7.8

CVE-2021-47497: nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells

Analyzed
AliasesUBUNTU-CVE-2021-47497DEBIAN-CVE-2021-47497
Published 22-05-2024Last modified 11-05-2026

Vulnerability summary

CVE-2021-47497 is a high (CVSS 7.8) Out-of-bounds Write vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (NVD)
EPSS score
0.22%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 15 · Related 11
RHSA-2024:7000RHSA-2024:7001RHSA-2024:9315RHSA-2025:2490SUSE-SU-2024:1979-1SUSE-SU-2024:1983-1

Timeline

  1. 22-05-2024
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells If a cell has 'nbits' equal to a multiple of BITS_PER_BYTE the logic *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); will become undefined behavior because nbits modulo BITS_PER_BYTE is 0, and we subtract one from that making a large number that is then shifted more than the number of bits that fit into an unsigned long. UBSAN reports this problem: UBSAN: shift-out-of-bounds in drivers/nvmem/core.c:1386:8 shift exponent 64 is too large for 64-bit type 'unsigned long' CPU: 6 PID: 7 Comm: kworker/u16:0 Not tainted 5.15.0-rc3+ #9 Hardware name: Google Lazor (rev3+) with KB Backlight (DT) Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace+0x0/0x170 show_stack+0x24/0x30 dump_stack_lvl+0x64/0x7c dump_stack+0x18/0x38 ubsan_epilogue+0x10/0x54 __ubsan_handle_shift_out_of_bounds+0x180/0x194 __nvmem_cell_read+0x1ec/0x21c nvmem_cell_read+0x58/0x94 nvmem_cell_read_variable_common+0x4c/0xb0 nvmem_cell_read_variable_le_u32+0x40/0x100 a6xx_gpu_init+0x170/0x2f4 adreno_bind+0x174/0x284 component_bind_all+0xf0/0x264 msm_drm_bind+0x1d8/0x7a0 try_to_bring_up_master+0x164/0x1ac __component_add+0xbc/0x13c component_add+0x20/0x2c dp_display_probe+0x340/0x384 platform_probe+0xc0/0x100 really_probe+0x110/0x304 __driver_probe_device+0xb8/0x120 driver_probe_device+0x4c/0xfc __device_attach_driver+0xb0/0x128 bus_for_each_drv+0x90/0xdc __device_attach+0xc8/0x174 device_initial_probe+0x20/0x2c bus_probe_device+0x40/0xa4 deferred_probe_work_func+0x7c/0xb8 process_one_work+0x128/0x21c process_scheduled_works+0x40/0x54 worker_thread+0x1ec/0x2a8 kthread+0x138/0x158 ret_from_fork+0x10/0x20 Fix it by making sure there are any bits to mask out.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.22% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu87 products
  • linuxAll versions (No fix recorded) | < 4.15.0-166.174 | < 5.4.0-92.103
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 4.15.0-1118.125 | < 5.4.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < abcb8d33e4d2215ccde5ab5ccf9f730a59d79d97 | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < 60df06bbdf497e37ed25ad40572c362e5b0998df | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < 2df6c023050205c4d04ffc121bc549f65cb8d1df | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < eb0fc8e7170e61eaf65d28dee4a8baf4e86b19ca | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < 0594f1d048d8dc338eb9a240021b1d00ae1eb082 | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < 57e48886401b14cd351423fabfec2cfd18df4f66 | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < 0e822e5413da1af28cca350cb1cb42b6133bdcae | ≥ 69aba7948cbe53f2f1827e84e9dd0ae470a5072e, < 5d388fa01fa6eb310ac023a363a6cb216d9d8fe9 | 4.3
  • linux_kernel≥ 4.3, < 4.4.290 | ≥ 4.5, < 4.9.288 | ≥ 4.10, < 4.14.252 | ≥ 4.15, < 4.19.213 | ≥ 4.20, < 5.4.155 | ≥ 5.5, < 5.10.75 | ≥ 5.11, < 5.14.14 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3 | 5.15:rc4 | 5.15:rc5
Debian1 product
  • linux< 5.14.16-1

3 vendors · 90 products

References

12 links
Show all 12 references