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authorMatthew Wilcox (Oracle) <willy@infradead.org>2019-11-02 05:25:08 +0100
committerMatthew Wilcox (Oracle) <willy@infradead.org>2019-11-03 12:36:50 +0100
commitb7e9728f3d7fc5c5c8508d99f1675212af5cfd49 (patch)
tree15be71399abd81c6661f5cac4c79b79ec3fdf07e /lib
parentidr: Fix integer overflow in idr_for_each_entry (diff)
downloadlinux-b7e9728f3d7fc5c5c8508d99f1675212af5cfd49.tar.xz
linux-b7e9728f3d7fc5c5c8508d99f1675212af5cfd49.zip
idr: Fix idr_alloc_u32 on 32-bit systems
Attempting to allocate an entry at 0xffffffff when one is already present would succeed in allocating one at 2^32, which would confuse everything. Return -ENOSPC in this case, as expected. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/radix-tree.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 18c1dfbb1765..c8fa1d274530 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1529,7 +1529,7 @@ void __rcu **idr_get_free(struct radix_tree_root *root,
offset = radix_tree_find_next_bit(node, IDR_FREE,
offset + 1);
start = next_index(start, node, offset);
- if (start > max)
+ if (start > max || start == 0)
return ERR_PTR(-ENOSPC);
while (offset == RADIX_TREE_MAP_SIZE) {
offset = node->offset + 1;