Commit 70a6f46d authored Nov 14, 2012 by Colin Ian King Committed by Anton Vorontsov Nov 14, 2012

pstore: Fix NULL pointer dereference in console writes



Passing a NULL id causes a NULL pointer deference in writers such as
erst_writer and efi_pstore_write because they expect to update this id.
Pass a dummy id instead.

This avoids a cascade of oopses caused when the initial
pstore_console_write passes a null which in turn causes writes to the
console causing further oopses in subsequent pstore_console_write calls.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

parent 77b67063

fs/pstore/platform.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -161,6 +161,7 @@ static void pstore_console_write(struct console con, const char s, unsigned c)

		while (s < e) {
		unsigned long flags;
		u64 id;

		if (c > psinfo->bufsize)
		c = psinfo->bufsize;
		@@ -172,7 +173,7 @@ static void pstore_console_write(struct console con, const char s, unsigned c)
		spin_lock_irqsave(&psinfo->buf_lock, flags);
		}
		memcpy(psinfo->buf, s, c);
		psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo);
		psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, c, psinfo);
		spin_unlock_irqrestore(&psinfo->buf_lock, flags);
		s += c;
		c = e - s;

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