Commit a647502c authored by Keno Fischer's avatar Keno Fischer Committed by Greg Kurz
Browse files

9p: xattr: Fix crashes due to free of uninitialized value 



If the size returned from llistxattr/lgetxattr is 0, we skipped
the malloc call, leaving xattr.value uninitialized. However, this
value is later passed to `g_free` without any further checks,
causing an error. Fix that by always calling g_malloc unconditionally.
If `size` is 0, it will return NULL, which is safe to pass to g_free.

Signed-off-by: default avatarKeno Fischer <keno@juliacomputing.com>
Signed-off-by: default avatarGreg Kurz <groug@kaod.org>
parent ec70b956

hw/9pfs/9p.c

+2 −2
Original line number Diff line number Diff line
@@ -3256,8 +3256,8 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque) 
        xattr_fidp->fs.xattr.len = size;

        xattr_fidp->fid_type = P9_FID_XATTR;

        xattr_fidp->fs.xattr.xattrwalk_fid = true;

        if (size) {

        xattr_fidp->fs.xattr.value = g_malloc0(size);

        if (size) {

            err = v9fs_co_llistxattr(pdu, &xattr_fidp->path,

                                     xattr_fidp->fs.xattr.value,

                                     xattr_fidp->fs.xattr.len);
@@ -3289,8 +3289,8 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque) 
        xattr_fidp->fs.xattr.len = size;

        xattr_fidp->fid_type = P9_FID_XATTR;

        xattr_fidp->fs.xattr.xattrwalk_fid = true;

        if (size) {

        xattr_fidp->fs.xattr.value = g_malloc0(size);

        if (size) {

            err = v9fs_co_lgetxattr(pdu, &xattr_fidp->path,

                                    &name, xattr_fidp->fs.xattr.value,

                                    xattr_fidp->fs.xattr.len);