76 lines
1.9 KiB
Diff
76 lines
1.9 KiB
Diff
From c3f0124b1817dd4bdc79c86491d77a7a2b08d479 Mon Sep 17 00:00:00 2001
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From: James Carter <jwcart2@gmail.com>
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Date: Wed, 16 Mar 2022 16:15:57 -0400
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Subject: [PATCH] libsepol: Validate conditional expressions
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When validating a policydb, validate the conditional expressions
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including the values of the booleans within them.
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Found by oss-fuzz (#45523)
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Signed-off-by: James Carter <jwcart2@gmail.com>
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Reference: https://github.com/SELinuxProject/selinux/commit/c3f0124b1817dd4bdc79c86491d77a7a2b08d479
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Conflict: NA
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---
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libsepol/src/policydb_validate.c | 43 +++++++++++++++++++++++++++++++++++++++++
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1 file changed, 43 insertions(+)
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diff --git a/libsepol/src/policydb_validate.c b/libsepol/src/policydb_validate.c
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index 40e68ac..da3c7c5 100644
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--- a/libsepol/src/policydb_validate.c
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+++ b/libsepol/src/policydb_validate.c
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@@ -470,9 +470,52 @@ bad:
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return -1;
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}
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+static int validate_cond_expr(sepol_handle_t *handle, struct cond_expr *expr, validate_t *bool)
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+{
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+ int depth = -1;
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+
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+ for (; expr; expr = expr->next) {
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+ switch(expr->expr_type) {
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+ case COND_BOOL:
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+ if (validate_value(expr->bool, bool))
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+ goto bad;
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+ if (depth == (COND_EXPR_MAXDEPTH - 1))
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+ goto bad;
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+ depth++;
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+ break;
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+ case COND_NOT:
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+ if (depth < 0)
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+ goto bad;
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+ break;
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+ case COND_OR:
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+ case COND_AND:
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+ case COND_XOR:
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+ case COND_EQ:
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+ case COND_NEQ:
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+ if (depth < 1)
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+ goto bad;
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+ depth--;
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+ break;
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+ default:
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+ goto bad;
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+ }
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+ }
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+
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+ if (depth != 0)
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+ goto bad;
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+
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+ return 0;
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+
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+bad:
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+ ERR(handle, "Invalid cond expression");
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+ return -1;
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+}
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+
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static int validate_cond_list(sepol_handle_t *handle, cond_list_t *cond, validate_t flavors[])
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{
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for (; cond; cond = cond->next) {
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+ if (validate_cond_expr(handle, cond->expr, &flavors[SYM_BOOLS]))
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+ goto bad;
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if (validate_cond_av_list(handle, cond->true_list, flavors))
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goto bad;
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if (validate_cond_av_list(handle, cond->false_list, flavors))
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