{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-45842", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-45842", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-05-27T09:24:42.637Z", "updatedAt": "2026-10-15T01:19:45.645Z", "importedAt": "2026-10-24T01:58:14.884Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "slip: reject VJ receive packets on instances with no rstate array", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nslip: reject VJ receive packets on instances with no rstate array\n\nslhc_init() accepts rslots == 0 as a valid configuration, with the\ndocumented meaning of 'no receive compression'. In that case the\nallocation loop in slhc_init() is skipped, so comp->rstate stays\nNULL and comp->rslot_limit stays 0 (from the kzalloc of struct\nslcompress).\n\nThe receive helpers do not defend against that configuration.\nslhc_uncompress() dereferences comp->rstate[x] when the VJ header\ncarries an explicit connection ID, and slhc_remember() later assigns\ncs = &comp->rstate[...] after only comparing the packet's slot number\nto comp->rslot_limit. Because rslot_limit is 0, slot 0 passes the\nrange check, and the code dereferences a NULL rstate.\n\nThe configuration is reachable in-tree through PPP. PPPIOCSMAXCID\nstores its argument in a signed int, and (val >> 16) uses arithmetic\nshift. Passing 0xffff0000 therefore sign-extends to -1, so val2 + 1\nis 0 and ppp_generic.c ends up calling slhc_init(0, 1). Because\n/dev/ppp open is gated by ns_capable(CAP_NET_ADMIN), the whole path\nis reachable from an unprivileged user namespace. Once the malformed\nVJ state is installed, any inbound VJ-compressed or VJ-uncompressed\nframe that selects slot 0 crashes the kernel in softirq context:\n\n Oops: general protection fault, probably for non-canonical\n address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n RIP: 0010:slhc_uncompress (drivers/net/slip/slhc.c:519)\n Call Trace:\n \n ppp_receive_nonmp_frame (drivers/net/ppp/ppp_generic.c:2466)\n ppp_input (drivers/net/ppp/ppp_generic.c:2359)\n ppp_async_process (drivers/net/ppp/ppp_async.c:492)\n tasklet_action_common (kernel/softirq.c:926)\n handle_softirqs (kernel/softirq.c:623)\n run_ksoftirqd (kernel/softirq.c:1055)\n smpboot_thread_fn (kernel/smpboot.c:160)\n kthread (kernel/kthread.c:436)\n ret_from_fork (arch/x86/kernel/process.c:164)\n \n\nReject the receive side on such instances instead of touching rstate.\nslhc_uncompress() falls through to its existing 'bad' label, which\nbumps sls_i_error and enters the toss state. slhc_remember() mirrors\nthat with an explicit sls_i_error increment followed by slhc_toss();\nthe sls_i_runt counter is not used here because a missing rstate is\nan internal configuration state, not a runt packet.\n\nThe transmit path is unaffected: the only in-tree caller that picks\nrslots from userspace (ppp_generic.c) still supplies tslots >= 1, and\nslip.c always calls slhc_init(16, 16), so comp->tstate remains valid\nand slhc_compress() continues to work.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "3d71c961febddd855d3ae9a519eeb96c8023f430" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "72304fec672e8aac9ee7b9c475db96b37cca8d8d" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "4aa9eca6fda2919027dfd7a7cc69334982d89586" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "c6980e8b1a86288167f34966fa5219031999b6f1" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "de42f86e2cf5028a97e74c25869d1a962b13c301" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "9e1ff0eead073c4f46d874ad2526b7dda5465faf" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "7b0d9e878ec2b21d99ae8051b3dda59cdb66c152" }, { "version": "4ab42d78e37a294ac7bc56901d563c642e03c4ae", "status": "affected", "versionType": "git", "lessThan": "e76607442d5b73e1ba6768f501ef815bb58c2c0e" }, { "version": "42fc512469e78939c1e419d3310c47de55bdcbb8", "status": "affected", "versionType": "git" }, { "version": "df085f1cb3acd3d75408ff94f366983873bce7d2", "status": "affected", "versionType": "git" }, { "version": "a1c3860d3c5fc62bd35f089bcb03f18a37242de9", "status": "affected", "versionType": "git" }, { "version": "f82699de104eaf8a7ffc2849a566a94818dd8a3c", "status": "affected", "versionType": "git" }, { "version": "354b254af5c1350de9586af75fe5a821b35bfb33", "status": "affected", "versionType": "git" }, { "version": "5148857f5d4c812cc918cf4627f7880521e987eb", "status": "affected", "versionType": "git" }, { "version": "82185755d90c8047c6f4b589c39998ff3d4ca3ad", "status": "affected", "versionType": "git" }, { "version": "a50a93cc99286dc444c7e5ccc7dfb9d58c2d346d", "status": "affected", "versionType": "git" }, { "version": "6b4fa561e26526c62636414d267342c945084f44", "status": "affected", "versionType": "git" }, { "version": "2.6.32.70", "status": "affected", "versionType": "semver", "lessThan": "2.6.33" }, { "version": "3.2.75", "status": "affected", "versionType": "semver", "lessThan": "3.3" }, { "version": "3.4.111", "status": "affected", "versionType": "semver", "lessThan": "3.5" }, { "version": "3.10.96", "status": "affected", "versionType": "semver", "lessThan": "3.11" }, { "version": "3.12.53", "status": "affected", "versionType": "semver", "lessThan": "3.13" }, { "version": "3.14.60", "status": "affected", "versionType": "semver", "lessThan": "3.15" }, { "version": "3.18.27", "status": "affected", "versionType": "semver", "lessThan": "3.19" }, { "version": "4.1.17", "status": "affected", "versionType": "semver", "lessThan": "4.2" }, { "version": "4.3.5", "status": "affected", "versionType": "semver", "lessThan": "4.4" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.4", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.4" }, { "version": "5.10.258", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.209", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.175", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.141", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.91", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.33", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.0.10", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.0.*" }, { "version": "7.1", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }