xfs: fix a UAF problem in xattr repair

commit 5990fd7569 upstream.

The xchk_setup_xattr_buf function can allocate a new value buffer, which
means that any reference to ab->value before the call could become a
dangling pointer.  Fix this by moving an assignment to after the buffer
setup.

Cc: stable@vger.kernel.org # v6.10
Fixes: e47dcf113a ("xfs: repair extended attributes")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Darrick J. Wong 2025-12-04 13:43:50 -08:00 • committed by Greg Kroah-Hartman
commit 1e2d3aa19c