[syzbot] [ext4?] general protection fault in ext4_quota_read

From: syzbot
Date: Fri Jun 30 2023 - 10:42:43 EST

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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@xxxxxxxxxxxxxxxxxxxxxxxxx

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

---
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Next message: Bjorn Helgaas: "Re: [PATCH V10 2/5] PCI: Create device tree node for bridge"
Previous message: Zhangjin Wu: "[PATCH v3 00/14] selftests/nolibc: allow run with minimal kernel config"
Next in thread: Theodore Ts'o: "Re: [syzbot] [ext4?] general protection fault in ext4_quota_read"
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