Patch "ext4: fix overflow caused by missing cast in ext4_resize_fs()" has been added to the 3.18-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2017-08-07 21:50:48
This is a note to let you know that I've just added the patch titled
ext4: fix overflow caused by missing cast in ext4_resize_fs()
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-overflow-caused-by-missing-cast-in-ext4_resize_fs.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.
From aec51758ce10a9c847a62a48a168f8c804c6e053 Mon Sep 17 00:00:00 2001
From: Jerry Lee <redacted> Date: Sun, 6 Aug 2017 01:18:31 -0400 Subject: ext4: fix overflow caused by missing cast in ext4_resize_fs() From: Jerry Lee <redacted> commit aec51758ce10a9c847a62a48a168f8c804c6e053 upstream. On a 32-bit platform, the value of n_blcoks_count may be wrong during the file system is resized to size larger than 2^32 blocks. This may caused the superblock being corrupted with zero blocks count. Fixes: 1c6bd7173d66 Signed-off-by: Jerry Lee <redacted> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/ext4/resize.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c@@ -1929,7 +1929,8 @@ retry: n_desc_blocks = o_desc_blocks + le16_to_cpu(es->s_reserved_gdt_blocks); n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); - n_blocks_count = n_group * EXT4_BLOCKS_PER_GROUP(sb); + n_blocks_count = (ext4_fsblk_t)n_group * + EXT4_BLOCKS_PER_GROUP(sb); n_group--; /* set to last group number */ }
Patches currently in stable-queue which might be from jerrylee@qnap.com are queue-3.18/ext4-fix-overflow-caused-by-missing-cast-in-ext4_resize_fs.patch