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Date:   Tue, 18 Jul 2023 03:57:43 -0700
Message-ID: <000000000000d8352e0600c0c804@google.com>
Subject: [syzbot] [hfs?] kernel BUG in hfsplus_show_options
From:   syzbot <syzbot+98d3ceb7e01269e7bf4f@syzkaller.appspotmail.com>
To:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs@googlegroups.com
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Precedence: bulk

Hello,

syzbot found the following issue on:

HEAD commit:    aeba456828b4 Add linux-next specific files for 20230718
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=111d6a62a80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e7ec534f91cfce6c
dashboard link: https://syzkaller.appspot.com/bug?extid=98d3ceb7e01269e7bf4f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15ecf646a80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1476f30aa80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/94f67a948e1d/disk-aeba4568.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9818a252eddd/vmlinux-aeba4568.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fbf9befe9bc9/bzImage-aeba4568.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/d8265d21ad1c/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+98d3ceb7e01269e7bf4f@syzkaller.appspotmail.com

memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=5032 'syz-executor324'
loop0: detected capacity change from 0 to 1024
detected buffer overflow in strnlen
------------[ cut here ]------------
kernel BUG at lib/string_helpers.c:1031!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5032 Comm: syz-executor324 Not tainted 6.5.0-rc2-next-20230718-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
RIP: 0010:fortify_panic+0x1c/0x20 lib/string_helpers.c:1031
Code: ba fd eb d7 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 23 de 65 fd 48 89 de 48 c7 c7 00 2c c8 8a e8 e4 28 49 fd <0f> 0b 66 90 f3 0f 1e fa 41 55 41 54 55 53 48 89 fb e8 fe dd 65 fd
RSP: 0018:ffffc90003a1f7b8 EFLAGS: 00010282
RAX: 0000000000000023 RBX: ffffffff8a873580 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff816aad20 RDI: 0000000000000005
RBP: ffff888019f16cb8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 1ffff92000743efa
R13: 0000000000000004 R14: ffff888078fa69c0 R15: ffffc90003a1f7f0
FS:  0000555556e72380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000456b30 CR3: 0000000079883000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 strnlen include/linux/fortify-string.h:181 [inline]
 strscpy include/linux/fortify-string.h:324 [inline]
 hfsplus_show_options+0x658/0x740 fs/hfsplus/options.c:226
 show_mountinfo+0x671/0x990 fs/proc_namespace.c:191
 seq_read_iter+0xaf0/0x1280 fs/seq_file.c:272
 call_read_iter include/linux/fs.h:1911 [inline]
 copy_splice_read+0x418/0x8f0 fs/splice.c:366
 vfs_splice_read fs/splice.c:993 [inline]
 vfs_splice_read+0x2c8/0x3b0 fs/splice.c:962
 splice_direct_to_actor+0x2a5/0xa30 fs/splice.c:1069
 do_splice_direct+0x1af/0x280 fs/splice.c:1194
 do_sendfile+0xb88/0x1390 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x1d6/0x220 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4339573a79
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff9271428 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007ffff9271430 RCX: 00007f4339573a79
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007f43395e7610 R08: 0000000000000000 R09: 65732f636f72702f
R10: 0800000080004105 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffff9271668 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fortify_panic+0x1c/0x20 lib/string_helpers.c:1031
Code: ba fd eb d7 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 23 de 65 fd 48 89 de 48 c7 c7 00 2c c8 8a e8 e4 28 49 fd <0f> 0b 66 90 f3 0f 1e fa 41 55 41 54 55 53 48 89 fb e8 fe dd 65 fd
RSP: 0018:ffffc90003a1f7b8 EFLAGS: 00010282
RAX: 0000000000000023 RBX: ffffffff8a873580 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff816aad20 RDI: 0000000000000005
RBP: ffff888019f16cb8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 1ffff92000743efa
R13: 0000000000000004 R14: ffff888078fa69c0 R15: ffffc90003a1f7f0
FS:  0000555556e72380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000456b30 CR3: 0000000079883000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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