Messages in this thread Patch in this message | | | From | vbendel@redhat ... | Subject | [PATCH v2] selinux: fix double free of cond_list on error paths | Date | Wed, 2 Feb 2022 12:25:11 +0100 |
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From: Vratislav Bendel <vbendel@redhat.com>
On error path from cond_read_list() and duplicate_policydb_cond_list() the cond_list_destroy() gets called a second time in caller functions, resulting in NULL pointer deref. Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), making subsequent calls a noop.
Also consistently reset the cond_list pointer to NULL after freeing.
Signed-off-by: Vratislav Bendel <vbendel@redhat.com> --- security/selinux/ss/conditional.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index 2ec6e5cd25d9..feb206f3acb4 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -152,6 +152,8 @@ static void cond_list_destroy(struct policydb *p) for (i = 0; i < p->cond_list_len; i++) cond_node_destroy(&p->cond_list[i]); kfree(p->cond_list); + p->cond_list = NULL; + p->cond_list_len = 0; } void cond_policydb_destroy(struct policydb *p) @@ -441,7 +443,6 @@ int cond_read_list(struct policydb *p, void *fp) return 0; err: cond_list_destroy(p); - p->cond_list = NULL; return rc; } -- 2.26.3
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