Message-ID: <ea9222df2c7beb4fe846128833d7eeb82b0a0398.camel@huaweicloud.com>
Date: Wed, 02 Oct 2024 09:56:52 +0200
From: Roberto Sassu <roberto.sassu@...weicloud.com>
To: syzbot <syzbot+91ae49e1c1a2634d20c0@...kaller.appspotmail.com>, 
 dmitry.kasatkin@...il.com, eric.snowberg@...cle.com, jmorris@...ei.org, 
 linux-integrity@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-security-module@...r.kernel.org, paul@...l-moore.com, 
 roberto.sassu@...wei.com, serge@...lyn.com,
 syzkaller-bugs@...glegroups.com,  zohar@...ux.ibm.com, willy@...radead.org,
 Yuezhang.Mo@...y.com
Subject: Re: [syzbot] [integrity?] [lsm?] KMSAN: uninit-value in
 ima_add_template_entry (2)

On Wed, 2024-10-02 at 00:26 -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    ad46e8f95e93 Merge tag 'pm-6.12-rc1-2' of git://git.kernel..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1177d507980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=85d8f50d88ddf2a
> dashboard link: https://syzkaller.appspot.com/bug?extid=91ae49e1c1a2634d20c0
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=106026a9980000

At a first look, it seems that IMA is measuring an uninitialized buffer
from exfat.

Uninit was created at:
 __alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4756
 alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2265
 alloc_pages_noprof mm/mempolicy.c:2345 [inline]
 folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2352
 filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1010
 __filemap_get_folio+0xac4/0x1550 mm/filemap.c:1952
 block_write_begin+0x6e/0x2b0 fs/buffer.c:2226

I saw there are some relevant commits in this area from the latest PRs.

Matthew, Yuezhang, could you please have a look?

Thanks!

Roberto

> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/265feec46ffa/disk-ad46e8f9.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/d0f41ea693d3/vmlinux-ad46e8f9.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/45082d33d192/bzImage-ad46e8f9.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/5b5b4e4b4ff9/mount_0.gz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+91ae49e1c1a2634d20c0@...kaller.appspotmail.com
> 
> =====================================================
> BUG: KMSAN: uninit-value in ima_add_template_entry+0x52b/0x880 security/integrity/ima/ima_queue.c:172
>  ima_add_template_entry+0x52b/0x880 security/integrity/ima/ima_queue.c:172
>  ima_store_template security/integrity/ima/ima_api.c:122 [inline]
>  ima_store_measurement+0x36b/0x8d0 security/integrity/ima/ima_api.c:383
>  process_measurement+0x2c11/0x3f30 security/integrity/ima/ima_main.c:380
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> <Zero or more stacks not recorded to save memory>
> 
> Uninit was stored to memory at:
>  sha256_transform lib/crypto/sha256.c:117 [inline]
>  sha256_transform_blocks+0x2dbf/0x2e90 lib/crypto/sha256.c:127
>  lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
>  sha256_update+0x2ff/0x340 lib/crypto/sha256.c:136
>  crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39
>  crypto_shash_update+0x79/0xa0 crypto/shash.c:52
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:491 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1804/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was stored to memory at:
>  sha256_transform lib/crypto/sha256.c:117 [inline]
>  sha256_transform_blocks+0x2dbf/0x2e90 lib/crypto/sha256.c:127
>  lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
>  sha256_update+0x2ff/0x340 lib/crypto/sha256.c:136
>  crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39
>  crypto_shash_update+0x79/0xa0 crypto/shash.c:52
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:491 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1804/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was stored to memory at:
>  BLEND_OP lib/crypto/sha256.c:61 [inline]
>  sha256_transform lib/crypto/sha256.c:91 [inline]
>  sha256_transform_blocks+0xf33/0x2e90 lib/crypto/sha256.c:127
>  lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
>  sha256_update+0x2ff/0x340 lib/crypto/sha256.c:136
>  crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39
>  crypto_shash_update+0x79/0xa0 crypto/shash.c:52
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:491 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1804/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was stored to memory at:
>  BLEND_OP lib/crypto/sha256.c:61 [inline]
>  sha256_transform lib/crypto/sha256.c:92 [inline]
>  sha256_transform_blocks+0xf7d/0x2e90 lib/crypto/sha256.c:127
>  lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
>  sha256_update+0x2ff/0x340 lib/crypto/sha256.c:136
>  crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39
>  crypto_shash_update+0x79/0xa0 crypto/shash.c:52
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:491 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1804/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was stored to memory at:
>  BLEND_OP lib/crypto/sha256.c:61 [inline]
>  sha256_transform lib/crypto/sha256.c:93 [inline]
>  sha256_transform_blocks+0xfb5/0x2e90 lib/crypto/sha256.c:127
>  lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
>  sha256_update+0x2ff/0x340 lib/crypto/sha256.c:136
>  crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39
>  crypto_shash_update+0x79/0xa0 crypto/shash.c:52
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:491 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1804/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was stored to memory at:
>  LOAD_OP lib/crypto/sha256.c:56 [inline]
>  sha256_transform lib/crypto/sha256.c:82 [inline]
>  sha256_transform_blocks+0x2c35/0x2e90 lib/crypto/sha256.c:127
>  lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
>  sha256_update+0x2ff/0x340 lib/crypto/sha256.c:136
>  crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39
>  crypto_shash_update+0x79/0xa0 crypto/shash.c:52
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:491 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1804/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was stored to memory at:
>  memcpy_to_iter lib/iov_iter.c:65 [inline]
>  iterate_kvec include/linux/iov_iter.h:86 [inline]
>  iterate_and_advance2 include/linux/iov_iter.h:306 [inline]
>  iterate_and_advance include/linux/iov_iter.h:328 [inline]
>  _copy_to_iter+0x124a/0x2b30 lib/iov_iter.c:185
>  copy_page_to_iter+0x419/0x880 lib/iov_iter.c:362
>  copy_folio_to_iter include/linux/uio.h:189 [inline]
>  filemap_read+0xc13/0x1500 mm/filemap.c:2696
>  generic_file_read_iter+0x136/0xad0 mm/filemap.c:2833
>  __kernel_read+0x726/0xd30 fs/read_write.c:527
>  integrity_kernel_read+0x77/0x90 security/integrity/iint.c:28
>  ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
>  ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
>  ima_calc_file_hash+0x1731/0x3c90 security/integrity/ima/ima_crypto.c:568
>  ima_collect_measurement+0x464/0xd20 security/integrity/ima/ima_api.c:293
>  process_measurement+0x2948/0x3f30 security/integrity/ima/ima_main.c:372
>  ima_file_check+0xb4/0x100 security/integrity/ima/ima_main.c:572
>  security_file_post_open+0xc6/0x540 security/security.c:3127
>  do_open fs/namei.c:3776 [inline]
>  path_openat+0x58cc/0x6200 fs/namei.c:3933
>  do_filp_open+0x20e/0x590 fs/namei.c:3960
>  do_sys_openat2+0x1bf/0x2f0 fs/open.c:1415
>  do_sys_open fs/open.c:1430 [inline]
>  __do_sys_open fs/open.c:1438 [inline]
>  __se_sys_open fs/open.c:1434 [inline]
>  __x64_sys_open+0x275/0x2d0 fs/open.c:1434
>  x64_sys_call+0x15a2/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:3
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Uninit was created at:
>  __alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4756
>  alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2265
>  alloc_pages_noprof mm/mempolicy.c:2345 [inline]
>  folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2352
>  filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1010
>  __filemap_get_folio+0xac4/0x1550 mm/filemap.c:1952
>  block_write_begin+0x6e/0x2b0 fs/buffer.c:2226
>  exfat_write_begin+0xfb/0x400 fs/exfat/inode.c:434
>  exfat_extend_valid_size fs/exfat/file.c:553 [inline]
>  exfat_file_write_iter+0x474/0xfb0 fs/exfat/file.c:588
>  new_sync_write fs/read_write.c:590 [inline]
>  vfs_write+0xb28/0x1540 fs/read_write.c:683
>  ksys_write+0x24f/0x4c0 fs/read_write.c:736
>  __do_sys_write fs/read_write.c:748 [inline]
>  __se_sys_write fs/read_write.c:745 [inline]
>  __x64_sys_write+0x93/0xe0 fs/read_write.c:745
>  x64_sys_call+0x306a/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:2
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> CPU: 1 UID: 0 PID: 7910 Comm: syz.2.975 Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> =====================================================
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@...glegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup

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