{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21801", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.770Z", "datePublished": "2025-02-27T20:00:55.572Z", "dateUpdated": "2026-08-05T11:54:32.458Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:32.458Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ravb: Fix missing rtnl lock in suspend/resume path\n\nFix the suspend/resume path by ensuring the rtnl lock is held where\nrequired. Calls to ravb_open, ravb_close and wol operations must be\nperformed under the rtnl lock to prevent conflicts with ongoing ndo\noperations.\n\nWithout this fix, the following warning is triggered:\n[ 39.032969] =============================\n[ 39.032983] WARNING: suspicious RCU usage\n[ 39.033019] -----------------------------\n[ 39.033033] drivers/net/phy/phy_device.c:2004 suspicious\nrcu_dereference_protected() usage!\n...\n[ 39.033597] stack backtrace:\n[ 39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted\n6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7\n[ 39.033623] Hardware name: Renesas SMARC EVK version 2 based on\nr9a08g045s33 (DT)\n[ 39.033628] Call trace:\n[ 39.033633] show_stack+0x14/0x1c (C)\n[ 39.033652] dump_stack_lvl+0xb4/0xc4\n[ 39.033664] dump_stack+0x14/0x1c\n[ 39.033671] lockdep_rcu_suspicious+0x16c/0x22c\n[ 39.033682] phy_detach+0x160/0x190\n[ 39.033694] phy_disconnect+0x40/0x54\n[ 39.033703] ravb_close+0x6c/0x1cc\n[ 39.033714] ravb_suspend+0x48/0x120\n[ 39.033721] dpm_run_callback+0x4c/0x14c\n[ 39.033731] device_suspend+0x11c/0x4dc\n[ 39.033740] dpm_suspend+0xdc/0x214\n[ 39.033748] dpm_suspend_start+0x48/0x60\n[ 39.033758] suspend_devices_and_enter+0x124/0x574\n[ 39.033769] pm_suspend+0x1ac/0x274\n[ 39.033778] state_store+0x88/0x124\n[ 39.033788] kobj_attr_store+0x14/0x24\n[ 39.033798] sysfs_kf_write+0x48/0x6c\n[ 39.033808] kernfs_fop_write_iter+0x118/0x1a8\n[ 39.033817] vfs_write+0x27c/0x378\n[ 39.033825] ksys_write+0x64/0xf4\n[ 39.033833] __arm64_sys_write+0x18/0x20\n[ 39.033841] invoke_syscall+0x44/0x104\n[ 39.033852] el0_svc_common.constprop.0+0xb4/0xd4\n[ 39.033862] do_el0_svc+0x18/0x20\n[ 39.033870] el0_svc+0x3c/0xf0\n[ 39.033880] el0t_64_sync_handler+0xc0/0xc4\n[ 39.033888] el0t_64_sync+0x154/0x158\n[ 39.041274] ravb 11c30000.ethernet eth0: Link is Down" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is a platform Ethernet driver's PM callback pair reached only through local activity — a suspend/resume transition plus a concurrent local rtnl-protected operation (ethtool ioctl, netlink, or an internally scheduled work item). No remote peer can reach or drive the unlocked window.\nAC:L - The attacker influences both sides: suspend/resume cycles are continuously and automatically driven on these Renesas embedded/automotive targets (and requestable by an unprivileged local session on general-purpose systems), while unprivileged ethtool/ioctl calls and interface traffic supply the concurrent rtnl-side operation, and the attempt can be repeated indefinitely until it lands.\nPR:L - An unprivileged local user suffices — `ETHTOOL_GSET`/`GLINKSETTINGS`/`GSTATS` are explicitly exempt from any capability check yet still run under `rtnl_lock()`, and generating the traffic that arms `ravb_tx_timeout_work()` needs only an ordinary socket; no root or `CAP_NET_ADMIN` is required.\nUI:N - System suspend/resume is triggered automatically by autosleep, idle timeouts, or RTC wakeups on the affected embedded and automotive platforms, so no victim action is needed for the window to open.\nS:U - The corruption is confined to kernel heap and DMA-coherent memory managed by the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The unlocked teardown frees the `phy_device` and the descriptor rings while concurrent rtnl holders still hold pointers to them, and use-after-free of these objects lets an attacker who reclaims the freed slabs read back kernel memory contents through the surviving accessors.\nI:H - Concurrent `ravb_ring_free()` from suspend and `ravb_tx_timeout_work()` double-frees DMA-coherent rings, page-pool objects, and kmalloc'd arrays, and the DMAC can remain programmed to write into freed pages — heap corruption plus a device-driven write primitive suitable for control-flow hijacking.\nA:H - The race reliably produces kernel crashes — double `dma_free_coherent`/`page_pool_destroy`, use-after-free oopses on the detached PHY, and external aborts from MMIO access to an AVB block whose reset is asserted and clocks gated — taking down the system's primary network interface and the machine itself." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/renesas/ravb_main.c" ], "versions": [ { "version": "0184165b2f42c4b032da9dd11546bfbaeb5afd4e", "lessThan": "0296981941cf291edfbc318d3255a93439f368e4", "status": "affected", "versionType": "git" }, { "version": "0184165b2f42c4b032da9dd11546bfbaeb5afd4e", "lessThan": "ad19522c007bb24ed874468f8baa1503c4662cf4", "status": "affected", "versionType": "git" }, { "version": "0184165b2f42c4b032da9dd11546bfbaeb5afd4e", "lessThan": "2c2ebb2b49573e5f8726112ad06b1dffc3c9ea03", "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/renesas/ravb_main.c" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.13", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.2", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "4.9", "versionEndExcluding": "6.12.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.13.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0296981941cf291edfbc318d3255a93439f368e4" }, { "url": "https://git.kernel.org/stable/c/ad19522c007bb24ed874468f8baa1503c4662cf4" }, { "url": "https://git.kernel.org/stable/c/2c2ebb2b49573e5f8726112ad06b1dffc3c9ea03" } ], "title": "net: ravb: Fix missing rtnl lock in suspend/resume path", "x_generator": { "engine": "bippy-1.2.0" } } } }