{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45842","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.078Z","datePublished":"2026-05-27T09:24:42.637Z","dateUpdated":"2026-06-14T17:46:17.557Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-14T17:46:17.557Z"},"descriptions":[{"lang":"en","value":"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  <TASK>\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  </TASK>\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":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/slip/slhc.c"],"versions":[{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"3d71c961febddd855d3ae9a519eeb96c8023f430","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"72304fec672e8aac9ee7b9c475db96b37cca8d8d","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"4aa9eca6fda2919027dfd7a7cc69334982d89586","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"c6980e8b1a86288167f34966fa5219031999b6f1","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"de42f86e2cf5028a97e74c25869d1a962b13c301","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"9e1ff0eead073c4f46d874ad2526b7dda5465faf","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"7b0d9e878ec2b21d99ae8051b3dda59cdb66c152","status":"affected","versionType":"git"},{"version":"4ab42d78e37a294ac7bc56901d563c642e03c4ae","lessThan":"e76607442d5b73e1ba6768f501ef815bb58c2c0e","status":"affected","versionType":"git"},{"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","lessThan":"2.6.33","status":"affected","versionType":"semver"},{"version":"3.2.75","lessThan":"3.3","status":"affected","versionType":"semver"},{"version":"3.4.111","lessThan":"3.5","status":"affected","versionType":"semver"},{"version":"3.10.96","lessThan":"3.11","status":"affected","versionType":"semver"},{"version":"3.12.53","lessThan":"3.13","status":"affected","versionType":"semver"},{"version":"3.14.60","lessThan":"3.15","status":"affected","versionType":"semver"},{"version":"3.18.27","lessThan":"3.19","status":"affected","versionType":"semver"},{"version":"4.1.17","lessThan":"4.2","status":"affected","versionType":"semver"},{"version":"4.3.5","lessThan":"4.4","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/slip/slhc.c"],"versions":[{"version":"4.4","status":"affected"},{"version":"0","lessThan":"4.4","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.32.70"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.10.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.12.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14.60"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.18.27"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3.5"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/3d71c961febddd855d3ae9a519eeb96c8023f430"},{"url":"https://git.kernel.org/stable/c/72304fec672e8aac9ee7b9c475db96b37cca8d8d"},{"url":"https://git.kernel.org/stable/c/4aa9eca6fda2919027dfd7a7cc69334982d89586"},{"url":"https://git.kernel.org/stable/c/c6980e8b1a86288167f34966fa5219031999b6f1"},{"url":"https://git.kernel.org/stable/c/de42f86e2cf5028a97e74c25869d1a962b13c301"},{"url":"https://git.kernel.org/stable/c/9e1ff0eead073c4f46d874ad2526b7dda5465faf"},{"url":"https://git.kernel.org/stable/c/7b0d9e878ec2b21d99ae8051b3dda59cdb66c152"},{"url":"https://git.kernel.org/stable/c/e76607442d5b73e1ba6768f501ef815bb58c2c0e"}],"title":"slip: reject VJ receive packets on instances with no rstate array","x_generator":{"engine":"bippy-1.2.0"}}}}