This is a note to let you know that I've just added the patch titled
clk: visconti: Add bounds-checking coverage for struct visconti_pll_provider
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
clk-visconti-add-bounds-checking-coverage-for-struct.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit db365cdc9787cdc829e1ae15ca3218ca535b8c6f
Author: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Date: Mon Oct 16 16:06:16 2023 -0600
clk: visconti: Add bounds-checking coverage for struct visconti_pll_provider
[ Upstream commit 397d887c1601a71e8a8abdb6beea67d58f0472d3 ]
In order to gain the bounds-checking coverage that __counted_by provides
to flexible-array members at run-time via CONFIG_UBSAN_BOUNDS (for array
indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions),
we must make sure that the counter member, in this particular case `num`,
is updated before the first access to the flex-array member, in this
particular case array `hws`. See below:
commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with
__counted_by") introduced `__counted_by` for `struct clk_hw_onecell_data`
together with changes to relocate some of assignments of counter `num`
before `hws` is accessed:
include/linux/clk-provider.h:
1380 struct clk_hw_onecell_data {
1381 unsigned int num;
1382 struct clk_hw *hws[] __counted_by(num);
1383 };
However, this structure is used as a member in other structs, in this
case in `struct visconti_pll_provider`:
drivers/clk/visconti/pll.h:
16 struct visconti_pll_provider {
17 void __iomem *reg_base;
18 struct device_node *node;
19
20 /* Must be last */
21 struct clk_hw_onecell_data clk_data;
22 };
Hence, we need to move the assignments to `ctx->clk_data.num` after
allocation for `struct visconti_pll_provider` and before accessing the
flexible array `ctx->clk_data.hws`. And, as assignments for all members
in `struct visconti_pll_provider` are originally adjacent to each other,
relocate all assignments together, so we don't split up
`ctx->clk_data.hws = nr_plls` from the rest. :)
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Link: https://lore.kernel.org/r/e3189f3e40e8723b6d794fb2260e2e9ab6b960bd.1697492890.git.gustavoars@xxxxxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/clk/visconti/pll.c b/drivers/clk/visconti/pll.c
index 1f3234f226674..e9cd80e085dc3 100644
--- a/drivers/clk/visconti/pll.c
+++ b/drivers/clk/visconti/pll.c
@@ -329,12 +329,12 @@ struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np,
if (!ctx)
return ERR_PTR(-ENOMEM);
- for (i = 0; i < nr_plls; ++i)
- ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
-
ctx->node = np;
ctx->reg_base = base;
ctx->clk_data.num = nr_plls;
+ for (i = 0; i < nr_plls; ++i)
+ ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
+
return ctx;
}
