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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Gerald SchaeferandGreg Kroah-Hartman
759d913782
commit 2995ccec26 upstream.
When data buffers are reused, e.g. for interval sample records, the
first record determines the data length, and the size of the buffer for
user copy. Current monwriter code does not check if the data length was
changed for subsequent records, which also would never happen for valid
user programs.
However, a malicious user could change the data length, resulting in out
of bounds user copy to the kernel buffer, and memory corruption. By
default, the monwriter misc device is created with root-only permissions,
so practical impact is typically low.
Fix this by checking for changed data length and rejecting such records.
Cc: stable@vger.kernel.org
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
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.