{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64550", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.796Z", "datePublished": "2026-07-27T20:10:39.459Z", "dateUpdated": "2026-08-17T04:57:27.672Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:57:27.672Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: qualcomm: rmnet: validate MAP frame length before ingress parsing\n\nWhen ingress deaggregation is disabled, rmnet_map_ingress_handler() passes\nthe skb straight to __rmnet_map_ingress_handler(), skipping the length\nvalidation that rmnet_map_deaggregate() performs on the aggregated path.\nThe parser then dereferences the MAP header and csum header/trailer based on\nthe on-wire pkt_len without checking skb->len, so a short frame is read out\nof bounds:\n\n BUG: KASAN: slab-out-of-bounds in rmnet_map_checksum_downlink_packet\n Read of size 1 at addr ffff88801118ed00 by task exploit/147\n Call Trace:\n ...\n rmnet_map_checksum_downlink_packet (drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:413)\n __rmnet_map_ingress_handler (drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:96)\n rmnet_rx_handler (drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:129)\n __netif_receive_skb_core.constprop.0 (net/core/dev.c:6089)\n netif_receive_skb (net/core/dev.c:6460)\n tun_get_user (drivers/net/tun.c:1955)\n tun_chr_write_iter (drivers/net/tun.c:2001)\n vfs_write (fs/read_write.c:688)\n ksys_write (fs/read_write.c:740)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n ...\n\nFactor that validation out of rmnet_map_deaggregate() into\nrmnet_map_validate_packet_len() and run it on the no-aggregation path too.\nThe MAP header is bounds-checked first, since this path can receive a frame\nshorter than the header." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H", "baseScore": 7.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is reached by `write()` to a tun fd owned by the attacker, exactly as in the reporter's KASAN trace (`tun_chr_write_iter` → `netif_receive_skb` → `rmnet_rx_handler`), requiring a local account. Although rmnet can be stacked on an Ethernet device (commit 74692caf1b0b), the universally available and demonstrated vector is local.\nAC:L - Every precondition is attacker-chosen — the `data_format` flags (deaggregation off, CKSUMV4 on) via `IFLA_RMNET_FLAGS`, the frame length, and the `pkt_len`/`pad` fields that select the OOB offset — with no race, timing, or uncontrolled memory-layout dependency. The trigger is a single deterministic `write()` that can be repeated indefinitely to sweep offsets.\nPR:L - Only an unprivileged local account is needed: `/dev/net/tun` is world-accessible, and both `TUNSETIFF` and `rtnl_newlink` gate on namespace-scoped `ns_capable`/`netlink_net_capable(CAP_NET_ADMIN)`, which `unshare -Urn` grants without real root.\nUI:N - The attacker creates the tun device, the rmnet link, and writes the malformed frame entirely on its own. No victim action or pre-existing configuration is required.\nS:U - The out-of-bounds access and its consequences are confined to kernel memory within the same security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is an attacker-positioned read up to 65535 bytes past a small slab object, and the result is disclosed back to userspace through the unprivileged rmnet ethtool counters — because the pseudo-header checksum is computed from the attacker's own IP header, the exact 16-bit heap word at a chosen offset is recoverable in a few probes, yielding a precise heap-read primitive for KASLR bypass and secret disclosure.\nI:L - There is no arbitrary write, but out-of-bounds data determines `skb->ip_summed = CHECKSUM_UNNECESSARY`, causing packets whose checksums were never validated to be accepted by the IP stack as verified. On the MAP-command path `rmnet_map_send_ack()` also writes `cmd->cmd_type` past the end of a short frame after `skb_trim()` underflows into a no-op.\nA:H - A 64 KB overshoot from a small kmalloc object can land on an unmapped page (guard pages, DEBUG_PAGEALLOC/hardened allocators, memory-region edges), faulting in kernel context and producing an oops; on the real WWAN receive path (ipa/qmi_wwan/mhi_net NAPI) this executes in softirq, where the fault is a panic. KASAN builds abort immediately, as the reporter's trace shows." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c", "drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h", "drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c" ], "versions": [ { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "ed25befc8c36f896b5878f9078faddb67fd7e2d0", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "a54d76d176e50d2fdbd39b7231efe256170339e4", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "00f4c366dbca16a40772c3b7ec2d8cba839e9724", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "3868c3244369ab709a90c9aad7534d406009b824", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "14eb0c9491385d5361a292ea4974aec0e6887299", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "1b12612c367e4be9b0814c0468e7e687835315b4", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "231a8a4b76cb1b1827b3b19d7b3603642f5aaaef", "status": "affected", "versionType": "git" }, { "version": "ceed73a2cf4aff2921802aa3d21d45280677547d", "lessThan": "f0f1887a9e30712a1df03e152dce6fb91344b1f3", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c", "drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h", "drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c" ], "versions": [ { "version": "4.14", "status": "affected" }, { "version": "0", "lessThan": "4.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "4.14", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ed25befc8c36f896b5878f9078faddb67fd7e2d0" }, { "url": "https://git.kernel.org/stable/c/a54d76d176e50d2fdbd39b7231efe256170339e4" }, { "url": "https://git.kernel.org/stable/c/00f4c366dbca16a40772c3b7ec2d8cba839e9724" }, { "url": "https://git.kernel.org/stable/c/3868c3244369ab709a90c9aad7534d406009b824" }, { "url": "https://git.kernel.org/stable/c/14eb0c9491385d5361a292ea4974aec0e6887299" }, { "url": "https://git.kernel.org/stable/c/1b12612c367e4be9b0814c0468e7e687835315b4" }, { "url": "https://git.kernel.org/stable/c/231a8a4b76cb1b1827b3b19d7b3603642f5aaaef" }, { "url": "https://git.kernel.org/stable/c/f0f1887a9e30712a1df03e152dce6fb91344b1f3" } ], "title": "net: qualcomm: rmnet: validate MAP frame length before ingress parsing", "x_generator": { "engine": "bippy-1.2.0" } } } }