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author | Miklos Szeredi <mszeredi@redhat.com> | 2016-10-01 07:32:32 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-22 12:06:47 +0200 |
commit | d902d889db76fb07d9dc7d605fef6b427b89e8ca (patch) | |
tree | a5e592f2816e1f4a00a29d3f3680b92dcee29a40 | |
parent | 74589581898e4df964dceacc73aa887169085ba8 (diff) | |
download | linux-stable-d902d889db76fb07d9dc7d605fef6b427b89e8ca.tar.gz linux-stable-d902d889db76fb07d9dc7d605fef6b427b89e8ca.tar.bz2 linux-stable-d902d889db76fb07d9dc7d605fef6b427b89e8ca.zip |
fuse: listxattr: verify xattr list
commit cb3ae6d25a5471be62bfe6ac1fccc0e91edeaba0 upstream.
Make sure userspace filesystem is returning a well formed list of xattr
names (zero or more nonzero length, null terminated strings).
[Michael Theall: only verify in the nonzero size case]
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | fs/fuse/dir.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index cca7b048c07b..8980931e1dd2 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1800,6 +1800,23 @@ static ssize_t fuse_getxattr(struct dentry *entry, struct inode *inode, return ret; } +static int fuse_verify_xattr_list(char *list, size_t size) +{ + size_t origsize = size; + + while (size) { + size_t thislen = strnlen(list, size); + + if (!thislen || thislen == size) + return -EIO; + + size -= thislen + 1; + list += thislen + 1; + } + + return origsize; +} + static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) { struct inode *inode = d_inode(entry); @@ -1835,6 +1852,8 @@ static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) ret = fuse_simple_request(fc, &args); if (!ret && !size) ret = outarg.size; + if (ret > 0 && size) + ret = fuse_verify_xattr_list(list, ret); if (ret == -ENOSYS) { fc->no_listxattr = 1; ret = -EOPNOTSUPP; |