linux-kernel - [PATCH v2] fat: Fix non-atomic NFS i

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]

Date:	Fri, 29 Jun 2012 13:23:32 -0500
From:	"Steven J. Magnani" <steve@...idescorp.com>
To:	OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
Cc:	linux-kernel@...r.kernel.org,
	"Steven J. Magnani" <steve@...idescorp.com>
Subject: [PATCH v2] fat: Fix non-atomic NFS i_pos read

fat_encode_fh() can fetch an invalid i_pos value on systems
where 64-bit accesses are not atomic. Make it use the same
accessor as the rest of the FAT code.

Signed-off-by: Steven J. Magnani <steve@...idescorp.com>
Acked-by: OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
---
diff -uprN linux-3.5-rc4/fs/fat/inode.c new/fs/fat/inode.c
--- linux-3.5-rc4/fs/fat/inode.c	2012-06-29 11:20:12.781348652 -0500
+++ new/fs/fat/inode.c	2012-06-29 13:18:13.712940800 -0500
@@ -738,22 +738,21 @@ static int
 fat_encode_fh(struct inode *inode, __u32 *fh, int *lenp, struct inode *parent)
 {
 	int len = *lenp;
-	u32 ipos_h, ipos_m, ipos_l;
+	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+	loff_t i_pos;
 
 	if (len < 5) {
 		*lenp = 5;
 		return 255; /* no room */
 	}
 
-	ipos_h = MSDOS_I(inode)->i_pos >> 8;
-	ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
-	ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
+	i_pos = fat_i_pos_read(sbi, inode);
 	*lenp = 5;
 	fh[0] = inode->i_ino;
 	fh[1] = inode->i_generation;
-	fh[2] = ipos_h;
-	fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
-	fh[4] = ipos_l;
+	fh[2] = i_pos >> 8;
+	fh[3] = ((i_pos & 0xf0) << 24) | MSDOS_I(inode)->i_logstart;
+	fh[4] = (i_pos & 0x0f) << 28;
 	if (parent)
 		fh[4] |= MSDOS_I(parent)->i_logstart;
 	return 3;

--
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/