Breno Leitao 47984e9db9 netconsole: propagate device name truncation in dev_name_store()
[ Upstream commit 92ceb7bff6 ]

dev_name_store() calls strscpy(nt->np.dev_name, buf, IFNAMSIZ) without
checking the return value. If userspace writes an interface name longer
than IFNAMSIZ - 1, strscpy() silently truncates and returns -E2BIG, but
the function ignores it and reports a fully successful write back to
userspace.

If a real interface happens to match the truncated name, netconsole will
bind to the wrong device on the next enable, sending kernel logs and
panic output to an unintended network segment with no indication to
userspace that anything was rewritten.

Reject writes whose length cannot fit in nt->np.dev_name up front:

	if (count >= IFNAMSIZ)
		return -ENAMETOOLONG;

This is not a big deal of a problem, but, it is still the correct
approach.

Fixes: 0bcc181618 ("[NET] netconsole: Support dynamic reconfiguration using configfs")
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260427-netconsole_ai_fixes-v2-3-59965f29d9cc@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-23 13:07:12 +02:00
2026-05-23 13:06:48 +02:00
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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 reStructuredText 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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