{"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"}}}}