lkml.org 
[lkml]   [2023]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4] fs/sysv: Null check to prevent null-ptr-deref bug
Date
sb_getblk(inode->i_sb, parent) return a null ptr and taking lock on
that leads to the null-ptr-deref bug.

Reported-by: syzbot+aad58150cbc64ba41bdc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=aad58150cbc64ba41bdc
Signed-off-by: Prince Kumar Maurya <princekumarmaurya06@gmail.com>
---
Change since v3: Added cleanup code for the branch[n].key on
failure code path.

fs/sysv/itree.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index b22764fe669c..58d7f43a1371 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -145,6 +145,10 @@ static int alloc_branch(struct inode *inode,
*/
parent = block_to_cpu(SYSV_SB(inode->i_sb), branch[n-1].key);
bh = sb_getblk(inode->i_sb, parent);
+ if (!bh) {
+ sysv_free_block(inode->i_sb, branch[n].key);
+ break;
+ }
lock_buffer(bh);
memset(bh->b_data, 0, blocksize);
branch[n].bh = bh;
--
2.40.1
\
 
 \ /
  Last update: 2023-05-31 03:37    [W:0.278 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site