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stephan-ghvireshk
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opp: Fix use-after-free in lazy_opp_tables after probe deferral
When dev_pm_opp_of_find_icc_paths() in _allocate_opp_table() returns -EPROBE_DEFER, the opp_table is freed again, to wait until all the interconnect paths are available. However, if the OPP table is using required-opps then it may already have been added to the global lazy_opp_tables list. The error path does not remove the opp_table from the list again. This can cause crashes later when the provider of the required-opps is added, since we will iterate over OPP tables that have already been freed. E.g.: Unable to handle kernel NULL pointer dereference when read CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.4.0-rc3 PC is at _of_add_opp_table_v2 (include/linux/of.h:949 drivers/opp/of.c:98 drivers/opp/of.c:344 drivers/opp/of.c:404 drivers/opp/of.c:1032) -> lazy_link_required_opp_table() Fix this by calling _of_clear_opp_table() to remove the opp_table from the list and clear other allocated resources. While at it, also add the missing mutex_destroy() calls in the error path. Cc: stable@vger.kernel.org Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Fixes: 7eba0c7 ("opp: Allow lazy-linking of required-opps") Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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drivers/opp/core.c

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1358,7 +1358,10 @@ static struct opp_table *_allocate_opp_table(struct device *dev, int index)
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return opp_table;
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remove_opp_dev:
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_of_clear_opp_table(opp_table);
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_remove_opp_dev(opp_dev, opp_table);
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mutex_destroy(&opp_table->genpd_virt_dev_lock);
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mutex_destroy(&opp_table->lock);
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err:
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kfree(opp_table);
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return ERR_PTR(ret);

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