* [PATCH] cifs: Fix memory and information leak in smb3_reconfigure()
@ 2025-12-24 15:21 Zilin Guan
2025-12-24 16:23 ` ChenXiaoSong
0 siblings, 1 reply; 2+ messages in thread
From: Zilin Guan @ 2025-12-24 15:21 UTC (permalink / raw)
To: sfrench
Cc: pc, ronniesahlberg, sprasad, tom, bharathsm, linux-cifs,
samba-technical, linux-kernel, jianhao.xu, Zilin Guan
In smb3_reconfigure(), if smb3_sync_session_ctx_passwords() fails, the
function returns immediately without freeing and erasing the newly
allocated new_password and new_password2. This causes both a memory leak
and a potential information leak.
Fix this by calling kfree_sensitive() on both password buffers before
returning in this error case.
Fixes: 0f0e357902957 ("cifs: during remount, make sure passwords are in sync")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
---
fs/smb/client/fs_context.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index c2de97e4ad59..d4291d3a9a48 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -1139,6 +1139,8 @@ static int smb3_reconfigure(struct fs_context *fc)
rc = smb3_sync_session_ctx_passwords(cifs_sb, ses);
if (rc) {
mutex_unlock(&ses->session_mutex);
+ kfree_sensitive(new_password);
+ kfree_sensitive(new_password2);
return rc;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] cifs: Fix memory and information leak in smb3_reconfigure()
2025-12-24 15:21 [PATCH] cifs: Fix memory and information leak in smb3_reconfigure() Zilin Guan
@ 2025-12-24 16:23 ` ChenXiaoSong
0 siblings, 0 replies; 2+ messages in thread
From: ChenXiaoSong @ 2025-12-24 16:23 UTC (permalink / raw)
To: Zilin Guan, sfrench, Steve French
Cc: pc, ronniesahlberg, sprasad, tom, bharathsm, linux-cifs,
samba-technical, linux-kernel, jianhao.xu
Good catch. Looks good to me.
Thanks,
ChenXiaoSong.
On 12/24/25 11:21 PM, Zilin Guan wrote:
> In smb3_reconfigure(), if smb3_sync_session_ctx_passwords() fails, the
> function returns immediately without freeing and erasing the newly
> allocated new_password and new_password2. This causes both a memory leak
> and a potential information leak.
>
> Fix this by calling kfree_sensitive() on both password buffers before
> returning in this error case.
>
> Fixes: 0f0e357902957 ("cifs: during remount, make sure passwords are in sync")
> Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
> ---
> fs/smb/client/fs_context.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
> index c2de97e4ad59..d4291d3a9a48 100644
> --- a/fs/smb/client/fs_context.c
> +++ b/fs/smb/client/fs_context.c
> @@ -1139,6 +1139,8 @@ static int smb3_reconfigure(struct fs_context *fc)
> rc = smb3_sync_session_ctx_passwords(cifs_sb, ses);
> if (rc) {
> mutex_unlock(&ses->session_mutex);
> + kfree_sensitive(new_password);
> + kfree_sensitive(new_password2);
> return rc;
> }
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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