From: Kent Overstreet <kent.overstreet@linux.dev> stable inclusion from stable-v5.10.226 commit 99418ec776a39609f50934720419e0b464ca2283 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAVU82 CVE: CVE-2024-47668 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ----------------------------------------------------------- [ Upstream commit b2f11c6f3e1fc60742673b8675c95b78447f3dae ] If we need to increase the tree depth, allocate a new node, and then race with another thread that increased the tree depth before us, we'll still have a preallocated node that might be used later. If we then use that node for a new non-root node, it'll still have a pointer to the old root instead of being zeroed - fix this by zeroing it in the cmpxchg failure path. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com> --- lib/generic-radix-tree.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c index 7dfa88282b00..78f081d695d0 100644 --- a/lib/generic-radix-tree.c +++ b/lib/generic-radix-tree.c @@ -131,6 +131,8 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset, if ((v = cmpxchg_release(&radix->root, r, new_root)) == r) { v = new_root; new_node = NULL; + } else { + new_node->children[0] = NULL; } } -- 2.17.1