On Mon, 2024-02-19 at 22:41 -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 4f5e5092fdbf Merge tag 'net-6.8-rc5' of git://git.kernel.o.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=135ba81c180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e3dd779fba027968 > dashboard link: https://syzkaller.appspot.com/bug?extid=7bc44a489f0ef0670bd5 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/34924e0466d4/disk-4f5e5092.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/29d0b1935c61/vmlinux-4f5e5092.xz > kernel image: https://storage.googleapis.com/syzbot-assets/2e033c3d8679/bzImage-4f5e5092.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+7bc44a489f0ef0670bd5@xxxxxxxxxxxxxxxxxxxxxxxxx > > ===================================================== > BUG: KMSAN: uninit-value in ima_add_template_entry+0x52b/0x870 security/integrity/ima/ima_queue.c:172 > ima_add_template_entry+0x52b/0x870 security/integrity/ima/ima_queue.c:172 > ima_store_template security/integrity/ima/ima_api.c:122 [inline] > ima_store_measurement+0x371/0x8d0 security/integrity/ima/ima_api.c:376 > process_measurement+0x2c6e/0x3ef0 security/integrity/ima/ima_main.c:367 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > <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/0x2e80 lib/crypto/sha256.c:127 > lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline] > sha256_update+0x2fb/0x340 lib/crypto/sha256.c:136 > crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39 > crypto_shash_update+0x75/0xa0 crypto/shash.c:70 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:496 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1816/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > Uninit was stored to memory at: > sha256_transform lib/crypto/sha256.c:117 [inline] > sha256_transform_blocks+0x2dbf/0x2e80 lib/crypto/sha256.c:127 > lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline] > sha256_update+0x2fb/0x340 lib/crypto/sha256.c:136 > crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39 > crypto_shash_update+0x75/0xa0 crypto/shash.c:70 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:496 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1816/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > 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+0xf33/0x2e80 lib/crypto/sha256.c:127 > lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline] > sha256_update+0x2fb/0x340 lib/crypto/sha256.c:136 > crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39 > crypto_shash_update+0x75/0xa0 crypto/shash.c:70 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:496 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1816/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > 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/0x2e80 lib/crypto/sha256.c:127 > lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline] > sha256_update+0x2fb/0x340 lib/crypto/sha256.c:136 > crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39 > crypto_shash_update+0x75/0xa0 crypto/shash.c:70 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:496 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1816/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > 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+0xfb5/0x2e80 lib/crypto/sha256.c:127 > lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline] > sha256_update+0x2fb/0x340 lib/crypto/sha256.c:136 > crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39 > crypto_shash_update+0x75/0xa0 crypto/shash.c:70 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:496 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1816/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > 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+0x2c35/0x2e80 lib/crypto/sha256.c:127 > lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline] > sha256_update+0x2fb/0x340 lib/crypto/sha256.c:136 > crypto_sha256_update+0x37/0x60 crypto/sha256_generic.c:39 > crypto_shash_update+0x75/0xa0 crypto/shash.c:70 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:496 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1816/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b If I understood what the report is saying (ima_calc_file_hash_tfm()): while (offset < i_size) { int rbuf_len; rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE); if (rbuf_len < 0) { rc = rbuf_len; break; } if (rbuf_len == 0) { /* unexpected EOF */ rc = -EINVAL; break; } offset += rbuf_len; rc = crypto_shash_update(shash, rbuf, rbuf_len); if (rc) break; } we are reading a non-initialized rbuf, which should not happen because integrity_kernel_read() returned a positive value (success). The other information we have is that the filesystem in question uses generic_file_read_iter() as read_iter method. I would add the VFS people in CC, in case they have some ideas. Thanks Roberto > Uninit was stored to memory at: > memcpy_to_iter lib/iov_iter.c:65 [inline] > iterate_kvec include/linux/iov_iter.h:85 [inline] > iterate_and_advance2 include/linux/iov_iter.h:251 [inline] > iterate_and_advance include/linux/iov_iter.h:271 [inline] > _copy_to_iter+0x125a/0x2520 lib/iov_iter.c:186 > copy_page_to_iter+0x419/0x870 lib/iov_iter.c:381 > copy_folio_to_iter include/linux/uio.h:181 [inline] > filemap_read+0xbf4/0x14d0 mm/filemap.c:2654 > generic_file_read_iter+0x136/0xad0 mm/filemap.c:2784 > __kernel_read+0x724/0xce0 fs/read_write.c:434 > integrity_kernel_read+0x77/0x90 security/integrity/iint.c:221 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1743/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > Uninit was created at: > __alloc_pages+0x9a6/0xe00 mm/page_alloc.c:4590 > alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133 > alloc_pages mm/mempolicy.c:2204 [inline] > folio_alloc+0x1da/0x380 mm/mempolicy.c:2211 > filemap_alloc_folio+0xa5/0x430 mm/filemap.c:975 > page_cache_ra_unbounded+0x2cc/0x960 mm/readahead.c:247 > do_page_cache_ra mm/readahead.c:299 [inline] > page_cache_ra_order+0xe31/0xee0 mm/readahead.c:544 > ondemand_readahead+0x157d/0x1750 mm/readahead.c:666 > page_cache_sync_ra+0x724/0x760 mm/readahead.c:693 > page_cache_sync_readahead include/linux/pagemap.h:1300 [inline] > filemap_get_pages+0x4c4/0x2bd0 mm/filemap.c:2498 > filemap_read+0x59e/0x14d0 mm/filemap.c:2594 > generic_file_read_iter+0x136/0xad0 mm/filemap.c:2784 > __kernel_read+0x724/0xce0 fs/read_write.c:434 > integrity_kernel_read+0x77/0x90 security/integrity/iint.c:221 > ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline] > ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] > ima_calc_file_hash+0x1743/0x3cc0 security/integrity/ima/ima_crypto.c:573 > ima_collect_measurement+0x44d/0xdd0 security/integrity/ima/ima_api.c:290 > process_measurement+0x2936/0x3ef0 security/integrity/ima/ima_main.c:359 > ima_file_check+0xb3/0x100 security/integrity/ima/ima_main.c:557 > do_open fs/namei.c:3643 [inline] > path_openat+0x4d09/0x5ad0 fs/namei.c:3798 > do_filp_open+0x20d/0x590 fs/namei.c:3825 > do_sys_openat2+0x1bf/0x2f0 fs/open.c:1404 > do_sys_open fs/open.c:1419 [inline] > __do_sys_open fs/open.c:1427 [inline] > __se_sys_open fs/open.c:1423 [inline] > __x64_sys_open+0x275/0x2d0 fs/open.c:1423 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > CPU: 1 PID: 9243 Comm: syz-executor.3 Not tainted 6.8.0-rc4-syzkaller-00180-g4f5e5092fdbf #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 > ===================================================== > > > --- > 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@xxxxxxxxxxxxxxxx. > > 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 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