From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793987934; b=F5wIf4TeRqy+ivUtzfaLdZswURoyqeCHIBmGvMYbAPzwTbGDi4W8F1cMgnwlTCiQI4nr WBwRWUIX9M2MfsuQVfi/LO0EIoFEisbIug20wTv+wP08Nja9oU+J1A/n3SMsBYcDOINqa fRadNjyzLQ9KEZxtm4FtErv6C+31vLo6iIbcRJA2pjjsOYzoJIp5msd+kQ7EtzBxlaeRf yd4Bf6l15KOQp5hsCD4S8OMeTN92P90K7Xrbr3PGgFJncS6CMR2xVVto5jdoNk0OvklK7 x1YmhfDhQ4BGnBa3r4oUIvtejRw1gPmddSCmYA1sLnEJzGWoUWPH3JfJnSku4sZgywA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793987934; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=aitHP8o6bbKI4rA3xgyStjglLQTh52Mr5AOfh+EMPh4=; b=yYSv046rLx2q6XHYy5zLCqOwL+0dJ8Wk06JX7NVVRQMZlXa57Hdaq5tGsemBuw50PT5S SkwRbnIQUds9kb5K5cjnkaGCyJojIZuHr400keh5Mp6kdQ4rEGvnKRlZu1wguKrBeaQAQ vpXXYs3i7/uIwO3VVyqBCpWTp7j4xrIt0jCuRrkEE6Nj1RQ5BggG1sRGl6Gy4bOjh/RBj pGOhAh2tM8s+yCCRqwhvGof/9kPAghr+y8M1dit2W5TvXI07Lktnt9lM8r79RmNZvnUzj 4p1rDS20YhuC7dsRJz0I8eYeF/9jb+9iPqlsCe868iHMf8sa3XNvuVKfxBDozG06fvQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=M0LN5gVW; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD2C2606A33E for ; Fri, 6 Nov 2026 17:58:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=M0LN5gVW Received: by smtp.kernel.org (Postfix) with ESMTPSA id E664E1F0089F; Fri, 6 Nov 2026 17:58:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793987933; bh=aitHP8o6bbKI4rA3xgyStjglLQTh52Mr5AOfh+EMPh4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=M0LN5gVWG1t1e1PDcbCgF8g4EV/4RQLb0R8RVV8QVzqVtvpgo3VkYq6RxlcN3TjDg DbAtLTW+X9Bwnq2PfQvQWkKHmRdTTCH54BcYGzbqLBmGOTFb2oq4AY7evlVR1GBx0q +THV2kOlpWnu9SsfA5OY4qPkEFL28kTGC9Y98jTAvNcI1F+g+7KHFlfUgmEgzCjfCi ctJJr5+e0b/uWeAFuM9ttyd0RC6blZNQhuVSlZ7Sk+/YPZRx/zJURAGigx559WOaiP V3DRUHETSylzro5qmfB5W6jWhAuAIMm9slIEvVn3ywBLmjMfCl3dCvBtOqzXx6LDiK zo+6DG5dyP/ww== From: Sasha Levin To: stable@vger.kernel.org Cc: Gael Blivet , Namjae Jeon , Sasha Levin Subject: [PATCH 6.12.y] ksmbd: look up stream size by exact xattr name Date: Fri, 6 Nov 2026 12:58:51 -0500 Message-ID: <20261106175840.528183-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110444-overfull-uniformed-0087@gregkh> References: <2026110444-overfull-uniformed-0087@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Gael Blivet [ Upstream commit 10ea20d6584ecdaf2f7505855412a856a88d8934 ] get_file_stream_info() walks the xattr list from a single ksmbd_vfs_listxattr() and sizes each stream it finds with ksmbd_vfs_casexattr_len(), which matches with strncasecmp(). Linux xattr names are case-sensitive, so two streams differing only in case report each other's size. The loop already holds the exact name, so query it directly with ksmbd_vfs_xattr_len(), which is what casexattr_len() calls once its search succeeds. Make it non-static and declare it in vfs.h, and drop the comment above it, which describes a different bug and no longer matches the code. This also drops a full listing per stream: casexattr_len() runs its own listxattr on every call, so enumerating a file with N xattrs cost N listings instead of one. Fixes: 689f1eb3719d ("ksmbd: report actual xattr value length in stream enumeration") Signed-off-by: Gael Blivet Assisted-by: Claude:claude-opus-5 Signed-off-by: Namjae Jeon [ sashal: adapted ksmbd_vfs_xattr_len() to accept a non-const struct mnt_idmap pointer ] Signed-off-by: Sasha Levin --- fs/smb/server/smb2pdu.c | 13 ++----------- fs/smb/server/vfs.c | 4 ++-- fs/smb/server/vfs.h | 2 ++ 3 files changed, 6 insertions(+), 13 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 4e0f43051d9e0..1ed32310c73a5 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -5275,17 +5275,8 @@ static int get_file_stream_info(struct ksmbd_work *work, streamlen *= 2; kfree(stream_buf); file_info->StreamNameLength = cpu_to_le32(streamlen); - /* - * stream_name_len is the byte length of the xattr's *name*, - * not its value -- same class of bug ksmbd_stream_eof() - * (smb2pdu.c) already fixes for EndOfFile/AllocationSize on - * a stream handle; this enumeration path needs the same - * real xattr value length, not the name length reused as a - * size. - */ - slen = ksmbd_vfs_casexattr_len(file_mnt_idmap(fp->filp), - path->dentry, stream_name, - strlen(stream_name) + 1, NULL); + slen = ksmbd_vfs_xattr_len(file_mnt_idmap(fp->filp), + path->dentry, stream_name); ssize = slen < 0 ? 0 : (loff_t)slen; file_info->StreamSize = cpu_to_le64(ssize); file_info->StreamAllocationSize = cpu_to_le64(ssize); diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index dafb92aa39a6c..9aee0214e8fdc 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -943,8 +943,8 @@ ssize_t ksmbd_vfs_listxattr(struct dentry *dentry, char **list) return size; } -static ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap, - struct dentry *dentry, char *xattr_name) +ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap, + struct dentry *dentry, char *xattr_name) { return vfs_getxattr(idmap, dentry, xattr_name, NULL, 0); } diff --git a/fs/smb/server/vfs.h b/fs/smb/server/vfs.h index 397dd2dd09886..1ca170dfb349d 100644 --- a/fs/smb/server/vfs.h +++ b/fs/smb/server/vfs.h @@ -106,6 +106,8 @@ ssize_t ksmbd_vfs_getxattr(struct mnt_idmap *idmap, struct dentry *dentry, char *xattr_name, char **xattr_buf); +ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap, + struct dentry *dentry, char *xattr_name); ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap, struct dentry *dentry, char *attr_name, int attr_name_len, char *actual_name); -- 2.53.0