From b9b5560b342e40bd6a0a131fb1bd99684ee8f1e7 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 14 Sep 2022 17:29:33 +0200 Subject: [PATCH] ext2: Use kvmalloc() for group descriptor array [ 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 Signed-off-by: Sasha Levin --- 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 fd855574ef09..02d82f8fe85d 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); @@ -1080,7 +1080,7 @@ 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) { @@ -1206,7 +1206,7 @@ failed_mount2: 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);