* [PATCH v3 1/3] crypto: lib/mpi - Extend support for scope-based resource management
2024-10-12 15:00 ` [PATCH v3 0/3] lib: Extending " Markus Elfring
@ 2024-10-12 15:05 ` Markus Elfring
2024-10-12 15:08 ` [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa() Markus Elfring
2024-10-12 15:10 ` [PATCH v3 3/3] lib/digsig: Use scope-based resource management for two " Markus Elfring
2 siblings, 0 replies; 16+ messages in thread
From: Markus Elfring @ 2024-10-12 15:05 UTC (permalink / raw)
To: linux-crypto, kernel-janitors, Andrew Morton, Herbert Xu,
Peter Zijlstra
Cc: LKML
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Wed, 18 Sep 2024 11:06:35 +0200
Scope-based resource management became supported for some
programming interfaces by contributions of Peter Zijlstra on 2023-05-26.
See also the commit 54da6a0924311c7cf5015533991e44fb8eb12773 ("locking:
Introduce __cleanup() based infrastructure").
Thus add a macro call so that the attribute “__free(mpi_free)” can be
applied accordingly.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
V3:
This suggestion was integrated into a patch series.
include/linux/mpi.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/mpi.h b/include/linux/mpi.h
index 47be46f36435..6fbcb88ce296 100644
--- a/include/linux/mpi.h
+++ b/include/linux/mpi.h
@@ -19,6 +19,8 @@
#include <linux/types.h>
#include <linux/scatterlist.h>
+#include <linux/cleanup.h>
+#include <linux/err.h>
#define BYTES_PER_MPI_LIMB (BITS_PER_LONG / 8)
#define BITS_PER_MPI_LIMB BITS_PER_LONG
@@ -44,6 +46,8 @@ typedef struct gcry_mpi *MPI;
/*-- mpiutil.c --*/
MPI mpi_alloc(unsigned nlimbs);
void mpi_free(MPI a);
+DEFINE_FREE(mpi_free, MPI, if (!IS_ERR_OR_NULL(_T)) mpi_free(_T))
+
int mpi_resize(MPI a, unsigned nlimbs);
MPI mpi_copy(MPI a);
--
2.46.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa()
2024-10-12 15:00 ` [PATCH v3 0/3] lib: Extending " Markus Elfring
2024-10-12 15:05 ` [PATCH v3 1/3] crypto: lib/mpi - Extend " Markus Elfring
@ 2024-10-12 15:08 ` Markus Elfring
2024-10-15 21:27 ` kernel test robot
2024-10-16 11:21 ` kernel test robot
2024-10-12 15:10 ` [PATCH v3 3/3] lib/digsig: Use scope-based resource management for two " Markus Elfring
2 siblings, 2 replies; 16+ messages in thread
From: Markus Elfring @ 2024-10-12 15:08 UTC (permalink / raw)
To: linux-crypto, kernel-janitors, Andrew Morton, Herbert Xu,
Peter Zijlstra
Cc: LKML
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 12 Oct 2024 14:21:28 +0200
The support for scope-based resource management was extended.
* Thus use the attribute “__free(mpi_free)”.
* Reduce the scopes for the local variables “nret”, “in” and “res”.
* Omit two mpi_free() calls accordingly.
* Update jump targets.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
V3:
Applications were added as requested (by Herbert Xu) for the proposed
programming interface extension.
lib/digsig.c | 80 ++++++++++++++++++++++++++++------------------------
1 file changed, 43 insertions(+), 37 deletions(-)
diff --git a/lib/digsig.c b/lib/digsig.c
index 04b5e55ed95f..2481120094ab 100644
--- a/lib/digsig.c
+++ b/lib/digsig.c
@@ -71,11 +71,11 @@ static int digsig_verify_rsa(struct key *key,
int err = -EINVAL;
unsigned long len;
unsigned long mlen, mblen;
- unsigned nret, l;
+ unsigned int l;
int head, i;
unsigned char *out1 = NULL;
const char *m;
- MPI in = NULL, res = NULL, pkey[2];
+ MPI pkey[2];
uint8_t *p, *datap;
const uint8_t *endp;
const struct user_key_payload *ukp;
@@ -112,7 +112,7 @@ static int digsig_verify_rsa(struct key *key,
pkey[i] = mpi_read_from_buffer(datap, &remaining);
if (IS_ERR(pkey[i])) {
err = PTR_ERR(pkey[i]);
- goto err;
+ goto free_keys;
}
datap += remaining;
}
@@ -122,57 +122,63 @@ static int digsig_verify_rsa(struct key *key,
if (mlen == 0) {
err = -EINVAL;
- goto err;
+ goto free_keys;
}
err = -ENOMEM;
out1 = kzalloc(mlen, GFP_KERNEL);
if (!out1)
- goto err;
+ goto free_keys;
- nret = siglen;
- in = mpi_read_from_buffer(sig, &nret);
- if (IS_ERR(in)) {
- err = PTR_ERR(in);
- goto err;
- }
+ {
+ unsigned int nret = siglen;
+ MPI in __free(mpi_free) = mpi_read_from_buffer(sig, &nret);
- res = mpi_alloc(mpi_get_nlimbs(in) * 2);
- if (!res)
- goto err;
+ if (IS_ERR(in)) {
+ err = PTR_ERR(in);
+ goto in_exit;
+ }
- err = mpi_powm(res, in, pkey[1], pkey[0]);
- if (err)
- goto err;
+ {
+ MPI res __free(mpi_free) = mpi_alloc(mpi_get_nlimbs(in) * 2);
- if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
- err = -EINVAL;
- goto err;
- }
+ if (!res)
+ goto res_exit;
- p = mpi_get_buffer(res, &l, NULL);
- if (!p) {
- err = -EINVAL;
- goto err;
- }
+ err = mpi_powm(res, in, pkey[1], pkey[0]);
+ if (err)
+ goto res_exit;
- len = mlen;
- head = len - l;
- memset(out1, 0, head);
- memcpy(out1 + head, p, l);
+ if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
+ err = -EINVAL;
+ goto res_exit;
+ }
- kfree(p);
+ p = mpi_get_buffer(res, &l, NULL);
+ if (!p) {
+ err = -EINVAL;
+ goto res_exit;
+ }
- m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
+ len = mlen;
+ head = len - l;
+ memset(out1, 0, head);
+ memcpy(out1 + head, p, l);
- if (!m || len != hlen || memcmp(m, h, hlen))
- err = -EINVAL;
+ kfree(p);
+
+ m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
+
+ if (!m || len != hlen || memcmp(m, h, hlen))
+ err = -EINVAL;
+res_exit:
+ }
+in_exit:
+ }
-err:
- mpi_free(in);
- mpi_free(res);
kfree(out1);
+free_keys:
while (--i >= 0)
mpi_free(pkey[i]);
err1:
--
2.46.1
^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa()
2024-10-12 15:08 ` [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa() Markus Elfring
@ 2024-10-15 21:27 ` kernel test robot
2024-10-16 11:21 ` kernel test robot
1 sibling, 0 replies; 16+ messages in thread
From: kernel test robot @ 2024-10-15 21:27 UTC (permalink / raw)
To: Markus Elfring, linux-crypto, kernel-janitors, Andrew Morton,
Herbert Xu, Peter Zijlstra
Cc: llvm, oe-kbuild-all, Linux Memory Management List, LKML
Hi Markus,
kernel test robot noticed the following build warnings:
[auto build test WARNING on akpm-mm/mm-nonmm-unstable]
[also build test WARNING on herbert-crypto-2.6/master herbert-cryptodev-2.6/master linus/master v6.12-rc3 next-20241015]
[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/Markus-Elfring/crypto-lib-mpi-Extend-support-for-scope-based-resource-management/20241012-231156
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-nonmm-unstable
patch link: https://lore.kernel.org/r/300a0376-f003-4862-bb16-7e004733c9c1%40web.de
patch subject: [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa()
config: arm-randconfig-002-20241016 (https://download.01.org/0day-ci/archive/20241016/202410160438.SOIZeFku-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 70e0a7e7e6a8541bcc46908c592eed561850e416)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241016/202410160438.SOIZeFku-lkp@intel.com/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 <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410160438.SOIZeFku-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from lib/digsig.c:25:
In file included from include/linux/mpi.h:21:
In file included from include/linux/scatterlist.h:8:
In file included from include/linux/mm.h:2213:
include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
>> lib/digsig.c:176:3: warning: label at end of compound statement is a C23 extension [-Wc23-extensions]
176 | }
| ^
lib/digsig.c:178:2: warning: label at end of compound statement is a C23 extension [-Wc23-extensions]
178 | }
| ^
3 warnings generated.
vim +176 lib/digsig.c
16
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/key.h>
21 #include <linux/crypto.h>
22 #include <crypto/hash.h>
23 #include <crypto/sha1.h>
24 #include <keys/user-type.h>
> 25 #include <linux/mpi.h>
26 #include <linux/digsig.h>
27
28 static struct crypto_shash *shash;
29
30 static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
31 unsigned long msglen,
32 unsigned long modulus_bitlen,
33 unsigned long *outlen)
34 {
35 unsigned long modulus_len, ps_len, i;
36
37 modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0);
38
39 /* test message size */
40 if ((msglen > modulus_len) || (modulus_len < 11))
41 return NULL;
42
43 /* separate encoded message */
44 if (msg[0] != 0x00 || msg[1] != 0x01)
45 return NULL;
46
47 for (i = 2; i < modulus_len - 1; i++)
48 if (msg[i] != 0xFF)
49 break;
50
51 /* separator check */
52 if (msg[i] != 0)
53 /* There was no octet with hexadecimal value 0x00
54 to separate ps from m. */
55 return NULL;
56
57 ps_len = i - 2;
58
59 *outlen = (msglen - (2 + ps_len + 1));
60
61 return msg + 2 + ps_len + 1;
62 }
63
64 /*
65 * RSA Signature verification with public key
66 */
67 static int digsig_verify_rsa(struct key *key,
68 const char *sig, int siglen,
69 const char *h, int hlen)
70 {
71 int err = -EINVAL;
72 unsigned long len;
73 unsigned long mlen, mblen;
74 unsigned int l;
75 int head, i;
76 unsigned char *out1 = NULL;
77 const char *m;
78 MPI pkey[2];
79 uint8_t *p, *datap;
80 const uint8_t *endp;
81 const struct user_key_payload *ukp;
82 struct pubkey_hdr *pkh;
83
84 down_read(&key->sem);
85 ukp = user_key_payload_locked(key);
86
87 if (!ukp) {
88 /* key was revoked before we acquired its semaphore */
89 err = -EKEYREVOKED;
90 goto err1;
91 }
92
93 if (ukp->datalen < sizeof(*pkh))
94 goto err1;
95
96 pkh = (struct pubkey_hdr *)ukp->data;
97
98 if (pkh->version != 1)
99 goto err1;
100
101 if (pkh->algo != PUBKEY_ALGO_RSA)
102 goto err1;
103
104 if (pkh->nmpi != 2)
105 goto err1;
106
107 datap = pkh->mpi;
108 endp = ukp->data + ukp->datalen;
109
110 for (i = 0; i < pkh->nmpi; i++) {
111 unsigned int remaining = endp - datap;
112 pkey[i] = mpi_read_from_buffer(datap, &remaining);
113 if (IS_ERR(pkey[i])) {
114 err = PTR_ERR(pkey[i]);
115 goto free_keys;
116 }
117 datap += remaining;
118 }
119
120 mblen = mpi_get_nbits(pkey[0]);
121 mlen = DIV_ROUND_UP(mblen, 8);
122
123 if (mlen == 0) {
124 err = -EINVAL;
125 goto free_keys;
126 }
127
128 err = -ENOMEM;
129
130 out1 = kzalloc(mlen, GFP_KERNEL);
131 if (!out1)
132 goto free_keys;
133
134 {
135 unsigned int nret = siglen;
136 MPI in __free(mpi_free) = mpi_read_from_buffer(sig, &nret);
137
138 if (IS_ERR(in)) {
139 err = PTR_ERR(in);
140 goto in_exit;
141 }
142
143 {
144 MPI res __free(mpi_free) = mpi_alloc(mpi_get_nlimbs(in) * 2);
145
146 if (!res)
147 goto res_exit;
148
149 err = mpi_powm(res, in, pkey[1], pkey[0]);
150 if (err)
151 goto res_exit;
152
153 if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
154 err = -EINVAL;
155 goto res_exit;
156 }
157
158 p = mpi_get_buffer(res, &l, NULL);
159 if (!p) {
160 err = -EINVAL;
161 goto res_exit;
162 }
163
164 len = mlen;
165 head = len - l;
166 memset(out1, 0, head);
167 memcpy(out1 + head, p, l);
168
169 kfree(p);
170
171 m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
172
173 if (!m || len != hlen || memcmp(m, h, hlen))
174 err = -EINVAL;
175 res_exit:
> 176 }
177 in_exit:
178 }
179
180 kfree(out1);
181 free_keys:
182 while (--i >= 0)
183 mpi_free(pkey[i]);
184 err1:
185 up_read(&key->sem);
186
187 return err;
188 }
189
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa()
2024-10-12 15:08 ` [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa() Markus Elfring
2024-10-15 21:27 ` kernel test robot
@ 2024-10-16 11:21 ` kernel test robot
1 sibling, 0 replies; 16+ messages in thread
From: kernel test robot @ 2024-10-16 11:21 UTC (permalink / raw)
To: Markus Elfring, linux-crypto, kernel-janitors, Andrew Morton,
Herbert Xu, Peter Zijlstra
Cc: oe-kbuild-all, Linux Memory Management List, LKML
Hi Markus,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-nonmm-unstable]
[also build test ERROR on herbert-crypto-2.6/master herbert-cryptodev-2.6/master linus/master v6.12-rc3 next-20241016]
[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/Markus-Elfring/crypto-lib-mpi-Extend-support-for-scope-based-resource-management/20241012-231156
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-nonmm-unstable
patch link: https://lore.kernel.org/r/300a0376-f003-4862-bb16-7e004733c9c1%40web.de
patch subject: [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa()
config: hexagon-randconfig-r064-20241016 (https://download.01.org/0day-ci/archive/20241016/202410161914.lY62TWL3-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241016/202410161914.lY62TWL3-lkp@intel.com/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 <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410161914.lY62TWL3-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from lib/digsig.c:25:
In file included from include/linux/mpi.h:21:
In file included from include/linux/scatterlist.h:9:
In file included from arch/hexagon/include/asm/io.h:328:
include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from lib/digsig.c:25:
In file included from include/linux/mpi.h:21:
In file included from include/linux/scatterlist.h:9:
In file included from arch/hexagon/include/asm/io.h:328:
include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from lib/digsig.c:25:
In file included from include/linux/mpi.h:21:
In file included from include/linux/scatterlist.h:9:
In file included from arch/hexagon/include/asm/io.h:328:
include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
>> lib/digsig.c:176:3: error: expected statement
}
^
lib/digsig.c:178:2: error: expected statement
}
^
6 warnings and 2 errors generated.
vim +176 lib/digsig.c
63
64 /*
65 * RSA Signature verification with public key
66 */
67 static int digsig_verify_rsa(struct key *key,
68 const char *sig, int siglen,
69 const char *h, int hlen)
70 {
71 int err = -EINVAL;
72 unsigned long len;
73 unsigned long mlen, mblen;
74 unsigned int l;
75 int head, i;
76 unsigned char *out1 = NULL;
77 const char *m;
78 MPI pkey[2];
79 uint8_t *p, *datap;
80 const uint8_t *endp;
81 const struct user_key_payload *ukp;
82 struct pubkey_hdr *pkh;
83
84 down_read(&key->sem);
85 ukp = user_key_payload_locked(key);
86
87 if (!ukp) {
88 /* key was revoked before we acquired its semaphore */
89 err = -EKEYREVOKED;
90 goto err1;
91 }
92
93 if (ukp->datalen < sizeof(*pkh))
94 goto err1;
95
96 pkh = (struct pubkey_hdr *)ukp->data;
97
98 if (pkh->version != 1)
99 goto err1;
100
101 if (pkh->algo != PUBKEY_ALGO_RSA)
102 goto err1;
103
104 if (pkh->nmpi != 2)
105 goto err1;
106
107 datap = pkh->mpi;
108 endp = ukp->data + ukp->datalen;
109
110 for (i = 0; i < pkh->nmpi; i++) {
111 unsigned int remaining = endp - datap;
112 pkey[i] = mpi_read_from_buffer(datap, &remaining);
113 if (IS_ERR(pkey[i])) {
114 err = PTR_ERR(pkey[i]);
115 goto free_keys;
116 }
117 datap += remaining;
118 }
119
120 mblen = mpi_get_nbits(pkey[0]);
121 mlen = DIV_ROUND_UP(mblen, 8);
122
123 if (mlen == 0) {
124 err = -EINVAL;
125 goto free_keys;
126 }
127
128 err = -ENOMEM;
129
130 out1 = kzalloc(mlen, GFP_KERNEL);
131 if (!out1)
132 goto free_keys;
133
134 {
135 unsigned int nret = siglen;
136 MPI in __free(mpi_free) = mpi_read_from_buffer(sig, &nret);
137
138 if (IS_ERR(in)) {
139 err = PTR_ERR(in);
140 goto in_exit;
141 }
142
143 {
144 MPI res __free(mpi_free) = mpi_alloc(mpi_get_nlimbs(in) * 2);
145
146 if (!res)
147 goto res_exit;
148
149 err = mpi_powm(res, in, pkey[1], pkey[0]);
150 if (err)
151 goto res_exit;
152
153 if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
154 err = -EINVAL;
155 goto res_exit;
156 }
157
158 p = mpi_get_buffer(res, &l, NULL);
159 if (!p) {
160 err = -EINVAL;
161 goto res_exit;
162 }
163
164 len = mlen;
165 head = len - l;
166 memset(out1, 0, head);
167 memcpy(out1 + head, p, l);
168
169 kfree(p);
170
171 m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
172
173 if (!m || len != hlen || memcmp(m, h, hlen))
174 err = -EINVAL;
175 res_exit:
> 176 }
177 in_exit:
178 }
179
180 kfree(out1);
181 free_keys:
182 while (--i >= 0)
183 mpi_free(pkey[i]);
184 err1:
185 up_read(&key->sem);
186
187 return err;
188 }
189
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v3 3/3] lib/digsig: Use scope-based resource management for two variables in digsig_verify_rsa()
2024-10-12 15:00 ` [PATCH v3 0/3] lib: Extending " Markus Elfring
2024-10-12 15:05 ` [PATCH v3 1/3] crypto: lib/mpi - Extend " Markus Elfring
2024-10-12 15:08 ` [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa() Markus Elfring
@ 2024-10-12 15:10 ` Markus Elfring
2 siblings, 0 replies; 16+ messages in thread
From: Markus Elfring @ 2024-10-12 15:10 UTC (permalink / raw)
To: linux-crypto, kernel-janitors, Andrew Morton, Herbert Xu,
Peter Zijlstra
Cc: LKML
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 12 Oct 2024 15:28:22 +0200
Scope-based resource management became supported for some
programming interfaces by contributions of Peter Zijlstra on 2023-05-26.
See also the commit 54da6a0924311c7cf5015533991e44fb8eb12773 ("locking:
Introduce __cleanup() based infrastructure").
* Thus use the attribute “__free(kfree)”.
* Reduce the scopes for the local variables “out1” and “p”.
* Omit explicit kfree() calls accordingly.
* Add a jump target.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
V3:
Further adjustments were provided for the demonstration of an evolving
programming interface.
lib/digsig.c | 87 +++++++++++++++++++++++++---------------------------
1 file changed, 42 insertions(+), 45 deletions(-)
diff --git a/lib/digsig.c b/lib/digsig.c
index 2481120094ab..1a24677af643 100644
--- a/lib/digsig.c
+++ b/lib/digsig.c
@@ -73,10 +73,9 @@ static int digsig_verify_rsa(struct key *key,
unsigned long mlen, mblen;
unsigned int l;
int head, i;
- unsigned char *out1 = NULL;
const char *m;
MPI pkey[2];
- uint8_t *p, *datap;
+ uint8_t *datap;
const uint8_t *endp;
const struct user_key_payload *ukp;
struct pubkey_hdr *pkh;
@@ -126,58 +125,56 @@ static int digsig_verify_rsa(struct key *key,
}
err = -ENOMEM;
-
- out1 = kzalloc(mlen, GFP_KERNEL);
- if (!out1)
- goto free_keys;
-
{
- unsigned int nret = siglen;
- MPI in __free(mpi_free) = mpi_read_from_buffer(sig, &nret);
-
- if (IS_ERR(in)) {
- err = PTR_ERR(in);
- goto in_exit;
- }
+ unsigned char *out1 __free(kfree) = kzalloc(mlen, GFP_KERNEL);
+ if (out1)
{
- MPI res __free(mpi_free) = mpi_alloc(mpi_get_nlimbs(in) * 2);
-
- if (!res)
- goto res_exit;
-
- err = mpi_powm(res, in, pkey[1], pkey[0]);
- if (err)
- goto res_exit;
-
- if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
- err = -EINVAL;
- goto res_exit;
- }
+ unsigned int nret = siglen;
+ MPI in __free(mpi_free) = mpi_read_from_buffer(sig, &nret);
- p = mpi_get_buffer(res, &l, NULL);
- if (!p) {
- err = -EINVAL;
- goto res_exit;
+ if (IS_ERR(in)) {
+ err = PTR_ERR(in);
+ goto in_exit;
}
- len = mlen;
- head = len - l;
- memset(out1, 0, head);
- memcpy(out1 + head, p, l);
-
- kfree(p);
-
- m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
-
- if (!m || len != hlen || memcmp(m, h, hlen))
- err = -EINVAL;
+ {
+ MPI res __free(mpi_free) = mpi_alloc(mpi_get_nlimbs(in) * 2);
+
+ if (!res)
+ goto res_exit;
+
+ err = mpi_powm(res, in, pkey[1], pkey[0]);
+ if (err)
+ goto res_exit;
+
+ if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
+ err = -EINVAL;
+ goto res_exit;
+ }
+
+ {
+ uint8_t *p __free(kfree) = mpi_get_buffer(res, &l, NULL);
+
+ if (!p) {
+ err = -EINVAL;
+ goto p_exit;
+ }
+
+ len = mlen;
+ head = len - l;
+ memset(out1, 0, head);
+ memcpy(out1 + head, p, l);
+ m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
+ if (!m || len != hlen || memcmp(m, h, hlen))
+ err = -EINVAL;
+p_exit:
+ }
res_exit:
- }
+ }
in_exit:
+ }
}
-
- kfree(out1);
free_keys:
while (--i >= 0)
mpi_free(pkey[i]);
--
2.46.1
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