CVE-2023-53742
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-08

Last updated on: 2025-12-08

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: kcsan: Avoid READ_ONCE() in read_instrumented_memory() Haibo Li reported: | Unable to handle kernel paging request at virtual address | ffffff802a0d8d7171 | Mem abort info:o: | ESR = 0x9600002121 | EC = 0x25: DABT (current EL), IL = 32 bitsts | SET = 0, FnV = 0 0 | EA = 0, S1PTW = 0 0 | FSC = 0x21: alignment fault | Data abort info:o: | ISV = 0, ISS = 0x0000002121 | CM = 0, WnR = 0 0 | swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000002835200000 | [ffffff802a0d8d71] pgd=180000005fbf9003, p4d=180000005fbf9003, | pud=180000005fbf9003, pmd=180000005fbe8003, pte=006800002a0d8707 | Internal error: Oops: 96000021 [#1] PREEMPT SMP | Modules linked in: | CPU: 2 PID: 45 Comm: kworker/u8:2 Not tainted | 5.15.78-android13-8-g63561175bbda-dirty #1 | ... | pc : kcsan_setup_watchpoint+0x26c/0x6bc | lr : kcsan_setup_watchpoint+0x88/0x6bc | sp : ffffffc00ab4b7f0 | x29: ffffffc00ab4b800 x28: ffffff80294fe588 x27: 0000000000000001 | x26: 0000000000000019 x25: 0000000000000001 x24: ffffff80294fdb80 | x23: 0000000000000000 x22: ffffffc00a70fb68 x21: ffffff802a0d8d71 | x20: 0000000000000002 x19: 0000000000000000 x18: ffffffc00a9bd060 | x17: 0000000000000001 x16: 0000000000000000 x15: ffffffc00a59f000 | x14: 0000000000000001 x13: 0000000000000000 x12: ffffffc00a70faa0 | x11: 00000000aaaaaaab x10: 0000000000000054 x9 : ffffffc00839adf8 | x8 : ffffffc009b4cf00 x7 : 0000000000000000 x6 : 0000000000000007 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffffffc00a70fb70 | x2 : 0005ff802a0d8d71 x1 : 0000000000000000 x0 : 0000000000000000 | Call trace: | kcsan_setup_watchpoint+0x26c/0x6bc | __tsan_read2+0x1f0/0x234 | inflate_fast+0x498/0x750 | zlib_inflate+0x1304/0x2384 | __gunzip+0x3a0/0x45c | gunzip+0x20/0x30 | unpack_to_rootfs+0x2a8/0x3fc | do_populate_rootfs+0xe8/0x11c | async_run_entry_fn+0x58/0x1bc | process_one_work+0x3ec/0x738 | worker_thread+0x4c4/0x838 | kthread+0x20c/0x258 | ret_from_fork+0x10/0x20 | Code: b8bfc2a8 2a0803f7 14000007 d503249f (78bfc2a8) ) | ---[ end trace 613a943cb0a572b6 ]----- The reason for this is that on certain arm64 configuration since e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y"), READ_ONCE() may be promoted to a full atomic acquire instruction which cannot be used on unaligned addresses. Fix it by avoiding READ_ONCE() in read_instrumented_memory(), and simply forcing the compiler to do the required access by casting to the appropriate volatile type. In terms of generated code this currently only affects architectures that do not use the default READ_ONCE() implementation. The only downside is that we are not guaranteed atomicity of the access itself, although on most architectures a plain load up to machine word size should still be atomic (a fact the default READ_ONCE() still relies on itself).
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Meta Information
Published
2025-12-08
Last Modified
2025-12-08
Generated
2026-05-07
AI Q&A
2025-12-08
EPSS Evaluated
2026-05-05
NVD
CVE-2023-53742
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel 5.15.78
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel involves the use of READ_ONCE() in the function read_instrumented_memory(). On certain arm64 configurations with CONFIG_LTO enabled, READ_ONCE() can be promoted to a full atomic acquire instruction that cannot be used on unaligned memory addresses, causing kernel paging faults and crashes. The fix avoids using READ_ONCE() in this function and instead uses a volatile type cast to perform the memory access, which may not guarantee atomicity but prevents the fault.


How can this vulnerability impact me? :

This vulnerability can cause the Linux kernel to crash or experience internal errors due to unaligned memory access faults on affected arm64 systems. This can lead to system instability, unexpected reboots, or denial of service conditions.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability is fixed by avoiding the use of READ_ONCE() in read_instrumented_memory() and instead forcing the compiler to do the required access by casting to the appropriate volatile type. To mitigate this vulnerability, you should update your Linux kernel to a version that includes this fix. There are no specific immediate configuration changes or commands mentioned to mitigate the issue other than applying the patch or kernel update.


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