From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77F7B3C3C for ; Thu, 24 Oct 2024 03:01:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729738896; cv=none; b=ReGQ7Pu6KbpLWYVZuEGhK64S7yAmuJs4SPVIbsgvvA8wLyvnH3wF5dyR4q7MhpyNFhjhArS39A1+Zar0IhIG5o8Q4a7Qwub9KVUp6RnCT3Vuvipzzrr2ymB7iMK2t4NpmMSSZLGeIFtcvhKVsV2UUV7p4lsfSQAkx7oWjOfFSKM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729738896; c=relaxed/simple; bh=c1OYydnuFmQ3Q5I5yHsxFJApnJ2ddSNpnUQsE5V/ttE=; h=Date:To:From:Subject:Message-Id; b=Zr2UgUJRPZ7w1hgSGs0EiX2Jb3coWiA0Fb+wg+SMJihlgnUEQBw/WNGaXdNbNzQsVgjTiJaEPzAWh/2RTDgL5A3K7VoKoXulLe/lBGFqThsJxQr5hdRsENDoOiphJe9kZTDBAxn+IkxraopHrSJkipbLDL7XPWD5wN1FaFw7cgU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=U23zROww; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="U23zROww" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CB08C4CEC6; Thu, 24 Oct 2024 03:01:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1729738896; bh=c1OYydnuFmQ3Q5I5yHsxFJApnJ2ddSNpnUQsE5V/ttE=; h=Date:To:From:Subject:From; b=U23zROwwzhwTrQjuolqXafEaaQt0EdhpO0cAGyRI5JMeJhU+QqQlvJjfOLirb8wYQ ZUMjI0m7JrAyukjge8pIU6gXYb7evrD8XULE2Ni6fcxexsL0QtVQC8O35/kTLaJ+EG 3XaxA5P2HS/EJQ9nZutMjI2kkYr3Ne1VYvaOcLJs= Date: Wed, 23 Oct 2024 20:01:35 -0700 To: mm-commits@vger.kernel.org,yi1.lai@linux.intel.com,phillip@squashfs.org.uk,akpm@linux-foundation.org From: Andrew Morton Subject: + squashfs-fix-variable-overflow-in-squashfs_readpage_block.patch added to mm-hotfixes-unstable branch Message-Id: <20241024030136.0CB08C4CEC6@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: Squashfs: fix variable overflow in squashfs_readpage_block has been added to the -mm mm-hotfixes-unstable branch. Its filename is squashfs-fix-variable-overflow-in-squashfs_readpage_block.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/squashfs-fix-variable-overflow-in-squashfs_readpage_block.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Phillip Lougher Subject: Squashfs: fix variable overflow in squashfs_readpage_block Date: Mon, 21 Oct 2024 00:22:00 +0100 Syzbot reports a slab out of bounds access in squashfs_readpage_block(). This is caused by an attempt to read page index 0x2000000000. This value (start_index) is stored in an integer loop variable which overflows producing a value of 0. This causes a loop which iterates over pages start_index -> end_index to iterate over 0 -> end_index, which ultimately causes an out of bounds page array access. Fix by changing variable to a loff_t, and rename to index to make it clearer it is a page index, and not a loop count. Link: https://lkml.kernel.org/r/20241020232200.837231-1-phillip@squashfs.org.uk Signed-off-by: Phillip Lougher Reported-by: "Lai, Yi" Closes: https://lore.kernel.org/all/ZwzcnCAosIPqQ9Ie@ly-workstation/ Signed-off-by: Andrew Morton --- fs/squashfs/file_direct.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/fs/squashfs/file_direct.c~squashfs-fix-variable-overflow-in-squashfs_readpage_block +++ a/fs/squashfs/file_direct.c @@ -30,7 +30,8 @@ int squashfs_readpage_block(struct page int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; loff_t start_index = folio->index & ~mask; loff_t end_index = start_index | mask; - int i, n, pages, bytes, res = -ENOMEM; + loff_t index; + int i, pages, bytes, res = -ENOMEM; struct page **page, *last_page; struct squashfs_page_actor *actor; void *pageaddr; @@ -45,9 +46,9 @@ int squashfs_readpage_block(struct page return res; /* Try to grab all the pages covered by the Squashfs block */ - for (i = 0, n = start_index; n <= end_index; n++) { - page[i] = (n == folio->index) ? target_page : - grab_cache_page_nowait(target_page->mapping, n); + for (i = 0, index = start_index; index <= end_index; index++) { + page[i] = (index == folio->index) ? target_page : + grab_cache_page_nowait(target_page->mapping, index); if (page[i] == NULL) continue; _ Patches currently in -mm which might be from phillip@squashfs.org.uk are squashfs-fix-variable-overflow-in-squashfs_readpage_block.patch