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libsepol: invert only valid range of role bitmap

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The length of an ebitmap is the current highest allocated (not set) bit
and always a multiple of MAPTYPE (= 64). The role ebitmap should only
have valid role bits set, even after inverting. The length might be
smaller than the maximum number of defined roles leading to non defined
role bits set afterwards.
Only invert up to the number of roles defined instead the full ebitmap
length, similar to type_set_expand().

This also avoids timeouts on an invalid huge highbit set, since the
ebitmap has not been validated yet, on which inverting will take
excessive amount of memory and time, found by oss-fuzz (#43709).

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
This commit is contained in:
Christian Göttsche 2022-01-25 14:50:22 +01:00 committed by James Carter
parent 42a8dc46a7
commit 7385004162
1 changed files with 1 additions and 1 deletions
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libsepol/src/expand.c
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@ -2481,7 +2481,7 @@ int role_set_expand(role_set_t * x, ebitmap_t * r, policydb_t * out, policydb_t
/* if role is to be complimented, invert the entire bitmap here */
if (x->flags & ROLE_COMP) {
for (i = 0; i < ebitmap_length(r); i++) {
for (i = 0; i < p->p_roles.nprim; i++) {
if (ebitmap_get_bit(r, i)) {
if (ebitmap_set_bit(r, i, 0))
return -1;