2020-06-01 13:32:51

by Roberto Sassu

[permalink] [raw]
Subject: RE: [linux-next:master 2476/12912] security/integrity/ima/ima_crypto.c:575:12: warning: stack frame size of 1152 bytes in function 'ima_calc_field_array_hash_tfm'

> From: kbuild test robot [mailto:[email protected]]
> security/integrity/ima/ima_crypto.c:575:12: warning: stack frame size of
> 1152 bytes in function 'ima_calc_field_array_hash_tfm'
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> master
> head: b0523c7b1c9d0edcd6c0fe6d2cb558a9ad5c60a8
> commit: 1ea973df6e2166d1a576cabe5d08925d3261ff9d [2476/12912] ima:
> Calculate and extend PCR with digests in ima_template_entry
> config: mips-randconfig-r012-20200526 (attached as .config)
> compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project
> 3393cc4cebf9969db94dc424b7a2b6195589c33b)
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-
> tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install mips cross compiling tool for clang build
> # apt-get install binutils-mips-linux-gnu
> git checkout 1ea973df6e2166d1a576cabe5d08925d3261ff9d
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
> ARCH=mips
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kbuild test robot <[email protected]>
>
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
>
> >> security/integrity/ima/ima_crypto.c:575:12: warning: stack frame size of
> 1152 bytes in function 'ima_calc_field_array_hash_tfm' [-Wframe-larger-
> than=]
> static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
> ^
> 1 warning generated.

It seems that the problem is caused by the definition of
SHASH_DESC_ON_STACK:

+#define SHASH_DESC_ON_STACK(shash, ctx) \
+ char __##shash##_desc[sizeof(struct shash_desc) + \
+ crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \

CRYPTO_MINALIGN_ATTR is equal to __attribute__ ((__aligned__(128))).

It is defined in include/linux/crypto.h:

#define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN

#define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))


I found in include/linux/slab.h:

#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
#else
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
#endif

If I set ARCH_KMALLOC_MINALIGN to __alignof__(unsigned long long)
the warning message disappears.

Herbert, can you please have a look?

Thanks

Roberto

HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Li Peng, Li Jian, Shi Yanli

> vim +/ima_calc_field_array_hash_tfm +575
> security/integrity/ima/ima_crypto.c
>
> 3bcced39ea7d1b0 Dmitry Kasatkin 2014-02-26 571
> 3323eec921efd81 Mimi Zohar 2009-02-04 572 /*
> a71dc65d30a4724 Roberto Sassu 2013-06-07 573 * Calculate the hash of
> template data
> 3323eec921efd81 Mimi Zohar 2009-02-04 574 */
> a71dc65d30a4724 Roberto Sassu 2013-06-07 @575 static int
> ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
> 7ca79645a1f8837 Roberto Sassu 2020-03-25 576
> struct ima_template_entry *entry,
> 6d94809af6b0830 Roberto Sassu 2020-03-25 577
> int tfm_idx)
> 3323eec921efd81 Mimi Zohar 2009-02-04 578 {
> 6d94809af6b0830 Roberto Sassu 2020-03-25 579
> SHASH_DESC_ON_STACK(shash, ima_algo_array[tfm_idx].tfm);
> 7ca79645a1f8837 Roberto Sassu 2020-03-25 580 struct
> ima_template_desc *td = entry->template_desc;
> 7ca79645a1f8837 Roberto Sassu 2020-03-25 581 int num_fields =
> entry->template_desc->num_fields;
> a71dc65d30a4724 Roberto Sassu 2013-06-07 582 int rc, i;
> 3323eec921efd81 Mimi Zohar 2009-02-04 583
> 6d94809af6b0830 Roberto Sassu 2020-03-25 584 shash->tfm =
> ima_algo_array[tfm_idx].tfm;
> 3323eec921efd81 Mimi Zohar 2009-02-04 585
> 357aabed626fe3f Behan Webster 2014-04-04 586 rc =
> crypto_shash_init(shash);
> a71dc65d30a4724 Roberto Sassu 2013-06-07 587 if (rc != 0)
> a71dc65d30a4724 Roberto Sassu 2013-06-07 588 return rc;
> a71dc65d30a4724 Roberto Sassu 2013-06-07 589
> a71dc65d30a4724 Roberto Sassu 2013-06-07 590 for (i = 0; i <
> num_fields; i++) {
> e3b64c268b485f5 Roberto Sassu 2014-02-03 591 u8
> buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };
> e3b64c268b485f5 Roberto Sassu 2014-02-03 592 u8
> *data_to_hash = field_data[i].data;
> e3b64c268b485f5 Roberto Sassu 2014-02-03 593 u32 datalen
> = field_data[i].len;
> 98e1d55d033eed2 Andreas Steffen 2016-12-19 594 u32
> datalen_to_hash =
> 98e1d55d033eed2 Andreas Steffen 2016-12-19 595
> !ima_canonical_fmt ? datalen : cpu_to_le32(datalen);
> e3b64c268b485f5 Roberto Sassu 2014-02-03 596
> b6f8f16f41d9286 Roberto Sassu 2013-11-08 597 if
> (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
> 357aabed626fe3f Behan Webster 2014-04-04 598 rc =
> crypto_shash_update(shash,
> 98e1d55d033eed2 Andreas Steffen 2016-12-19 599
> (const u8 *) &datalen_to_hash,
> 98e1d55d033eed2 Andreas Steffen 2016-12-19 600
> sizeof(datalen_to_hash));
> b6f8f16f41d9286 Roberto Sassu 2013-11-08 601 if (rc)
> b6f8f16f41d9286 Roberto Sassu 2013-11-08 602
> break;
> e3b64c268b485f5 Roberto Sassu 2014-02-03 603 } else if
> (strcmp(td->fields[i]->field_id, "n") == 0) {
> e3b64c268b485f5 Roberto Sassu 2014-02-03 604
> memcpy(buffer, data_to_hash, datalen);
> e3b64c268b485f5 Roberto Sassu 2014-02-03 605
> data_to_hash = buffer;
> e3b64c268b485f5 Roberto Sassu 2014-02-03 606
> datalen = IMA_EVENT_NAME_LEN_MAX + 1;
> b6f8f16f41d9286 Roberto Sassu 2013-11-08 607 }
> 357aabed626fe3f Behan Webster 2014-04-04 608 rc =
> crypto_shash_update(shash, data_to_hash, datalen);
> a71dc65d30a4724 Roberto Sassu 2013-06-07 609 if (rc)
> a71dc65d30a4724 Roberto Sassu 2013-06-07 610
> break;
> a71dc65d30a4724 Roberto Sassu 2013-06-07 611 }
> a71dc65d30a4724 Roberto Sassu 2013-06-07 612
> a71dc65d30a4724 Roberto Sassu 2013-06-07 613 if (!rc)
> 6d94809af6b0830 Roberto Sassu 2020-03-25 614 rc =
> crypto_shash_final(shash, entry->digests[tfm_idx].digest);
> a71dc65d30a4724 Roberto Sassu 2013-06-07 615
> a71dc65d30a4724 Roberto Sassu 2013-06-07 616 return rc;
> 3323eec921efd81 Mimi Zohar 2009-02-04 617 }
> 3323eec921efd81 Mimi Zohar 2009-02-04 618
>
> :::::: The code at line 575 was first introduced by commit
> :::::: a71dc65d30a472409f05d247f4eab91b14acf2f5 ima: switch to new
> template management mechanism
>
> :::::: TO: Roberto Sassu <[email protected]>
> :::::: CC: Mimi Zohar <[email protected]>
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/[email protected]