{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68293", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.380Z", "datePublished": "2026-08-10T12:02:26.414Z", "dateUpdated": "2026-08-17T05:02:29.111Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:02:29.111Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5: Fix MCIA register buffer overflow on 32 dword reads\n\nThe MCIA register can return up to 32 dwords (128 bytes) when the device\nadvertises the mcia_32dwords capability, but struct\nmlx5_ifc_mcia_reg_bits only defines dword_0..11, leaving room for just\n12 dwords (48 bytes) of data.\n\nmlx5_query_mcia() clamps the read size to mlx5_mcia_max_bytes() and then\nmemcpy()s that many bytes out of the register, potentially reading past\nthe end of the 'out' buffer. On kernels built with FORTIFY_SOURCE this\nis caught as a buffer overflow while reading the module EEPROM via\nethtool:\n\n detected buffer overflow in memcpy\n kernel BUG at lib/string_helpers.c:1048!\n RIP: 0010:fortify_panic+0x13/0x20\n Call Trace:\n mlx5_query_mcia.isra.0+0x200/0x210 [mlx5_core]\n mlx5_query_module_eeprom_by_page+0x4a/0xa0 [mlx5_core]\n mlx5e_get_module_eeprom_by_page+0xbb/0x120 [mlx5_core]\n eeprom_prepare_data+0xf3/0x170\n ethnl_default_doit+0xf1/0x3b0\n\nExtend the mcia_reg layout to 32 dwords." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only through local ethtool interfaces on the mlx5 netdev — the ETHTOOL_MSG_MODULE_EEPROM_GET genetlink message or the ETHTOOL_GMODULEEEPROM ioctl on a socket. No remote peer or received packet can trigger it.\nAC:L - A single ethtool module-EEPROM read of 128 bytes deterministically triggers the over-read on any adapter whose firmware advertises mcia_32dwords, which is the normal case on modern ConnectX hardware with a transceiver installed. No race, no memory-layout grooming, fully repeatable.\nPR:L - Both entry points check ns_capable(net->user_ns, CAP_NET_ADMIN), which is namespace-relative, so the root of an unprivileged user namespace owning a netns that holds an mlx5 VF/subfunction netdev (a standard SR-IOV container setup) can trigger it without any privilege in the initial namespace.\nUI:N - The attacker triggers the read entirely on their own by issuing an ethtool query; no action by another user or administrator is needed.\nS:U - The out-of-bounds read and its consequences are confined to the kernel of the same host; no VM, IOMMU, or other security-authority boundary is crossed.\nC:H - Up to 80 bytes of kernel stack adjacent to the 64-byte 'out' buffer are memcpy()'d into the EEPROM data returned to userspace, disclosing saved registers, pointers and potentially return addresses or the stack canary — enough to defeat KASLR and stack protection and aid further exploitation.\nI:N - The defect is purely a read overflow; the destination buffer is sized from the caller's own request length, so no kernel memory is written out of bounds and no data is modified.\nA:H - On the widely enabled CONFIG_FORTIFY_SOURCE the copy hits fortify_panic(), producing a kernel BUG/oops in mlx5_query_mcia() while rtnl/netdev locks are held (per the reported trace), wedging networking and panicking outright with panic_on_oops." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/mellanox/mlx5/core/port.c", "include/linux/mlx5/mlx5_ifc.h" ], "versions": [ { "version": "271907ee2f29cd1078fd219f0778fd824fb1971c", "lessThan": "5be4eebd5a3a198dab0adcd550e1cadca79bdfed", "status": "affected", "versionType": "git" }, { "version": "271907ee2f29cd1078fd219f0778fd824fb1971c", "lessThan": "87b39a8c875ca744b7de69af0a8ef8874cffccf1", "status": "affected", "versionType": "git" }, { "version": "271907ee2f29cd1078fd219f0778fd824fb1971c", "lessThan": "88b2a16ddac3357e3f1d528e758b51e2c945d546", "status": "affected", "versionType": "git" }, { "version": "271907ee2f29cd1078fd219f0778fd824fb1971c", "lessThan": "11c057d23465c7a5817a7284c896d19d54c0b616", "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/mellanox/mlx5/core/port.c", "include/linux/mlx5/mlx5_ifc.h" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "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": "5.18", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5be4eebd5a3a198dab0adcd550e1cadca79bdfed" }, { "url": "https://git.kernel.org/stable/c/87b39a8c875ca744b7de69af0a8ef8874cffccf1" }, { "url": "https://git.kernel.org/stable/c/88b2a16ddac3357e3f1d528e758b51e2c945d546" }, { "url": "https://git.kernel.org/stable/c/11c057d23465c7a5817a7284c896d19d54c0b616" } ], "title": "net/mlx5: Fix MCIA register buffer overflow on 32 dword reads", "x_generator": { "engine": "bippy-1.2.0" } } } }