CVE-2023-53272
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-16

Last updated on: 2025-12-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net: ena: fix shift-out-of-bounds in exponential backoff The ENA adapters on our instances occasionally reset. Once recently logged a UBSAN failure to console in the process: UBSAN: shift-out-of-bounds in build/linux/drivers/net/ethernet/amazon/ena/ena_com.c:540:13 shift exponent 32 is too large for 32-bit type 'unsigned int' CPU: 28 PID: 70012 Comm: kworker/u72:2 Kdump: loaded not tainted 5.15.117 Hardware name: Amazon EC2 c5d.9xlarge/, BIOS 1.0 10/16/2017 Workqueue: ena ena_fw_reset_device [ena] Call Trace: <TASK> dump_stack_lvl+0x4a/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x36 __ubsan_handle_shift_out_of_bounds.cold+0x61/0x10e ? __const_udelay+0x43/0x50 ena_delay_exponential_backoff_us.cold+0x16/0x1e [ena] wait_for_reset_state+0x54/0xa0 [ena] ena_com_dev_reset+0xc8/0x110 [ena] ena_down+0x3fe/0x480 [ena] ena_destroy_device+0xeb/0xf0 [ena] ena_fw_reset_device+0x30/0x50 [ena] process_one_work+0x22b/0x3d0 worker_thread+0x4d/0x3f0 ? process_one_work+0x3d0/0x3d0 kthread+0x12a/0x150 ? set_kthread_struct+0x50/0x50 ret_from_fork+0x22/0x30 </TASK> Apparently, the reset delays are getting so large they can trigger a UBSAN panic. Looking at the code, the current timeout is capped at 5000us. Using a base value of 100us, the current code will overflow after (1<<29). Even at values before 32, this function wraps around, perhaps unintentionally. Cap the value of the exponent used for this backoff at (1<<16) which is larger than currently necessary, but large enough to support bigger values in the future.
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Meta Information
Published
2025-09-16
Last Modified
2025-12-03
Generated
2026-05-07
AI Q&A
2025-09-16
EPSS Evaluated
2026-05-05
NVD
CVE-2023-53272
Affected Vendors & Products
Showing 5 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 5.8 (inc) to 5.10.188 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.121 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.40 (exc)
linux linux_kernel From 6.2 (inc) to 6.4.5 (exc)
linux linux_kernel 6.5
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-125 The product reads data past the end, or before the beginning, of the intended buffer.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a shift-out-of-bounds error in the Linux kernel's ENA network driver. It occurs during an exponential backoff calculation used for resetting ENA adapters. The shift exponent can exceed the size limit of a 32-bit unsigned integer, causing an overflow and potentially triggering a UBSAN (Undefined Behavior Sanitizer) panic. The fix caps the exponent value to prevent this overflow and avoid large reset delays that cause instability.


How can this vulnerability impact me? :

This vulnerability can cause ENA network adapters to reset unexpectedly and may lead to kernel panics due to the UBSAN failure. This can result in network instability or downtime on affected systems using ENA adapters, impacting system reliability and availability.


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