linux-kernel - [PATCH] fs: sysfs: return EGBIG on write if offset is larger than file size

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>] [day] [month] [year] [list]

Message-ID: <1411572064-2871-1-git-send-email-vladimir_zapolskiy@mentor.com>
Date:	Wed, 24 Sep 2014 18:21:04 +0300
From:	Vladimir Zapolskiy <vladimir_zapolskiy@...tor.com>
To:	<linux-kernel@...r.kernel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: [PATCH] fs: sysfs: return EGBIG on write if offset is larger than file size

According to the user expectations common utilities like dd or sh
redirection operator > should work correctly over binary files from
sysfs. At the moment doing excessive write can not be completed:

  write(1, "\0\0\0\0\0\0\0\0", 8)         = 4
  write(1, "\0\0\0\0", 4)                 = 0
  write(1, "\0\0\0\0", 4)                 = 0
  write(1, "\0\0\0\0", 4)                 = 0
  ...

Fix the problem by returning EFBIG described in man 2 write.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@...tor.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 fs/sysfs/file.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index e9ef59b..589abee 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -125,7 +125,7 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
 
 	if (size) {
 		if (size <= pos)
-			return 0;
+			return -EFBIG;
 		count = min_t(ssize_t, count, size - pos);
 	}
 	if (!count)
-- 
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/