[PATCH v2] clk: tegra: tegra124-emc: fix krealloc() memory leak

Alexander A. Klimov posted 1 patch 1 week ago
drivers/clk/tegra/clk-tegra124-emc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
[PATCH v2] clk: tegra: tegra124-emc: fix krealloc() memory leak
Posted by Alexander A. Klimov 1 week ago
Don't just overwrite the original pointer passed to krealloc()
with its return value without checking latter:

    MEM = krealloc(MEM, SZ, GFP);

If krealloc() returns NULL, that erases the pointer
to the still allocated memory, hence leaks this memory.
Instead, use a temporary variable, check it's not NULL
and only then assign it to the original pointer:

    TMP = krealloc(MEM, SZ, GFP);
    if (!TMP) return;
    MEM = TMP;

Fixes: 888ca40e2843 ("clk: tegra: emc: Support multiple RAM codes")
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
---
 v2: Separate variable declaration/init
 v2: While on it, enhance variable name
 v2: While on it, explicit variable type
 v2: While on it, re-order variables (reverse Xmas tree)

 [✓] scripts/checkpatch.pl --strict
 [✓] allmodconfig compiled (i686, LLVM)
 [✓] localyesconfig booted (IBM T43)

 Note to myself: use --in-reply-to=ahilgKKwkttOd9H6@orome

 drivers/clk/tegra/clk-tegra124-emc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/tegra/clk-tegra124-emc.c b/drivers/clk/tegra/clk-tegra124-emc.c
index f3b2c96fdcfc..81e4c02a807c 100644
--- a/drivers/clk/tegra/clk-tegra124-emc.c
+++ b/drivers/clk/tegra/clk-tegra124-emc.c
@@ -445,15 +445,17 @@ static int load_timings_from_dt(struct tegra_clk_emc *tegra,
 {
 	struct emc_timing *timings_ptr;
 	int child_count = of_get_child_count(node);
+	struct emc_timing *timings;
 	int i = 0, err;
 	size_t size;
 
 	size = (tegra->num_timings + child_count) * sizeof(struct emc_timing);
 
-	tegra->timings = krealloc(tegra->timings, size, GFP_KERNEL);
-	if (!tegra->timings)
+	timings = krealloc(tegra->timings, size, GFP_KERNEL);
+	if (!timings)
 		return -ENOMEM;
 
+	tegra->timings = timings;
 	timings_ptr = tegra->timings + tegra->num_timings;
 	tegra->num_timings += child_count;
 
-- 
2.54.0