From patchwork Sat Nov 2 07:31:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 13860030 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BDB6C1448C1; Sat, 2 Nov 2024 07:31:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730532714; cv=none; b=Z+yxuPnepy1QUKK6ONyE5dT5M8ikl7i0mLagmG05tdVBXHbtuVjlVP3OHUqpJ/TbBQke4XdCOHgn+R3EnMowMK4A32DDcZPX/kh+C7kWpVynK/Oc7xDvlOfiUT2IKLMrI7/5vzRDknSfi2+eIIo5s8JFnAXJk/RnBD+C93aKpgw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730532714; c=relaxed/simple; bh=zQQnTZimkNdhhEgtbCqbtkYZqWPqNugT62UQir086FU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jlgh9ycwRnAwOvQ/aZMwbl+AQd3It+cNAfPiJQOebvQlvY5B1qAF0diMfTgA2+vBdigDmwuFBDmzumNL3Qz6pklrcu9+2CKTSqEsuQNahuoRugYdFdQddlWtSAPrWCwu2/zhIF0qC5GpmcNb4r5AEo3RbJ/wYDbNpwI4CMaNdg4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=MKwDjBw1; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="MKwDjBw1" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=VVU5A6PnIxPNnXJuEEHW+GW30MbPjzG1/fG7IlvwPPI=; b=MKwDjBw1sBmmI/D74EgozmiWm0 fpIxTIW22+42Pd8/PoYYZkv9vWqwweNjspaDDcpRn1aPT3dxE5iWRs91JSrNKk/yx0v6kftuJecd/ oWoc3eDVTZHw/HeVTY+nva6b3oqe1okHdpco+o+gU9BzK42lPLxx9OzxCTk0TLwlewevlNDsbbSJM 2fB8VO9iqnQdp+PSEsR7E8mIxGcfR1vlENRASEk+mSR5lPpztxOF2w/q6YkhC48Fak3/88UNamZy7 c9T0kBLU+eT+A46fwhCD1SZPrPufBCXzJYgDRqKg8cDEXRV7QRsyxFy+x+58UH1cNOL6/s/Z4Lnnd +7IUydkg==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98 #2 (Red Hat Linux)) id 1t78bt-0000000AJFS-3qTt; Sat, 02 Nov 2024 07:31:49 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: Christian Brauner , io-uring@vger.kernel.org, =?utf-8?q?Christian_G=C3=B6ttsche?= Subject: [PATCH v2 07/13] new helper: import_xattr_name() Date: Sat, 2 Nov 2024 07:31:43 +0000 Message-ID: <20241102073149.2457240-7-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241102073149.2457240-1-viro@zeniv.linux.org.uk> References: <20241102072834.GQ1350452@ZenIV> <20241102073149.2457240-1-viro@zeniv.linux.org.uk> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: Al Viro common logics for marshalling xattr names. Reviewed-by: Christian Brauner Signed-off-by: Al Viro --- fs/internal.h | 3 +++ fs/xattr.c | 45 +++++++++++++++++++++++---------------------- io_uring/xattr.c | 7 ++----- 3 files changed, 28 insertions(+), 27 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index 81c7a085355c..b9f5ac4d39fc 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -288,6 +288,9 @@ ssize_t do_getxattr(struct mnt_idmap *idmap, int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx); int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, struct kernel_xattr_ctx *ctx); + +int import_xattr_name(struct xattr_name *kname, const char __user *name); + int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode); #ifdef CONFIG_FS_POSIX_ACL diff --git a/fs/xattr.c b/fs/xattr.c index 1214ae7e71db..d8f7c766f28a 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -586,6 +586,17 @@ vfs_removexattr(struct mnt_idmap *idmap, struct dentry *dentry, } EXPORT_SYMBOL_GPL(vfs_removexattr); +int import_xattr_name(struct xattr_name *kname, const char __user *name) +{ + int error = strncpy_from_user(kname->name, name, + sizeof(kname->name)); + if (error == 0 || error == sizeof(kname->name)) + return -ERANGE; + if (error < 0) + return error; + return 0; +} + /* * Extended attribute SET operations */ @@ -597,14 +608,10 @@ int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx) if (ctx->flags & ~(XATTR_CREATE|XATTR_REPLACE)) return -EINVAL; - error = strncpy_from_user(ctx->kname->name, name, - sizeof(ctx->kname->name)); - if (error == 0 || error == sizeof(ctx->kname->name)) - return -ERANGE; - if (error < 0) + error = import_xattr_name(ctx->kname, name); + if (error) return error; - error = 0; if (ctx->size) { if (ctx->size > XATTR_SIZE_MAX) return -E2BIG; @@ -763,10 +770,8 @@ getxattr(struct mnt_idmap *idmap, struct dentry *d, .flags = 0, }; - error = strncpy_from_user(kname.name, name, sizeof(kname.name)); - if (error == 0 || error == sizeof(kname.name)) - error = -ERANGE; - if (error < 0) + error = import_xattr_name(&kname, name); + if (error) return error; error = do_getxattr(idmap, d, &ctx); @@ -906,12 +911,10 @@ static int path_removexattr(const char __user *pathname, { struct path path; int error; - char kname[XATTR_NAME_MAX + 1]; + struct xattr_name kname; - error = strncpy_from_user(kname, name, sizeof(kname)); - if (error == 0 || error == sizeof(kname)) - error = -ERANGE; - if (error < 0) + error = import_xattr_name(&kname, name); + if (error) return error; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); @@ -919,7 +922,7 @@ static int path_removexattr(const char __user *pathname, return error; error = mnt_want_write(path.mnt); if (!error) { - error = removexattr(mnt_idmap(path.mnt), path.dentry, kname); + error = removexattr(mnt_idmap(path.mnt), path.dentry, kname.name); mnt_drop_write(path.mnt); } path_put(&path); @@ -945,23 +948,21 @@ SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) { CLASS(fd, f)(fd); - char kname[XATTR_NAME_MAX + 1]; + struct xattr_name kname; int error; if (fd_empty(f)) return -EBADF; audit_file(fd_file(f)); - error = strncpy_from_user(kname, name, sizeof(kname)); - if (error == 0 || error == sizeof(kname)) - error = -ERANGE; - if (error < 0) + error = import_xattr_name(&kname, name); + if (error) return error; error = mnt_want_write_file(fd_file(f)); if (!error) { error = removexattr(file_mnt_idmap(fd_file(f)), - fd_file(f)->f_path.dentry, kname); + fd_file(f)->f_path.dentry, kname.name); mnt_drop_write_file(fd_file(f)); } return error; diff --git a/io_uring/xattr.c b/io_uring/xattr.c index f440121c3984..0b3b871eaa65 100644 --- a/io_uring/xattr.c +++ b/io_uring/xattr.c @@ -62,11 +62,8 @@ static int __io_getxattr_prep(struct io_kiocb *req, if (!ix->ctx.kname) return -ENOMEM; - ret = strncpy_from_user(ix->ctx.kname->name, name, - sizeof(ix->ctx.kname->name)); - if (!ret || ret == sizeof(ix->ctx.kname->name)) - ret = -ERANGE; - if (ret < 0) { + ret = import_xattr_name(ix->ctx.kname, name); + if (ret) { kfree(ix->ctx.kname); return ret; }