lkml.org 
[lkml]   [2019]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] f2fs: add a condition to detect overflow in f2fs_ioc_gc_range()
Date
end = range.start + range.len;

If the range.start/range.len is a very large value, then end can overflow
in this operation. It results into a crash in get_valid_blocks() when
accessing the invalid range.start segno.

This issue is reported in ioctl fuzz testing.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
---
fs/f2fs/file.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 5474aaa..c2b4767 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2123,9 +2123,8 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
return -EROFS;

end = range.start + range.len;
- if (range.start < MAIN_BLKADDR(sbi) || end >= MAX_BLKADDR(sbi)) {
+ if (end < range.start || range.start < MAIN_BLKADDR(sbi) || end >= MAX_BLKADDR(sbi))
return -EINVAL;
- }

ret = mnt_want_write_file(filp);
if (ret)
--
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
\
 
 \ /
  Last update: 2019-09-17 06:51    [W:0.032 / U:0.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site