From: Tuo Li <islituo@gmail.com> stable inclusion from stable-5.10.63 commit 23c29490b84dd89582b7d3233e97f73c41f1a065 bugzilla: 182231 https://gitee.com/openeuler/kernel/issues/I4EFS1 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit a9e6ffbc5b7324b6639ee89028908b1e91ceed51 ] kcalloc() is called to allocate memory for m->m_info, and if it fails, ceph_mdsmap_destroy() behind the label out_err will be called: ceph_mdsmap_destroy(m); In ceph_mdsmap_destroy(), m->m_info is dereferenced through: kfree(m->m_info[i].export_targets); To fix this possible null-pointer dereference, check m->m_info before the for loop to free m->m_info[i].export_targets. [ jlayton: fix up whitespace damage only kfree(m->m_info) if it's non-NULL ] Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Tuo Li <islituo@gmail.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- fs/ceph/mdsmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c index 1096d1d3a84c..47f2903bacb9 100644 --- a/fs/ceph/mdsmap.c +++ b/fs/ceph/mdsmap.c @@ -393,9 +393,11 @@ void ceph_mdsmap_destroy(struct ceph_mdsmap *m) { int i; - for (i = 0; i < m->possible_max_rank; i++) - kfree(m->m_info[i].export_targets); - kfree(m->m_info); + if (m->m_info) { + for (i = 0; i < m->possible_max_rank; i++) + kfree(m->m_info[i].export_targets); + kfree(m->m_info); + } kfree(m->m_data_pg_pools); kfree(m); } -- 2.20.1