diff options
| author | Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp> | 2024-12-17 18:14:34 +0900 |
|---|---|---|
| committer | Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> | 2024-12-22 11:02:39 +0100 |
| commit | b9784e5cde1f9fb83661a70e580e381ae1264d12 (patch) | |
| tree | f24fc017bb036d155d4f778912ad174e27505d90 /drivers/memory | |
| parent | 5119e6b44f8ada5f5cea19935a7f005fee062aef (diff) | |
memory: tegra20-emc: fix an OF node reference bug in tegra_emc_find_node_by_ram_code()
As of_find_node_by_name() release the reference of the argument device
node, tegra_emc_find_node_by_ram_code() releases some device nodes while
still in use, resulting in possible UAFs. According to the bindings and
the in-tree DTS files, the "emc-tables" node is always device's child
node with the property "nvidia,use-ram-code", and the "lpddr2" node is a
child of the "emc-tables" node. Thus utilize the
for_each_child_of_node() macro and of_get_child_by_name() instead of
of_find_node_by_name() to simplify the code.
This bug was found by an experimental verification tool that I am
developing.
Fixes: 96e5da7c8424 ("memory: tegra: Introduce Tegra20 EMC driver")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Link: https://lore.kernel.org/r/20241217091434.1993597-1-joe@pf.is.s.u-tokyo.ac.jp
Link: https://lore.kernel.org/r/20241218024415.2494267-3-joe@pf.is.s.u-tokyo.ac.jp
[krzysztof: applied v1, adjust the commit msg to incorporate v2 parts]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Diffstat (limited to 'drivers/memory')
| -rw-r--r-- | drivers/memory/tegra/tegra20-emc.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c index 7193f848d17e..9b7d30a21a5b 100644 --- a/drivers/memory/tegra/tegra20-emc.c +++ b/drivers/memory/tegra/tegra20-emc.c @@ -474,14 +474,15 @@ tegra_emc_find_node_by_ram_code(struct tegra_emc *emc) ram_code = tegra_read_ram_code(); - for (np = of_find_node_by_name(dev->of_node, "emc-tables"); np; - np = of_find_node_by_name(np, "emc-tables")) { + for_each_child_of_node(dev->of_node, np) { + if (!of_node_name_eq(np, "emc-tables")) + continue; err = of_property_read_u32(np, "nvidia,ram-code", &value); if (err || value != ram_code) { struct device_node *lpddr2_np; bool cfg_mismatches = false; - lpddr2_np = of_find_node_by_name(np, "lpddr2"); + lpddr2_np = of_get_child_by_name(np, "lpddr2"); if (lpddr2_np) { const struct lpddr2_info *info; @@ -518,7 +519,6 @@ tegra_emc_find_node_by_ram_code(struct tegra_emc *emc) } if (cfg_mismatches) { - of_node_put(np); continue; } } |