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Linux KernelOperating system · Linux

CVE-2023-52623

MEDIUM · 5.5 CVSS v3.1 Published 2024-03-26
Fix available
A fix is available. Upgrade to 4.19.307 / 5.4.269 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix a suspicious RCU usage warning I received the following warning while running cthon against an ontap server running pNFS: [ 57.202521] ============================= [ 57.202522] WARNING: suspicious RCU usage [ 57.202523] 6.7.0-rc3-g2cc14f52aeb7 #41492 Not tainted [ 57.202525] ----------------------------- [ 57.202525] net/sunrpc/xprtmultipath.c:349 RCU-list traversed in non-reader section!! [ 57.202527] other info that might help us debug this: [ 57.202528] rcu_scheduler_active = 2, debug_locks = 1 [ 57.202529] no locks held by test5/3567. [ 57.202530] stack backtrace: [ 57.202532] CPU: 0 PID: 3567 Comm: test5 Not tainted 6.7.0-rc3-g2cc14f52aeb7 #41492 5b09971b4965c0aceba19f3eea324a4a806e227e [ 57.202534] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022 [ 57.202536] Call Trace: [ 57.202537] <TASK> [ 57.202540] dump_stack_lvl+0x77/0xb0 [ 57.202551] lockdep_rcu_suspicious+0x154/0x1a0 [ 57.202556] rpc_xprt_switch_has_addr+0x17c/0x190 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6] [ 57.202596] rpc_clnt_setup_test_and_add_xprt+0x50/0x180 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6] [ 57.202621] ? rpc_clnt_add_xprt+0x254/0x300 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6] [ 57.202646] rpc_clnt_add_xprt+0x27a/0x300 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6] [ 57.202671] ? __pfx_rpc_clnt_setup_test_and_add_xprt+0x10/0x10 [sunrpc ebe02571b9a8ceebf7d98e71675af20c19bdb1f6] [ 57.202696] nfs4_pnfs_ds_connect+0x345/0x760 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9] [ 57.202728] ? __pfx_nfs4_test_session_trunk+0x10/0x10 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9] [ 57.202754] nfs4_fl_prepare_ds+0x75/0xc0 [nfs_layout_nfsv41_files e3a4187f18ae8a27b630f9feae6831b584a9360a] [ 57.202760] filelayout_write_pagelist+0x4a/0x200 [nfs_layout_nfsv41_files e3a4187f18ae8a27b630f9feae6831b584a9360a] [ 57.202765] pnfs_generic_pg_writepages+0xbe/0x230 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9] [ 57.202788] __nfs_pageio_add_request+0x3fd/0x520 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202813] nfs_pageio_add_request+0x18b/0x390 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202831] nfs_do_writepage+0x116/0x1e0 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202849] nfs_writepages_callback+0x13/0x30 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202866] write_cache_pages+0x265/0x450 [ 57.202870] ? __pfx_nfs_writepages_callback+0x10/0x10 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202891] nfs_writepages+0x141/0x230 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202913] do_writepages+0xd2/0x230 [ 57.202917] ? filemap_fdatawrite_wbc+0x5c/0x80 [ 57.202921] filemap_fdatawrite_wbc+0x67/0x80 [ 57.202924] filemap_write_and_wait_range+0xd9/0x170 [ 57.202930] nfs_wb_all+0x49/0x180 [nfs 6c976fa593a7c2976f5a0aeb4965514a828e6902] [ 57.202947] nfs4_file_flush+0x72/0xb0 [nfsv4 c716d88496ded0ea6d289bbea684fa996f9b57a9] [ 57.202969] __se_sys_close+0x46/0xd0 [ 57.202972] do_syscall_64+0x68/0x100 [ 57.202975] ? do_syscall_64+0x77/0x100 [ 57.202976] ? do_syscall_64+0x77/0x100 [ 57.202979] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 57.202982] RIP: 0033:0x7fe2b12e4a94 [ 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 [ 57.202987] RSP: 002b:00007ffe857ddb38 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 [ 57.202989] RAX: ffffffffffffffda RBX: 00007ffe857dfd68 RCX: 00007fe2b12e4a94 [ 57.202991] RDX: 0000000000002000 RSI: 00007ffe857ddc40 RDI: 0000000000000003 [ 57.202992] RBP: 00007ffe857dfc50 R08: 7fffffffffffffff R09: 0000000065650f49 [ 57.202993] R10: 00007f ---truncated---

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-22

A file path is built from user input without being confined, so sequences like “../” let an attacker step outside the intended directory. That can expose configuration, credentials, or source code, and in the worst case lets an attacker write files where they shouldn't. A durable fix resolves and canonicalises the path, then rejects anything that escapes a known-safe base directory.

General guidance for the path traversal class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 4.9, < 4.19.307>= 4.20, < 5.4.269>= 5.5, < 5.10.210>= 5.11, < 5.15.149>= 5.16, < 6.1.77>= 6.2, < 6.6.16>= 6.7, < 6.7.4
Debian LinuxOperating system
Affected:= 10.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.19.307 / 5.4.269 / 5.10.210 or later
Fixed in 4.19.3075.4.2695.10.210
Vendor patch git.kernel.org →
Recommended fix High confidence

Kernel 4.19.307+, 5.4.269+, 5.10.210+, or 5.15.149+ depending on your current branch

  1. Upgrade the Linux kernel to a fixed version. For your current kernel branch, identify the next stable release that includes the fix: If using 4.19.x, upgrade to 4.19.307 or later. If using 5.4.x, upgrade to 5.4.269 or later. If using 5.10.x, upgrade to 5.10.210 or later. If using 5.15.x, upgrade to 5.15.149 or later.
  2. After kernel upgrade, reboot the system to load the fixed kernel.
  3. Verify the fix by checking that the RCU warning no longer appears in kernel logs during NFS/pNFS operations.
Caveat Kernel upgrades may require rebooting services and could have compatibility implications with out-of-tree kernel modules or specific hardware drivers

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-52623 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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