5a8e2a605a6c3017cddd3e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ffa56cbdd2409b522b4cb56461bea1c45889417b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8b0acb768a06083b0d28bace1481c1f6679e76f4\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"4.19.92\",\n \"lessThan\": \"4.20\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.4.7\",\n \"lessThan\": \"5.5\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/nvme/host/core.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.5\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.5\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.270\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.221\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.188\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.157\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.109\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.50\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.4\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/76139b5bbf531e675934b97227be3521c7fdd537","https://git.kernel.org/stable/c/3f84d2bd0d8ae8c7e8e0f8fc3cbf018a282971a1","https://git.kernel.org/stable/c/415f2772ebcbc7f3f1ab1a71915dab82cee3465e","https://git.kernel.org/stable/c/66b5af23b6f956e57f8205c46aa80b054631be34","https://git.kernel.org/stable/c/dc4d4b70a863f7e39ef8bd137634be4e6db8b084","https://git.kernel.org/stable/c/67551d8430df94c827e1830bd3a5fae1f66a5219","https://git.kernel.org/stable/c/f5827817b4fc7feeabf4f53fb4b626e6edc52fef","https://git.kernel.org/stable/c/bededeaaeff404978a5a8e2a605a6c3017cddd3e"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89483","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89483","identifiers":["CVE-2026-89483"]},"retained":false,"historicalAffected":[]}],"coverage":[]}