linux-kernel - [PATCH] fs: sync_file_range: avoid overflowing signed calculation

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

Date:	Mon,  1 Dec 2014 23:04:10 -0500
From:	Sasha Levin <sasha.levin@...cle.com>
To:	linux-kernel@...r.kernel.org
Cc:	Sasha Levin <sasha.levin@...cle.com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	linux-fsdevel@...r.kernel.org
Subject: [PATCH] fs: sync_file_range: avoid overflowing signed calculation

When calculating the end byte for the sync we preform an addition which might
result in an overflow, which is undefined. Avoid it by doing unsigned
addition.

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

diff --git a/fs/sync.c b/fs/sync.c
index 6ccfc38..f9cb38f 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -286,7 +286,7 @@ SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
 	if (flags & ~VALID_FLAGS)
 		goto out;
 
-	endbyte = offset + nbytes;
+	endbyte = offset + (u64)nbytes;
 
 	if ((s64)offset < 0)
 		goto out;
-- 
1.7.10.4

--
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/