From: Minchan Kim minchan@kernel.org Subject: mm: validate inode in mapping_set_error()
The swap address_space doesn't have host. Thus, it makes kernel crash once swap write meets error. Fix it.
Link: https://lkml.kernel.org/r/20201010000650.750063-1-minchan@kernel.org Fixes: 735e4ae5ba28 ("vfs: track per-sb writeback errors and report them to syncfs") Signed-off-by: Minchan Kim minchan@kernel.org Acked-by: Jeff Layton jlayton@kernel.org Cc: Jan Kara jack@suse.cz Cc: Andres Freund andres@anarazel.de Cc: Matthew Wilcox willy@infradead.org Cc: Al Viro viro@zeniv.linux.org.uk Cc: Christoph Hellwig hch@infradead.org Cc: Dave Chinner david@fromorbit.com Cc: David Howells dhowells@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
include/linux/pagemap.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/include/linux/pagemap.h~mm-validate-inode-in-mapping_set_error +++ a/include/linux/pagemap.h @@ -54,7 +54,8 @@ static inline void mapping_set_error(str __filemap_set_wb_err(mapping, error);
/* Record it in superblock */ - errseq_set(&mapping->host->i_sb->s_wb_err, error); + if (mapping->host) + errseq_set(&mapping->host->i_sb->s_wb_err, error);
/* Record it in flags for now, for legacy callers */ if (error == -ENOSPC) _