From: Ondrej Mosnacek omosnace@redhat.com
stable inclusion form stable-v5.10.82 commit b17dd53cac769dd13031b0ca34f90cc65e523fab bugzilla: 185877 https://gitee.com/openeuler/kernel/issues/I4QU6V
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit dc27f3c5d10c58069672215787a96b4fae01818b upstream.
When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size.
Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.
Cc: stable@vger.kernel.org Fixes: 03414a49ad5f ("selinux: do not allocate hashtabs dynamically") Signed-off-by: Ondrej Mosnacek omosnace@redhat.com Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- security/selinux/ss/hashtab.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c index dab8c25c739b..7335f67ce54e 100644 --- a/security/selinux/ss/hashtab.c +++ b/security/selinux/ss/hashtab.c @@ -30,13 +30,20 @@ static u32 hashtab_compute_size(u32 nel)
int hashtab_init(struct hashtab *h, u32 nel_hint) { - h->size = hashtab_compute_size(nel_hint); + u32 size = hashtab_compute_size(nel_hint); + + /* should already be zeroed, but better be safe */ h->nel = 0; - if (!h->size) - return 0; + h->size = 0; + h->htable = NULL;
- h->htable = kcalloc(h->size, sizeof(*h->htable), GFP_KERNEL); - return h->htable ? 0 : -ENOMEM; + if (size) { + h->htable = kcalloc(size, sizeof(*h->htable), GFP_KERNEL); + if (!h->htable) + return -ENOMEM; + h->size = size; + } + return 0; }
int __hashtab_insert(struct hashtab *h, struct hashtab_node **dst,