On Thu, Jun 07, 2018 at 06:07:02AM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11289b9f800000 > kernel config: https://syzkaller.appspot.com/x/.config?x=2e1a31e8576e013a > dashboard link: https://syzkaller.appspot.com/bug?extid=29d17b7898b41ee120a5 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=146fbb9f800000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=119de79f800000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+29d17b7898b41ee120a5@xxxxxxxxxxxxxxxxxxxxxxxxx > > random: sshd: uninitialized urandom read (32 bytes read) > random: sshd: uninitialized urandom read (32 bytes read) > random: sshd: uninitialized urandom read (32 bytes read) > random: sshd: uninitialized urandom read (32 bytes read) > ================================================================== > BUG: KASAN: slab-out-of-bounds in put_unaligned_be32 > include/linux/unaligned/access_ok.h:60 [inline] > BUG: KASAN: slab-out-of-bounds in sha256_base_finish > include/crypto/sha256_base.h:124 [inline] > BUG: KASAN: slab-out-of-bounds in sha256_finup+0x4bf/0x540 > arch/x86/crypto/sha256_ssse3_glue.c:80 > Write of size 4 at addr ffff8801b39b2ca0 by task syz-executor364/4468 > > CPU: 0 PID: 4468 Comm: syz-executor364 Not tainted 4.17.0+ #88 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1b9/0x294 lib/dump_stack.c:113 > print_address_description+0x6c/0x20b mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 > __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437 > put_unaligned_be32 include/linux/unaligned/access_ok.h:60 [inline] > sha256_base_finish include/crypto/sha256_base.h:124 [inline] > sha256_finup+0x4bf/0x540 arch/x86/crypto/sha256_ssse3_glue.c:80 > sha256_avx_finup arch/x86/crypto/sha256_ssse3_glue.c:161 [inline] > sha256_avx_final+0x28/0x30 arch/x86/crypto/sha256_ssse3_glue.c:166 > crypto_shash_final+0x104/0x260 crypto/shash.c:152 > kdf_ctr security/keys/dh.c:186 [inline] > keyctl_dh_compute_kdf security/keys/dh.c:217 [inline] > __keyctl_dh_compute+0x1184/0x1bc0 security/keys/dh.c:389 > keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425 > __do_sys_keyctl security/keys/keyctl.c:1741 [inline] > __se_sys_keyctl security/keys/keyctl.c:1637 [inline] > __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x440019 > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff > 0f 83 6b 45 00 00 c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffcb5a0db48 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa > RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440019 > RDX: 0000000020a53ffb RSI: 0000000020000100 RDI: 0000000000000017 > RBP: 00000000006ca018 R08: 0000000020c61fc8 R09: 00000000004002c8 > R10: 0000000000000005 R11: 0000000000000217 R12: 0000000000401940 > R13: 00000000004019d0 R14: 0000000000000000 R15: 0000000000000000 > > Allocated by task 4468: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 > __do_kmalloc mm/slab.c:3718 [inline] > __kmalloc+0x14e/0x760 mm/slab.c:3727 > kmalloc include/linux/slab.h:518 [inline] > keyctl_dh_compute_kdf security/keys/dh.c:211 [inline] > __keyctl_dh_compute+0xfe9/0x1bc0 security/keys/dh.c:389 > keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425 > __do_sys_keyctl security/keys/keyctl.c:1741 [inline] > __se_sys_keyctl security/keys/keyctl.c:1637 [inline] > __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 2842: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > __cache_free mm/slab.c:3498 [inline] > kfree+0xd9/0x260 mm/slab.c:3813 > single_release+0x8f/0xb0 fs/seq_file.c:609 > __fput+0x353/0x890 fs/file_table.c:209 > ____fput+0x15/0x20 fs/file_table.c:243 > task_work_run+0x1e4/0x290 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:192 [inline] > exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8801b39b2c80 > which belongs to the cache kmalloc-32 of size 32 > The buggy address is located 0 bytes to the right of > 32-byte region [ffff8801b39b2c80, ffff8801b39b2ca0) > The buggy address belongs to the page: > page:ffffea0006ce6c80 count:1 mapcount:0 mapping:ffff8801b39b2000 > index:0xffff8801b39b2fc1 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffff8801b39b2000 ffff8801b39b2fc1 0000000100000039 > raw: ffffea00075c03a0 ffffea000764c620 ffff8801da8001c0 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801b39b2b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ffff8801b39b2c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > > ffff8801b39b2c80: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc > ^ > ffff8801b39b2d00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ffff8801b39b2d80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc > ================================================================== > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009913f4056e0cf508%40google.com. > For more options, visit https://groups.google.com/d/optout. Duplicate: #syz dup: KASAN: slab-out-of-bounds Write in sha1_finup Tentative fix is "[PATCH] dh key: fix rounding up KDF output length".
