Bug 2468245 (CVE-2026-43380) - CVE-2026-43380 kernel: hwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read
Summary: CVE-2026-43380 kernel: hwmon: (pmbus/q54sj108a2) fix stack overflow in debugf...
Keywords:
Status: NEW
Alias: CVE-2026-43380
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-08 15:06 UTC by OSIDB Bzimport
Modified: 2026-05-08 21:15 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-05-08 15:06:46 UTC
In the Linux kernel, the following vulnerability has been resolved:

hwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read

The q54sj108a2_debugfs_read function suffers from a stack buffer overflow
due to incorrect arguments passed to bin2hex(). The function currently
passes 'data' as the destination and 'data_char' as the source.

Because bin2hex() converts each input byte into two hex characters, a
32-byte block read results in 64 bytes of output. Since 'data' is only
34 bytes (I2C_SMBUS_BLOCK_MAX + 2), this writes 30 bytes past the end
of the buffer onto the stack.

Additionally, the arguments were swapped: it was reading from the
zero-initialized 'data_char' and writing to 'data', resulting in
all-zero output regardless of the actual I2C read.

Fix this by:
1. Expanding 'data_char' to 66 bytes to safely hold the hex output.
2. Correcting the bin2hex() argument order and using the actual read count.
3. Using a pointer to select the correct output buffer for the final
   simple_read_from_buffer call.


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