[PATCH v3] drivers/misc: Add NULL check in aspeed_lpc_enable_snoop
From: Henry Martin <hidden>
Date: 2025-03-31 15:40:17
Also in:
linux-aspeed, lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
devm_kasprintf() returns NULL if memory allocation fails. Currently,
aspeed_lpc_enable_snoop() does not check for this case, leading to a NULL
pointer dereference.
The corrected code adds error checking and optimizes resource release logic
to ensure no memory or kernel resources are leaked in case of failure.
Fixes: 3772e5da4454 ("drivers/misc: Aspeed LPC snoop output using misc chardev")
Signed-off-by: Henry Martin <redacted>
---
V2 -> V3: The enhanced code introduces proper error handling and
improves resource cleanup mechanisms to prevent memory or kernel
resource leaks during failure scenarios.
V1 -> V2: Removed blank line between tags.
drivers/soc/aspeed/aspeed-lpc-snoop.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
index 9ab5ba9cf1d6..b79365a34baa 100644
--- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
+++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c@@ -200,11 +200,16 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop, lpc_snoop->chan[channel].miscdev.minor = MISC_DYNAMIC_MINOR; lpc_snoop->chan[channel].miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, channel); + if (!lpc_snoop->chan[channel].miscdev.name) { + rc = -ENOMEM; + goto err_free_fifo; + } + lpc_snoop->chan[channel].miscdev.fops = &snoop_fops; lpc_snoop->chan[channel].miscdev.parent = dev; rc = misc_register(&lpc_snoop->chan[channel].miscdev); if (rc) - return rc; + goto err_free_fifo; /* Enable LPC snoop channel at requested port */ switch (channel) {
@@ -221,7 +226,8 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop, hicrb_en = HICRB_ENSNP1D; break; default: - return -EINVAL; + rc = -EINVAL; + goto err_misc_deregister; } regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
@@ -232,6 +238,12 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop, hicrb_en, hicrb_en); return rc; + +err_misc_deregister: + misc_deregister(&lpc_snoop->chan[channel].miscdev); +err_free_fifo: + kfifo_free(&lpc_snoop->chan[channel].fifo); + return rc; } static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
--
2.34.1