On 12/9/21 7:20 PM, Jeff Layton wrote:
On Thu, 2021-12-09 at 10:50 +0800, Jiasheng Jiang wrote:
The return value of kzalloc() needs to be checked.
To avoid use of null pointer in case of the failure of alloc.
Fixes: 3d14c5d2b6e1 ("ceph: factor out libceph from Ceph file system")
Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
---
net/ceph/osd_client.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index ff8624a7c964..3203e8a34370 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1234,6 +1234,8 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
WARN_ON(onum == CEPH_HOMELESS_OSD);
osd = kzalloc(sizeof(*osd), GFP_NOIO | __GFP_NOFAIL);
+ if (!osd)
+ return NULL;
osd_init(osd);
osd->o_osdc = osdc;
osd->o_osd = onum;
__GFP_NOFAIL should ensure that it never returns NULL, right?
Yeah, from the comment, it make no sense to test for failure here:
204 * %__GFP_NOFAIL: The VM implementation _must_ retry infinitely: the
caller
205 * cannot handle allocation failures. The allocation could block
206 * indefinitely but will never return with failure. Testing for
207 * failure is pointless.
208 * New users should be evaluated carefully (and the flag should be
209 * used only when there is no reasonable failure policy) but it is
210 * definitely preferable to use the flag rather than opencode endless
211 * loop around allocator.
212 * Using this flag for costly allocations is _highly_ discouraged.
213 */
Also, if you're going to fix this up to handle that error then you
probably also need to fix lookup_create_osd to handle a NULL return from
create_osd as well.
