Commit 1c24de60 authored Sep 09, 2010 by Jerome Marchand Committed by Linus Torvalds Sep 09, 2010

kernel/groups.c: fix integer overflow in groups_search



gid_t is a unsigned int.  If group_info contains a gid greater than
MAX_INT, groups_search() function may look on the wrong side of the search
tree.

This solves some unfair "permission denied" problems.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 94131e17

kernel/groups.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -143,10 +143,9 @@ int groups_search(const struct group_info *group_info, gid_t grp)
		right = group_info->ngroups;
		while (left < right) {
		unsigned int mid = (left+right)/2;
		int cmp = grp - GROUP_AT(group_info, mid);
		if (cmp > 0)
		if (grp > GROUP_AT(group_info, mid))
		left = mid + 1;
		else if (cmp < 0)
		else if (grp < GROUP_AT(group_info, mid))
		right = mid;
		else
		return 1;

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