ext4: Avoid null pointer dereference when decoding EROFS w/o a journal



We need to check to make sure a journal is present before checking the
journal flags in ext4_decode_error().

Signed-off-by: Eric Sesterhenn <eric.sesterhenn@lsexperts.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

parent 43b38520

fs/ext4/super.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -344,7 +344,8 @@ static const char ext4_decode_error(struct super_block sb, int errno,
		errstr = "Out of memory";
		break;
		case -EROFS:
		if (!sb \|\| EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
		if (!sb \|\| (EXT4_SB(sb)->s_journal &&
		EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
		errstr = "Journal has aborted";
		else
		errstr = "Readonly filesystem";