[ 32/83] pstore: Fix NULL pointer dereference in console writes

[Greg Kroah-Hartman]

3.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

commit 70a6f46d7b0ec03653b9ab3f8063a9717a4a53ef upstream.

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@xxxxxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/pstore/platform.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -161,12 +161,13 @@ static void pstore_console_write(struct
 
 	while (s < e) {
 		unsigned long flags;
+		u64 id;
 
 		if (c > psinfo->bufsize)
 			c = psinfo->bufsize;
 		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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