CVE-2026-89515

Not scored yetLast modified Oct 19, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

scsi: core: Fill in DMA padding bytes in scsi_alloc_sgtables()

During fuzz testing, the following issue was discovered:

BUG: KMSAN: uninit-value in __dma_map_sg_attrs+0x217/0x310 __dma_map_sg_attrs+0x217/0x310 dma_map_sg_attrs+0x4a/0x70 ata_qc_issue+0x9f8/0x1420 __ata_scsi_queuecmd+0x1657/0x1740 ata_scsi_queuecmd+0x79a/0x920 scsi_queue_rq+0x4472/0x4f40 blk_mq_dispatch_rq_list+0x1cca/0x3ee0 __blk_mq_sched_dispatch_requests+0x458/0x630 blk_mq_sched_dispatch_requests+0x15b/0x340 __blk_mq_run_hw_queue+0xe5/0x250 __blk_mq_delay_run_hw_queue+0x138/0x780 blk_mq_run_hw_queue+0x4bb/0x7e0 blk_mq_sched_insert_request+0x2a7/0x4c0 blk_execute_rq+0x497/0x8a0 sg_io+0xbe0/0xe20 scsi_ioctl+0x2b36/0x3c60 sr_block_ioctl+0x319/0x440 blkdev_ioctl+0x80f/0xd70 __se_sys_ioctl+0x219/0x420 __x64_sys_ioctl+0x93/0xe0 x64_sys_call+0x1d6c/0x3ad0 do_syscall_64+0x4c/0xa0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Uninit was created at: __alloc_pages+0x5c0/0xc80 alloc_pages+0xe0e/0x1050 blk_rq_map_user_iov+0x2b77/0x6100 blk_rq_map_user_io+0x2fa/0x4d0 sg_io+0xad6/0xe20 scsi_ioctl+0x2b36/0x3c60 sr_block_ioctl+0x319/0x440 blkdev_ioctl+0x80f/0xd70 __se_sys_ioctl+0x219/0x420 __x64_sys_ioctl+0x93/0xe0 x64_sys_call+0x1d6c/0x3ad0 do_syscall_64+0x4c/0xa0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Bytes 14-15 of 16 are uninitialized Memory access of size 16 starts at ffff88800cbdb000

When processing the last unaligned element of the scatterlist, it is supplemented with missing bytes in the amount of pad_len. These bytes remain uninitialized, which leads to a problem.

Extend last_sg->length by pad_len first, then use sg_zero_buffer() to zero those pad_len bytes. sg_zero_buffer() uses sg_miter internally, which correctly handles sg entries spanning multiple pages and padding that crosses a page boundary.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Metrics

No CVSS score has been published yet.

Affected software

Source: the vendor's advisory (CNA). NVD analysis pending.

No affected versions have been published.

Timeline

Published
Sep 11, 2026
Last modified
Oct 19, 2026
NVD status
Received

Related CVEs from 2026

CVE-2026-89516In the Linux kernel, the following vulnerability has been resolved: sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_usersCVE-2026-89517In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix rq->core_pick corruption under core scheduling Core schCVE-2026-89518In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix this_rq() assumptions in dispatch kfuncs Under core schCVE-2026-89519In the Linux kernel, the following vulnerability has been resolved: sched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return SCX_CVE-2026-89528.8Privilege escalation in the Application Update component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.CVE-2026-895207.8In the Linux kernel, the following vulnerability has been resolved: sched/core: Make core-sched flips wait for in-flight selections Core sCVE-2026-895217.3In the Linux kernel, the following vulnerability has been resolved: sched/core: Handle pick_task() releasing the rq lock Core scheduling'sCVE-2026-895227.8In the Linux kernel, the following vulnerability has been resolved: media: staging/ipu7: fix async notifier UAF on probe error path isys_rCVE-2026-895237.8In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7925: cancel pending mlo_pm_work If the device is reset,CVE-2026-895248.1In the Linux kernel, the following vulnerability has been resolved: wifi: ath6kl: clamp assoc request/response lengths before subtracting ICVE-2026-89525In the Linux kernel, the following vulnerability has been resolved: udf: reject VAT indexes equal to the entry count UDF 1.50 virtual partCVE-2026-895269.8In the Linux kernel, the following vulnerability has been resolved: svcrdma: Validate Read chunk positions before reconstruction The RPC/R
CVE-2026-89515: Unscored | Vulnix