From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Mon, 8 Sep 2014 17:59:43 +0000 (-0700)
Subject: f2fs: fix negative value for lseek offset
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0b4c5afde9b57c08b55d26725d228d5314cfc57a;p=linux-beck.git

f2fs: fix negative value for lseek offset

If application throws negative value of lseek with SEEK_DATA|SEEK_HOLE,
previous f2fs went into BUG_ON in get_dnode_of_data, which was reported
by Tommi Rantala.

He could make a simple code to detect this having:
	lseek(fd, -17595150933902LL, SEEK_DATA);

This patch should resolve that bug.

Reported-by: Tommi Rentala <tt.rantala@gmail.com>
[Jaegeuk Kim: relocate the condition as suggested by Chao]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9f0ea3d3251b..5cde363cf7a8 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -353,6 +353,8 @@ static loff_t f2fs_llseek(struct file *file, loff_t offset, int whence)
 						maxbytes, i_size_read(inode));
 	case SEEK_DATA:
 	case SEEK_HOLE:
+		if (offset < 0)
+			return -ENXIO;
 		return f2fs_seek_block(file, offset, whence);
 	}