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crypto: caam: Add check for kcalloc() in test_len()

PATCH Superseded Guangshuo Li 2 participants 3 messages Sep 22, 2025 – Sep 23, 2025

Subsystems (5)
Networking Network drivers Stable branch Crypto API +1 more subsystems

v2 of 3 Superseded Latest is v3 →

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Guangshuo Li

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#0 lore raw

PATCH v2 1/1 crypto: caam: Add check for kcalloc() in test_len()

As kcalloc() may fail, check its return value to avoid a NULL pointer dereference when passing the buffer to rng->read().

Fixes 2be0d806e25e ("crypto: caam - add a test for the RNG")
Cc [email protected]

---
changelog:
v2:
- Return -ENOMEM directly on allocation failure.

Signed-off-by Guangshuo Li <[email protected]>
---
 drivers/crypto/caam/caamrng.c | 3 +++
 1 file changed, 3 insertions(+)
drivers/crypto/caam/caamrng.c +3 -0
index b3d14a7f4dd1..357860ee532c 100644
@@ -182,6 +182,9 @@ static inline void test_len(struct hwrng *rng, size_t len, bool wait)
 
 	buf = kcalloc(CAAM_RNG_MAX_FIFO_STORE_SIZE, sizeof(u8), GFP_KERNEL);
 
+	if (!buf) {
+		return -ENOMEM;
+	}
 	while (len > 0) {
 		read_len = rng->read(rng, buf, len, wait);
Signature · 1 line
2.43.0
build bot
#1 lore raw
kernel test robot noticed the following build warnings:

Hi Guangshuo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on herbert-cryptodev-2.6/master]
[also build test WARNING on herbert-crypto-2.6/master linus/master v6.17-rc7 next-20250922] [If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Guangshuo-Li/crypto-caam-Add-check-for-kcalloc-in-test_len/20250922-235723
base:   https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
patch link:    https://lore.kernel.org/r/20250922155322.1825714-1-lgs201920130244%40gmail.com
patch subject: [PATCH v2] crypto: caam: Add check for kcalloc() in test_len()
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20250923/[email protected]/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project cafc064fc7a96b3979a023ddae1da2b499d6c954)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250923/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

In file included from <built-in>:3:
In file included from include/linux/compiler_types.h:171:
include/linux/compiler-clang.h:28:9: warning: '__SANITIZE_ADDRESS__' macro redefined [-Wmacro-redefined]

      28 | #define __SANITIZE_ADDRESS__
         |         ^
   <built-in>:371:9: note: previous definition is here
     371 | #define __SANITIZE_ADDRESS__ 1
         |         ^
>> drivers/crypto/caam/caamrng.c:186:3: warning: void function 'test_len' should not return a value [-Wreturn-mismatch]
     186 |                 return -ENOMEM;
         |                 ^      ~~~~~~~

2 warnings generated.

vim +/test_len +186 drivers/crypto/caam/caamrng.c

174
175 #ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST
176 static inline void test_len(struct hwrng *rng, size_t len, bool wait)
177 {
178 u8 *buf;
179 int read_len;
180 struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
181 struct device *dev = ctx->ctrldev;
182
183 buf = kcalloc(CAAM_RNG_MAX_FIFO_STORE_SIZE, sizeof(u8), GFP_KERNEL);
184
185 if (!buf) {

 > 186			return -ENOMEM;

187 }
188 while (len > 0) {
189 read_len = rng->read(rng, buf, len, wait);
190
191 if (read_len < 0 || (read_len == 0 && wait)) {
192 dev_err(dev, "RNG Read FAILED received %d bytes\n",
193 read_len);
194 kfree(buf);
195 return;
196 }
197
198 print_hex_dump_debug("random bytes@: ",
199 DUMP_PREFIX_ADDRESS, 16, 4,
200 buf, read_len, 1);
201
202 len = len - read_len;
203 }
204
205 kfree(buf);
206 }
207

Signature · 2 lines
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
build bot
#2 lore raw
In reply to Guangshuo Li
kernel test robot noticed the following build errors:

Hi Guangshuo,

kernel test robot noticed the following build errors:

[auto build test ERROR on herbert-cryptodev-2.6/master]
[also build test ERROR on herbert-crypto-2.6/master linus/master v6.17-rc7 next-20250922] [If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Guangshuo-Li/crypto-caam-Add-check-for-kcalloc-in-test_len/20250922-235723
base:   https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
patch link:    https://lore.kernel.org/r/20250922155322.1825714-1-lgs201920130244%40gmail.com
patch subject: [PATCH v2] crypto: caam: Add check for kcalloc() in test_len()
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20250923/[email protected]/config)
compiler: m68k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250923/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All errors (new ones prefixed by >>):

drivers/crypto/caam/caamrng.c: In function 'test_len':

>> drivers/crypto/caam/caamrng.c:186:24: error: 'return' with a value, in function returning void [-Wreturn-mismatch]
     186 |                 return -ENOMEM;
         |                        ^

drivers/crypto/caam/caamrng.c:176:20: note: declared here
176 | static inline void test_len(struct hwrng *rng, size_t len, bool wait)
| ^~~~~~~~

vim +/return +186 drivers/crypto/caam/caamrng.c

174
175 #ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST
176 static inline void test_len(struct hwrng *rng, size_t len, bool wait)
177 {
178 u8 *buf;
179 int read_len;
180 struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
181 struct device *dev = ctx->ctrldev;
182
183 buf = kcalloc(CAAM_RNG_MAX_FIFO_STORE_SIZE, sizeof(u8), GFP_KERNEL);
184
185 if (!buf) {

 > 186			return -ENOMEM;

187 }
188 while (len > 0) {
189 read_len = rng->read(rng, buf, len, wait);
190
191 if (read_len < 0 || (read_len == 0 && wait)) {
192 dev_err(dev, "RNG Read FAILED received %d bytes\n",
193 read_len);
194 kfree(buf);
195 return;
196 }
197
198 print_hex_dump_debug("random bytes@: ",
199 DUMP_PREFIX_ADDRESS, 16, 4,
200 buf, read_len, 1);
201
202 len = len - read_len;
203 }
204
205 kfree(buf);
206 }
207

Signature · 2 lines
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki