{"id":"CVE-2024-26828","state":"PUBLISHED","title":"cifs: fix underflow in parse_server_interfaces()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix underflow in parse_server_interfaces()\n\nIn this loop, we step through the buffer and after each item we check\nif the size_left is greater than the minimum size we need.  However,\nthe problem is that \"bytes_left\" is type ssize_t while sizeof() is type\nsize_t.  That means that because of type promotion, the comparison is\ndone as an unsigned and if we have negative bytes left the loop\ncontinues instead of ending.","publishedAt":"2024-04-17T09:43:52.995Z","updatedAt":"2026-10-30T12:17:52.665Z","severity":{"score":9.4,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"3babdcb5f1809a9a41e31547a063dedf6bb44cca","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"7190353835b4a219abb70f90b06cdcae97f11512","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"f7ff1c89fb6e9610d2b01c1821727729e6609308","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"df2af9fdbc4ddde18a3371c4ca1a86596e8be301","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"cffe487026be13eaf37ea28b783d9638ab147204","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2ops.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.18","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.79","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.18","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.6","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2ops.c"]}],"references":["https://git.kernel.org/stable/c/3babdcb5f1809a9a41e31547a063dedf6bb44cca","https://git.kernel.org/stable/c/7190353835b4a219abb70f90b06cdcae97f11512","https://git.kernel.org/stable/c/f7ff1c89fb6e9610d2b01c1821727729e6609308","https://git.kernel.org/stable/c/df2af9fdbc4ddde18a3371c4ca1a86596e8be301","https://git.kernel.org/stable/c/cffe487026be13eaf37ea28b783d9638ab147204"],"weaknesses":[],"ingestedAt":"2026-10-30T12:34:06.950Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/26xxx/CVE-2024-26828.json","commit":"db8103c5921aac81d5d90efcf3745980dafabf49","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-26828","state":"PUBLISHED","datePublished":"2024-04-17T09:43:52.995Z","dateUpdated":"2026-10-30T12:17:52.665Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-02-19T14:20:24.181Z"},"containers":{"cna":{"title":"cifs: fix underflow in parse_server_interfaces()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix underflow in parse_server_interfaces()\n\nIn this loop, we step through the buffer and after each item we check\nif the size_left is greater than the minimum size we need.  However,\nthe problem is that \"bytes_left\" is type ssize_t while sizeof() is type\nsize_t.  That means that because of type promotion, the comparison is\ndone as an unsigned and if we have negative bytes left the loop\ncontinues instead of ending."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"3babdcb5f1809a9a41e31547a063dedf6bb44cca","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"7190353835b4a219abb70f90b06cdcae97f11512","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"f7ff1c89fb6e9610d2b01c1821727729e6609308","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"df2af9fdbc4ddde18a3371c4ca1a86596e8be301","versionType":"git"},{"version":"fe856be475f7cf5ffcde57341d175ce9fd09434b","status":"affected","lessThan":"cffe487026be13eaf37ea28b783d9638ab147204","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2ops.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.18","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.79","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.18","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.7.6","status":"unaffected","lessThanOrEqual":"6.7.*","versionType":"semver"},{"version":"6.8","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/smb2ops.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3babdcb5f1809a9a41e31547a063dedf6bb44cca"},{"url":"https://git.kernel.org/stable/c/7190353835b4a219abb70f90b06cdcae97f11512"},{"url":"https://git.kernel.org/stable/c/f7ff1c89fb6e9610d2b01c1821727729e6609308"},{"url":"https://git.kernel.org/stable/c/df2af9fdbc4ddde18a3371c4ca1a86596e8be301"},{"url":"https://git.kernel.org/stable/c/cffe487026be13eaf37ea28b783d9638ab147204"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H","baseScore":9.4,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable parser consumes an SMB2 IOCTL response body received over TCP/445 from the remote SMB server, so a malicious or compromised server (or a MITM on an unsigned connection) triggers it purely with network data. No local access to the victim is required.\nAC:L - The server controls both the response length and every `Next` field, so making `bytes_left` underflow is a single deterministic value choice (e.g. buf_len=152, Next=160) with no race, timing, or memory-layout condition outside the attacker's control.\nPR:N - The attacker is the server side of the connection and needs no credentials or privileges on the victim host; it simply answers the client's own FSCTL_QUERY_NETWORK_INTERFACE_INFO request with a crafted reply.\nUI:N - Beyond the mount path, `smb2_query_server_interfaces()` re-issues the query from a self-re-arming cifsiod delayed work every 600 seconds, and `smb2_reconnect()` issues it on every tcon reconnect, so an already-mounted share is attacked with zero user action.\nS:U - The out-of-bounds read and the resulting crash are entirely within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The loop walks arbitrary kernel memory at an attacker-chosen stride and stores the OOB bytes as interface speeds and IPv4/IPv6 addresses in `ses->iface_list`, which is printed verbatim to world-readable `/proc/fs/cifs/DebugData` and used as multichannel connect targets — an unbounded, repeatable kernel heap disclosure primitive.\nI:L - There is no out-of-bounds write, but garbage harvested from unrelated kernel heap memory is installed as the session's authoritative interface list and drives which addresses the client opens additional SMB channels to, a limited unauthorized modification of client connection state.\nA:H - With `Next` up to 4 GiB the pointer walk dereferences unmapped memory and oopses the kernel, and the loop can only exit when an OOB `Next` is zero, additionally causing unbounded `iface_list`/`iface_count` growth from a workqueue context."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:17:52.665Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.1.79"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.6.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.7.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.8"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":6.7,"attackVector":"ADJACENT_NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H","integrityImpact":"HIGH","userInteraction":"REQUIRED","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2024-06-12T17:36:16.490979Z","id":"CVE-2024-26828","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"type":"CWE","lang":"en","description":"CWE-noinfo Not enough information"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-11-04T18:28:47.130Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/7190353835b4a219abb70f90b06cdcae97f11512","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/f7ff1c89fb6e9610d2b01c1821727729e6609308","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/df2af9fdbc4ddde18a3371c4ca1a86596e8be301","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/cffe487026be13eaf37ea28b783d9638ab147204","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-02T00:14:13.603Z"}}]}}}