| Message ID | 20230531013141.19487-1-princekumarmaurya06@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v4] fs/sysv: Null check to prevent null-ptr-deref bug | expand |
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;
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(+)