{"id":"AZL-100178","summary":"CVE-2026-89586 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nata: libata-scsi: fix DSM TRIM for sector sizes larger than 2048 bytes\n\nata_scsi_write_same_xlat() translates a SCSI WRITE SAME command with the\nUNMAP bit set into an ATA DATA SET MANAGEMENT TRIM command.  The TRIM\ndescriptor is built by ata_format_dsm_trim_descr() into the 2048-byte\nata_scsi_rbuf staging buffer, and the number of bytes copied is compared\nagainst the logical sector size by the caller:\n\n\tsize = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);\n\tif (size != len)\t\t/* len == sdp-\u003esector_size */\n\t\tgoto invalid_param_len;\n\nata_format_dsm_trim_descr() clamps the copy length to ATA_SCSI_RBUF_SIZE\n(2048).  On a device whose logical sector size exceeds that (e.g. a 4Kn\ndevice, where sector_size == 4096) the function can never return more than\n2048, while the caller expects it to return sector_size.  The comparison\ntherefore always fails, so every TRIM is rejected with \"Parameter list\nlength error\" and WARN_ON() splats on each attempt.  TRIM / discard is\nthus completely broken on such devices.\n\nThe descriptor was incorrectly sized from the logical sector size.  A DSM\nTRIM payload is a list of 512-byte pages, each holding up to\nATA_MAX_TRIM_RNUM (64) LBA Range Entries, and is independent of the logical\nsector size.  The Block Limits VPD page already advertises a single such\npage as the maximum WRITE SAME length (65535 * ATA_MAX_TRIM_RNUM logical\nblocks), so the block layer never sends a request that needs more than one\npage.\n\nEmit exactly one 512-byte page, independent of the logical sector size,\nand transfer only that page (COUNT == 1).  For a 512-byte-sector device\nthis is unchanged; devices with larger logical sectors now work instead of\nfailing every TRIM.","modified":"2026-09-13T06:06:36Z","published":"2026-09-11T20:19:43Z","upstream":["CVE-2026-89586"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89586"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100178.json"}}],"schema_version":"1.9.0"}