Messages in this thread Patch in this message | | | Subject | [PATCH] FUSE: serious information leak fix | From | Miklos Szeredi <> | Date | Thu, 02 Jun 2005 12:42:48 +0200 |
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In certain situations the user can read out previous contents of pages. To do this, create a filesystem that returns a short count on a read request. Then issue a read for a file. If there are pages to be read, that are not touched at all, these will not be zeroed.
The fix is to zero out all pages that are not touched.
Thanks to Sven Tantau for the bug report.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Index: linux/fs/fuse/dev.c =================================================================== --- linux.orig/fs/fuse/dev.c 2005-06-01 12:22:08.000000000 +0200 +++ linux/fs/fuse/dev.c 2005-06-02 11:10:08.000000000 +0200 @@ -525,7 +525,7 @@ static int fuse_copy_pages(struct fuse_c unsigned offset = req->page_offset; unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset); - for (i = 0; i < req->num_pages && nbytes; i++) { + for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) { struct page *page = req->pages[i]; int err = fuse_copy_page(cs, page, offset, count, zeroing); if (err) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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