This is a note to let you know that I've just added the patch titled
fs/sysv: Null check to prevent null-ptr-deref bug
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-sysv-null-check-to-prevent-null-ptr-deref-bug.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ea2b62f305893992156a798f665847e0663c9f41 Mon Sep 17 00:00:00 2001
From: Prince Kumar Maurya <princekumarmaurya06@xxxxxxxxx>
Date: Tue, 30 May 2023 18:31:41 -0700
Subject: fs/sysv: Null check to prevent null-ptr-deref bug
From: Prince Kumar Maurya <princekumarmaurya06@xxxxxxxxx>
commit ea2b62f305893992156a798f665847e0663c9f41 upstream.
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@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=aad58150cbc64ba41bdc
Signed-off-by: Prince Kumar Maurya <princekumarmaurya06@xxxxxxxxx>
Message-Id: <20230531013141.19487-1-princekumarmaurya06@xxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/sysv/itree.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -145,6 +145,10 @@ static int alloc_branch(struct inode *in
*/
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;
Patches currently in stable-queue which might be from princekumarmaurya06@xxxxxxxxx are
queue-4.19/fs-sysv-null-check-to-prevent-null-ptr-deref-bug.patch
