CVE-2023-53272: linux Out-of-bounds Read
Vulnerability summary
CVE-2023-53272 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 15 · Related 15Timeline
- 16-09-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- NVDNIST7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
0.16%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
0.00 pp
From 0.16% on 22-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu119 products
- linuxAll versions (No fix recorded) | < 5.15.0-86.96
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1047.52
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 4bb7f4cf60e38a00965d22aa5979ab143193d41f, < 1e760b2d18bf129b3da052c2946c02758e97d15e | ≥ 4bb7f4cf60e38a00965d22aa5979ab143193d41f, < 3e36cc94d6e60a27f27498adf1c71eeba769ab33 | ≥ 4bb7f4cf60e38a00965d22aa5979ab143193d41f, < 90947ebf8794e3c229fb2e16e37f1bfea6877f14 | ≥ 4bb7f4cf60e38a00965d22aa5979ab143193d41f, < 0939c264729d4a081ff88efce2ffdf85dc5331e0 | ≥ 4bb7f4cf60e38a00965d22aa5979ab143193d41f, < 1e9cb763e9bacf0c932aa948f50dcfca6f519a26 | 5.8
- linux_kernel≥ 5.8, < 5.10.188 | ≥ 5.11, < 5.15.121 | ≥ 5.16, < 6.1.40 | ≥ 6.2, < 6.4.5 | 6.5:rc1
Debian1 product
- linux< 6.1.52-1 | < 6.4.11-1
3 vendors · 122 products