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[Qemu-devel] [PATCH RFC 34/36] 9pfs: local: llistxattr: don't follow sym
From: |
Greg Kurz |
Subject: |
[Qemu-devel] [PATCH RFC 34/36] 9pfs: local: llistxattr: don't follow symlinks |
Date: |
Mon, 30 Jan 2017 13:13:56 +0100 |
User-agent: |
StGit/0.17.1-20-gc0b1b-dirty |
This fixes CVE-2016-9602 for all security models.
Signed-off-by: Greg Kurz <address@hidden>
---
hw/9pfs/9p-xattr.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/hw/9pfs/9p-xattr.c b/hw/9pfs/9p-xattr.c
index 29f4f940a23f..08df02e0bab2 100644
--- a/hw/9pfs/9p-xattr.c
+++ b/hw/9pfs/9p-xattr.c
@@ -214,6 +214,11 @@ ssize_t pt_listxattr(FsContext *ctx, const char *path,
return name_size;
}
+static ssize_t flistxattrat(int dirfd, const char *path, char *list,
+ size_t size)
+{
+ return do_xattrat_op(XATTRAT_OP_LIST, dirfd, path, NULL, list, size, 0);
+}
/*
* Get the list and pass to each layer to find out whether
@@ -223,24 +228,37 @@ ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
void *value, size_t vsize)
{
ssize_t size = 0;
- char *buffer;
void *ovalue = value;
XattrOperations *xops;
char *orig_value, *orig_value_start;
ssize_t xattr_len, parsed_len = 0, attr_len;
+ char *dirpath, *name;
+ int dirfd;
/* Get the actual len */
- buffer = rpath(ctx, path);
- xattr_len = llistxattr(buffer, value, 0);
+ dirpath = local_dirname(path);
+ dirfd = local_opendir_nofollow(ctx, dirpath);
+ g_free(dirpath);
+ if (dirfd == -1) {
+ return -1;
+ }
+
+ name = local_basename(path);
+ xattr_len = flistxattrat(dirfd, name, value, 0);
if (xattr_len <= 0) {
- g_free(buffer);
+ g_free(name);
+ close_preserve_errno(dirfd);
return xattr_len;
}
/* Now fetch the xattr and find the actual size */
orig_value = g_malloc(xattr_len);
- xattr_len = llistxattr(buffer, orig_value, xattr_len);
- g_free(buffer);
+ xattr_len = flistxattrat(dirfd, name, orig_value, xattr_len);
+ g_free(name);
+ close_preserve_errno(dirfd);
+ if (xattr_len < 0) {
+ return -1;
+ }
/* store the orig pointer */
orig_value_start = orig_value;
- [Qemu-devel] [PATCH RFC 25/36] 9pfs: local: symlink: don't follow symlinks, (continued)
- [Qemu-devel] [PATCH RFC 25/36] 9pfs: local: symlink: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 26/36] 9pfs: local: chown: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 27/36] 9pfs: local: link: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 28/36] 9pfs: local: rename: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 29/36] 9pfs: local: remove: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 30/36] 9pfs: local: unlinkat: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 32/36] 9pfs: local: lstat: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 33/36] 9pfs: local: lgetxattr: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 35/36] 9pfs: local: lsetxattr: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 36/36] 9pfs: local: lremovexattr: don't follow symlinks, Greg Kurz, 2017/01/30
- [Qemu-devel] [PATCH RFC 34/36] 9pfs: local: llistxattr: don't follow symlinks,
Greg Kurz <=
- [Qemu-devel] [PATCH RFC 31/36] 9pfs: local: introduce symlink-attack safe xattr helpers, Greg Kurz, 2017/01/30