Bug 2424888 (CVE-2025-68352)

Summary: CVE-2025-68352 kernel: spi: ch341: fix out-of-bounds memory access in ch341_transfer_one
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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OS: Linux   
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Description OSIDB Bzimport 2025-12-24 11:03:53 UTC 
In the Linux kernel, the following vulnerability has been resolved:

spi: ch341: fix out-of-bounds memory access in ch341_transfer_one

Discovered by Atuin - Automated Vulnerability Discovery Engine.

The 'len' variable is calculated as 'min(32, trans->len + 1)',
which includes the 1-byte command header.

When copying data from 'trans->tx_buf' to 'ch341->tx_buf + 1', using 'len'
as the length is incorrect because:

1. It causes an out-of-bounds read from 'trans->tx_buf' (which has size
   'trans->len', i.e., 'len - 1' in this context).
2. It can cause an out-of-bounds write to 'ch341->tx_buf' if 'len' is
   CH341_PACKET_LENGTH (32). Writing 32 bytes to ch341->tx_buf + 1
   overflows the buffer.

Fix this by copying 'len - 1' bytes.
Comment 1 Vipul Nair 2025-12-24 12:39:18 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122454-CVE-2025-68352-a3fe@gregkh/T