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    SubjectRe: [PATCH v2 1/7] kdb: Fix buffer overflow during tab-complete
    Hi,

    On Mon, Apr 22, 2024 at 9:37 AM Daniel Thompson
    <daniel.thompson@linaro.org> wrote:
    >
    > Currently, when the user attempts symbol completion with the Tab key, kdb
    > will use strncpy() to insert the completed symbol into the command buffer.
    > Unfortunately it passes the size of the source buffer rather than the
    > destination to strncpy() with predictably horrible results. Most obviously
    > if the command buffer is already full but cp, the cursor position, is in
    > the middle of the buffer, then we will write past the end of the supplied
    > buffer.
    >
    > Fix this by replacing the dubious strncpy() calls with memmove()/memcpy()
    > calls plus explicit boundary checks to make sure we have enough space
    > before we start moving characters around.
    >
    > Reported-by: Justin Stitt <justinstitt@google.com>
    > Closes: https://lore.kernel.org/all/CAFhGd8qESuuifuHsNjFPR-Va3P80bxrw+LqvC8deA8GziUJLpw@mail.gmail.com/
    > Cc: stable@vger.kernel.org
    > Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
    > ---
    > kernel/debug/kdb/kdb_io.c | 21 +++++++++++++--------
    > 1 file changed, 13 insertions(+), 8 deletions(-)

    Boy, this function (and especially the tab handling) is hard to read.
    I spent a bit of time trying to grok it and, as far as I can tell,
    your patch makes things better and I don't see any bugs.

    Reviewed-by: Douglas Anderson <dianders@chromium.org>

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