linux-kernel - [PATCH 6.0 827/862] ext2: Use kvmalloc() for group descriptor array

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221019083326.446951244@linuxfoundation.org>
Date:   Wed, 19 Oct 2022 10:35:14 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        syzbot+0f2f7e65a3007d39539f@...kaller.appspotmail.com,
        Jan Kara <jack@...e.cz>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 6.0 827/862] ext2: Use kvmalloc() for group descriptor array

From: Jan Kara <jack@...e.cz>

[ Upstream commit e7c7fbb9a8574ebd89cc05db49d806c7476863ad ]

Array of group descriptor block buffers can get rather large. In theory
in can reach 1MB for perfectly valid filesystem and even more for
maliciously crafted ones. Use kvmalloc() to allocate the array to avoid
straining memory allocator with large order allocations unnecessarily.

Reported-by: syzbot+0f2f7e65a3007d39539f@...kaller.appspotmail.com
Signed-off-by: Jan Kara <jack@...e.cz>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/ext2/super.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index afb31af9302d..03f2af98b1b4 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -163,7 +163,7 @@ static void ext2_put_super (struct super_block * sb)
 	db_count = sbi->s_gdb_count;
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
-	kfree(sbi->s_group_desc);
+	kvfree(sbi->s_group_desc);
 	kfree(sbi->s_debts);
 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
@@ -1092,7 +1092,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 		   EXT2_DESC_PER_BLOCK(sb);
-	sbi->s_group_desc = kmalloc_array(db_count,
+	sbi->s_group_desc = kvmalloc_array(db_count,
 					   sizeof(struct buffer_head *),
 					   GFP_KERNEL);
 	if (sbi->s_group_desc == NULL) {
@@ -1218,7 +1218,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
 failed_mount_group_desc:
-	kfree(sbi->s_group_desc);
+	kvfree(sbi->s_group_desc);
 	kfree(sbi->s_debts);
 failed_mount:
 	brelse(bh);
-- 
2.35.1