CVE-2023-52623 — linux / linux_kernel
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')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---
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 4.9 | 4.19.307 |
| linux / linux_kernel | 4.20 | 5.4.269 |
| linux / linux_kernel | 5.5 | 5.10.210 |
| linux / linux_kernel | 5.11 | 5.15.149 |
| linux / linux_kernel | 5.16 | 6.1.77 |
| linux / linux_kernel | 6.2 | 6.6.16 |
| linux / linux_kernel | 6.7 | 6.7.4 |
| debian / debian_linux | 10.0 | 10.0.x |
- https://git.kernel.org/stable/c/31b62908693c90d4d07db597e685d9f25a120073
- https://git.kernel.org/stable/c/69c7eeb4f622c2a28da965f970f982db171f3dc6
- https://git.kernel.org/stable/c/7a96d85bf196c170dcf1b47a82e9bb97cca69aa6
- https://git.kernel.org/stable/c/8f860c8407470baff2beb9982ad6b172c94f1d0a
- https://git.kernel.org/stable/c/c430e6bb43955c6bf573665fcebf31694925b9f7
- https://git.kernel.org/stable/c/e8ca3e73301e23e8c0ac0ce2e6bac4545cd776e0
- https://git.kernel.org/stable/c/f8cf4dabbdcb8bef85335b0ed7ad5b25fd82ff56
- https://git.kernel.org/stable/c/fece80a2a6718ed58487ce397285bb1b83a3e54e
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html
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A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
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