From 362e8cbc7c72ec76a793b8e6ac5adc687e292539 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sat, 22 Dec 2018 11:22:26 +0100 Subject: [PATCH] f2fs: fix validation of the block count in sanity_check_raw_super commit 88960068f25fcc3759455d85460234dcc9d43fef upstream. Treat "block_count" from struct f2fs_super_block as 64-bit little endian value in sanity_check_raw_super() because struct f2fs_super_block declares "block_count" as "__le64". This fixes a bug where the superblock validation fails on big endian devices with the following error: F2FS-fs (sda1): Wrong segment_count / block_count (61439 > 0) F2FS-fs (sda1): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (sda1): Wrong segment_count / block_count (61439 > 0) F2FS-fs (sda1): Can't find valid F2FS filesystem in 2th superblock As result of this the partition cannot be mounted. With this patch applied the superblock validation works fine and the partition can be mounted again: F2FS-fs (sda1): Mounted with checkpoint version = 7c84 My little endian x86-64 hardware was able to mount the partition without this fix. To confirm that mounting f2fs filesystems works on big endian machines again I tested this on a 32-bit MIPS big endian (lantiq) device. Fixes: 0cfe75c5b01199 ("f2fs: enhance sanity_check_raw_super() to avoid potential overflows") Cc: stable@vger.kernel.org Signed-off-by: Martin Blumenstingl Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/super.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index c8f408d8a582..83a96334dc07 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1427,10 +1427,10 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi, return 1; } - if (segment_count > (le32_to_cpu(raw_super->block_count) >> 9)) { + if (segment_count > (le64_to_cpu(raw_super->block_count) >> 9)) { f2fs_msg(sb, KERN_INFO, - "Wrong segment_count / block_count (%u > %u)", - segment_count, le32_to_cpu(raw_super->block_count)); + "Wrong segment_count / block_count (%u > %llu)", + segment_count, le64_to_cpu(raw_super->block_count)); return 1; } -- 2.20.1