[syzbot] [ntfs3?] WARNING in indx_insert_into_buffer (3)

[syzbot] [ntfs3?] WARNING in indx_insert_into_buffer (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    6093a688a07d Merge tag 'char-misc-6.18-rc1' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13962458580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e654219ed2546322
dashboard link: https://syzkaller.appspot.com/bug?extid=3a1878433bc1cb97b42a
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=104b692f980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17962458580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/660883fc9bdb/disk-6093a688.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/29f543ec9187/vmlinux-6093a688.xz
kernel image: https://storage.googleapis.com/syzbot-assets/456918818f89/bzImage-6093a688.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/dc6369359d19/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3a1878433bc1cb97b42a@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
memcpy: detected field-spanning write (size 3656) of single field "hdr1" at fs/ntfs3/index.c:1927 (size 16)
WARNING: CPU: 0 PID: 6065 at fs/ntfs3/index.c:1927 indx_insert_into_buffer.isra.0+0x1041/0x12a0 fs/ntfs3/index.c:1927
Modules linked in:
CPU: 0 UID: 0 PID: 6065 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:indx_insert_into_buffer.isra.0+0x1041/0x12a0 fs/ntfs3/index.c:1927
Code: b5 ed a3 fe c6 05 52 41 31 0d 01 90 48 8b 74 24 68 b9 10 00 00 00 48 c7 c2 20 53 a7 8b 48 c7 c7 80 53 a7 8b e8 a0 74 62 fe 90 <0f> 0b 90 90 e9 df fd ff ff e8 71 6d 0b ff e9 4d f4 ff ff e8 67 6d
RSP: 0018:ffffc900039af748 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 00000000ffffffe4 RCX: ffffffff81799b88
RDX: ffff88802ed50000 RSI: ffffffff81799b95 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888146f46800
R13: ffff888069637800 R14: 0000000000000e48 R15: ffff88807ae74018
FS:  0000555563ff7500(0000) GS:ffff888124e6a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdbd7fd4286 CR3: 0000000069517000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 indx_insert_entry+0x1a0/0x460 fs/ntfs3/index.c:1996
 ni_add_name+0x4dd/0x820 fs/ntfs3/frecord.c:2995
 ni_rename+0x98/0x170 fs/ntfs3/frecord.c:3026
 ntfs_rename+0xab9/0xf00 fs/ntfs3/namei.c:332
 vfs_rename+0xfa3/0x2290 fs/namei.c:5216
 do_renameat2+0x7d8/0xc20 fs/namei.c:5364
 __do_sys_rename fs/namei.c:5411 [inline]
 __se_sys_rename fs/namei.c:5409 [inline]
 __x64_sys_rename+0x7d/0xa0 fs/namei.c:5409
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f780118eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcbf706748 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f78013e5fa0 RCX: 00007f780118eec9
RDX: 0000000000000000 RSI: 0000200000000f40 RDI: 00002000000003c0
RBP: 00007f7801211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78013e5fa0 R14: 00007f78013e5fa0 R15: 0000000000000002
 </TASK>


---
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Re: [syzbot] [ntfs3?] WARNING in indx_insert_into_buffer (3)

[syzbot]

syzbot has bisected this issue to:

commit acdbd67bf939577d6f9e3cf796a005c31cec52d8
Author: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Date:   Fri Jun 28 15:27:46 2024 +0000

    fs/ntfs3: Optimize large writes into sparse file

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=147995cd980000
start commit:   6093a688a07d Merge tag 'char-misc-6.18-rc1' of git://git.k..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=167995cd980000
console output: https://syzkaller.appspot.com/x/log.txt?x=127995cd980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e654219ed2546322
dashboard link: https://syzkaller.appspot.com/bug?extid=3a1878433bc1cb97b42a
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=104b692f980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17962458580000

Reported-by: syzbot+3a1878433bc1cb97b42a@syzkaller.appspotmail.com
Fixes: acdbd67bf939 ("fs/ntfs3: Optimize large writes into sparse file")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[PATCH] ntfs3: avoid memcpy size warning

[Lizhi Xu]

There are more entries after the structure, use unsafe_memcpy() to avoid
this warning.

syzbot reported:
memcpy: detected field-spanning write (size 3656) of single field "hdr1" at fs/ntfs3/index.c:1927 (size 16)
Call Trace:
 indx_insert_entry+0x1a0/0x460 fs/ntfs3/index.c:1996
 ni_add_name+0x4dd/0x820 fs/ntfs3/frecord.c:2995
 ni_rename+0x98/0x170 fs/ntfs3/frecord.c:3026
 ntfs_rename+0xab9/0xf00 fs/ntfs3/namei.c:332

Reported-by: syzbot+3a1878433bc1cb97b42a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3a1878433bc1cb97b42a
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
---
 fs/ntfs3/index.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
index 6d1bf890929d..7157cfd70fdc 100644
--- a/fs/ntfs3/index.c
+++ b/fs/ntfs3/index.c
@@ -1924,7 +1924,8 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
 		 * Undo critical operations.
 		 */
 		indx_mark_free(indx, ni, new_vbn >> indx->idx2vbn_bits);
-		memcpy(hdr1, hdr1_saved, used1);
+		unsafe_memcpy(hdr1, hdr1_saved, used1,
+			      "There are entries after the structure");
 		indx_write(indx, ni, n1, 0);
 	}
 
-- 
2.43.0

Re: [PATCH] ntfs3: avoid memcpy size warning

[Konstantin Komarov]

On 10/9/25 04:37, Lizhi Xu wrote:

> There are more entries after the structure, use unsafe_memcpy() to avoid
> this warning.
>
> syzbot reported:
> memcpy: detected field-spanning write (size 3656) of single field "hdr1" at fs/ntfs3/index.c:1927 (size 16)
> Call Trace:
>   indx_insert_entry+0x1a0/0x460 fs/ntfs3/index.c:1996
>   ni_add_name+0x4dd/0x820 fs/ntfs3/frecord.c:2995
>   ni_rename+0x98/0x170 fs/ntfs3/frecord.c:3026
>   ntfs_rename+0xab9/0xf00 fs/ntfs3/namei.c:332
>
> Reported-by: syzbot+3a1878433bc1cb97b42a@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=3a1878433bc1cb97b42a
> Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
> ---
>   fs/ntfs3/index.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
> index 6d1bf890929d..7157cfd70fdc 100644
> --- a/fs/ntfs3/index.c
> +++ b/fs/ntfs3/index.c
> @@ -1924,7 +1924,8 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
>   		 * Undo critical operations.
>   		 */
>   		indx_mark_free(indx, ni, new_vbn >> indx->idx2vbn_bits);
> -		memcpy(hdr1, hdr1_saved, used1);
> +		unsafe_memcpy(hdr1, hdr1_saved, used1,
> +			      "There are entries after the structure");
>   		indx_write(indx, ni, n1, 0);
>   	}
>   

Thanks for the patch. Applied.

Regards,
Konstantin