[PATCH v6] lib: fix dereferencing of a NULL pointer

[Abdelrahman Youssef via B4 Relay]

From: Abdelrahman Youssef <abdelrahmanyossef12 at gmail.com>

Runtime reported by AddressSanitizer due to time a NULL pointer dereference.

This is the stack trace:
    #0 0x5b2550e70c4b in get_param_by_name /barebox/lib/parameter.c:56:2
    #1 0x5b2550e70c4b in __dev_add_param /barebox/lib/parameter.c:153:6
    #2 0x5b2550e71666 in __dev_add_param_int /barebox/lib/parameter.c:471:8
    #3 0x5b2550daece8 in dev_add_param_uint32 /barebox/include/param.h:266:1
    #4 0x5b2550daece8 in dos_partition /barebox/common/partitions/dos.c:289:2
    #5 0x5b2550dadc62 in fuzz_partition_table_parser /barebox/common/partitions.c:331:10
    #6 0x5b2550dadc62 in fuzz_partition_table_parser_ramdisk /barebox/common/partitions.c:344:1
    #7 0x5b2550ebb94d in fuzz_test_once /barebox/include/fuzz.h:68:2
    #8 0x5b2550ebb94d in fuzz_main /barebox/lib/fuzz.c:38:3
    #9 0x5b2550d8eb41 in start_barebox /barebox/common/startup.c:381:3
    #10 0x5b2550f4ea6d in sandbox_main (/barebox/images/main.elf+0x411a6d) (BuildId: dfdb3401891b94e86545eddb1502f0815ffd0afb)
    #11 0x5b2550f4f2b2 in start_barebox_coop fuzz.c

Signed-off-by: Abdelrahman Youssef <abdelrahmanyossef12 at gmail.com>
---
 lib/parameter.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/parameter.c b/lib/parameter.c
index bf9e83152b..21fa9e7e70 100644
--- a/lib/parameter.c
+++ b/lib/parameter.c
@@ -51,6 +51,9 @@ const char *get_param_type(struct param_d *param)
 
 struct param_d *get_param_by_name(struct device *dev, const char *name)
 {
+	if (!dev)
+		return NULL;
+
 	struct param_d *p;
 
 	list_for_each_entry(p, &dev->parameters, list) {

---
base-commit: 9d47ff66c3892c5a6ddd4704993365a797fbeb68
change-id: 20241021-null_der-1378213f0da2

Best regards,
-- 
Abdelrahman Youssef <abdelrahmanyossef12 at gmail.com>