Commit 7f86b294 authored by qasdev's avatar qasdev Committed by Andrew Morton
Browse files

ocfs2: fix shift-out-of-bounds UBSAN bug in ocfs2_verify_volume() 

This patch addresses a shift-out-of-bounds error in the
ocfs2_verify_volume() function, identified by UBSAN.  The bug was
triggered by an invalid s_clustersize_bits value (e.g., 1548), which
caused the expression "1 <<
le32_to_cpu(di->id2.i_super.s_clustersize_bits)" to exceed the limits of a
32-bit integer, leading to an out-of-bounds shift.

Link: https://lkml.kernel.org/r/ZsPvwQAXd5R/jNY+@hostname


Signed-off-by: default avatarQasim Ijaz <qasdev00@gmail.com>
Reported-by: default avatarsyzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=f3fff775402751ebb471


Tested-by: default avatarsyzbot <syzbot+f3fff775402751ebb471@syzkaller.appspotmail.com>
Reviewed-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent d994c238

fs/ocfs2/super.c

+2 −2
Original line number Diff line number Diff line
@@ -2357,8 +2357,8 @@ static int ocfs2_verify_volume(struct ocfs2_dinode *di, 
			     (unsigned long long)bh->b_blocknr);

		} else if (le32_to_cpu(di->id2.i_super.s_clustersize_bits) < 12 ||

			    le32_to_cpu(di->id2.i_super.s_clustersize_bits) > 20) {

			mlog(ML_ERROR, "bad cluster size found: %u\n",

			     1 << le32_to_cpu(di->id2.i_super.s_clustersize_bits));

			mlog(ML_ERROR, "bad cluster size bit found: %u\n",

			     le32_to_cpu(di->id2.i_super.s_clustersize_bits));

		} else if (!le64_to_cpu(di->id2.i_super.s_root_blkno)) {

			mlog(ML_ERROR, "bad root_blkno: 0\n");

		} else if (!le64_to_cpu(di->id2.i_super.s_system_dir_blkno)) {