Ma Ke make24@iscas.ac.cn writes:
In read_handle(), of_get_address() may return NULL if getting address and size of the node failed. When of_read_number() uses prop to handle conversions between different byte orders, it could lead to a null pointer dereference. Add NULL check to fix potential issue.
Found by static analysis.
Cc: stable@vger.kernel.org Fixes: 14baf4d9c739 ("cxl: Add guest-specific code") Signed-off-by: Ma Ke make24@iscas.ac.cn
Acked-by: Michael Ellerman mpe@ellerman.id.au (powerpc)
In practice I don't this bug is triggerable, because the device tree that's being parsed comes from a single source (IBM hypervisor), and if this property was malformed that would simply be considered a bug in the hypervisor.
cheers
Changes in v4:
- modified vulnerability description according to suggestions, making the
process of static analysis of vulnerabilities clearer. No active research on developer behavior. Changes in v3:
- fixed up the changelog text as suggestions.
Changes in v2:
- added an explanation of how the potential vulnerability was discovered,
but not meet the description specification requirements.
drivers/misc/cxl/of.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/misc/cxl/of.c b/drivers/misc/cxl/of.c index bcc005dff1c0..d8dbb3723951 100644 --- a/drivers/misc/cxl/of.c +++ b/drivers/misc/cxl/of.c @@ -58,7 +58,7 @@ static int read_handle(struct device_node *np, u64 *handle) /* Get address and size of the node */ prop = of_get_address(np, 0, &size, NULL);
- if (size)
- if (!prop || size) return -EINVAL;
/* Helper to read a big number; size is in cells (not bytes) */ -- 2.25.1