9pfs: local: statfs: don't follow symlinks
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 <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 31e51d1c15
)
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This commit is contained in:
parent
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@ -1078,13 +1078,11 @@ static int local_fsync(FsContext *ctx, int fid_type,
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static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
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static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
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{
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{
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char *buffer;
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int fd, ret;
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int ret;
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char *path = fs_path->data;
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buffer = rpath(s, path);
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fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0);
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ret = statfs(buffer, stbuf);
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ret = fstatfs(fd, stbuf);
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g_free(buffer);
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close_preserve_errno(fd);
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return ret;
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return ret;
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}
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}
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