[PATCH 6.6] ext4: filesystems without casefold feature cannot be mounted with siphash

[PATCH 6.6] ext4: filesystems without casefold feature cannot be mounted with siphash

[vgiraud.opensource]

From: Lizhi Xu <lizhi.xu@windriver.com>

commit 985b67cd86392310d9e9326de941c22fc9340eec upstream.

When mounting the ext4 filesystem, if the default hash version is set to
DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.

Reported-by: syzbot+340581ba9dceb7e06fb3@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Link: https://patch.msgid.link/20240605012335.44086-1-lizhi.xu@windriver.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Bruno VERNAY <bruno.vernay@se.com>
Signed-off-by: Victor Giraud <vgiraud.opensource@witekio.com>
---
 fs/ext4/super.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f019ce64eba4..b69d791be846 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3627,6 +3627,14 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
 	}
 #endif
 
+	if (EXT4_SB(sb)->s_es->s_def_hash_version == DX_HASH_SIPHASH &&
+	    !ext4_has_feature_casefold(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Filesystem without casefold feature cannot be "
+			 "mounted with siphash");
+		return 0;
+	}
+
 	if (readonly)
 		return 1;
 
-- 
2.34.1

Re: [PATCH 6.6] ext4: filesystems without casefold feature cannot be mounted with siphash

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 985b67cd86392310d9e9326de941c22fc9340eec

WARNING: Author mismatch between patch and upstream commit:
Backport author: vgiraud.opensource@witekio.com
Commit author: Lizhi Xu<lizhi.xu@windriver.com>


Status in newer kernel trees:
6.13.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Not found

Note: The patch differs from the upstream commit:
---
1:  985b67cd86392 < -:  ------------- ext4: filesystems without casefold feature cannot be mounted with siphash
-:  ------------- > 1:  e8a78ebe11154 ext4: filesystems without casefold feature cannot be mounted with siphash
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Failed    |

Build Errors:
Build error for stable/linux-6.6.y:
    ssh: connect to host 192.168.1.58 port 22: No route to host

Re: [PATCH 6.6] ext4: filesystems without casefold feature cannot be mounted with siphash

[Greg KH]

On Fri, Feb 07, 2025 at 12:37:03PM +0100, vgiraud.opensource@witekio.com wrote:
> From: Lizhi Xu <lizhi.xu@windriver.com>
> 
> commit 985b67cd86392310d9e9326de941c22fc9340eec upstream.
> 
> When mounting the ext4 filesystem, if the default hash version is set to
> DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.
> 
> Reported-by: syzbot+340581ba9dceb7e06fb3@syzkaller.appspotmail.com
> Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
> Link: https://patch.msgid.link/20240605012335.44086-1-lizhi.xu@windriver.com
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> Signed-off-by: Bruno VERNAY <bruno.vernay@se.com>
> Signed-off-by: Victor Giraud <vgiraud.opensource@witekio.com>
> ---
>  fs/ext4/super.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index f019ce64eba4..b69d791be846 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -3627,6 +3627,14 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
>  	}
>  #endif
>  
> +	if (EXT4_SB(sb)->s_es->s_def_hash_version == DX_HASH_SIPHASH &&
> +	    !ext4_has_feature_casefold(sb)) {
> +		ext4_msg(sb, KERN_ERR,
> +			 "Filesystem without casefold feature cannot be "
> +			 "mounted with siphash");
> +		return 0;
> +	}
> +
>  	if (readonly)
>  		return 1;
>  
> -- 
> 2.34.1
> 
> 

Any specific reason you asked for just this one commit to be backported
and NOT the fix for this commit?

How did you test this?

ugh,

greg k-h

Re: [PATCH 6.6] ext4: filesystems without casefold feature cannot be mounted with siphash

[Greg KH]

On Thu, Feb 13, 2025 at 02:53:56PM +0100, Greg KH wrote:
> On Fri, Feb 07, 2025 at 12:37:03PM +0100, vgiraud.opensource@witekio.com wrote:
> > From: Lizhi Xu <lizhi.xu@windriver.com>
> > 
> > commit 985b67cd86392310d9e9326de941c22fc9340eec upstream.
> > 
> > When mounting the ext4 filesystem, if the default hash version is set to
> > DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.
> > 
> > Reported-by: syzbot+340581ba9dceb7e06fb3@syzkaller.appspotmail.com
> > Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
> > Link: https://patch.msgid.link/20240605012335.44086-1-lizhi.xu@windriver.com
> > Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> > Signed-off-by: Bruno VERNAY <bruno.vernay@se.com>
> > Signed-off-by: Victor Giraud <vgiraud.opensource@witekio.com>
> > ---
> >  fs/ext4/super.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> > index f019ce64eba4..b69d791be846 100644
> > --- a/fs/ext4/super.c
> > +++ b/fs/ext4/super.c
> > @@ -3627,6 +3627,14 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
> >  	}
> >  #endif
> >  
> > +	if (EXT4_SB(sb)->s_es->s_def_hash_version == DX_HASH_SIPHASH &&
> > +	    !ext4_has_feature_casefold(sb)) {
> > +		ext4_msg(sb, KERN_ERR,
> > +			 "Filesystem without casefold feature cannot be "
> > +			 "mounted with siphash");
> > +		return 0;
> > +	}
> > +
> >  	if (readonly)
> >  		return 1;
> >  
> > -- 
> > 2.34.1
> > 
> > 
> 
> Any specific reason you asked for just this one commit to be backported
> and NOT the fix for this commit?
> 
> How did you test this?

And the fix did not apply either, so I'm dropping this from all queues.

Be more careful please!  Don't submit patches that actually cause
documented problems.

greg k-h

Re: [PATCH 6.6] ext4: filesystems without casefold feature cannot be mounted with siphash

[Vasiliy Kovalev]

A backport requires the fix commit a2187431c395 ("ext4: fix error message when rejecting the default hash").

See the patch series: https://lore.kernel.org/all/20241118101811.15896-1-kovalev@altlinux.org/t/#u

--
Thanks,
Vasiliy