clk: spacemit: Set clk_hw_onecell_data::num before using flex array

Browse source

[ Upstream commit 23b2d2fb13 ]

When booting with KASAN enabled the following splat is
encountered during probe of the k1 clock driver:

UBSAN: array-index-out-of-bounds in drivers/clk/spacemit/ccu-k1.c:1044:16
index 0 is out of range for type 'clk_hw *[*]'
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.0-rc5+ #1 PREEMPT(lazy)
Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2022.10spacemit 10/01/2022
Call Trace:
[<ffffffff8002b628>] dump_backtrace+0x28/0x38
[<ffffffff800027d2>] show_stack+0x3a/0x50
[<ffffffff800220c2>] dump_stack_lvl+0x5a/0x80
[<ffffffff80022100>] dump_stack+0x18/0x20
[<ffffffff800164b8>] ubsan_epilogue+0x10/0x48
[<ffffffff8099034e>] __ubsan_handle_out_of_bounds+0xa6/0xa8
[<ffffffff80acbfa6>] k1_ccu_probe+0x37e/0x420
[<ffffffff80b79e6e>] platform_probe+0x56/0x98
[<ffffffff80b76a7e>] really_probe+0x9e/0x350
[<ffffffff80b76db0>] __driver_probe_device+0x80/0x138
[<ffffffff80b76f52>] driver_probe_device+0x3a/0xd0
[<ffffffff80b771c4>] __driver_attach+0xac/0x1b8
[<ffffffff80b742fc>] bus_for_each_dev+0x6c/0xc8
[<ffffffff80b76296>] driver_attach+0x26/0x38
[<ffffffff80b759ae>] bus_add_driver+0x13e/0x268
[<ffffffff80b7836a>] driver_register+0x52/0x100
[<ffffffff80b79a78>] __platform_driver_register+0x28/0x38
[<ffffffff814585da>] k1_ccu_driver_init+0x22/0x38
[<ffffffff80023a8a>] do_one_initcall+0x62/0x2a0
[<ffffffff81401c60>] do_initcalls+0x170/0x1a8
[<ffffffff81401e7a>] kernel_init_freeable+0x16a/0x1e0
[<ffffffff811f7534>] kernel_init+0x2c/0x180
[<ffffffff80025f56>] ret_from_fork_kernel+0x16/0x1d8
[<ffffffff81205336>] ret_from_fork_kernel_asm+0x16/0x18
---[ end trace ]---

This is bogus and is simply a result of KASAN consulting the
`.num` member of the struct for bounds information (as it should
due to `__counted_by`) and finding 0 set by kzalloc() because it
has not been initialized before the loop that fills in the array.
The easy fix is to just move the line that sets `num` to before
the loop that fills the array so that KASAN has the information
it needs to accurately conclude that the access is valid.

Fixes: 1b72c59db0 ("clk: spacemit: Add clock support for SpacemiT K1 SoC")
Tested-by: Yanko Kaneti <yaneti@declera.com>
Signed-off-by: Charles Mirabile <cmirabil@redhat.com>
Reviewed-by: Alex Elder <elder@riscstar.com>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Reviewed-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Charles Mirabile 2025-11-17 14:03:29 -05:00 • committed by Greg Kroah-Hartman

parent 04c79e05e1

commit ee5b0b28c9

1 changed files with 2 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

4

drivers/clk/spacemit/ccu-k1.c

View file