Message-ID: <0000000000007720b405ff59d161@google.com>
Date:   Fri, 30 Jun 2023 07:41:54 -0700
From:   syzbot <syzbot+b960a0fea3fa8df1cd22@...kaller.appspotmail.com>
To:     adilger.kernel@...ger.ca, linux-ext4@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        llvm@...ts.linux.dev, nathan@...nel.org, ndesaulniers@...gle.com,
        syzkaller-bugs@...glegroups.com, trix@...hat.com, tytso@....edu
Subject: [syzbot] [ext4?] general protection fault in ext4_quota_read

Hello,

syzbot found the following issue on:

HEAD commit:    6995e2de6891 Linux 6.4
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=175bc8bf280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f4df35260418daa6
dashboard link: https://syzkaller.appspot.com/bug?extid=b960a0fea3fa8df1cd22
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=17e661af280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1f2e8d4aac75/disk-6995e2de.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/db793abf1e91/vmlinux-6995e2de.xz
kernel image: https://storage.googleapis.com/syzbot-assets/60215f5bf9ff/bzImage-6995e2de.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/428a4f7e064c/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b960a0fea3fa8df1cd22@...kaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
CPU: 0 PID: 6808 Comm: syz-executor.0 Not tainted 6.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:i_size_read include/linux/fs.h:883 [inline]
RIP: 0010:ext4_quota_read+0xd5/0x330 fs/ext4/super.c:7107
Code: ff 41 80 fc 3f 0f 87 00 11 cd 07 e8 05 93 49 ff 48 8b 44 24 08 48 8d 78 50 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 0d 02 00 00 48 8b 44 24 08 4c 89 ef 45 31 ff 48
RSP: 0018:ffffc9000c17f420 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000000a RSI: ffffffff823ab65b RDI: 0000000000000050
RBP: 0000000000000001 R08: 0000000000000001 R09: 000000000000003f
R10: 000000000000000c R11: 0000000000094001 R12: 000000000000000c
R13: 0000000000000400 R14: ffff888021014800 R15: ffff888028e6fc00
FS:  00007f94b3a7f700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5437a8000 CR3: 000000002826f000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 do_insert_tree+0x117/0x12d0 fs/quota/quota_tree.c:347
 dq_insert_tree fs/quota/quota_tree.c:401 [inline]
 qtree_write_dquot+0x3b4/0x570 fs/quota/quota_tree.c:420
 v2_write_dquot+0x120/0x250 fs/quota/quota_v2.c:358
 dquot_acquire+0x3d1/0x6c0 fs/quota/dquot.c:444
 ext4_acquire_dquot+0x2b1/0x3d0 fs/ext4/super.c:6814
 dqget+0x67d/0x1080 fs/quota/dquot.c:914
 __dquot_initialize+0x560/0xbe0 fs/quota/dquot.c:1492
 dquot_initialize fs/quota/dquot.c:1550 [inline]
 dquot_file_open fs/quota/dquot.c:2181 [inline]
 dquot_file_open+0x90/0xb0 fs/quota/dquot.c:2175
 ext4_file_open fs/ext4/file.c:904 [inline]
 ext4_file_open+0x35d/0xbf0 fs/ext4/file.c:873
 do_dentry_open+0x6cc/0x13f0 fs/open.c:920
 do_open fs/namei.c:3636 [inline]
 path_openat+0x1baa/0x2750 fs/namei.c:3791
 do_filp_open+0x1ba/0x410 fs/namei.c:3818
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0x143/0x1f0 fs/open.c:1383
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f94b2c8c389
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f94b3a7f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f94b2dabf80 RCX: 00007f94b2c8c389
RDX: 000000000000275a RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007f94b2cd7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff112e5fcf R14: 00007f94b3a7f300 R15: 0000000000022000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:i_size_read include/linux/fs.h:883 [inline]
RIP: 0010:ext4_quota_read+0xd5/0x330 fs/ext4/super.c:7107
Code: ff 41 80 fc 3f 0f 87 00 11 cd 07 e8 05 93 49 ff 48 8b 44 24 08 48 8d 78 50 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 0d 02 00 00 48 8b 44 24 08 4c 89 ef 45 31 ff 48
RSP: 0018:ffffc9000c17f420 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000000a RSI: ffffffff823ab65b RDI: 0000000000000050
RBP: 0000000000000001 R08: 0000000000000001 R09: 000000000000003f
R10: 000000000000000c R11: 0000000000094001 R12: 000000000000000c
R13: 0000000000000400 R14: ffff888021014800 R15: ffff888028e6fc00
FS:  00007f94b3a7f700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f5d63e000 CR3: 000000002826f000 CR4: 0000000000350ee0
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	41 80 fc 3f          	cmp    $0x3f,%r12b
   4:	0f 87 00 11 cd 07    	ja     0x7cd110a
   a:	e8 05 93 49 ff       	callq  0xff499314
   f:	48 8b 44 24 08       	mov    0x8(%rsp),%rax
  14:	48 8d 78 50          	lea    0x50(%rax),%rdi
  18:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1f:	fc ff df
  22:	48 89 fa             	mov    %rdi,%rdx
  25:	48 c1 ea 03          	shr    $0x3,%rdx
* 29:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2d:	0f 85 0d 02 00 00    	jne    0x240
  33:	48 8b 44 24 08       	mov    0x8(%rsp),%rax
  38:	4c 89 ef             	mov    %r13,%rdi
  3b:	45 31 ff             	xor    %r15d,%r15d
  3e:	48                   	rex.W


---
This report is generated by a bot. It may contain errors.
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