[syzbot] kernel BUG in ntfs_read_inode_mount

[syzbot] kernel BUG in ntfs_read_inode_mount

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d0a231f01e5b Merge tag 'pci-v5.17-changes' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11f83837b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=986ed422f1741853
dashboard link: https://syzkaller.appspot.com/bug?extid=3c765c5248797356edaa
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3c765c5248797356edaa@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/ntfs/malloc.h:31!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 13085 Comm: syz-executor.4 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__ntfs_malloc fs/ntfs/malloc.h:31 [inline]
RIP: 0010:ntfs_malloc_nofs fs/ntfs/malloc.h:52 [inline]
RIP: 0010:ntfs_read_inode_mount+0x1df3/0x2490 fs/ntfs/inode.c:1884
Code: 24 30 48 39 c3 0f 83 e2 01 00 00 e8 87 85 e5 fe 48 89 ef be 42 0c 00 00 e8 ba c9 21 ff 48 89 c5 e9 59 f4 ff ff e8 6d 85 e5 fe <0f> 0b 4c 8b 7c 24 30 e8 61 85 e5 fe 48 c7 c2 c0 b3 df 89 48 c7 c7
RSP: 0018:ffffc90003a37a80 EFLAGS: 00010212
RAX: 0000000000003063 RBX: 0000000000000000 RCX: ffffc9000fc69000
RDX: 0000000000040000 RSI: ffffffff82924583 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff82923991 R11: 0000000000000000 R12: ffff88807d0f4038
R13: ffff88807d0f4040 R14: ffff888071f5f6a0 R15: ffff88801e2ca000
FS:  00007f29a2160700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555c25708 CR3: 00000000793be000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ntfs_fill_super+0xa2f/0x8440 fs/ntfs/super.c:2854
 mount_bdev+0x34d/0x410 fs/super.c:1370
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 do_new_mount fs/namespace.c:2994 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3324
 do_mount fs/namespace.c:3337 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount fs/namespace.c:3522 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3522
 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+0x44/0xae
RIP: 0033:0x7f29a37ec51a
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f29a215ff88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f29a37ec51a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f29a215ffe0
RBP: 00007f29a2160020 R08: 00007f29a2160020 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f29a215ffe0 R15: 000000002007dd00
 </TASK>
Modules linked in:
---[ end trace 20309b23609f3571 ]---
RIP: 0010:__ntfs_malloc fs/ntfs/malloc.h:31 [inline]
RIP: 0010:ntfs_malloc_nofs fs/ntfs/malloc.h:52 [inline]
RIP: 0010:ntfs_read_inode_mount+0x1df3/0x2490 fs/ntfs/inode.c:1884
Code: 24 30 48 39 c3 0f 83 e2 01 00 00 e8 87 85 e5 fe 48 89 ef be 42 0c 00 00 e8 ba c9 21 ff 48 89 c5 e9 59 f4 ff ff e8 6d 85 e5 fe <0f> 0b 4c 8b 7c 24 30 e8 61 85 e5 fe 48 c7 c2 c0 b3 df 89 48 c7 c7
RSP: 0018:ffffc90003a37a80 EFLAGS: 00010212
RAX: 0000000000003063 RBX: 0000000000000000 RCX: ffffc9000fc69000
RDX: 0000000000040000 RSI: ffffffff82924583 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff82923991 R11: 0000000000000000 R12: ffff88807d0f4038
R13: ffff88807d0f4040 R14: ffff888071f5f6a0 R15: ffff88801e2ca000
FS:  00007f29a2160700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b9a64ffc8 CR3: 00000000793be000 CR4: 0000000000350ee0


---
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Re: [syzbot] kernel BUG in ntfs_read_inode_mount

[Pavel Skripkin]

On 1/17/22 13:09, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    d0a231f01e5b Merge tag 'pci-v5.17-changes' of git://git.ke..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=11f83837b00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=986ed422f1741853
> dashboard link: https://syzkaller.appspot.com/bug?extid=3c765c5248797356edaa
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 

Sad :(

> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3c765c5248797356edaa@syzkaller.appspotmail.com
> 

__ntfs_malloc() calls BUG_ON() in case of requested size is equal to 
zero. Seems like syzbot has once again crafted malicious fs image that 
has attr_list_size == 0

Just for thoughts


With regards,
Pavel Skripkin

Re: [syzbot] kernel BUG in ntfs_read_inode_mount

[Pavel Skripkin]

[-- Attachment #1: Type: text/plain, Size: 1088 bytes --]

On 1/17/22 22:02, Pavel Skripkin wrote:
> On 1/17/22 13:09, syzbot wrote:
>> Hello,
>> 
>> syzbot found the following issue on:
>> 
>> HEAD commit:    d0a231f01e5b Merge tag 'pci-v5.17-changes' of git://git.ke..
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=11f83837b00000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=986ed422f1741853
>> dashboard link: https://syzkaller.appspot.com/bug?extid=3c765c5248797356edaa
>> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>> 
>> Unfortunately, I don't have any reproducer for this issue yet.
>> 
> 
> Sad :(
> 
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+3c765c5248797356edaa@syzkaller.appspotmail.com
>> 
> 
> __ntfs_malloc() calls BUG_ON() in case of requested size is equal to
> zero. Seems like syzbot has once again crafted malicious fs image that
> has attr_list_size == 0
> 
> Just for thoughts
> 
> 

Clicked 'Send' button too early, sorry

With regards,
Pavel Skripkin


[-- Attachment #2: ph --]
[-- Type: text/plain, Size: 500 bytes --]

diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index f5c058b3192c..a93fc3dbd4fd 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -1881,6 +1881,9 @@ int ntfs_read_inode_mount(struct inode *vi)
 		}
 		/* Now allocate memory for the attribute list. */
 		ni->attr_list_size = (u32)ntfs_attr_size(a);
+		if (ni->attr_list_size == 0)
+			goto put_err_out;
+
 		ni->attr_list = ntfs_malloc_nofs(ni->attr_list_size);
 		if (!ni->attr_list) {
 			ntfs_error(sb, "Not enough memory to allocate buffer "