From 8c91c57907d3ad8f88a12097213bb0920eb453b8 Mon Sep 17 00:00:00 2001 From: Ritesh Harjani Date: Wed, 16 Feb 2022 12:32:51 +0530 Subject: ext4: add extra check in ext4_mb_mark_bb() to prevent against possible corruption This patch adds an extra checks in ext4_mb_mark_bb() function to make sure we mark & report error if we were to mark/clear any of the critical FS metadata specific bitmaps (&bail out) to prevent from any accidental corruption. Suggested-by: Jan Kara Signed-off-by: Ritesh Harjani Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/53cbb6f2573db162a57f935365050d8b1df202ee.1644992610.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o --- fs/ext4/mballoc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 0a95bdb1e07b..5f0bc6d0aabe 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3918,6 +3918,14 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff)); clen = EXT4_NUM_B2C(sbi, thisgrp_len); + if (!ext4_sb_block_valid(sb, NULL, block, thisgrp_len)) { + ext4_error(sb, "Marking blocks in system zone - " + "Block = %llu, len = %u", + block, thisgrp_len); + bitmap_bh = NULL; + break; + } + bitmap_bh = ext4_read_block_bitmap(sb, group); if (IS_ERR(bitmap_bh)) { err = PTR_ERR(bitmap_bh); -- cgit v1.2.3