CVE-2021-47386

hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field

State: Published
Severity: 7.8 High
Published: May 21, 2024
Updated: May 11, 2026
Reserved: May 21, 2024

Description

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field

If driver read val value sufficient for (val & 0x08) && (!(val & 0x80)) && ((val & 0x7) == ((val >> 4) & 0x7)) from device then Null pointer dereference occurs. (It is possible if tmp = 0b0xyz1xyz, where same literals mean same numbers) Also lm75[] does not serve a purpose anymore after switching to devm_i2c_new_dummy_device() in w83791d_detect_subclients().

The patch fixes possible NULL pointer dereference by removing lm75[].

Found by Linux Driver Verification project (linuxtesting.org).

[groeck: Dropped unnecessary continuation lines, fixed multi-line alignment]

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-476 NULL Pointer Dereference

Affected Products

Product	Versions
LinuxLinux	358d2071100d84cfe6ef4a9d70ac0d998a1d501e to before 44d3c480e4e2a75bf6296a18b4356157991ccd80Affected 358d2071100d84cfe6ef4a9d70ac0d998a1d501e to before 516d9055039017a20a698103be2b556b4c976bb8Affected 358d2071100d84cfe6ef4a9d70ac0d998a1d501e to before 16887ae4e3defd2c4e7913b6c539f33eaf4eac5cAffected 358d2071100d84cfe6ef4a9d70ac0d998a1d501e to before 943c15ac1b84d378da26bba41c83c67e16499ac4Affected
LinuxLinux	5.4Affected before 5.4Not affected 5.4.151 through 5.4.Not affected 5.10.71 through 5.10.Not affected 5.14.10 through 5.14.*Not affected 5.15 and laterNot affected

References

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