{"cve":"CVE-2025-21868","nvd":{"published":"2025-03-27T14:15:47.873","modified":"2026-07-30T06:21:42.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: allow small head cache usage with large MAX_SKB_FRAGS values\n\nSabrina reported the following splat:\n\n    WARNING: CPU: 0 PID: 1 at net/core/dev.c:6935 netif_napi_add_weight_locked+0x8f2/0xba0\n    Modules linked in:\n    CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc1-net-00092-g011b03359038 #996\n    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014\n    RIP: 0010:netif_napi_add_weight_locked+0x8f2/0xba0\n    Code: e8 c3 e6 6a fe 48 83 c4 28 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc c7 44 24 10 ff ff ff ff e9 8f fb ff ff e8 9e e6 6a fe <0f> 0b e9 d3 fe ff ff e8 92 e6 6a fe 48 8b 04 24 be ff ff ff ff 48\n    RSP: 0000:ffffc9000001fc60 EFLAGS: 00010293\n    RAX: 0000000000000000 RBX: ffff88806ce48128 RCX: 1ffff11001664b9e\n    RDX: ffff888008f00040 RSI: ffffffff8317ca42 RDI: ffff88800b325cb6\n    RBP: ffff88800b325c40 R08: 0000000000000001 R09: ffffed100167502c\n    R10: ffff88800b3a8163 R11: 0000000000000000 R12: ffff88800ac1c168\n    R13: ffff88800ac1c168 R14: ffff88800ac1c168 R15: 0000000000000007\n    FS:  0000000000000000(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000\n    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n    CR2: ffff888008201000 CR3: 0000000004c94001 CR4: 0000000000370ef0\n    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n    Call Trace:\n    <TASK>\n    gro_cells_init+0x1ba/0x270\n    xfrm_input_init+0x4b/0x2a0\n    xfrm_init+0x38/0x50\n    ip_rt_init+0x2d7/0x350\n    ip_init+0xf/0x20\n    inet_init+0x406/0x590\n    do_one_initcall+0x9d/0x2e0\n    do_initcalls+0x23b/0x280\n    kernel_init_freeable+0x445/0x490\n    kernel_init+0x20/0x1d0\n    ret_from_fork+0x46/0x80\n    ret_from_fork_asm+0x1a/0x30\n    </TASK>\n    irq event stamp: 584330\n    hardirqs last  enabled at (584338): [<ffffffff8168bf87>] __up_console_sem+0x77/0xb0\n    hardirqs last disabled at (584345): [<ffffffff8168bf6c>] __up_console_sem+0x5c/0xb0\n    softirqs last  enabled at (583242): [<ffffffff833ee96d>] netlink_insert+0x14d/0x470\n    softirqs last disabled at (583754): [<ffffffff8317c8cd>] netif_napi_add_weight_locked+0x77d/0xba0\n\non kernel built with MAX_SKB_FRAGS=45, where SKB_WITH_OVERHEAD(1024)\nis smaller than GRO_MAX_HEAD.\n\nSuch built additionally contains the revert of the single page frag cache\nso that napi_get_frags() ends up using the page frag allocator, triggering\nthe splat.\n\nNote that the underlying issue is independent from the mentioned\nrevert; address it ensuring that the small head cache will fit either TCP\nand GRO allocation and updating napi_alloc_skb() and __netdev_alloc_skb()\nto select kmalloc() usage for any allocation fitting such cache.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/14ad6ed30a10afbe91b0749d6378285f4225d482","https://git.kernel.org/stable/c/648e440c98e260dec835e48a5d7a9993477b1f9d","https://git.kernel.org/stable/c/ed0ca7d2127c63991cfaf1932b827e3f4f8ee480","https://git.kernel.org/stable/c/ed8a77fee4618facd2a539cad7b7366697b5a575"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:28.034033815+00:00"},"epss":{"cve":"CVE-2025-21868","score":0.00389,"percentile":0.32994,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}