[PATCH] fat: Fix potential shift wrap with FITRIM ioctl on FAT
From: OGAWA Hirofumi
Date: Fri Jul 13 2018 - 02:47:14 EST
This patch is the fix of fat-add-fitrim-ioctl-for-fat-file-system.patch.
Maybe better to merge with it (if it is easy).
Anyway, please apply this with above patch.
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From: Wentao Wang <witallwang@xxxxxxxxx>
If we keep "trimmed" as an u32, there will be a potential shift wrap.
It would be a problem on a larger than 4GB partition with
FAT32. Though most tools who call this ioctl would ignore this value,
it would be great to fix it.
Signed-off-by: Wentao Wang <witallwang@xxxxxxxxx>
Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
---
fs/fat/fatent.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN fs/fat/fatent.c~fat-fitrim-fix fs/fat/fatent.c
--- linux/fs/fat/fatent.c~fat-fitrim-fix 2018-07-13 15:39:14.417110998 +0900
+++ linux-hirofumi/fs/fat/fatent.c 2018-07-13 15:39:14.418110996 +0900
@@ -705,8 +705,8 @@ int fat_trim_fs(struct inode *inode, str
struct msdos_sb_info *sbi = MSDOS_SB(sb);
const struct fatent_operations *ops = sbi->fatent_ops;
struct fat_entry fatent;
- u64 ent_start, ent_end, minlen;
- u32 free = 0, trimmed = 0;
+ u64 ent_start, ent_end, minlen, trimmed = 0;
+ u32 free = 0;
unsigned long reada_blocks, reada_mask, cur_block = 0;
int err = 0;
_
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>