Tianchu Chen d285517429 char: applicom: fix NULL pointer dereference in ac_ioctl
commit 82d12088c297fa1cef670e1718b3d24f414c23f7 upstream.

Discovered by Atuin - Automated Vulnerability Discovery Engine.

In ac_ioctl, the validation of IndexCard and the check for a valid
RamIO pointer are skipped when cmd is 6. However, the function
unconditionally executes readb(apbs[IndexCard].RamIO + VERS) at the
end.

If cmd is 6, IndexCard may reference a board that does not exist
(where RamIO is NULL), leading to a NULL pointer dereference.

Fix this by skipping the readb access when cmd is 6, as this
command is a global information query and does not target a specific
board context.

Signed-off-by: Tianchu Chen <flynnnchen@tencent.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20251128155323.a786fde92ebb926cbe96fcb1@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11 15:21:58 +01:00
2022-09-28 09:02:20 +02:00
2025-12-07 06:18:54 +09:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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