{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38640", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.030Z", "datePublished": "2025-08-22T16:00:46.760Z", "dateUpdated": "2026-08-05T12:03:38.510Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:03:38.510Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Disable migration in nf_hook_run_bpf().\n\nsyzbot reported that the netfilter bpf prog can be called without\nmigration disabled in xmit path.\n\nThen the assertion in __bpf_prog_run() fails, triggering the splat\nbelow. [0]\n\nLet's use bpf_prog_run_pin_on_cpu() in nf_hook_run_bpf().\n\n[0]:\nBUG: assuming non migratable context at ./include/linux/filter.h:703\nin_atomic(): 0, irqs_disabled(): 0, migration_disabled() 0 pid: 5829, name: sshd-session\n3 locks held by sshd-session/5829:\n #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]\n #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x20/0x50 net/ipv4/tcp.c:1395\n #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]\n #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]\n #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x69/0x26c0 net/ipv4/ip_output.c:470\n #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]\n #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]\n #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: nf_hook+0xb2/0x680 include/linux/netfilter.h:241\nCPU: 0 UID: 0 PID: 5829 Comm: sshd-session Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025\nCall Trace:\n \n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120\n __cant_migrate kernel/sched/core.c:8860 [inline]\n __cant_migrate+0x1c7/0x250 kernel/sched/core.c:8834\n __bpf_prog_run include/linux/filter.h:703 [inline]\n bpf_prog_run include/linux/filter.h:725 [inline]\n nf_hook_run_bpf+0x83/0x1e0 net/netfilter/nf_bpf_link.c:20\n nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]\n nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623\n nf_hook+0x370/0x680 include/linux/netfilter.h:272\n NF_HOOK_COND include/linux/netfilter.h:305 [inline]\n ip_output+0x1bc/0x2a0 net/ipv4/ip_output.c:433\n dst_output include/net/dst.h:459 [inline]\n ip_local_out net/ipv4/ip_output.c:129 [inline]\n __ip_queue_xmit+0x1d7d/0x26c0 net/ipv4/ip_output.c:527\n __tcp_transmit_skb+0x2686/0x3e90 net/ipv4/tcp_output.c:1479\n tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline]\n tcp_write_xmit+0x1274/0x84e0 net/ipv4/tcp_output.c:2838\n __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3021\n tcp_push+0x225/0x700 net/ipv4/tcp.c:759\n tcp_sendmsg_locked+0x1870/0x42b0 net/ipv4/tcp.c:1359\n tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1396\n inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851\n sock_sendmsg_nosec net/socket.c:712 [inline]\n __sock_sendmsg net/socket.c:727 [inline]\n sock_write_iter+0x4aa/0x5b0 net/socket.c:1131\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x6c7/0x1150 fs/read_write.c:686\n ksys_write+0x1f8/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fe7d365d407\nCode: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff\nRSP:" } ], "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 - Exploitation requires local access to the bpf() syscall to load and link a BPF_PROG_TYPE_NETFILTER program plus a local socket write to drive the process-context transmit path through the hook; per kernel scoring guidance both netfilter and BPF attach surfaces are Local.\nAC:L - The invariant violation is deterministic on any CONFIG_PREEMPTION kernel (the distro default via PREEMPT_DYNAMIC/PREEMPT_RCU) — attach on NF_INET_LOCAL_OUT and one sendmsg() reproduces it, as syzbot confirmed with a C reproducer; the follow-on per-CPU free-list race is fully attacker-driven via sched_setaffinity, thread count and traffic rate, so both sides are under attacker control.\nPR:L - Loading and linking the netfilter program is gated by bpf_capable()/bpf_net_capable(), which this project consistently treats as an unprivileged-reachable capability (delegable via BPF tokens and routinely granted to BPF tooling); additionally, on any host where an admin has legitimately attached a netfilter BPF link, an ordinary local user drives the migratable-context execution with plain socket traffic.\nUI:N - The attacker performs every step — program load, link attach, and packet transmission — with no action by any other user or administrator.\nS:U - The corruption is confined to kernel BPF per-CPU allocator and map state within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Racing two CPUs on the same bpf_mem_cache free_llist can return one object to two allocation sites, yielding type confusion over attacker-shaped map values and a use-after-free read primitive over kernel heap contents.\nI:H - The same free-list and htab extra_elems corruption gives a write primitive through a stale/doubly-owned element, and per-CPU map values are mutated on the wrong CPU concurrently — memory corruption exploitable for control-flow hijacking.\nA:H - The bug produces a kernel splat with TAINT_WARN on debug kernels and, more seriously, allocator free-list corruption that leads to oops or panic; it is triggerable repeatedly on every outgoing packet." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_bpf_link.c" ], "versions": [ { "version": "fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d", "lessThan": "ee2502485702e4398cd74dbfb288bfa111d25e62", "status": "affected", "versionType": "git" }, { "version": "fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d", "lessThan": "62f6175d145e00fc999fd2fcbffad3f59253c66a", "status": "affected", "versionType": "git" }, { "version": "fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d", "lessThan": "e0199c28167a8a4adec036005a8df268b2b68529", "status": "affected", "versionType": "git" }, { "version": "fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d", "lessThan": "0a356da16fb933abbeeb7aea038c351f3342cd3f", "status": "affected", "versionType": "git" }, { "version": "fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d", "lessThan": "17ce3e5949bc37557305ad46316f41c7875d6366", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_bpf_link.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.102", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.42", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.10", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.1", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "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": "6.4", "versionEndExcluding": "6.6.102" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.15.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.16.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ee2502485702e4398cd74dbfb288bfa111d25e62" }, { "url": "https://git.kernel.org/stable/c/62f6175d145e00fc999fd2fcbffad3f59253c66a" }, { "url": "https://git.kernel.org/stable/c/e0199c28167a8a4adec036005a8df268b2b68529" }, { "url": "https://git.kernel.org/stable/c/0a356da16fb933abbeeb7aea038c351f3342cd3f" }, { "url": "https://git.kernel.org/stable/c/17ce3e5949bc37557305ad46316f41c7875d6366" } ], "title": "bpf: Disable migration in nf_hook_run_bpf().", "x_generator": { "engine": "bippy-1.2.0" } } } }