{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38525", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.023Z", "datePublished": "2025-08-16T11:12:19.191Z", "dateUpdated": "2026-08-10T12:10:47.387Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-10T12:10:47.387Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix irq-disabled in local_bh_enable()\n\nThe rxrpc_assess_MTU_size() function calls down into the IP layer to find\nout the MTU size for a route. When accepting an incoming call, this is\ncalled from rxrpc_new_incoming_call() which holds interrupts disabled\nacross the code that calls down to it. Unfortunately, the IP layer uses\nlocal_bh_enable() which, config dependent, throws a warning if IRQs are\nenabled:\n\nWARNING: CPU: 1 PID: 5544 at kernel/softirq.c:387 __local_bh_enable_ip+0x43/0xd0\n...\nRIP: 0010:__local_bh_enable_ip+0x43/0xd0\n...\nCall Trace:\n \n rt_cache_route+0x7e/0xa0\n rt_set_nexthop.isra.0+0x3b3/0x3f0\n __mkroute_output+0x43a/0x460\n ip_route_output_key_hash+0xf7/0x140\n ip_route_output_flow+0x1b/0x90\n rxrpc_assess_MTU_size.isra.0+0x2a0/0x590\n rxrpc_new_incoming_peer+0x46/0x120\n rxrpc_alloc_incoming_call+0x1b1/0x400\n rxrpc_new_incoming_call+0x1da/0x5e0\n rxrpc_input_packet+0x827/0x900\n rxrpc_io_thread+0x403/0xb60\n kthread+0x2f7/0x310\n ret_from_fork+0x2a/0x230\n ret_from_fork_asm+0x1a/0x30\n...\nhardirqs last enabled at (23): _raw_spin_unlock_irq+0x24/0x50\nhardirqs last disabled at (24): _raw_read_lock_irq+0x17/0x70\nsoftirqs last enabled at (0): copy_process+0xc61/0x2730\nsoftirqs last disabled at (25): rt_add_uncached_list+0x3c/0x90\n\nFix this by moving the call to rxrpc_assess_MTU_size() out of\nrxrpc_init_peer() and further up the stack where it can be done without\ninterrupts disabled.\n\nIt shouldn't be a problem for rxrpc_new_incoming_call() to do it after the\nlocks are dropped as pmtud is going to be performed by the I/O thread - and\nwe're in the I/O thread at this point." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable path is entered directly from `rxrpc_encap_rcv()`/`rxrpc_input_packet()` when an rxrpc DATA packet arrives over UDP from an unknown peer, and kAFS binds its callback-manager service socket to `in6addr_any:7001`, so any routable remote host can reach it.\nAC:L - The attacker fully controls every precondition — a single crafted rxrpc DATA packet (`callNumber != 0`, `seq == 1`, matching serviceId) from a source port not yet in the peer hash deterministically forces new-peer creation and the MTU assessment under `read_lock_irq()`; no memory layout, timing, or victim state is involved.\nPR:N - `rxrpc_new_incoming_call()` runs entirely before any rxrpc authentication — the CHALLENGE/RESPONSE handshake is only queued after the call is made live, and `rxrpc_get_incoming_security()` merely validates that the security index is supported, so an unauthenticated off-path attacker suffices.\nUI:N - The AFS/rxrpc service socket is already bound and listening as soon as AFS is in use; processing of the attacker's packet happens autonomously in the rxrpc I/O kernel thread with no victim action.\nS:U - The fault and its effects are confined to the kernel's own security authority on the affected host; no VM, IOMMU, or sandbox boundary is crossed.\nC:N - The defect is purely a locking/IRQ-context violation with no out-of-bounds read, use-after-free, or uninitialised data exposure; nothing is leaked to the remote attacker, who cannot observe the kernel log.\nI:N - No memory is corrupted and no attacker-controlled data is written out of bounds — the peer backlog ring update completes before the offending call, so there is no write primitive or state modification available.\nA:H - `lockdep_assert_irqs_enabled()` WARNs on `CONFIG_PROVE_LOCKING` kernels, which is a hard panic under the widely deployed `panic_on_warn=1`; independently of that config, `do_softirq()`/`handle_softirqs()` re-enables hardirqs and burns up to 2 ms × 10 restarts of softirq work inside the `read_lock_irq()` + `spin_lock()` section, stalling the rxrpc I/O thread — and the whole sequence is remotely repeatable at packet rate by rotating source ports." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/rxrpc/ar-internal.h", "net/rxrpc/call_accept.c", "net/rxrpc/peer_object.c" ], "versions": [ { "version": "77433b730970ca6e51d03016e830d8ab1b22685a", "lessThan": "d94b82d452ca27a200cd67660dc48476386651d8", "status": "affected", "versionType": "git" }, { "version": "09c59a82298f424f6212c67fbea531853e88ce6c", "lessThan": "8ac0b3baa7d8f732bd9e5cbf1d8b57e4802c6b36", "status": "affected", "versionType": "git" }, { "version": "a2ea9a9072607c2fd6442bd1ffb4dbdbf882aed7", "lessThan": "2029f21f10dedb88c0f86abffcf8d6c21dcf6040", "status": "affected", "versionType": "git" }, { "version": "a2ea9a9072607c2fd6442bd1ffb4dbdbf882aed7", "lessThan": "e4d2878369d590bf8455e3678a644e503172eafa", "status": "affected", "versionType": "git" }, { "version": "6.6.148", "lessThan": "6.6.151", "status": "affected", "versionType": "semver" }, { "version": "6.12.101", "lessThan": "6.12.103", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/rxrpc/ar-internal.h", "net/rxrpc/call_accept.c", "net/rxrpc/peer_object.c" ], "versions": [ { "version": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.8", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "6.6.148", "versionEndExcluding": "6.6.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.101", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.15.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d94b82d452ca27a200cd67660dc48476386651d8" }, { "url": "https://git.kernel.org/stable/c/8ac0b3baa7d8f732bd9e5cbf1d8b57e4802c6b36" }, { "url": "https://git.kernel.org/stable/c/2029f21f10dedb88c0f86abffcf8d6c21dcf6040" }, { "url": "https://git.kernel.org/stable/c/e4d2878369d590bf8455e3678a644e503172eafa" } ], "title": "rxrpc: Fix irq-disabled in local_bh_enable()", "x_generator": { "engine": "bippy-1.2.0" } } } }