Description
In the Linux kernel, the following vulnerability has been resolved:
nvme: zero the discard fallback page
nvme_setup_discard() always maps sizeof(struct nvme_dsm_range) *
NVME_DSM_MAX_RANGES = 4096 bytes as the DSM payload however many ranges
the command declares, because some devices ignore the 'Number of Ranges'
field - the Fixes: commit records two that read past the declared ranges.
A single-range discard fills only the first 16 bytes.
Normally the buffer comes from kzalloc() and the other 4080 bytes are
zero. When that allocation fails the code falls back to the
per-controller ctrl->discard_page, which nvme_init_ctrl() obtains with
alloc_page(GFP_KERNEL) and nothing ever zeroes, so those 4080 bytes are
whatever the page last held and are handed to the controller. Reaching
it requires the kzalloc(GFP_ATOMIC | __GFP_NOWARN) to fail, that is
memory pressure; it is not remotely triggerable. Failing the allocation
under KMSAN reproduces it, with the leaked tail full of vmemmap struct
page pointers. The extent in the report is a partial transfer of the
payload, not the whole 4096 bytes; the 16-byte boundary in it is the one
declared range:
[ 11.991601] BUG: KMSAN: uninit-value in dma_map_phys+0x14c8/0x1900
[ 11.991969] dma_map_phys+0x14c8/0x1900
[ 11.992220] dma_map_page_attrs+0xcf/0x130
[ 11.992485] e1000_xmit_frame+0x4099/0x6d10
[ 11.992768] dev_hard_start_xmit+0x22f/0xa80
[ 11.993068] sch_direct_xmit+0x35c/0xcb0
[ 11.993315] __dev_queue_xmit+0x1ee5/0x5eb0
[ 11.993608] ip_finish_output2+0x1903/0x1c30
[ 11.993881] ip_finish_output+0x288/0x870
[ 11.994125] ip_output+0x15e/0x400
[ 11.994365] __ip_queue_xmit+0x1e85/0x1fb0
[ 11.994639] ip_queue_xmit+0x60/0x80
[ 11.994899] __tcp_transmit_skb+0x4e71/0x5fa0
[ 11.995210] tcp_write_xmit+0x3a36/0x9160
[ 11.995533] __tcp_push_pending_frames+0xc5/0x3c0
[ 11.995854] tcp_push+0x7dc/0x840
[ 11.996076] tcp_sendmsg_locked+0x766c/0x8400
[ 11.996371] tcp_sendmsg+0x4b/0x90
[ 11.996572] inet_sendmsg+0x134/0x2a0
[ 11.996823] __sock_sendmsg+0x265/0x360
[ 11.997076] sock_sendmsg+0x100/0x1e0
[ 11.997293] nvme_tcp_try_send+0x196f/0x6370
[ 11.997605] nvme_tcp_queue_rq+0x1d54/0x20b0
[ 11.997882] blk_mq_dispatch_rq_list+0x5ee/0x2e50
[ 11.998175] __blk_mq_sched_dispatch_requests+0x16dc/0x24a0
[ 11.998539] blk_mq_sched_dispatch_requests+0x11b/0x2c0
[ 11.998865] blk_mq_run_work_fn+0x13b/0x280
[ 11.999146] process_scheduled_works+0x966/0x1ad0
[ 11.999465] worker_thread+0xe44/0x1480
[ 11.999709] kthread+0x53b/0x600
[ 11.999927] ret_from_fork+0x29f/0x7c0
[ 12.000191] ret_from_fork_asm+0x1a/0x30
[ 12.000460]
[ 12.000558] Uninit was created at:
[ 12.000788] __alloc_frozen_pages_noprof+0x8bf/0xd30
[ 12.001096] alloc_pages_mpol+0x1d0/0x5f0
[ 12.001326] alloc_pages_noprof+0x102/0x290
[ 12.001627] nvme_init_ctrl+0x5a3/0x9f0
[ 12.001891] nvme_tcp_create_ctrl+0xd75/0x19b0
[ 12.002170] nvmf_dev_write+0x4c68/0x4fd0
[ 12.002426] vfs_write+0x587/0x1a10
[ 12.002636] __x64_sys_write+0x207/0x4f0
[ 12.002874] x64_sys_call+0x2ff0/0x3ea0
[ 12.003123] do_syscall_64+0x147/0x3b0
[ 12.003400] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 12.003680]
[ 12.003777] Bytes 16-2843 of 2844 are uninitialized
[ 12.004068] Memory access of size 2844 starts at ffff888109f82000
[ 12.004412]
[ 12.004530] CPU: 0 UID: 0 PID: 101 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMECTL-gf5098b6bae76 #1 PREEMPT(lazy)
[ 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
[ 12.005762] Workqueue: kblockd blk_mq_run_work_fn
[ 12.006073] =====================================================
Allocate the page with __GFP_ZERO. The single allocation site covers
every use of it: bytes no discard has written stay zero, and bytes one
did write hold that controller's own range list, which it has already
been sent.
nvme: zero the discard fallback page
nvme_setup_discard() always maps sizeof(struct nvme_dsm_range) *
NVME_DSM_MAX_RANGES = 4096 bytes as the DSM payload however many ranges
the command declares, because some devices ignore the 'Number of Ranges'
field - the Fixes: commit records two that read past the declared ranges.
A single-range discard fills only the first 16 bytes.
Normally the buffer comes from kzalloc() and the other 4080 bytes are
zero. When that allocation fails the code falls back to the
per-controller ctrl->discard_page, which nvme_init_ctrl() obtains with
alloc_page(GFP_KERNEL) and nothing ever zeroes, so those 4080 bytes are
whatever the page last held and are handed to the controller. Reaching
it requires the kzalloc(GFP_ATOMIC | __GFP_NOWARN) to fail, that is
memory pressure; it is not remotely triggerable. Failing the allocation
under KMSAN reproduces it, with the leaked tail full of vmemmap struct
page pointers. The extent in the report is a partial transfer of the
payload, not the whole 4096 bytes; the 16-byte boundary in it is the one
declared range:
[ 11.991601] BUG: KMSAN: uninit-value in dma_map_phys+0x14c8/0x1900
[ 11.991969] dma_map_phys+0x14c8/0x1900
[ 11.992220] dma_map_page_attrs+0xcf/0x130
[ 11.992485] e1000_xmit_frame+0x4099/0x6d10
[ 11.992768] dev_hard_start_xmit+0x22f/0xa80
[ 11.993068] sch_direct_xmit+0x35c/0xcb0
[ 11.993315] __dev_queue_xmit+0x1ee5/0x5eb0
[ 11.993608] ip_finish_output2+0x1903/0x1c30
[ 11.993881] ip_finish_output+0x288/0x870
[ 11.994125] ip_output+0x15e/0x400
[ 11.994365] __ip_queue_xmit+0x1e85/0x1fb0
[ 11.994639] ip_queue_xmit+0x60/0x80
[ 11.994899] __tcp_transmit_skb+0x4e71/0x5fa0
[ 11.995210] tcp_write_xmit+0x3a36/0x9160
[ 11.995533] __tcp_push_pending_frames+0xc5/0x3c0
[ 11.995854] tcp_push+0x7dc/0x840
[ 11.996076] tcp_sendmsg_locked+0x766c/0x8400
[ 11.996371] tcp_sendmsg+0x4b/0x90
[ 11.996572] inet_sendmsg+0x134/0x2a0
[ 11.996823] __sock_sendmsg+0x265/0x360
[ 11.997076] sock_sendmsg+0x100/0x1e0
[ 11.997293] nvme_tcp_try_send+0x196f/0x6370
[ 11.997605] nvme_tcp_queue_rq+0x1d54/0x20b0
[ 11.997882] blk_mq_dispatch_rq_list+0x5ee/0x2e50
[ 11.998175] __blk_mq_sched_dispatch_requests+0x16dc/0x24a0
[ 11.998539] blk_mq_sched_dispatch_requests+0x11b/0x2c0
[ 11.998865] blk_mq_run_work_fn+0x13b/0x280
[ 11.999146] process_scheduled_works+0x966/0x1ad0
[ 11.999465] worker_thread+0xe44/0x1480
[ 11.999709] kthread+0x53b/0x600
[ 11.999927] ret_from_fork+0x29f/0x7c0
[ 12.000191] ret_from_fork_asm+0x1a/0x30
[ 12.000460]
[ 12.000558] Uninit was created at:
[ 12.000788] __alloc_frozen_pages_noprof+0x8bf/0xd30
[ 12.001096] alloc_pages_mpol+0x1d0/0x5f0
[ 12.001326] alloc_pages_noprof+0x102/0x290
[ 12.001627] nvme_init_ctrl+0x5a3/0x9f0
[ 12.001891] nvme_tcp_create_ctrl+0xd75/0x19b0
[ 12.002170] nvmf_dev_write+0x4c68/0x4fd0
[ 12.002426] vfs_write+0x587/0x1a10
[ 12.002636] __x64_sys_write+0x207/0x4f0
[ 12.002874] x64_sys_call+0x2ff0/0x3ea0
[ 12.003123] do_syscall_64+0x147/0x3b0
[ 12.003400] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 12.003680]
[ 12.003777] Bytes 16-2843 of 2844 are uninitialized
[ 12.004068] Memory access of size 2844 starts at ffff888109f82000
[ 12.004412]
[ 12.004530] CPU: 0 UID: 0 PID: 101 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMECTL-gf5098b6bae76 #1 PREEMPT(lazy)
[ 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
[ 12.005762] Workqueue: kblockd blk_mq_run_work_fn
[ 12.006073] =====================================================
Allocate the page with __GFP_ZERO. The single allocation site covers
every use of it: bytes no discard has written stay zero, and bytes one
did write hold that controller's own range list, which it has already
been sent.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
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| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
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References
History
Sat, 12 Sep 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-824 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: nvme: zero the discard fallback page nvme_setup_discard() always maps sizeof(struct nvme_dsm_range) * NVME_DSM_MAX_RANGES = 4096 bytes as the DSM payload however many ranges the command declares, because some devices ignore the 'Number of Ranges' field - the Fixes: commit records two that read past the declared ranges. A single-range discard fills only the first 16 bytes. Normally the buffer comes from kzalloc() and the other 4080 bytes are zero. When that allocation fails the code falls back to the per-controller ctrl->discard_page, which nvme_init_ctrl() obtains with alloc_page(GFP_KERNEL) and nothing ever zeroes, so those 4080 bytes are whatever the page last held and are handed to the controller. Reaching it requires the kzalloc(GFP_ATOMIC | __GFP_NOWARN) to fail, that is memory pressure; it is not remotely triggerable. Failing the allocation under KMSAN reproduces it, with the leaked tail full of vmemmap struct page pointers. The extent in the report is a partial transfer of the payload, not the whole 4096 bytes; the 16-byte boundary in it is the one declared range: [ 11.991601] BUG: KMSAN: uninit-value in dma_map_phys+0x14c8/0x1900 [ 11.991969] dma_map_phys+0x14c8/0x1900 [ 11.992220] dma_map_page_attrs+0xcf/0x130 [ 11.992485] e1000_xmit_frame+0x4099/0x6d10 [ 11.992768] dev_hard_start_xmit+0x22f/0xa80 [ 11.993068] sch_direct_xmit+0x35c/0xcb0 [ 11.993315] __dev_queue_xmit+0x1ee5/0x5eb0 [ 11.993608] ip_finish_output2+0x1903/0x1c30 [ 11.993881] ip_finish_output+0x288/0x870 [ 11.994125] ip_output+0x15e/0x400 [ 11.994365] __ip_queue_xmit+0x1e85/0x1fb0 [ 11.994639] ip_queue_xmit+0x60/0x80 [ 11.994899] __tcp_transmit_skb+0x4e71/0x5fa0 [ 11.995210] tcp_write_xmit+0x3a36/0x9160 [ 11.995533] __tcp_push_pending_frames+0xc5/0x3c0 [ 11.995854] tcp_push+0x7dc/0x840 [ 11.996076] tcp_sendmsg_locked+0x766c/0x8400 [ 11.996371] tcp_sendmsg+0x4b/0x90 [ 11.996572] inet_sendmsg+0x134/0x2a0 [ 11.996823] __sock_sendmsg+0x265/0x360 [ 11.997076] sock_sendmsg+0x100/0x1e0 [ 11.997293] nvme_tcp_try_send+0x196f/0x6370 [ 11.997605] nvme_tcp_queue_rq+0x1d54/0x20b0 [ 11.997882] blk_mq_dispatch_rq_list+0x5ee/0x2e50 [ 11.998175] __blk_mq_sched_dispatch_requests+0x16dc/0x24a0 [ 11.998539] blk_mq_sched_dispatch_requests+0x11b/0x2c0 [ 11.998865] blk_mq_run_work_fn+0x13b/0x280 [ 11.999146] process_scheduled_works+0x966/0x1ad0 [ 11.999465] worker_thread+0xe44/0x1480 [ 11.999709] kthread+0x53b/0x600 [ 11.999927] ret_from_fork+0x29f/0x7c0 [ 12.000191] ret_from_fork_asm+0x1a/0x30 [ 12.000460] [ 12.000558] Uninit was created at: [ 12.000788] __alloc_frozen_pages_noprof+0x8bf/0xd30 [ 12.001096] alloc_pages_mpol+0x1d0/0x5f0 [ 12.001326] alloc_pages_noprof+0x102/0x290 [ 12.001627] nvme_init_ctrl+0x5a3/0x9f0 [ 12.001891] nvme_tcp_create_ctrl+0xd75/0x19b0 [ 12.002170] nvmf_dev_write+0x4c68/0x4fd0 [ 12.002426] vfs_write+0x587/0x1a10 [ 12.002636] __x64_sys_write+0x207/0x4f0 [ 12.002874] x64_sys_call+0x2ff0/0x3ea0 [ 12.003123] do_syscall_64+0x147/0x3b0 [ 12.003400] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 12.003680] [ 12.003777] Bytes 16-2843 of 2844 are uninitialized [ 12.004068] Memory access of size 2844 starts at ffff888109f82000 [ 12.004412] [ 12.004530] CPU: 0 UID: 0 PID: 101 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMECTL-gf5098b6bae76 #1 PREEMPT(lazy) [ 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 [ 12.005762] Workqueue: kblockd blk_mq_run_work_fn [ 12.006073] ===================================================== Allocate the page with __GFP_ZERO. The single allocation site covers every use of it: bytes no discard has written stay zero, and bytes one did write hold that controller's own range list, which it has already been sent. | |
| Title | nvme: zero the discard fallback page | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-11T19:43:38.076Z
Reserved: 2026-09-11T19:38:34.712Z
Link: CVE-2026-89483
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-11T20:19:29.880
Modified: 2026-09-11T20:19:29.880
Link: CVE-2026-89483
Redhat
OpenCVE Enrichment
No data.
Weaknesses