4.9-stable review patch. If anyone has any objections, please let me know.
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From: Martin Blumenstingl martin.blumenstingl@googlemail.com
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 martin.blumenstingl@googlemail.com Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/f2fs/super.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1427,10 +1427,10 @@ static int sanity_check_raw_super(struct 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; }