--- id: CVE-2026-89515 title: 'scsi: core: Fill in DMA padding bytes in scsi_alloc_sgtables()' summary: |- 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… severity: medium cvss: 5.5 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H' cvssSource: vendor cwe: - CWE-824 vendor: Linux product: Linux affected: - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 1aa6df61cef1f47f503c3ccf60d08c4dd931fdc1 - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 6da140ebdfdd6aa3773945f2c0ebba01d2ef33d8 - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < fd2cbe08c6ccba7fc1ddb830653a93bb7e2d833c - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 28ed5343666ff424ce5e248fa1c5a402303b4aff - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < a4353ec7742bdf87dcdde5875270feb3a1982a51 - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < e7143c3f4e5c0a7986733c6f27009274bf6c4264 - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 6fd1cce5018fdcc8d928e00a6a1dd2997d5b9409 - >- Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 626147717bea776b61ed3631d2c26283760c4cc4 - Linux 2.6.25 published: '2026-09-11' updated: '2026-10-19' sourceUpdated: '2026-10-19T08:48:06.602Z' source: CVEORG sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89515' references: - url: 'https://git.kernel.org/stable/c/1aa6df61cef1f47f503c3ccf60d08c4dd931fdc1' - url: 'https://git.kernel.org/stable/c/6da140ebdfdd6aa3773945f2c0ebba01d2ef33d8' - url: 'https://git.kernel.org/stable/c/fd2cbe08c6ccba7fc1ddb830653a93bb7e2d833c' - url: 'https://git.kernel.org/stable/c/28ed5343666ff424ce5e248fa1c5a402303b4aff' - url: 'https://git.kernel.org/stable/c/a4353ec7742bdf87dcdde5875270feb3a1982a51' - url: 'https://git.kernel.org/stable/c/e7143c3f4e5c0a7986733c6f27009274bf6c4264' - url: 'https://git.kernel.org/stable/c/6fd1cce5018fdcc8d928e00a6a1dd2997d5b9409' - url: 'https://git.kernel.org/stable/c/626147717bea776b61ed3631d2c26283760c4cc4' - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89515.json - url: 'https://access.redhat.com/security/cve/CVE-2026-89515' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532059' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89515' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89515' - url: >- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89515.mbox tags: - cve.org - csaf - vex - red-hat epss: 0.00177 epssPercentile: 0.07262 ingestedAt: '2026-09-14T15:23:07.452Z' --- ## Overview 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. ## Affected - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 1aa6df61cef1f47f503c3ccf60d08c4dd931fdc1` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 6da140ebdfdd6aa3773945f2c0ebba01d2ef33d8` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < fd2cbe08c6ccba7fc1ddb830653a93bb7e2d833c` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 28ed5343666ff424ce5e248fa1c5a402303b4aff` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < a4353ec7742bdf87dcdde5875270feb3a1982a51` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < e7143c3f4e5c0a7986733c6f27009274bf6c4264` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 6fd1cce5018fdcc8d928e00a6a1dd2997d5b9409` - `Linux >= 40b01b9bbdf51ae543a04744283bf2d56c4a6afa < 626147717bea776b61ed3631d2c26283760c4cc4` - `Linux 2.6.25` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89515.json)