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| author | Lukasz Bartosik <lb@semihalf.com> | 2021-04-02 00:51:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-14 08:24:17 +0200 |
| commit | bedda47d5dce4de2f149ed3e9f19aca0723dd3d1 (patch) | |
| tree | a6201e681346403867a6bbee49c7b340e065820b /drivers/clk | |
| parent | b3717885865c6d07d5b541a62958b46120e7646d (diff) | |
| download | linux-bedda47d5dce4de2f149ed3e9f19aca0723dd3d1.tar.gz linux-bedda47d5dce4de2f149ed3e9f19aca0723dd3d1.tar.bz2 linux-bedda47d5dce4de2f149ed3e9f19aca0723dd3d1.zip | |
clk: fix invalid usage of list cursor in register
[ Upstream commit 8d3c0c01cb2e36b2bf3c06a82b18b228d0c8f5d0 ]
Fix invalid usage of a list_for_each_entry cursor in
clk_notifier_register(). When list is empty or if the list
is completely traversed (without breaking from the loop on one
of the entries) then the list cursor does not point to a valid
entry and therefore should not be used.
The issue was dicovered when running 5.12-rc1 kernel on x86_64
with KASAN enabled:
BUG: KASAN: global-out-of-bounds in clk_notifier_register+0xab/0x230
Read of size 8 at addr ffffffffa0d10588 by task swapper/0/1
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1 #1
Hardware name: Google Caroline/Caroline,
BIOS Google_Caroline.7820.430.0 07/20/2018
Call Trace:
dump_stack+0xee/0x15c
print_address_description+0x1e/0x2dc
kasan_report+0x188/0x1ce
? clk_notifier_register+0xab/0x230
? clk_prepare_lock+0x15/0x7b
? clk_notifier_register+0xab/0x230
clk_notifier_register+0xab/0x230
dw8250_probe+0xc01/0x10d4
...
Memory state around the buggy address:
ffffffffa0d10480: 00 00 00 00 00 03 f9 f9 f9 f9 f9 f9 00 00 00 00
ffffffffa0d10500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9
>ffffffffa0d10580: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
^
ffffffffa0d10600: 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 00 00 00 00
ffffffffa0d10680: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
==================================================================
Fixes: b2476490ef11 ("clk: introduce the common clock framework")
Reported-by: Lukasz Majczak <lma@semihalf.com>
Signed-off-by: Lukasz Bartosik <lb@semihalf.com>
Link: https://lore.kernel.org/r/20210401225149.18826-1-lb@semihalf.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/clk.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 36e9f38a3882..5db91903d02b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -4151,20 +4151,19 @@ int clk_notifier_register(struct clk *clk, struct notifier_block *nb) /* search the list of notifiers for this clk */ list_for_each_entry(cn, &clk_notifier_list, node) if (cn->clk == clk) - break; + goto found; /* if clk wasn't in the notifier list, allocate new clk_notifier */ - if (cn->clk != clk) { - cn = kzalloc(sizeof(*cn), GFP_KERNEL); - if (!cn) - goto out; + cn = kzalloc(sizeof(*cn), GFP_KERNEL); + if (!cn) + goto out; - cn->clk = clk; - srcu_init_notifier_head(&cn->notifier_head); + cn->clk = clk; + srcu_init_notifier_head(&cn->notifier_head); - list_add(&cn->node, &clk_notifier_list); - } + list_add(&cn->node, &clk_notifier_list); +found: ret = srcu_notifier_chain_register(&cn->notifier_head, nb); clk->core->notifier_count++; |