[GIT PULL] linux-pstore.git

Anton Vorontsov
2012-11-15T03:10:24Z

Hello Linus,

Please pull a small fixup for the persistent storage subsystem. A small
buglet can prevent kernel booting on a APEI-enabled machines w/
CONFIG_PSTORE_CONSOLE=y (this is N by default, though).

Thanks!

The following changes since commit 77b67063bb6bce6d475e910d3b886a606d0d91f7:

Linux 3.7-rc5 (2012-11-11 13:44:33 +0100)

are available in the git repository at:

git://git.infradead.org/users/cbou/linux-pstore.git tags/for-v3.7-fixes

for you to fetch changes up to 70a6f46d7b0ec03653b9ab3f8063a9717a4a53ef:

pstore: Fix NULL pointer dereference in console writes (2012-11-14 18:30:21 -0800)

----------------------------------------------------------------
A small fixup for the persistent storage subsystem. The bug can prevent
kernel booting on a APEI-enabled machines w/ CONFIG_PSTORE_CONSOLE=y (this
is N by default, though).

----------------------------------------------------------------
Colin Ian King (1):
pstore: Fix NULL pointer dereference in console writes

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

commit 70a6f46d7b0ec03653b9ab3f8063a9717a4a53ef
Author: Colin Ian King <colin.king@canonical.com>
Date: Wed Nov 14 11:49:53 2012 +0000

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>

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index a40da07..947fbe0 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -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;