{"id":"CVE-2026-43055","state":"PUBLISHED","title":"scsi: target: file: Use kzalloc_flex for aio_cmd","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: target: file: Use kzalloc_flex for aio_cmd\n\nThe target_core_file doesn't initialize the aio_cmd->iocb for the\nki_write_stream. When a write command fd_execute_rw_aio() is executed,\nwe may get a bogus ki_write_stream value, causing unintended write\nfailure status when checking iocb->ki_write_stream > max_write_streams\nin the block device.\n\nLet's just use kzalloc_flex when allocating the aio_cmd and let\nki_write_stream=0 to fix this issue.","publishedAt":"2026-05-01T14:15:48.139Z","updatedAt":"2026-10-19T19:06:11.626Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"732f25a2895a8c1c54fb56544f0b1e23770ef4d7","status":"affected","lessThan":"ce54802fe6bb78eb0feffc66fed6a45d41ffc3ab","versionType":"git"},{"version":"732f25a2895a8c1c54fb56544f0b1e23770ef4d7","status":"affected","lessThan":"4eaff1728d0e69b95933412241bbccf4f797dba8","versionType":"git"},{"version":"732f25a2895a8c1c54fb56544f0b1e23770ef4d7","status":"affected","lessThan":"01f784fc9d0ab2a6dac45ee443620e517cb2a19b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/target/target_core_file.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/target/target_core_file.c"]}],"references":["https://git.kernel.org/stable/c/ce54802fe6bb78eb0feffc66fed6a45d41ffc3ab","https://git.kernel.org/stable/c/4eaff1728d0e69b95933412241bbccf4f797dba8","https://git.kernel.org/stable/c/01f784fc9d0ab2a6dac45ee443620e517cb2a19b"],"weaknesses":["CWE-457"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43055.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43055","state":"PUBLISHED","datePublished":"2026-05-01T14:15:48.139Z","dateUpdated":"2026-10-19T19:06:11.626Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.980Z"},"containers":{"cna":{"title":"scsi: target: file: Use kzalloc_flex for aio_cmd","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: target: file: Use kzalloc_flex for aio_cmd\n\nThe target_core_file doesn't initialize the aio_cmd->iocb for the\nki_write_stream. When a write command fd_execute_rw_aio() is executed,\nwe may get a bogus ki_write_stream value, causing unintended write\nfailure status when checking iocb->ki_write_stream > max_write_streams\nin the block device.\n\nLet's just use kzalloc_flex when allocating the aio_cmd and let\nki_write_stream=0 to fix this issue."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"732f25a2895a8c1c54fb56544f0b1e23770ef4d7","status":"affected","lessThan":"ce54802fe6bb78eb0feffc66fed6a45d41ffc3ab","versionType":"git"},{"version":"732f25a2895a8c1c54fb56544f0b1e23770ef4d7","status":"affected","lessThan":"4eaff1728d0e69b95933412241bbccf4f797dba8","versionType":"git"},{"version":"732f25a2895a8c1c54fb56544f0b1e23770ef4d7","status":"affected","lessThan":"01f784fc9d0ab2a6dac45ee443620e517cb2a19b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/target/target_core_file.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/target/target_core_file.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ce54802fe6bb78eb0feffc66fed6a45d41ffc3ab"},{"url":"https://git.kernel.org/stable/c/4eaff1728d0e69b95933412241bbccf4f797dba8"},{"url":"https://git.kernel.org/stable/c/01f784fc9d0ab2a6dac45ee443620e517cb2a19b"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable FILEIO backend can be reached through network SCSI target fabrics, especially the in-kernel iSCSI target over TCP, by sending SCSI WRITE commands to an exported fileio LUN.\nAC:L - In an affected deployment with fileio async I/O enabled, triggering only requires ordinary WRITE CDB/DataOUT traffic; there is no race or attacker-uncontrolled timing condition.\nPR:N - iSCSI target supports no-auth/dynamic-ACL deployments, and in that reasonable worst-case a remote initiator can log in and issue writes without credentials.\nUI:N - No victim user action is needed after the target is configured and listening; the attacker sends protocol commands directly.\nS:U - The impact remains within the kernel target/storage service authority and does not cross a VM, IOMMU, or separate security boundary.\nC:N - The uninitialized field is a write-stream selector byte used internally and is not returned to the attacker or used as a memory read primitive.\nI:N - The bug causes bogus stream selection or write rejection, but it does not provide unauthorized modification of kernel memory or logical storage contents.\nA:H - A stale nonzero stream value can make valid block-device writes fail with CHECK CONDITION, and a remote initiator can repeatedly trigger write failure against the exported LUN."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:25:36.045Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-43055","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:14:04.426072Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-457","lang":"en","type":"CWE","description":"CWE-457 Use of Uninitialized Variable"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:06:11.626Z"}}]}}}