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Linux KernelOperating system · Linux

CVE-2023-52506

MEDIUM · 5.5 CVSS v3.1 Published 2024-03-02
Fix available
A fix is available. Upgrade to 6.1.56 / 6.5.6 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: LoongArch: Set all reserved memblocks on Node#0 at initialization After commit 61167ad5fecdea ("mm: pass nid to reserve_bootmem_region()") we get a panic if DEFERRED_STRUCT_PAGE_INIT is enabled: [ 0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000000000002b82, era == 90000000040e3f28, ra == 90000000040e3f18 [ 0.000000] Oops[#1]: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0+ #733 [ 0.000000] pc 90000000040e3f28 ra 90000000040e3f18 tp 90000000046f4000 sp 90000000046f7c90 [ 0.000000] a0 0000000000000001 a1 0000000000200000 a2 0000000000000040 a3 90000000046f7ca0 [ 0.000000] a4 90000000046f7ca4 a5 0000000000000000 a6 90000000046f7c38 a7 0000000000000000 [ 0.000000] t0 0000000000000002 t1 9000000004b00ac8 t2 90000000040e3f18 t3 90000000040f0800 [ 0.000000] t4 00000000000f0000 t5 80000000ffffe07e t6 0000000000000003 t7 900000047fff5e20 [ 0.000000] t8 aaaaaaaaaaaaaaab u0 0000000000000018 s9 0000000000000000 s0 fffffefffe000000 [ 0.000000] s1 0000000000000000 s2 0000000000000080 s3 0000000000000040 s4 0000000000000000 [ 0.000000] s5 0000000000000000 s6 fffffefffe000000 s7 900000000470b740 s8 9000000004ad4000 [ 0.000000] ra: 90000000040e3f18 reserve_bootmem_region+0xec/0x21c [ 0.000000] ERA: 90000000040e3f28 reserve_bootmem_region+0xfc/0x21c [ 0.000000] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) [ 0.000000] PRMD: 00000000 (PPLV0 -PIE -PWE) [ 0.000000] EUEN: 00000000 (-FPE -SXE -ASXE -BTE) [ 0.000000] ECFG: 00070800 (LIE=11 VS=7) [ 0.000000] ESTAT: 00010800 [PIL] (IS=11 ECode=1 EsubCode=0) [ 0.000000] BADV: 0000000000002b82 [ 0.000000] PRID: 0014d000 (Loongson-64bit, Loongson-3A6000) [ 0.000000] Modules linked in: [ 0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____)) [ 0.000000] Stack : 0000000000000000 9000000002eb5430 0000003a00000020 90000000045ccd00 [ 0.000000] 900000000470e000 90000000002c1918 0000000000000000 9000000004110780 [ 0.000000] 00000000fe6c0000 0000000480000000 9000000004b4e368 9000000004110748 [ 0.000000] 0000000000000000 900000000421ca84 9000000004620000 9000000004564970 [ 0.000000] 90000000046f7d78 9000000002cc9f70 90000000002c1918 900000000470e000 [ 0.000000] 9000000004564970 90000000040bc0e0 90000000046f7d78 0000000000000000 [ 0.000000] 0000000000004000 90000000045ccd00 0000000000000000 90000000002c1918 [ 0.000000] 90000000002c1900 900000000470b700 9000000004b4df78 9000000004620000 [ 0.000000] 90000000046200a8 90000000046200a8 0000000000000000 9000000004218b2c [ 0.000000] 9000000004270008 0000000000000001 0000000000000000 90000000045ccd00 [ 0.000000] ... [ 0.000000] Call Trace: [ 0.000000] [<90000000040e3f28>] reserve_bootmem_region+0xfc/0x21c [ 0.000000] [<900000000421ca84>] memblock_free_all+0x114/0x350 [ 0.000000] [<9000000004218b2c>] mm_core_init+0x138/0x3cc [ 0.000000] [<9000000004200e38>] start_kernel+0x488/0x7a4 [ 0.000000] [<90000000040df0d8>] kernel_entry+0xd8/0xdc [ 0.000000] [ 0.000000] Code: 02eb21ad 00410f4c 380c31ac <262b818d> 6800b70d 02c1c196 0015001c 57fe4bb1 260002cd The reason is early memblock_reserve() in memblock_init() set node id to MAX_NUMNODES, making NODE_DATA(nid) a NULL dereference in the call chain reserve_bootmem_region() -> init_reserved_page(). After memblock_init(), those late calls of memblock_reserve() operate on subregions of memblock .memory regions. As a result, these reserved regions will be set to the correct node at the first iteration of memmap_init_reserved_pages(). So set all reserved memblocks on Node#0 at initialization can avoid this panic.

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-476

The code follows a pointer that is null, crashing the process. An attacker who can reliably trigger it turns the crash into a denial of service. The fix is checking for null before use and handling the failure path gracefully.

General guidance for the null pointer dereference 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:< 6.1.56>= 6.2, < 6.5.6= 6.6

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 6.1.56 / 6.5.6 or later
Fixed in 6.1.566.5.6
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 6.1.56 (for 6.1.x branch), 6.5.6 (for 6.2-6.5.x branch), or 6.7+ (for 6.6.x branch)

  1. 1. Identify the current running kernel version using 'uname -r'
  2. 2. Determine the appropriate upgrade path based on your current kernel branch: if running 6.1.x, upgrade to >= 6.1.56; if running 6.2.x - 6.5.x, upgrade to >= 6.5.6; if running 6.6.x, upgrade to a version with the fix applied (6.7 or later)
  3. 3. Update the package repository and install the new kernel version using your distribution's package manager (e.g., 'apt update && apt install linux-image-<version>' for Debian/Ubuntu, or 'yum update kernel' for RHEL/CentOS)
  4. 4. Reboot the system to load the fixed kernel
  5. 5. Verify the fix is applied by checking 'uname -r' shows the patched version and the system boots without the NULL pointer dereference panic
Caveat Kernel upgrades may require rebuilding out-of-tree modules; ensure compatible drivers are available before rebooting

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 $2,850. 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-2023-52506 in production — separate from our analysis above.

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