[syzbot] UBSAN: shift-out-of-bounds in __access_remote_vm

2 views
Skip to first unread message

syzbot

unread,
Aug 23, 2022, 2:59:29 AM8/23/22
to almaz.ale...@paragon-software.com, clang-bu...@googlegroups.com, linux-...@vger.kernel.org, linux-...@vger.kernel.org, ll...@lists.linux.dev, nat...@kernel.org, ndesau...@google.com, nt...@lists.linux.dev, syzkall...@googlegroups.com, tr...@redhat.com, vi...@zeniv.linux.org.uk
Hello,

syzbot found the following issue on:

HEAD commit: 8755ae45a9e8 Add linux-next specific files for 20220819
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=144f3023080000
kernel config: https://syzkaller.appspot.com/x/.config?x=ead6107a3bbe3c62
dashboard link: https://syzkaller.appspot.com/bug?extid=35b87c668935bb55e666
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10a5c1f3080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16e9ce85080000

The issue was bisected to:

commit 6e5be40d32fb1907285277c02e74493ed43d77fe
Author: Konstantin Komarov <almaz.ale...@paragon-software.com>
Date: Fri Aug 13 14:21:30 2021 +0000

fs/ntfs3: Add NTFS3 in fs/Kconfig and fs/Makefile

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=112f1867080000
final oops: https://syzkaller.appspot.com/x/report.txt?x=132f1867080000
console output: https://syzkaller.appspot.com/x/log.txt?x=152f1867080000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+35b87c...@syzkaller.appspotmail.com
Fixes: 6e5be40d32fb ("fs/ntfs3: Add NTFS3 in fs/Kconfig and fs/Makefile")

loop0: detected capacity change from 0 to 64
================================================================================
UBSAN: shift-out-of-bounds in fs/ntfs3/super.c:675:13
shift exponent -247 is negative
CPU: 0 PID: 3617 Comm: syz-executor807 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1521
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 3617, name: syz-executor807
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by syz-executor807/3617:
#0: ffff888022d380e0 (&type->s_umount_key#41/1){+.+.}-{3:3}, at: alloc_super+0x22e/0xb60 fs/super.c:228
irq event stamp: 4810
hardirqs last enabled at (4809): [<ffffffff816199ce>] __up_console_sem+0xae/0xc0 kernel/printk/printk.c:264
hardirqs last disabled at (4810): [<ffffffff894c1738>] dump_stack_lvl+0x2e/0x134 lib/dump_stack.c:139
softirqs last enabled at (4804): [<ffffffff81491a33>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last enabled at (4804): [<ffffffff81491a33>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
softirqs last disabled at (4789): [<ffffffff81491a33>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last disabled at (4789): [<ffffffff81491a33>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
CPU: 0 PID: 3617 Comm: syz-executor807 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0
syz-executor807[3617] cmdline: ./syz-executor807082514
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:122 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:140
__might_resched.cold+0x222/0x26b kernel/sched/core.c:9896
down_read_killable+0x75/0x490 kernel/locking/rwsem.c:1521
mmap_read_lock_killable include/linux/mmap_lock.h:126 [inline]
__access_remote_vm+0xac/0x6f0 mm/memory.c:5461
get_mm_cmdline.part.0+0x217/0x620 fs/proc/base.c:299
get_mm_cmdline fs/proc/base.c:367 [inline]
get_task_cmdline_kernel+0x1d9/0x220 fs/proc/base.c:367
dump_stack_print_cmdline.part.0+0x82/0x150 lib/dump_stack.c:61
dump_stack_print_cmdline lib/dump_stack.c:89 [inline]
dump_stack_print_info+0x185/0x190 lib/dump_stack.c:97
__dump_stack lib/dump_stack.c:121 [inline]
dump_stack_lvl+0xc1/0x134 lib/dump_stack.c:140
ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
parse_ntfs_boot_sector fs/ntfs/super.c:915 [inline]
ntfs_fill_super.cold+0x147/0x56c fs/ntfs/super.c:2792
get_tree_bdev+0x440/0x760 fs/super.c:1323
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fcec358610a
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd5a5afbf8 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd5a5afc50 RCX: 00007fcec358610a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd5a5afc10
RBP: 00007ffd5a5afc10 R08: 00007ffd5a5afc50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000020000230
R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000002
</TASK>
syz-executor807[3617] cmdline: ./syz-executor807082514
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:122 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:140
ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
parse_ntfs_boot_sector fs/ntfs/super.c:915 [inline]
ntfs_fill_super.cold+0x147/0x56c fs/ntfs/super.c:2792
get_tree_bdev+0x440/0x760 fs/super.c:1323
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fcec358610a
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd5a5afbf8 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd5a5afc50 RCX: 00007fcec358610a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd5a5afc10
RBP: 00007ffd5a5afc10 R08: 00007ffd5a5afc50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000020000230
R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000002
</TASK>
================================================================================


---
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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
Reply all
Reply to author
Forward
0 new messages