From 7a77dad7e3be1280456508841ccdd2a091b1906a Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 30 Apr 2019 08:45:34 -0700 Subject: iomap: Fix use-after-free error in page_done callback In iomap_write_end, we're not holding a page reference anymore when calling the page_done callback, but the callback needs that reference to access the page. To fix that, move the put_page call in __generic_write_end into the callers of __generic_write_end. Then, in iomap_write_end, put the page after calling the page_done callback. Reported-by: Jan Kara Fixes: 63899c6f8851 ("iomap: add a page_done callback") Signed-off-by: Andreas Gruenbacher Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index e0d4c6a5e2d2..0faa41fb4c88 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2104,7 +2104,6 @@ void __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, } unlock_page(page); - put_page(page); if (old_size < pos) pagecache_isize_extended(inode, old_size, pos); @@ -2160,6 +2159,7 @@ int generic_write_end(struct file *file, struct address_space *mapping, { copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); __generic_write_end(mapping->host, pos, copied, page); + put_page(page); return copied; } EXPORT_SYMBOL(generic_write_end); -- cgit