diff mbox series

[6.0,827/862] ext2: Use kvmalloc() for group descriptor array

Message ID 20221019083326.446951244@linuxfoundation.org
State New
Headers
Series None |

Commit Message

Greg KH Oct. 19, 2022, 8:35 a.m. UTC 
  From: Jan Kara <jack@suse.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@syzkaller.appspotmail.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext2/super.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

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);