This is a note to let you know that I've just added the patch titled
usb: early: xhci-dbc: Fix a potential out-of-bound memory access
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-early-xhci-dbc-fix-a-potential-out-of-bound-memo.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e37332b258265767c737611f91da40e029120227
Author: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Date: Sun Jan 29 19:23:08 2023 +0100
usb: early: xhci-dbc: Fix a potential out-of-bound memory access
[ Upstream commit a4a97ab3db5c081eb6e7dba91306adefb461e0bd ]
If xdbc_bulk_write() fails, the values in 'buf' can be anything. So the
string is not guaranteed to be NULL terminated when xdbc_trace() is called.
Reserve an extra byte, which will be zeroed automatically because 'buf' is
a static variable, in order to avoid troubles, should it happen.
Fixes: aeb9dd1de98c ("usb/early: Add driver for xhci debug capability")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Link: https://lore.kernel.org/r/d6a7562c5e839a195cee85db6dc81817f9372cb1.1675016180.git.christophe.jaillet@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
index 6c0434100e38c..b0c4071f0b167 100644
--- a/drivers/usb/early/xhci-dbc.c
+++ b/drivers/usb/early/xhci-dbc.c
@@ -871,7 +871,8 @@ static int xdbc_bulk_write(const char *bytes, int size)
static void early_xdbc_write(struct console *con, const char *str, u32 n)
{
- static char buf[XDBC_MAX_PACKET];
+ /* static variables are zeroed, so buf is always NULL terminated */
+ static char buf[XDBC_MAX_PACKET + 1];
int chunk, ret;
int use_cr = 0;
