s390/ipl: add missing intersection check to ipl_report handling

commit a52e5cdbe8 upstream.

The code which handles the ipl report is searching for a free location
in memory where it could copy the component and certificate entries to.
It checks for intersection between the sections required for the kernel
and the component/certificate data area, but fails to check whether
the data structures linking these data areas together intersect.

This might cause the iplreport copy code to overwrite the iplreport
itself. Fix this by adding two addtional intersection checks.

Cc: <stable@vger.kernel.org>
Fixes: 9641b8cc73 ("s390/ipl: read IPL report at early boot")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sven Schnelle 2023-03-07 14:35:23 +01:00 committed by Greg Kroah-Hartman
parent 3f5a833dca
commit d2130f37a4

View file

@ -57,11 +57,19 @@ static unsigned long find_bootdata_space(struct ipl_rb_components *comps,
if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && INITRD_START && INITRD_SIZE &&
intersects(INITRD_START, INITRD_SIZE, safe_addr, size))
safe_addr = INITRD_START + INITRD_SIZE;
if (intersects(safe_addr, size, (unsigned long)comps, comps->len)) {
safe_addr = (unsigned long)comps + comps->len;
goto repeat;
}
for_each_rb_entry(comp, comps)
if (intersects(safe_addr, size, comp->addr, comp->len)) {
safe_addr = comp->addr + comp->len;
goto repeat;
}
if (intersects(safe_addr, size, (unsigned long)certs, certs->len)) {
safe_addr = (unsigned long)certs + certs->len;
goto repeat;
}
for_each_rb_entry(cert, certs)
if (intersects(safe_addr, size, cert->addr, cert->len)) {
safe_addr = cert->addr + cert->len;