linux-kernel - [PATCH] fs: aio: use correct integer overflow checks when creation aio ctx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1368815034-844-1-git-send-email-sasha.levin@oracle.com>
Date:	Fri, 17 May 2013 14:23:54 -0400
From:	Sasha Levin <sasha.levin@...cle.com>
To:	koverstreet@...gle.com, akpm@...ux-foundation.org
Cc:	tytso@....edu, viro@...iv.linux.org.uk, bcrl@...ck.org,
	linux-aio@...ck.org, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, Sasha Levin <sasha.levin@...cle.com>
Subject: [PATCH] fs: aio: use correct integer overflow checks when creation aio ctx

Commit "aio: percpu reqs_available" added some math to the nr_requests
calculation, but didn't correct the overflow calculations to handle that.

This means that this:

	#include <linux/aio_abi.h>
	void main(void)
	{
	        aio_context_t ctx_idp;
	        io_setup(0x80000001, &ctx_idp);
	}

Would trigger the newly added BUG() couple of lines after the overflow
checks.

Signed-off-by: Sasha Levin <sasha.levin@...cle.com>
---
 fs/aio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/aio.c b/fs/aio.c
index 5b7ed78..0ae450a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -411,7 +411,8 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 
 	/* Prevent overflows */
 	if ((nr_events > (0x10000000U / sizeof(struct io_event))) ||
-	    (nr_events > (0x10000000U / sizeof(struct kiocb)))) {
+	    (nr_events > (0x10000000U / sizeof(struct kiocb))) ||
+	    (nr_events < num_possible_cpus() * 4)) {
 		pr_debug("ENOMEM: nr_events too high\n");
 		return ERR_PTR(-EINVAL);
 	}
-- 
1.8.2.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/