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=1794061835; b=LuQdyhMH1E9zeUcqvrS4KhJioBrBeqaHGPk0JpA0SQT+FmyaGR/94hQwBG/GsQGJwuq4 kKy1n/SYM6Y1zsV5QKJQPk2QH0xf6qzCs/cvLKM3fMOGQsAMX3nPNpWLmrgJTXpJDQNjN McT0MlqyKPtxhMbUdgz+duwUH8OEGjkwDCtenPeWItR9/PCobJ5URUP2pnZEsRZSMcFTy 734ZDqVJ88CAXHakDCeLSn/dNwVrY1N8ILdqMOY2TKRTkDkqRPVrzQH3e03To29FhL5GQ Q0YrQymaIQ8iJpHaKWSW3McaRwI1IUsIkYt/wyKXydYymP7jjKlbJdtsG+Ah+/Y3CDQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061835; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=rM67meUsu8OVZUpiwlDBOJCMJUeFEoZkBNCm9nzOqDA=; b=waBkRMbTmqa+wYII/IHhLmzPBkxMGx7dJMXuQi8vpuMUHDSxWzqKRPxT+nwmJYCLLEiI 6YL7/1luXp34LoW2srVKm3NVymcdYxnM1Mn0+v5bgjTO1ZNije/DY+7OkJYPl96QtJIFQ J4ailzgsTy1z/sFZqrduXwPE4Xjtv75xpMD0aczNgzn5X6vyMY7pFAmhVG0QceqnX2cD6 E5kKK4zAAtuRrk+SsSdp8kJ1UKYIkA9K4eNE2FkagcYTOl9j5sRHQ5LxejV6xoi5Dies/ 00K+CL9s3P1Rv2/1hZSjZU0wSMxL0Ed+DAStbs8ANG5Thrm9U00QtVwF2OPiwcZNedw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=zrjvxjUG; 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 90BCF606A326; Sat, 7 Nov 2026 14:30:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=zrjvxjUG Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C44D1F008A1; Sat, 7 Nov 2026 14:30:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061835; bh=rM67meUsu8OVZUpiwlDBOJCMJUeFEoZkBNCm9nzOqDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=zrjvxjUGRRrAqMU6dNbBJbuVSf7Ny/y+xG5DjsUDRS2wW/7HB4OAXSKAR1/b9MIDg iK6/OljoDnqfIvLWmicgTShmOLU1Cyx2Oxf0NENj3vYMM8eNj23xkreHiDgncf8ArT suXm65VRgqdRkUgLmN9qItx4zfXMpep8REOgJs74= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, ChenXiaoSong , Henry Hu , Namjae Jeon , Sasha Levin Subject: [PATCH 6.12 0855/1536] ksmbd: fix invalid pointer dereference when get_inode_acl() fails Date: Sat, 7 Nov 2026 08:47:51 -0500 Message-ID: <20261107135021.562991607@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Henry Hu [ Upstream commit 19d180c7baab7126af5848ed87d5f7b5add0cef2 ] When get_inode_acl() fails, it returns an ERR_PTR(), but ksmbd_acls_fattr() stored that pointer in smb_fattr without checking for errors. Later callers then passed the error pointer to security descriptor helpers or posix_acl_release(), resulting in an invalid pointer dereference. This was reproduced on an XFS-backed share when xfs_get_acl() returned ERR_PTR(-ENOMEM). Querying the SMB ACL from a CIFS client triggered the crash: BUG: unable to handle page fault for address: fffffffffffffff8 RIP: smb_acl_sec_desc_scratch_len+0x58/0x90 [ksmbd] Call Trace: smb2_query_info+0x40d/0x17c0 [ksmbd] handle_ksmbd_work+0x1ca/0x770 [ksmbd] Fix this by checking the return values from get_inode_acl() in ksmbd_acls_fattr(). Treat -EOPNOTSUPP as indicating that no ACL is available, and propagate all other errors to the callers. Update smb2_open() and smb2_get_info_sec() to handle these errors. Cc: stable@vger.kernel.org Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Assisted-by: Codex:gpt-5.6-sol Reviewed-by: ChenXiaoSong Signed-off-by: Henry Hu Signed-off-by: Namjae Jeon [ sashal: kept the struct mnt_idmap parameter of ksmbd_acls_fattr() non-const ] Signed-off-by: Sasha Levin --- fs/smb/server/smb2pdu.c | 42 +++++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 2219bb6b73b29..0085265a52720 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2742,10 +2742,11 @@ static int smb2_create_sd_buffer(struct ksmbd_work *work, le32_to_cpu(sd_buf->ccontext.DataLength), true, false); } -static void ksmbd_acls_fattr(struct smb_fattr *fattr, - struct mnt_idmap *idmap, - struct inode *inode) +static int ksmbd_acls_fattr(struct smb_fattr *fattr, + struct mnt_idmap *idmap, + struct inode *inode) { + struct posix_acl *acl; vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode); vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); @@ -2756,10 +2757,28 @@ static void ksmbd_acls_fattr(struct smb_fattr *fattr, fattr->cf_dacls = NULL; if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { - fattr->cf_acls = get_inode_acl(inode, ACL_TYPE_ACCESS); - if (S_ISDIR(inode->i_mode)) - fattr->cf_dacls = get_inode_acl(inode, ACL_TYPE_DEFAULT); + acl = get_inode_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR(acl)) { + if (acl != ERR_PTR(-EOPNOTSUPP)) + return PTR_ERR(acl); + acl = NULL; + } + fattr->cf_acls = acl; + + if (S_ISDIR(inode->i_mode)) { + acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); + if (IS_ERR(acl)) { + if (acl != ERR_PTR(-EOPNOTSUPP)) { + posix_acl_release(fattr->cf_acls); + return PTR_ERR(acl); + } + acl = NULL; + } + fattr->cf_dacls = acl; + } } + + return 0; } enum { @@ -3491,7 +3510,10 @@ int smb2_open(struct ksmbd_work *work) int pntsd_size; size_t scratch_len; - ksmbd_acls_fattr(&fattr, idmap, inode); + rc = ksmbd_acls_fattr(&fattr, idmap, inode); + if (rc) + goto err_out; + scratch_len = smb_acl_sec_desc_scratch_len(&fattr, NULL, 0, OWNER_SECINFO | GROUP_SECINFO | @@ -5948,7 +5970,11 @@ static int smb2_get_info_sec(struct ksmbd_work *work, idmap = file_mnt_idmap(fp->filp); inode = file_inode(fp->filp); - ksmbd_acls_fattr(&fattr, idmap, inode); + rc = ksmbd_acls_fattr(&fattr, idmap, inode); + if (rc) { + ksmbd_fd_put(work, fp); + return rc; + } if (test_share_config_flag(work->tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) -- 2.53.0