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=1793991937; b=Ab+sHLGCODZuTMYROjTjUE464TVmO7tPf1AGlN9wTkqjpgYRCpkq3LsLHo1fSzTmintX 52ekj98rhcN7SWL+RuvABaCUGHFGlRHuZzMc8vd7z41k+tL93HIRYdIZuiQjDqWwBAlGF 93g7shq84ccMrV9/MNHYuOuvIyBeswJ0eVjSyyjkZ2Gl1O8FDypHV3NEfronHPr5AVe3T qAFTqAFT8Lp2F/P/XASQH7Xq/jocaFFV9KmIkrU2a9vBx78ctR3DxNHS4C52j5jQozuWo JfnWazY+6H0uP15VWu7Iex7n6ckHleQ/0wo+mcRhpQobR/OdpHnYNzTQlNKScUf/ltQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793991937; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=7osPQkuzp1BaetUyc8Ccppi80Dq54/ktTU/n1+Ddcpo=; b=TOIFMa89vN/ufUKTYrNOgTVc/VZFJeg5j2E0Ab60fnSU4yLvRXMjdSppVGJGegMGvNXh 6SDrQRfKWOEkXskb88q+MRM84w/gAu0HhLNI3amDd9jHp1bpYtWnyoX70eI/vpRwiIdjg CPk/p8Y2zItPk+LOPiLNCKvS0S937w9uVkDaryPMubQ/zoceRlYM05hHcvMPzdDLwp6I4 2u89HEpHGH9A3VVIxGYNUas6KO0ewavOZJn+0qLeAJ+8fOqUEux5k25siRKK3R4Cb6Dz8 nma5C+o+UBrVgwPCg0xclO/seXSN4bH4iY4lRZn4f2BWM7YiU1KTkChsxLA32Q+vzMw== 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=eiadGvaf; 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 AF454606A32C for ; Fri, 6 Nov 2026 19:05:36 +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=eiadGvaf Received: by smtp.kernel.org (Postfix) with ESMTPSA id D936F1F0089F; Fri, 6 Nov 2026 19:05:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793991936; bh=7osPQkuzp1BaetUyc8Ccppi80Dq54/ktTU/n1+Ddcpo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eiadGvafBb0RRwV16mUqQ8GdDG7hGUGx9/tAR6ZYCETF6h0qq1KW3T6+rLJj86D66 XgoR5wzTvUGT2FE4mV0yuQiZyfu5KekicnC5uvzc4/PcFhB8QbwtlQ7Z4m9J8JKvwU q5HZXh09TGiJLF7mb23rIQVk1ZCeyn16fsxvm+yWj0j0uCyasoB4jVZNe/kmneic+4 UvHOTyD3tYoTtkOF5jHElfuzOoLPuOLtXKCuIb9eOoDisKnBfcDV6Ivd0a7x5vRqWU jswV76GrBw4SbYYYyJ7Vr0EcC0YVupyDfCWXvuEL8HLfA/pBq36eQ5l1TOLDhtaQjl 23/nE1t40NIhA== From: Sasha Levin To: stable@vger.kernel.org Cc: Gael Blivet , Namjae Jeon , Sasha Levin Subject: [PATCH 6.6.y] ksmbd: look up stream size by exact xattr name Date: Fri, 6 Nov 2026 14:05:34 -0500 Message-ID: <20261106190519.1120084-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026110445-either-jimmy-6232@gregkh> References: <2026110445-either-jimmy-6232@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 to xattr helper signatures using non-const mnt_idmap pointers and an extra NULL argument in the replaced ksmbd_vfs_casexattr_len() call ] 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 2041811fedce9..f3b39f57ac64c 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -5247,17 +5247,8 @@ 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 3d1cfcfdfb627..54bd3e7012d7b 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -939,8 +939,8 @@ 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