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[Qemu-stable] [PATCH 14/81] 9pfs: local: statfs: don't follow symlinks
From: |
Michael Roth |
Subject: |
[Qemu-stable] [PATCH 14/81] 9pfs: local: statfs: don't follow symlinks |
Date: |
Mon, 20 Mar 2017 18:07:38 -0500 |
From: Greg Kurz <address@hidden>
The local_statfs() callback is vulnerable to symlink attacks because it
calls statfs() which follows symbolic links in all path elements.
This patch converts local_statfs() to rely on open_nofollow() and fstatfs()
instead.
This partly fixes CVE-2016-9602.
Signed-off-by: Greg Kurz <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
(cherry picked from commit 31e51d1c15b35dc98b88a301812914b70a2b55dc)
Signed-off-by: Greg Kurz <address@hidden>
Signed-off-by: Michael Roth <address@hidden>
---
hw/9pfs/9p-local.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index fa1477f..80b3964 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -1078,13 +1078,11 @@ static int local_fsync(FsContext *ctx, int fid_type,
static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
{
- char *buffer;
- int ret;
- char *path = fs_path->data;
+ int fd, ret;
- buffer = rpath(s, path);
- ret = statfs(buffer, stbuf);
- g_free(buffer);
+ fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0);
+ ret = fstatfs(fd, stbuf);
+ close_preserve_errno(fd);
return ret;
}
--
2.7.4
- [Qemu-stable] [PATCH 00/81] Patch Round-up for stable 2.8.1, freeze on 2017-03-27, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 10/81] 9pfs: local: lremovexattr: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 11/81] 9pfs: local: unlinkat: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 09/81] 9pfs: local: lsetxattr: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 16/81] 9pfs: local: readlink: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 13/81] 9pfs: local: utimensat: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 15/81] 9pfs: local: truncate: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 12/81] 9pfs: local: remove: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 17/81] 9pfs: local: lstat: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 18/81] 9pfs: local: renameat: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 14/81] 9pfs: local: statfs: don't follow symlinks,
Michael Roth <=
- [Qemu-stable] [PATCH 19/81] 9pfs: local: rename: use renameat, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 23/81] 9pfs: local: chown: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 20/81] 9pfs: local: improve error handling in link op, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 21/81] 9pfs: local: link: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 01/81] 9pfs: local: move xattr security ops to 9p-xattr.c, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 25/81] 9pfs: local: mknod: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 22/81] 9pfs: local: chmod: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 27/81] 9pfs: local: open2: don't follow symlinks, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 28/81] 9pfs: local: drop unused code, Michael Roth, 2017/03/20
- [Qemu-stable] [PATCH 31/81] 9pfs: fail local_statfs() earlier, Michael Roth, 2017/03/20