{ "schema_version": "1.6.1", "id": "RPI-CVE-2023-52623", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2023-52623" ], "published": "2024-03-26T17:21:35Z", "summary": "SUNRPC: Fix a suspicious RCU usage warning", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: Fix a suspicious RCU usage warning\n\nI received the following warning while running cthon against an ontap\nserver running pNFS:\n\n[ 57.202521] =============================\n[ 57.202522] WARNING: suspicious RCU usage\n[ 57.202523] 6.7.0-rc3-g2cc14f52aeb7 #41492 Not tainted\n[ 57.202525] -----------------------------\n[ 57.202525] net/sunrpc/xprtmultipath.c:349 RCU-list traversed in non-reader section!!\n[ 57.202527]\n other info that might help us debug this:\n\n[ 57.202528]\n rcu_scheduler_active = 2, debug_locks = 1\n[ 57.202529] no locks held by test5/3567.\n[ 57.202530]\n stack backtrace:\n[ 57.202532] CPU: 0 PID: 3567 Comm: test5 Not tainted 6.7.0-rc3-g2cc14f52aeb7 #41492 5b09971b4965c0aceba19f3eea324a4a806e227e\n[ 57.202534] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022\n[ 57.202536] Call Trace:\n[ 57.202537] \n[ 57.202540] dump_stack_lvl+0x77/0xb0\n[ 57.202551] lockdep_rcu_suspicious+0x154/0x1a0\n[ 57.202556] rpc_xprt_switch_has_addr+0x17c/0x190 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]\n[ 57.202596] rpc_clnt_setup_test_and_add_xprt+0x50/0x180 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]\n[ 57.202621] ? rpc_clnt_add_xprt+0x254/0x300 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]\n[ 57.202646] rpc_clnt_add_xprt+0x27a/0x300 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]\n[ 57.202671] ? __pfx_rpc_clnt_setup_test_and_add_xprt+0x10/0x10 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6]\n[ 57.202696] nfs4_pnfs_ds_connect+0x345/0x760 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]\n[ 57.202728] ? __pfx_nfs4_test_session_trunk+0x10/0x10 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]\n[ 57.202754] nfs4_fl_prepare_ds+0x75/0xc0 [nfs_layout_nfsv41_files e3a4187f18ae8a27b630f9feae6831b584a9360a]\n[ 57.202760] filelayout_write_pagelist+0x4a/0x200 [nfs_layout_nfsv41_files e3a4187f18ae8a27b630f9feae6831b584a9360a]\n[ 57.202765] pnfs_generic_pg_writepages+0xbe/0x230 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]\n[ 57.202788] __nfs_pageio_add_request+0x3fd/0x520 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202813] nfs_pageio_add_request+0x18b/0x390 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202831] nfs_do_writepage+0x116/0x1e0 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202849] nfs_writepages_callback+0x13/0x30 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202866] write_cache_pages+0x265/0x450\n[ 57.202870] ? __pfx_nfs_writepages_callback+0x10/0x10 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202891] nfs_writepages+0x141/0x230 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202913] do_writepages+0xd2/0x230\n[ 57.202917] ? filemap_fdatawrite_wbc+0x5c/0x80\n[ 57.202921] filemap_fdatawrite_wbc+0x67/0x80\n[ 57.202924] filemap_write_and_wait_range+0xd9/0x170\n[ 57.202930] nfs_wb_all+0x49/0x180 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902]\n[ 57.202947] nfs4_file_flush+0x72/0xb0 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9]\n[ 57.202969] __se_sys_close+0x46/0xd0\n[ 57.202972] do_syscall_64+0x68/0x100\n[ 57.202975] ? do_syscall_64+0x77/0x100\n[ 57.202976] ? do_syscall_64+0x77/0x100\n[ 57.202979] entry_SYSCALL_64_after_hwframe+0x6e/0x76\n[ 57.202982] RIP: 0033:0x7fe2b12e4a94\n[ 57.202985] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d d5 18 0e 00 00 74 13 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 44 c3 0f 1f 00 48 83 ec 18 89 7c 24 0c e8 c3\n[ 57.202987] RSP: 002b:00007ffe857ddb38 EFLAGS: 00000202 ORIG_RAX: 0000000000000003\n[ 57.202989] RAX: ffffffffffffffda RBX: 00007ffe857dfd68 RCX: 00007fe2b12e4a94\n[ 57.202991] RDX: 0000000000002000 RSI: 00007ffe857ddc40 RDI: 0000000000000003\n[ 57.202992] RBP: 00007ffe857dfc50 R08: 7fffffffffffffff R09: 0000000065650f49\n[ 57.202993] R10: 00007f\n---truncated---", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.21-1+rpt1", "1:6.1.47-1+rpt2", "1:6.1.47-1+rpt4", "1:6.1.54-1+rpt2", "1:6.1.58-1+rpt2", "1:6.1.63-1+rpt1", "1:6.1.73-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi1-rpi-v6", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi1-rpi-v8", "binary_version": "1:6.1.21-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v6", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v7l", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi2-rpi-v8", "binary_version": "1:6.1.47-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-2712", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v6", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v7l", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi4-rpi-v8", "binary_version": "1:6.1.54-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-2712", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v6", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v7l", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi6-rpi-v8", "binary_version": "1:6.1.58-1+rpt2" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-2712", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v6", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v7l", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi7-rpi-v8", "binary_version": "1:6.1.63-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-2712", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v6", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v7l", "binary_version": "1:6.1.73-1+rpt1" }, { "binary_name": "linux-image-6.1.0-rpi8-rpi-v8", "binary_version": "1:6.1.73-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.1.21-1+rpt1": { "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed", "upstream_version": "6.1.21", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.77" }, "1:6.1.47-1+rpt2": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.77" }, "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.77", "compiled_filter": false }, "1:6.1.54-1+rpt2": { "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7", "upstream_version": "6.1.54", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.77" }, "1:6.1.58-1+rpt2": { "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18", "upstream_version": "6.1.58", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.77" }, "1:6.1.63-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.63", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.77" }, "1:6.1.73-1+rpt1": { "linux_commit": null, "upstream_version": "6.1.73", "assessment": "upstream version (no usable Linux commit)", "upstream_fixed": "6.1.77" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2023-52623" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/fece80a2a6718ed58487ce397285bb1b83a3e54e" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/7a96d85bf196c170dcf1b47a82e9bb97cca69aa6" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c430e6bb43955c6bf573665fcebf31694925b9f7" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/f8cf4dabbdcb8bef85335b0ed7ad5b25fd82ff56" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/e8ca3e73301e23e8c0ac0ce2e6bac4545cd776e0" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/69c7eeb4f622c2a28da965f970f982db171f3dc6" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/8f860c8407470baff2beb9982ad6b172c94f1d0a" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/31b62908693c90d4d07db597e685d9f25a120073" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T11:24:39Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The vulnerable path runs in the NFS/SUNRPC client during pNFS DS connect and session trunking (`rpc_clnt_setup_test_and_add_xprt` / `rpc_clnt_test_and_add_xprt`), reached via local file operations on an NFS mount (e.g. writeback/close), not via an unauthenticated remote service like nfsd/ksmbd.\nAC:L - An attacker who can drive multipath/trunking I/O also influences transport add and remove (failed trunking calls `rpc_clnt_xprt_switch_remove_xprt`; connection failure paths delete xprts), so both sides of the RCU list race are attacker-driven rather than depending on an uncontrolled external condition.\nPR:L - Triggering requires only an unprivileged process with access to an already-mounted NFSv4.1/pNFS share (common on HPC/enterprise clients); mounting may need admin, but exploitation itself does not require init-namespace root or capabilities beyond a normal user on the mount.\nUI:N - The attacker triggers the buggy has_addr walk through their own reads/writes/closes on the NFS mount; no separate victim action is required once the share is available.\nS:U - Impact is a host-kernel use-after-free of `rpc_xprt` within the same security authority; there is no VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:H - Missing RCU read-side protection while iterating an RCU list whose entries are removed with `list_del_rcu` and freed with `kfree_rcu` yields a classic slab UAF; reclaim of the freed `rpc_xprt` enables disclosure of kernel heap contents (the walk reads `pos->addr` and `address_strings`).\nI:H - The same UAF on `rpc_xprt` is heap-sprayable to obtain attacker-controlled object contents and corruption/control-flow hijack primitives, consistent with scoring other kernel UAFs as High integrity.\nA:H - Use-after-free or wild dereference during the unlocked RCU-list walk can oops/panic the kernel, and CONFIG_PROVE_RCU builds also WARN on the missing lock (panic_on_warn converts that to DoS)." } } }